/*-------------------------------------------------------------------------
*
* varlena.c
* Functions for the variable-length built-in types.
*
* Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/utils/adt/varlena.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <ctype.h>
#include <limits.h>
#include "access/hash.h"
#include "access/tuptoaster.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_type.h"
#include "common/int.h"
#include "lib/hyperloglog.h"
#include "libpq/pqformat.h"
#include "miscadmin.h"
#include "parser/scansup.h"
#include "port/pg_bswap.h"
#include "regex/regex.h"
#include "utils/builtins.h"
#include "utils/bytea.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/pg_locale.h"
#include "utils/sortsupport.h"
#include "utils/varlena.h"
/* GUC variable */
int bytea_output = BYTEA_OUTPUT_HEX;
typedef struct varlena unknown;
typedef struct varlena VarString;
typedef struct
{
bool use_wchar; /* T if multibyte encoding */
char *str1; /* use these if not use_wchar */
char *str2; /* note: these point to original texts */
pg_wchar *wstr1; /* use these if use_wchar */
pg_wchar *wstr2; /* note: these are palloc'd */
int len1; /* string lengths in logical characters */
int len2;
/* Skip table for Boyer-Moore-Horspool search algorithm: */
int skiptablemask; /* mask for ANDing with skiptable subscripts */
int skiptable[256]; /* skip distance for given mismatched char */
} TextPositionState;
typedef struct
{
char *buf1; /* 1st string, or abbreviation original string
* buf */
char *buf2; /* 2nd string, or abbreviation strxfrm() buf */
int buflen1;
int buflen2;
int last_len1; /* Length of last buf1 string/strxfrm() input */
int last_len2; /* Length of last buf2 string/strxfrm() blob */
int last_returned; /* Last comparison result (cache) */
bool cache_blob; /* Does buf2 contain strxfrm() blob, etc? */
bool collate_c;
bool bpchar; /* Sorting bpchar, not varchar/text/bytea? */
hyperLogLogState abbr_card; /* Abbreviated key cardinality state */
hyperLogLogState full_card; /* Full key cardinality state */
double prop_card; /* Required cardinality proportion */
pg_locale_t locale;
} VarStringSortSupport;
/*
* This should be large enough that most strings will fit, but small enough
* that we feel comfortable putting it on the stack
*/
#define TEXTBUFLEN 1024
#define DatumGetUnknownP(X) ((unknown *) PG_DETOAST_DATUM(X))
#define DatumGetUnknownPCopy(X) ((unknown *) PG_DETOAST_DATUM_COPY(X))
#define PG_GETARG_UNKNOWN_P(n) DatumGetUnknownP(PG_GETARG_DATUM(n))
#define PG_GETARG_UNKNOWN_P_COPY(n) DatumGetUnknownPCopy(PG_GETARG_DATUM(n))
#define PG_RETURN_UNKNOWN_P(x) PG_RETURN_POINTER(x)
#define DatumGetVarStringP(X) ((VarString *) PG_DETOAST_DATUM(X))
#define DatumGetVarStringPP(X) ((VarString *) PG_DETOAST_DATUM_PACKED(X))
static int varstrfastcmp_c(Datum x, Datum y, SortSupport ssup);
static int bpcharfastcmp_c(Datum x, Datum y, SortSupport ssup);
static int varstrfastcmp_locale(Datum x, Datum y, SortSupport ssup);
static int varstrcmp_abbrev(Datum x, Datum y, SortSupport ssup);
static Datum varstr_abbrev_convert(Datum original, SortSupport ssup);
static bool varstr_abbrev_abort(int memtupcount, SortSupport ssup);
static int32 text_length(Datum str);
static text *text_catenate(text *t1, text *t2);
static text *text_substring(Datum str,
int32 start,
int32 length,
bool length_not_specified);
static text *text_overlay(text *t1, text *t2, int sp, int sl);
static int text_position(text *t1, text *t2);
static void text_position_setup(text *t1, text *t2, TextPositionState *state);
static int text_position_next(int start_pos, TextPositionState *state);
static void text_position_cleanup(TextPositionState *state);
static int text_cmp(text *arg1, text *arg2, Oid collid);
static bytea *bytea_catenate(bytea *t1, bytea *t2);
static bytea *bytea_substring(Datum str,
int S,
int L,
bool length_not_specified);
static bytea *bytea_overlay(bytea *t1, bytea *t2, int sp, int sl);
static void appendStringInfoText(StringInfo str, const text *t);
static Datum text_to_array_internal(PG_FUNCTION_ARGS);
static text *array_to_text_internal(FunctionCallInfo fcinfo, ArrayType *v,
const char *fldsep, const char *null_string);
static StringInfo makeStringAggState(FunctionCallInfo fcinfo);
static bool text_format_parse_digits(const char **ptr, const char *end_ptr,
int *value);
static const char *text_format_parse_format(const char *start_ptr,
const char *end_ptr,
int *argpos, int *widthpos,
int *flags, int *width);
static void text_format_string_conversion(StringInfo buf, char conversion,
FmgrInfo *typOutputInfo,
Datum value, bool isNull,
int flags, int width);
static void text_format_append_string(StringInfo buf, const char *str,
int flags, int width);
/*****************************************************************************
* CONVERSION ROUTINES EXPORTED FOR USE BY C CODE *
*****************************************************************************/
/*
* cstring_to_text
*
* Create a text value from a null-terminated C string.
*
* The new text value is freshly palloc'd with a full-size VARHDR.
*/
text *
cstring_to_text(const char *s)
{
return cstring_to_text_with_len(s, strlen(s));
}
/*
* cstring_to_text_with_len
*
* Same as cstring_to_text except the caller specifies the string length;
* the string need not be null_terminated.
*/
text *
cstring_to_text_with_len(const char *s, int len)
{
text *result = (text *) palloc(len + VARHDRSZ);
SET_VARSIZE(result, len + VARHDRSZ);
memcpy(VARDATA(result), s, len);
return result;
}
/*
* text_to_cstring
*
* Create a palloc'd, null-terminated C string from a text value.
*
* We support being passed a compressed or toasted text value.
* This is a bit bogus since such values shouldn't really be referred to as
* "text *", but it seems useful for robustness. If we didn't handle that
* case here, we'd need another routine that did, anyway.
*/
char *
text_to_cstring(const text *t)
{
/* must cast away the const, unfortunately */
text *tunpacked = pg_detoast_datum_packed((struct varlena *) t);
int len = VARSIZE_ANY_EXHDR(tunpacked);
char *result;
result = (char *) palloc(len + 1);
memcpy(result, VARDATA_ANY(tunpacked), len);
result[len] = '\0';
if (tunpacked != t)
pfree(tunpacked);
return result;
}
/*
* text_to_cstring_buffer
*
* Copy a text value into a caller-supplied buffer of size dst_len.
*
* The text string is truncated if necessary to fit. The result is
* guaranteed null-terminated (unless dst_len == 0).
*
* We support being passed a compressed or toasted text value.
* This is a bit bogus since such values shouldn't really be referred to as
* "text *", but it seems useful for robustness. If we didn't handle that
* case here, we'd need another routine that did, anyway.
*/
void
text_to_cstring_buffer(const text *src, char *dst, size_t dst_len)
{
/* must cast away the const, unfortunately */
text *srcunpacked = pg_detoast_datum_packed((struct varlena *) src);
size_t src_len = VARSIZE_ANY_EXHDR(srcunpacked);
if (dst_len > 0)
{
dst_len--;
if (dst_len >= src_len)
dst_len = src_len;
else /* ensure truncation is encoding-safe */
dst_len = pg_mbcliplen(VARDATA_ANY(srcunpacked), src_len, dst_len);
memcpy(dst, VARDATA_ANY(srcunpacked), dst_len);
dst[dst_len] = '\0';
}
if (srcunpacked != src)
pfree(srcunpacked);
}
/*****************************************************************************
* USER I/O ROUTINES *
*****************************************************************************/
#define VAL(CH) ((CH) - '0')
#define DIG(VAL) ((VAL) + '0')
/*
* byteain - converts from printable representation of byte array
*
* Non-printable characters must be passed as '\nnn' (octal) and are
* converted to internal form. '\' must be passed as '\\'.
* ereport(ERROR, ...) if bad form.
*
* BUGS:
* The input is scanned twice.
* The error checking of input is minimal.
*/
Datum
byteain(PG_FUNCTION_ARGS)
{
char *inputText = PG_GETARG_CSTRING(0);
char *tp;
char *rp;
int bc;
bytea *result;
/* Recognize hex input */
if (inputText[0] == '\\' && inputText[1] == 'x')
{
size_t len = strlen(inputText);
bc = (len - 2) / 2 + VARHDRSZ; /* maximum possible length */
result = palloc(bc);
bc = hex_decode(inputText + 2, len - 2, VARDATA(result));
SET_VARSIZE(result, bc + VARHDRSZ); /* actual length */
PG_RETURN_BYTEA_P(result);
}
/* Else, it's the traditional escaped style */
for (bc = 0, tp = inputText; *tp != '\0'; bc++)
{
if (tp[0] != '\\')
tp++;
else if ((tp[0] == '\\') &&
(tp[1] >= '0' && tp[1] <= '3') &&
(tp[2] >= '0' && tp[2] <= '7') &&
(tp[3] >= '0' && tp[3] <= '7'))
tp += 4;
else if ((tp[0] == '\\') &&
(tp[1] == '\\'))
tp += 2;
else
{
/*
* one backslash, not followed by another or ### valid octal
*/
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("invalid input syntax for type %s", "bytea")));
}
}
bc += VARHDRSZ;
result = (bytea *) palloc(bc);
SET_VARSIZE(result, bc);
tp = inputText;
rp = VARDATA(result);
while (*tp != '\0')
{
if (tp[0] != '\\')
*rp++ = *tp++;
else if ((tp[0] == '\\') &&
(tp[1] >= '0' && tp[1] <= '3') &&
(tp[2] >= '0' && tp[2] <= '7') &&
(tp[3] >= '0' && tp[3] <= '7'))
{
bc = VAL(tp[1]);
bc <<= 3;
bc += VAL(tp[2]);
bc <<= 3;
*rp++ = bc + VAL(tp[3]);
tp += 4;
}
else if ((tp[0] == '\\') &&
(tp[1] == '\\'))
{
*rp++ = '\\';
tp += 2;
}
else
{
/*
* We should never get here. The first pass should not allow it.
*/
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("invalid input syntax for type %s", "bytea")));
}
}
PG_RETURN_BYTEA_P(result);
}
/*
* byteaout - converts to printable representation of byte array
*
* In the traditional escaped format, non-printable characters are
* printed as '\nnn' (octal) and '\' as '\\'.
*/
Datum
byteaout(PG_FUNCTION_ARGS)
{
bytea *vlena = PG_GETARG_BYTEA_PP(0);
char *result;
char *rp;
if (bytea_output == BYTEA_OUTPUT_HEX)
{
/* Print hex format */
rp = result = palloc(VARSIZE_ANY_EXHDR(vlena) * 2 + 2 + 1);
*rp++ = '\\';
*rp++ = 'x';
rp += hex_encode(VARDATA_ANY(vlena), VARSIZE_ANY_EXHDR(vlena), rp);
}
else if (bytea_output == BYTEA_OUTPUT_ESCAPE)
{
/* Print traditional escaped format */
char *vp;
int len;
int i;
len = 1; /* empty string has 1 char */
vp = VARDATA_ANY(vlena);
for (i = VARSIZE_ANY_EXHDR(vlena); i != 0; i--, vp++)
{
if (*vp == '\\')
len += 2;
else if ((unsigned char) *vp < 0x20 || (unsigned char) *vp > 0x7e)
len += 4;
else
len++;
}
rp = result = (char *) palloc(len);
vp = VARDATA_ANY(vlena);
for (i = VARSIZE_ANY_EXHDR(vlena); i != 0; i--, vp++)
{
if (*vp == '\\')
{
*rp++ = '\\';
*rp++ = '\\';
}
else if ((unsigned char) *vp < 0x20 || (unsigned char) *vp > 0x7e)
{
int val; /* holds unprintable chars */
val = *vp;
rp[0] = '\\';
rp[3] = DIG(val & 07);
val >>= 3;
rp[2] = DIG(val & 07);
val >>= 3;
rp[1] = DIG(val & 03);
rp += 4;
}
else
*rp++ = *vp;
}
}
else
{
elog(ERROR, "unrecognized bytea_output setting: %d",
bytea_output);
rp = result = NULL; /* keep compiler quiet */
}
*rp = '\0';
PG_RETURN_CSTRING(result);
}
/*
* bytearecv - converts external binary format to bytea
*/
Datum
bytearecv(PG_FUNCTION_ARGS)
{
StringInfo buf = (StringInfo) PG_GETARG_POINTER(0);
bytea *result;
int nbytes;
nbytes = buf->len - buf->cursor;
result = (bytea *) palloc(nbytes + VARHDRSZ);
SET_VARSIZE(result, nbytes + VARHDRSZ);
pq_copymsgbytes(buf, VARDATA(result), nbytes);
PG_RETURN_BYTEA_P(result);
}
/*
* byteasend - converts bytea to binary format
*
* This is a special case: just copy the input...
*/
Datum
byteasend(PG_FUNCTION_ARGS)
{
bytea *vlena = PG_GETARG_BYTEA_P_COPY(0);
PG_RETURN_BYTEA_P(vlena);
}
Datum
bytea_string_agg_transfn(PG_FUNCTION_ARGS)
{
StringInfo state;
state = PG_ARGISNULL(0) ? NULL : (StringInfo) PG_GETARG_POINTER(0);
/* Append the value unless null. */
if (!PG_ARGISNULL(1))
{
bytea *value = PG_GETARG_BYTEA_PP(1);
/* On the first time through, we ignore the delimiter. */
if (state == NULL)
state = makeStringAggState(fcinfo);
else if (!PG_ARGISNULL(2))
{
bytea *delim = PG_GETARG_BYTEA_PP(2);
appendBinaryStringInfo(state, VARDATA_ANY(delim), VARSIZE_ANY_EXHDR(delim));
}
appendBinaryStringInfo(state, VARDATA_ANY(value), VARSIZE_ANY_EXHDR(value));
}
/*
* The transition type for string_agg() is declared to be "internal",
* which is a pass-by-value type the same size as a pointer.
*/
PG_RETURN_POINTER(state);
}
Datum
bytea_string_agg_finalfn(PG_FUNCTION_ARGS)
{
StringInfo state;
/* cannot be called directly because of internal-type argument */
Assert(AggCheckCallContext(fcinfo, NULL));
state = PG_ARGISNULL(0) ? NULL : (StringInfo) PG_GETARG_POINTER(0);
if (state != NULL)
{
bytea *result;
result = (bytea *) palloc(state->len + VARHDRSZ);
SET_VARSIZE(result, state->len + VARHDRSZ);
memcpy(VARDATA(result), state->data, state->len);
PG_RETURN_BYTEA_P(result);
}
else
PG_RETURN_NULL();
}
/*
* textin - converts "..." to internal representation
*/
Datum
textin(PG_FUNCTION_ARGS)
{
char *inputText = PG_GETARG_CSTRING(0);
PG_RETURN_TEXT_P(cstring_to_text(inputText));
}
/*
* textout - converts internal representation to "..."
*/
Datum
textout(PG_FUNCTION_ARGS)
{
Datum txt = PG_GETARG_DATUM(0);
PG_RETURN_CSTRING(TextDatumGetCString(txt));
}
/*
* textrecv - converts external binary format to text
*/
Datum
textrecv(PG_FUNCTION_ARGS)
{
StringInfo buf = (StringInfo) PG_GETARG_POINTER(0);
text *result;
char *str;
int nbytes;
str = pq_getmsgtext(buf, buf->len - buf->cursor, &nbytes);
result = cstring_to_text_with_len(str, nbytes);
pfree(str);
PG_RETURN_TEXT_P(result);
}
/*
* textsend - converts text to binary format
*/
Datum
textsend(PG_FUNCTION_ARGS)
{
text *t = PG_GETARG_TEXT_PP(0);
StringInfoData buf;
pq_begintypsend(&buf);
pq_sendtext(&buf, VARDATA_ANY(t), VARSIZE_ANY_EXHDR(t));
PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
}
/*
* unknownin - converts "..." to internal representation
*/
Datum
unknownin(PG_FUNCTION_ARGS)
{
char *str = PG_GETARG_CSTRING(0);
/* representation is same as cstring */
PG_RETURN_CSTRING(pstrdup(str));
}
/*
* unknownout - converts internal representation to "..."
*/
Datum
unknownout(PG_FUNCTION_ARGS)
{
/* representation is same as cstring */
char *str = PG_GETARG_CSTRING(0);
PG_RETURN_CSTRING(pstrdup(str));
}
/*
* unknownrecv - converts external binary format to unknown
*/
Datum
unknownrecv(PG_FUNCTION_ARGS)
{
StringInfo buf = (StringInfo) PG_GETARG_POINTER(0);
char *str;
int nbytes;
str = pq_getmsgtext(buf, buf->len - buf->cursor, &nbytes);
/* representation is same as cstring */
PG_RETURN_CSTRING(str);
}
/*
* unknownsend - converts unknown to binary format
*/
Datum
unknownsend(PG_FUNCTION_ARGS)
{
/* representation is same as cstring */
char *str = PG_GETARG_CSTRING(0);
StringInfoData buf;
pq_begintypsend(&buf);
pq_sendtext(&buf, str, strlen(str));
PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
}
/* ========== PUBLIC ROUTINES ========== */
/*
* textlen -
* returns the logical length of a text*
* (which is less than the VARSIZE of the text*)
*/
Datum
textlen(PG_FUNCTION_ARGS)
{
Datum str = PG_GETARG_DATUM(0);
/* try to avoid decompressing argument */
PG_RETURN_INT32(text_length(str));
}
/*
* text_length -
* Does the real work for textlen()
*
* This is broken out so it can be called directly by other string processing
* functions. Note that the argument is passed as a Datum, to indicate that
* it may still be in compressed form. We can avoid decompressing it at all
* in some cases.
*/
static int32
text_length(Datum str)
{
/* fastpath when max encoding length is one */
if (pg_database_encoding_max_length() == 1)
PG_RETURN_INT32(toast_raw_datum_size(str) - VARHDRSZ);
else
{
text *t = DatumGetTextPP(str);
PG_RETURN_INT32(pg_mbstrlen_with_len(VARDATA_ANY(t),
VARSIZE_ANY_EXHDR(t)));
}
}
/*
* textoctetlen -
* returns the physical length of a text*
* (which is less than the VARSIZE of the text*)
*/
Datum
textoctetlen(PG_FUNCTION_ARGS)
{
Datum str = PG_GETARG_DATUM(0);
/* We need not detoast the input at all */
PG_RETURN_INT32(toast_raw_datum_size(str) - VARHDRSZ);
}
/*
* textcat -
* takes two text* and returns a text* that is the concatenation of
* the two.
*
* Rewritten by Sapa, sapa@hq.icb.chel.su. 8-Jul-96.
* Updated by Thomas, Thomas.Lockhart@jpl.nasa.gov 1997-07-10.
* Allocate space for output in all cases.
* XXX - thomas 1997-07-10
*/
Datum
textcat(PG_FUNCTION_ARGS)
{
text *t1 = PG_GETARG_TEXT_PP(0);
text *t2 = PG_GETARG_TEXT_PP(1);
PG_RETURN_TEXT_P(text_catenate(t1, t2));
}
/*
* text_catenate
* Guts of textcat(), broken out so it can be used by other functions
*
* Arguments can be in short-header form, but not compressed or out-of-line
*/
static text *
text_catenate(text *t1, text *t2)
{
text *result;
int len1,
len2,
len;
char *ptr;
len1 = VARSIZE_ANY_EXHDR(t1);
len2 = VARSIZE_ANY_EXHDR(t2);
/* paranoia ... probably should throw error instead? */
if (len1 < 0)
len1 = 0;
if (len2 < 0)
len2 = 0;
len = len1 + len2 + VARHDRSZ;
result = (text *) palloc(len);
/* Set size of result string... */
SET_VARSIZE(result, len);
/* Fill data field of result string... */
ptr = VARDATA(result);
if (len1 > 0)
memcpy(ptr, VARDATA_ANY(t1), len1);
if (len2 > 0)
memcpy(ptr + len1, VARDATA_ANY(t2), len2);
return result;
}
/*
* charlen_to_bytelen()
* Compute the number of bytes occupied by n characters starting at *p
*
* It is caller's responsibility that there actually are n characters;
* the string need not be null-terminated.
*/
static int
charlen_to_bytelen(const char *p, int n)
{
if (pg_database_encoding_max_length() == 1)
{
/* Optimization for single-byte encodings */
return n;
}
else
{
const char *s;
for (s = p; n > 0; n--)
s += pg_mblen(s);
return s - p;
}
}
/*
* text_substr()
* Return a substring starting at the specified position.
* - thomas 1997-12-31
*
* Input:
* - string
* - starting position (is one-based)
* - string length
*
* If the starting position is zero or less, then return from the start of the string
* adjusting the length to be consistent with the "negative start" per SQL.
* If the length is less than zero, return the remaining string.
*
* Added multibyte support.
* - Tatsuo Ishii 1998-4-21
* Changed behavior if starting position is less than one to conform to SQL behavior.
* Formerly returned the entire string; now returns a portion.
* - Thomas Lockhart 1998-12-10
* Now uses faster TOAST-slicing interface
* - John Gray 2002-02-22
* Remove "#ifdef MULTIBYTE" and test for encoding_max_length instead. Change
* behaviors conflicting with SQL to meet SQL (if E = S + L < S throw
* error; if E < 1, return '', not entire string). Fixed MB related bug when
* S > LC and < LC + 4 sometimes garbage characters are returned.
* - Joe Conway 2002-08-10
*/
Datum
text_substr(PG_FUNCTION_ARGS)
{
PG_RETURN_TEXT_P(text_substring(PG_GETARG_DATUM(0),
PG_GETARG_INT32(1),
PG_GETARG_INT32(2),
false));
}
/*
* text_substr_no_len -
* Wrapper to avoid opr_sanity failure due to
* one function accepting a different number of args.
*/
Datum
text_substr_no_len(PG_FUNCTION_ARGS)
{
PG_RETURN_TEXT_P(text_substring(PG_GETARG_DATUM(0),
PG_GETARG_INT32(1),
-1, true));
}
/*
* text_substring -
* Does the real work for text_substr() and text_substr_no_len()
*
* This is broken out so it can be called directly by other string processing
* functions. Note that the argument is passed as a Datum, to indicate that
* it may still be in compressed/toasted form. We can avoid detoasting all
* of it in some cases.
*
* The result is always a freshly palloc'd datum.
*/
static text *
text_substring(Datum str, int32 start, int32 length, bool length_not_specified)
{
int32 eml = pg_database_encoding_max_length();
int32 S = start; /* start position */
int32 S1; /* adjusted start position */
int32 L1; /* adjusted substring length */
/* life is easy if the encoding max length is 1 */
if (eml == 1)
{
S1 = Max(S, 1);
if (length_not_specified) /* special case - get length to end of
* string */
L1 = -1;
else
{
/* end position */
int E = S + length;
/*
* A negative value for L is the only way for the end position to
* be before the start. SQL99 says to throw an error.
*/
if (E < S)
ereport(ERROR,
(errcode(ERRCODE_SUBSTRING_ERROR),
errmsg("negative substring length not allowed")));
/*
* A zero or negative value for the end position can happen if the
* start was negative or one. SQL99 says to return a zero-length
* string.
*/
if (E < 1)
return cstring_to_text("");
L1 = E - S1;
}
/*
* If the start position is past the end of the string, SQL99 says to
* return a zero-length string -- PG_GETARG_TEXT_P_SLICE() will do
* that for us. Convert to zero-based starting position
*/
return DatumGetTextPSlice(str, S1 - 1, L1);
}
else if (eml > 1)
{
/*
* When encoding max length is > 1, we can't get LC without
* detoasting, so we'll grab a conservatively large slice now and go
* back later to do the right thing
*/
int32 slice_start;
int32 slice_size;
int32 slice_strlen;
text *slice;
int32 E1;
int32 i;
char *p;
char *s;
text *ret;
/*
* if S is past the end of the string, the tuple toaster will return a
* zero-length string to us
*/
S1 = Max(S, 1);
/*
* We need to start at position zero because there is no way to know
* in advance which byte offset corresponds to the supplied start
* position.
*/
slice_start = 0;
if (length_not_specified) /* special case - get length to end of
* string */
slice_size = L1 = -1;
else
{
int E = S + length;
/*
* A negative value for L is the only way for the end position to
* be before the start. SQL99 says to throw an error.
*/
if (E < S)
ereport(ERROR,
(errcode(ERRCODE_SUBSTRING_ERROR),
errmsg("negative substring length not allowed")));
/*
* A zero or negative value for the end position can happen if the
* start was negative or one. SQL99 says to return a zero-length
* string.
*/
if (E < 1)
return cstring_to_text("");
/*
* if E is past the end of the string, the tuple toaster will
* truncate the length for us
*/
L1 = E - S1;
/*
* Total slice size in bytes can't be any longer than the start
* position plus substring length times the encoding max length.
*/
slice_size = (S1 + L1) * eml;
}
/*
* If we're working with an untoasted source, no need to do an extra
* copying step.
*/
if (VARATT_IS_COMPRESSED(DatumGetPointer(str)) ||
VARATT_IS_EXTERNAL(DatumGetPointer(str)))
slice = DatumGetTextPSlice(str, slice_start, slice_size);
else
slice = (text *) DatumGetPointer(str);
/* see if we got back an empty string */
if (VARSIZE_ANY_EXHDR(slice) == 0)
{
if (slice != (text *) DatumGetPointer(str))
pfree(slice);
return cstring_to_text("");
}
/* Now we can get the actual length of the slice in MB characters */
slice_strlen = pg_mbstrlen_with_len(VARDATA_ANY(slice),
VARSIZE_ANY_EXHDR(slice));
/*
* Check that the start position wasn't > slice_strlen. If so, SQL99
* says to return a zero-length string.
*/
if (S1 > slice_strlen)
{
if (slice != (text *) DatumGetPointer(str))
pfree(slice);
return cstring_to_text("");
}
/*
* Adjust L1 and E1 now that we know the slice string length. Again
* remember that S1 is one based, and slice_start is zero based.
*/
if (L1 > -1)
E1 = Min(S1 + L1, slice_start + 1 + slice_strlen);
else
E1 = slice_start + 1 + slice_strlen;
/*
* Find the start position in the slice; remember S1 is not zero based
*/
p = VARDATA_ANY(slice);
for (i = 0; i < S1 - 1; i++)
p += pg_mblen(p);
/* hang onto a pointer to our start position */
s = p;
/*
* Count the actual bytes used by the substring of the requested
* length.
*/
for (i = S1; i < E1; i++)
p += pg_mblen(p);
ret = (text *) palloc(VARHDRSZ + (p - s));
SET_VARSIZE(ret, VARHDRSZ + (p - s));
memcpy(VARDATA(ret), s, (p - s));
if (slice != (text *) DatumGetPointer(str))
pfree(slice);
return ret;
}
else
elog(ERROR, "invalid backend encoding: encoding max length < 1");
/* not reached: suppress compiler warning */
return NULL;
}
/*
* textoverlay
* Replace specified substring of first string with second
*
* The SQL standard defines OVERLAY() in terms of substring and concatenation.
* This code is a direct implementation of what the standard says.
*/
Datum
textoverlay(PG_FUNCTION_ARGS)
{
text *t1 = PG_GETARG_TEXT_PP(0);
text *t2 = PG_GETARG_TEXT_PP(1);
int sp = PG_GETARG_INT32(2); /* substring start position */
int sl = PG_GETARG_INT32(3); /* substring length */
PG_RETURN_TEXT_P(text_overlay(t1, t2, sp, sl));
}
Datum
textoverlay_no_len(PG_FUNCTION_ARGS)
{
text *t1 = PG_GETARG_TEXT_PP(0);
text *t2 = PG_GETARG_TEXT_PP(1);
int sp = PG_GETARG_INT32(2); /* substring start position */
int sl;
sl = text_length(PointerGetDatum(t2)); /* defaults to length(t2) */
PG_RETURN_TEXT_P(text_overlay(t1, t2, sp, sl));
}
static text *
text_overlay(text *t1, text *t2, int sp, int sl)
{
text *result;
text *s1;
text *s2;
int sp_pl_sl;
/*
* Check for possible integer-overflow cases. For negative sp, throw a
* "substring length" error because that's what should be expected
* according to the spec's definition of OVERLAY().
*/
if (sp <= 0)
ereport(ERROR,
(errcode(ERRCODE_SUBSTRING_ERROR),
errmsg("negative substring length not allowed")));
if (pg_add_s32_overflow(sp, sl, &sp_pl_sl))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
s1 = text_substring(PointerGetDatum(t1), 1, sp - 1, false);
s2 = text_substring(PointerGetDatum(t1), sp_pl_sl, -1, true);
result = text_catenate(s1, t2);
result = text_catenate(result, s2);
return result;
}
/*
* textpos -
* Return the position of the specified substring.
* Implements the SQL POSITION() function.
* Ref: A Guide To The SQL Standard, Date & Darwen, 1997
* - thomas 1997-07-27
*/
Datum
textpos(PG_FUNCTION_ARGS)
{
text *str = PG_GETARG_TEXT_PP(0);
text *search_str = PG_GETARG_TEXT_PP(1);
PG_RETURN_INT32((int32) text_position(str, search_str));
}
/*
* text_position -
* Does the real work for textpos()
*
* Inputs:
* t1 - string to be searched
* t2 - pattern to match within t1
* Result:
* Character index of the first matched char, starting from 1,
* or 0 if no match.
*
* This is broken out so it can be called directly by other string processing
* functions.
*/
static int
text_position(text *t1, text *t2)
{
TextPositionState state;
int result;
text_position_setup(t1, t2, &state);
result = text_position_next(1, &state);
text_position_cleanup(&state);
return result;
}
/*
* text_position_setup, text_position_next, text_position_cleanup -
* Component steps of text_position()
*
* These are broken out so that a string can be efficiently searched for
* multiple occurrences of the same pattern. text_position_next may be
* called multiple times with increasing values of start_pos, which is
* the 1-based character position to start the search from. The "state"
* variable is normally just a local variable in the caller.
*/
static void
text_position_setup(text *t1, text *t2, TextPositionState *state)
{
int len1 = VARSIZE_ANY_EXHDR(t1);
int len2 = VARSIZE_ANY_EXHDR(t2);
if (pg_database_encoding_max_length() == 1)
{
/* simple case - single byte encoding */
state->use_wchar = false;
state->str1 = VARDATA_ANY(t1);
state->str2 = VARDATA_ANY(t2);
state->len1 = len1;
state->len2 = len2;
}
else
{
/* not as simple - multibyte encoding */
pg_wchar *p1,
*p2;
p1 = (pg_wchar *) palloc((len1 + 1) * sizeof(pg_wchar));
len1 = pg_mb2wchar_with_len(VARDATA_ANY(t1), p1, len1);
p2 = (pg_wchar *) palloc((len2 + 1) * sizeof(pg_wchar));
len2 = pg_mb2wchar_with_len(VARDATA_ANY(t2), p2, len2);
state->use_wchar = true;
state->wstr1 = p1;
state->wstr2 = p2;
state->len1 = len1;
state->len2 = len2;
}
/*
* Prepare the skip table for Boyer-Moore-Horspool searching. In these
* notes we use the terminology that the "haystack" is the string to be
* searched (t1) and the "needle" is the pattern being sought (t2).
*
* If the needle is empty or bigger than the haystack then there is no
* point in wasting cycles initializing the table. We also choose not to
* use B-M-H for needles of length 1, since the skip table can't possibly
* save anything in that case.
*/
if (len1 >= len2 && len2 > 1)
{
int searchlength = len1 - len2;
int skiptablemask;
int last;
int i;
/*
* First we must determine how much of the skip table to use. The
* declaration of TextPositionState allows up to 256 elements, but for
* short search problems we don't really want to have to initialize so
* many elements --- it would take too long in comparison to the
* actual search time. So we choose a useful skip table size based on
* the haystack length minus the needle length. The closer the needle
* length is to the haystack length the less useful skipping becomes.
*
* Note: since we use bit-masking to select table elements, the skip
* table size MUST be a power of 2, and so the mask must be 2^N-1.
*/
if (searchlength < 16)
skiptablemask = 3;
else if (searchlength < 64)
skiptablemask = 7;
else if (searchlength < 128)
skiptablemask = 15;
else if (searchlength < 512)
skiptablemask = 31;
else if (searchlength < 2048)
skiptablemask = 63;
else if (searchlength < 4096)
skiptablemask = 127;
else
skiptablemask = 255;
state->skiptablemask = skiptablemask;
/*
* Initialize the skip table. We set all elements to the needle
* length, since this is the correct skip distance for any character
* not found in the needle.
*/
for (i = 0; i <= skiptablemask; i++)
state->skiptable[i] = len2;
/*
* Now examine the needle. For each character except the last one,
* set the corresponding table element to the appropriate skip
* distance. Note that when two characters share the same skip table
* entry, the one later in the needle must determine the skip
* distance.
*/
last = len2 - 1;
if (!state->use_wchar)
{
const char *str2 = state->str2;
for (i = 0; i < last; i++)
state->skiptable[(unsigned char) str2[i] & skiptablemask] = last - i;
}
else
{
const pg_wchar *wstr2 = state->wstr2;
for (i = 0; i < last; i++)
state->skiptable[wstr2[i] & skiptablemask] = last - i;
}
}
}
static int
text_position_next(int start_pos, TextPositionState *state)
{
int haystack_len = state->len1;
int needle_len = state->len2;
int skiptablemask = state->skiptablemask;
Assert(start_pos > 0); /* else caller error */
if (needle_len <= 0)
return start_pos; /* result for empty pattern */
start_pos--; /* adjust for zero based arrays */
/* Done if the needle can't possibly fit */
if (haystack_len < start_pos + needle_len)
return 0;
if (!state->use_wchar)
{
/* simple case - single byte encoding */
const char *haystack = state->str1;
const char *needle = state->str2;
const char *haystack_end = &haystack[haystack_len];
const char *hptr;
if (needle_len == 1)
{
/* No point in using B-M-H for a one-character needle */
char nchar = *needle;
hptr = &haystack[start_pos];
while (hptr < haystack_end)
{
if (*hptr == nchar)
return hptr - haystack + 1;
hptr++;
}
}
else
{
const char *needle_last = &needle[needle_len - 1];
/* Start at startpos plus the length of the needle */
hptr = &haystack[start_pos + needle_len - 1];
while (hptr < haystack_end)
{
/* Match the needle scanning *backward* */
const char *nptr;
const char *p;
nptr = needle_last;
p = hptr;
while (*nptr == *p)
{
/* Matched it all? If so, return 1-based position */
if (nptr == needle)
return p - haystack + 1;
nptr--, p--;
}
/*
* No match, so use the haystack char at hptr to decide how
* far to advance. If the needle had any occurrence of that
* character (or more precisely, one sharing the same
* skiptable entry) before its last character, then we advance
* far enough to align the last such needle character with
* that haystack position. Otherwise we can advance by the
* whole needle length.
*/
hptr += state->skiptable[(unsigned char) *hptr & skiptablemask];
}
}
}
else
{
/* The multibyte char version. This works exactly the same way. */
const pg_wchar *haystack = state->wstr1;
const pg_wchar *needle = state->wstr2;
const pg_wchar *haystack_end = &haystack[haystack_len];
const pg_wchar *hptr;
if (needle_len == 1)
{
/* No point in using B-M-H for a one-character needle */
pg_wchar nchar = *needle;
hptr = &haystack[start_pos];
while (hptr < haystack_end)
{
if (*hptr == nchar)
return hptr - haystack + 1;
hptr++;
}
}
else
{
const pg_wchar *needle_last = &needle[needle_len - 1];
/* Start at startpos plus the length of the needle */
hptr = &haystack[start_pos + needle_len - 1];
while (hptr < haystack_end)
{
/* Match the needle scanning *backward* */
const pg_wchar *nptr;
const pg_wchar *p;
nptr = needle_last;
p = hptr;
while (*nptr == *p)
{
/* Matched it all? If so, return 1-based position */
if (nptr == needle)
return p - haystack + 1;
nptr--, p--;
}
/*
* No match, so use the haystack char at hptr to decide how
* far to advance. If the needle had any occurrence of that
* character (or more precisely, one sharing the same
* skiptable entry) before its last character, then we advance
* far enough to align the last such needle character with
* that haystack position. Otherwise we can advance by the
* whole needle length.
*/
hptr += state->skiptable[*hptr & skiptablemask];
}
}
}
return 0; /* not found */
}
static void
text_position_cleanup(TextPositionState *state)
{
if (state->use_wchar)
{
pfree(state->wstr1);
pfree(state->wstr2);
}
}
/* varstr_cmp()
* Comparison function for text strings with given lengths.
* Includes locale support, but must copy strings to temporary memory
* to allow null-termination for inputs to strcoll().
* Returns an integer less than, equal to, or greater than zero, indicating
* whether arg1 is less than, equal to, or greater than arg2.
*/
int
varstr_cmp(const char *arg1, int len1, const char *arg2, int len2, Oid collid)
{
int result;
/*
* Unfortunately, there is no strncoll(), so in the non-C locale case we
* have to do some memory copying. This turns out to be significantly
* slower, so we optimize the case where LC_COLLATE is C. We also try to
* optimize relatively-short strings by avoiding palloc/pfree overhead.
*/
if (lc_collate_is_c(collid))
{
result = memcmp(arg1, arg2, Min(len1, len2));
if ((result == 0) && (len1 != len2))
result = (len1 < len2) ? -1 : 1;
}
else
{
char a1buf[TEXTBUFLEN];
char a2buf[TEXTBUFLEN];
char *a1p,
*a2p;
pg_locale_t mylocale = 0;
if (collid != DEFAULT_COLLATION_OID)
{
if (!OidIsValid(collid))
{
/*
* This typically means that the parser could not resolve a
* conflict of implicit collations, so report it that way.
*/
ereport(ERROR,
(errcode(ERRCODE_INDETERMINATE_COLLATION),
errmsg("could not determine which collation to use for string comparison"),
errhint("Use the COLLATE clause to set the collation explicitly.")));
}
mylocale = pg_newlocale_from_collation(collid);
}
/*
* memcmp() can't tell us which of two unequal strings sorts first,
* but it's a cheap way to tell if they're equal. Testing shows that
* memcmp() followed by strcoll() is only trivially slower than
* strcoll() by itself, so we don't lose much if this doesn't work out
* very often, and if it does - for example, because there are many
* equal strings in the input - then we win big by avoiding expensive
* collation-aware comparisons.
*/
if (len1 == len2 && memcmp(arg1, arg2, len1) == 0)
return 0;
#ifdef WIN32
/* Win32 does not have UTF-8, so we need to map to UTF-16 */
if (GetDatabaseEncoding() == PG_UTF8
&& (!mylocale || mylocale->provider == COLLPROVIDER_LIBC))
{
int a1len;
int a2len;
int r;
if (len1 >= TEXTBUFLEN / 2)
{
a1len = len1 * 2 + 2;
a1p = palloc(a1len);
}
else
{
a1len = TEXTBUFLEN;
a1p = a1buf;
}
if (len2 >= TEXTBUFLEN / 2)
{
a2len = len2 * 2 + 2;
a2p = palloc(a2len);
}
else
{
a2len = TEXTBUFLEN;
a2p = a2buf;
}
/* stupid Microsloth API does not work for zero-length input */
if (len1 == 0)
r = 0;
else
{
r = MultiByteToWideChar(CP_UTF8, 0, arg1, len1,
(LPWSTR) a1p, a1len / 2);
if (!r)
ereport(ERROR,
(errmsg("could not convert string to UTF-16: error code %lu",
GetLastError())));
}
((LPWSTR) a1p)[r] = 0;
if (len2 == 0)
r = 0;
else
{
r = MultiByteToWideChar(CP_UTF8, 0, arg2, len2,
(LPWSTR) a2p, a2len / 2);
if (!r)
ereport(ERROR,
(errmsg("could not convert string to UTF-16: error code %lu",
GetLastError())));
}
((LPWSTR) a2p)[r] = 0;
errno = 0;
#ifdef HAVE_LOCALE_T
if (mylocale)
result = wcscoll_l((LPWSTR) a1p, (LPWSTR) a2p, mylocale->info.lt);
else
#endif
result = wcscoll((LPWSTR) a1p, (LPWSTR) a2p);
if (result == 2147483647) /* _NLSCMPERROR; missing from mingw
* headers */
ereport(ERROR,
(errmsg("could not compare Unicode strings: %m")));
/*
* In some locales wcscoll() can claim that nonidentical strings
* are equal. Believing that would be bad news for a number of
* reasons, so we follow Perl's lead and sort "equal" strings
* according to strcmp (on the UTF-8 representation).
*/
if (result == 0)
{
result = memcmp(arg1, arg2, Min(len1, len2));
if ((result == 0) && (len1 != len2))
result = (len1 < len2) ? -1 : 1;
}
if (a1p != a1buf)
pfree(a1p);
if (a2p != a2buf)
pfree(a2p);
return result;
}
#endif /* WIN32 */
if (len1 >= TEXTBUFLEN)
a1p = (char *) palloc(len1 + 1);
else
a1p = a1buf;
if (len2 >= TEXTBUFLEN)
a2p = (char *) palloc(len2 + 1);
else
a2p = a2buf;
memcpy(a1p, arg1, len1);
a1p[len1] = '\0';
memcpy(a2p, arg2, len2);
a2p[len2] = '\0';
if (mylocale)
{
if (mylocale->provider == COLLPROVIDER_ICU)
{
#ifdef USE_ICU
#ifdef HAVE_UCOL_STRCOLLUTF8
if (GetDatabaseEncoding() == PG_UTF8)
{
UErrorCode status;
status = U_ZERO_ERROR;
result = ucol_strcollUTF8(mylocale->info.icu.ucol,
arg1, len1,
arg2, len2,
&status);
if (U_FAILURE(status))
ereport(ERROR,
(errmsg("collation failed: %s", u_errorName(status))));
}
else
#endif
{
int32_t ulen1,
ulen2;
UChar *uchar1,
*uchar2;
ulen1 = icu_to_uchar(&uchar1, arg1, len1);
ulen2 = icu_to_uchar(&uchar2, arg2, len2);
result = ucol_strcoll(mylocale->info.icu.ucol,
uchar1, ulen1,
uchar2, ulen2);
pfree(uchar1);
pfree(uchar2);
}
#else /* not USE_ICU */
/* shouldn't happen */
elog(ERROR, "unsupported collprovider: %c", mylocale->provider);
#endif /* not USE_ICU */
}
else
{
#ifdef HAVE_LOCALE_T
result = strcoll_l(a1p, a2p, mylocale->info.lt);
#else
/* shouldn't happen */
elog(ERROR, "unsupported collprovider: %c", mylocale->provider);
#endif
}
}
else
result = strcoll(a1p, a2p);
/*
* In some locales strcoll() can claim that nonidentical strings are
* equal. Believing that would be bad news for a number of reasons,
* so we follow Perl's lead and sort "equal" strings according to
* strcmp().
*/
if (result == 0)
result = strcmp(a1p, a2p);
if (a1p != a1buf)
pfree(a1p);
if (a2p != a2buf)
pfree(a2p);
}
return result;
}
/* text_cmp()
* Internal comparison function for text strings.
* Returns -1, 0 or 1
*/
static int
text_cmp(text *arg1, text *arg2, Oid collid)
{
char *a1p,
*a2p;
int len1,
len2;
a1p = VARDATA_ANY(arg1);
a2p = VARDATA_ANY(arg2);
len1 = VARSIZE_ANY_EXHDR(arg1);
len2 = VARSIZE_ANY_EXHDR(arg2);
return varstr_cmp(a1p, len1, a2p, len2, collid);
}
/*
* Comparison functions for text strings.
*
* Note: btree indexes need these routines not to leak memory; therefore,
* be careful to free working copies of toasted datums. Most places don't
* need to be so careful.
*/
Datum
texteq(PG_FUNCTION_ARGS)
{
Datum arg1 = PG_GETARG_DATUM(0);
Datum arg2 = PG_GETARG_DATUM(1);
bool result;
Size len1,
len2;
/*
* Since we only care about equality or not-equality, we can avoid all the
* expense of strcoll() here, and just do bitwise comparison. In fact, we
* don't even have to do a bitwise comparison if we can show the lengths
* of the strings are unequal; which might save us from having to detoast
* one or both values.
*/
len1 = toast_raw_datum_size(arg1);
len2 = toast_raw_datum_size(arg2);
if (len1 != len2)
result = false;
else
{
text *targ1 = DatumGetTextPP(arg1);
text *targ2 = DatumGetTextPP(arg2);
result = (memcmp(VARDATA_ANY(targ1), VARDATA_ANY(targ2),
len1 - VARHDRSZ) == 0);
PG_FREE_IF_COPY(targ1, 0);
PG_FREE_IF_COPY(targ2, 1);
}
PG_RETURN_BOOL(result);
}
Datum
textne(PG_FUNCTION_ARGS)
{
Datum arg1 = PG_GETARG_DATUM(0);
Datum arg2 = PG_GETARG_DATUM(1);
bool result;
Size len1,
len2;
/* See comment in texteq() */
len1 = toast_raw_datum_size(arg1);
len2 = toast_raw_datum_size(arg2);
if (len1 != len2)
result = true;
else
{
text *targ1 = DatumGetTextPP(arg1);
text *targ2 = DatumGetTextPP(arg2);
result = (memcmp(VARDATA_ANY(targ1), VARDATA_ANY(targ2),
len1 - VARHDRSZ) != 0);
PG_FREE_IF_COPY(targ1, 0);
PG_FREE_IF_COPY(targ2, 1);
}
PG_RETURN_BOOL(result);
}
Datum
text_lt(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_PP(0);
text *arg2 = PG_GETARG_TEXT_PP(1);
bool result;
result = (text_cmp(arg1, arg2, PG_GET_COLLATION()) < 0);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result);
}
Datum
text_le(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_PP(0);
text *arg2 = PG_GETARG_TEXT_PP(1);
bool result;
result = (text_cmp(arg1, arg2, PG_GET_COLLATION()) <= 0);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result);
}
Datum
text_gt(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_PP(0);
text *arg2 = PG_GETARG_TEXT_PP(1);
bool result;
result = (text_cmp(arg1, arg2, PG_GET_COLLATION()) > 0);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result);
}
Datum
text_ge(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_PP(0);
text *arg2 = PG_GETARG_TEXT_PP(1);
bool result;
result = (text_cmp(arg1, arg2, PG_GET_COLLATION()) >= 0);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result);
}
Datum
text_starts_with(PG_FUNCTION_ARGS)
{
Datum arg1 = PG_GETARG_DATUM(0);
Datum arg2 = PG_GETARG_DATUM(1);
bool result;
Size len1,
len2;
len1 = toast_raw_datum_size(arg1);
len2 = toast_raw_datum_size(arg2);
if (len2 > len1)
result = false;
else
{
text *targ1 = DatumGetTextPP(arg1);
text *targ2 = DatumGetTextPP(arg2);
result = (memcmp(VARDATA_ANY(targ1), VARDATA_ANY(targ2),
VARSIZE_ANY_EXHDR(targ2)) == 0);
PG_FREE_IF_COPY(targ1, 0);
PG_FREE_IF_COPY(targ2, 1);
}
PG_RETURN_BOOL(result);
}
Datum
bttextcmp(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_PP(0);
text *arg2 = PG_GETARG_TEXT_PP(1);
int32 result;
result = text_cmp(arg1, arg2, PG_GET_COLLATION());
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_INT32(result);
}
Datum
bttextsortsupport(PG_FUNCTION_ARGS)
{
SortSupport ssup = (SortSupport) PG_GETARG_POINTER(0);
Oid collid = ssup->ssup_collation;
MemoryContext oldcontext;
oldcontext = MemoryContextSwitchTo(ssup->ssup_cxt);
/* Use generic string SortSupport */
varstr_sortsupport(ssup, collid, false);
MemoryContextSwitchTo(oldcontext);
PG_RETURN_VOID();
}
/*
* Generic sortsupport interface for character type's operator classes.
* Includes locale support, and support for BpChar semantics (i.e. removing
* trailing spaces before comparison).
*
* Relies on the assumption that text, VarChar, BpChar, and bytea all have the
* same representation. Callers that always use the C collation (e.g.
* non-collatable type callers like bytea) may have NUL bytes in their strings;
* this will not work with any other collation, though.
*/
void
varstr_sortsupport(SortSupport ssup, Oid collid, bool bpchar)
{
bool abbreviate = ssup->abbreviate;
bool collate_c = false;
VarStringSortSupport *sss;
pg_locale_t locale = 0;
/*
* If possible, set ssup->comparator to a function which can be used to
* directly compare two datums. If we can do this, we'll avoid the
* overhead of a trip through the fmgr layer for every comparison, which
* can be substantial.
*
* Most typically, we'll set the comparator to varstrfastcmp_locale, which
* uses strcoll() to perform comparisons and knows about the special
* requirements of BpChar callers. However, if LC_COLLATE = C, we can
* make things quite a bit faster with varstrfastcmp_c or bpcharfastcmp_c,
* both of which use memcmp() rather than strcoll().
*/
if (lc_collate_is_c(collid))
{
if (!bpchar)
ssup->comparator = varstrfastcmp_c;
else
ssup->comparator = bpcharfastcmp_c;
collate_c = true;
}
else
{
/*
* We need a collation-sensitive comparison. To make things faster,
* we'll figure out the collation based on the locale id and cache the
* result.
*/
if (collid != DEFAULT_COLLATION_OID)
{
if (!OidIsValid(collid))
{
/*
* This typically means that the parser could not resolve a
* conflict of implicit collations, so report it that way.
*/
ereport(ERROR,
(errcode(ERRCODE_INDETERMINATE_COLLATION),
errmsg("could not determine which collation to use for string comparison"),
errhint("Use the COLLATE clause to set the collation explicitly.")));
}
locale = pg_newlocale_from_collation(collid);
}
/*
* There is a further exception on Windows. When the database
* encoding is UTF-8 and we are not using the C collation, complex
* hacks are required. We don't currently have a comparator that
* handles that case, so we fall back on the slow method of having the
* sort code invoke bttextcmp() (in the case of text) via the fmgr
* trampoline. ICU locales work just the same on Windows, however.
*/
#ifdef WIN32
if (GetDatabaseEncoding() == PG_UTF8 &&
!(locale && locale->provider == COLLPROVIDER_ICU))
return;
#endif
ssup->comparator = varstrfastcmp_locale;
}
/*
* Unfortunately, it seems that abbreviation for non-C collations is
* broken on many common platforms; testing of multiple versions of glibc
* reveals that, for many locales, strcoll() and strxfrm() do not return
* consistent results, which is fatal to this optimization. While no
* other libc other than Cygwin has so far been shown to have a problem,
* we take the conservative course of action for right now and disable
* this categorically. (Users who are certain this isn't a problem on
* their system can define TRUST_STRXFRM.)
*
* Even apart from the risk of broken locales, it's possible that there
* are platforms where the use of abbreviated keys should be disabled at
* compile time. Having only 4 byte datums could make worst-case
* performance drastically more likely, for example. Moreover, macOS's
* strxfrm() implementation is known to not effectively concentrate a
* significant amount of entropy from the original string in earlier
* transformed blobs. It's possible that other supported platforms are
* similarly encumbered. So, if we ever get past disabling this
* categorically, we may still want or need to disable it for particular
* platforms.
*/
#ifndef TRUST_STRXFRM
if (!collate_c && !(locale && locale->provider == COLLPROVIDER_ICU))
abbreviate = false;
#endif
/*
* If we're using abbreviated keys, or if we're using a locale-aware
* comparison, we need to initialize a StringSortSupport object. Both
* cases will make use of the temporary buffers we initialize here for
* scratch space (and to detect requirement for BpChar semantics from
* caller), and the abbreviation case requires additional state.
*/
if (abbreviate || !collate_c)
{
sss = palloc(sizeof(VarStringSortSupport));
sss->buf1 = palloc(TEXTBUFLEN);
sss->buflen1 = TEXTBUFLEN;
sss->buf2 = palloc(TEXTBUFLEN);
sss->buflen2 = TEXTBUFLEN;
/* Start with invalid values */
sss->last_len1 = -1;
sss->last_len2 = -1;
/* Initialize */
sss->last_returned = 0;
sss->locale = locale;
/*
* To avoid somehow confusing a strxfrm() blob and an original string,
* constantly keep track of the variety of data that buf1 and buf2
* currently contain.
*
* Comparisons may be interleaved with conversion calls. Frequently,
* conversions and comparisons are batched into two distinct phases,
* but the correctness of caching cannot hinge upon this. For
* comparison caching, buffer state is only trusted if cache_blob is
* found set to false, whereas strxfrm() caching only trusts the state
* when cache_blob is found set to true.
*
* Arbitrarily initialize cache_blob to true.
*/
sss->cache_blob = true;
sss->collate_c = collate_c;
sss->bpchar = bpchar;
ssup->ssup_extra = sss;
/*
* If possible, plan to use the abbreviated keys optimization. The
* core code may switch back to authoritative comparator should
* abbreviation be aborted.
*/
if (abbreviate)
{
sss->prop_card = 0.20;
initHyperLogLog(&sss->abbr_card, 10);
initHyperLogLog(&sss->full_card, 10);
ssup->abbrev_full_comparator = ssup->comparator;
ssup->comparator = varstrcmp_abbrev;
ssup->abbrev_converter = varstr_abbrev_convert;
ssup->abbrev_abort = varstr_abbrev_abort;
}
}
}
/*
* sortsupport comparison func (for C locale case)
*/
static int
varstrfastcmp_c(Datum x, Datum y, SortSupport ssup)
{
VarString *arg1 = DatumGetVarStringPP(x);
VarString *arg2 = DatumGetVarStringPP(y);
char *a1p,
*a2p;
int len1,
len2,
result;
a1p = VARDATA_ANY(arg1);
a2p = VARDATA_ANY(arg2);
len1 = VARSIZE_ANY_EXHDR(arg1);
len2 = VARSIZE_ANY_EXHDR(arg2);
result = memcmp(a1p, a2p, Min(len1, len2));
if ((result == 0) && (len1 != len2))
result = (len1 < len2) ? -1 : 1;
/* We can't afford to leak memory here. */
if (PointerGetDatum(arg1) != x)
pfree(arg1);
if (PointerGetDatum(arg2) != y)
pfree(arg2);
return result;
}
/*
* sortsupport comparison func (for BpChar C locale case)
*
* BpChar outsources its sortsupport to this module. Specialization for the
* varstr_sortsupport BpChar case, modeled on
* internal_bpchar_pattern_compare().
*/
static int
bpcharfastcmp_c(Datum x, Datum y, SortSupport ssup)
{
BpChar *arg1 = DatumGetBpCharPP(x);
BpChar *arg2 = DatumGetBpCharPP(y);
char *a1p,
*a2p;
int len1,
len2,
result;
a1p = VARDATA_ANY(arg1);
a2p = VARDATA_ANY(arg2);
len1 = bpchartruelen(a1p, VARSIZE_ANY_EXHDR(arg1));
len2 = bpchartruelen(a2p, VARSIZE_ANY_EXHDR(arg2));
result = memcmp(a1p, a2p, Min(len1, len2));
if ((result == 0) && (len1 != len2))
result = (len1 < len2) ? -1 : 1;
/* We can't afford to leak memory here. */
if (PointerGetDatum(arg1) != x)
pfree(arg1);
if (PointerGetDatum(arg2) != y)
pfree(arg2);
return result;
}
/*
* sortsupport comparison func (for locale case)
*/
static int
varstrfastcmp_locale(Datum x, Datum y, SortSupport ssup)
{
VarString *arg1 = DatumGetVarStringPP(x);
VarString *arg2 = DatumGetVarStringPP(y);
bool arg1_match;
VarStringSortSupport *sss = (VarStringSortSupport *) ssup->ssup_extra;
/* working state */
char *a1p,
*a2p;
int len1,
len2,
result;
a1p = VARDATA_ANY(arg1);
a2p = VARDATA_ANY(arg2);
len1 = VARSIZE_ANY_EXHDR(arg1);
len2 = VARSIZE_ANY_EXHDR(arg2);
/* Fast pre-check for equality, as discussed in varstr_cmp() */
if (len1 == len2 && memcmp(a1p, a2p, len1) == 0)
{
/*
* No change in buf1 or buf2 contents, so avoid changing last_len1 or
* last_len2. Existing contents of buffers might still be used by
* next call.
*
* It's fine to allow the comparison of BpChar padding bytes here,
* even though that implies that the memcmp() will usually be
* performed for BpChar callers (though multibyte characters could
* still prevent that from occurring). The memcmp() is still very
* cheap, and BpChar's funny semantics have us remove trailing spaces
* (not limited to padding), so we need make no distinction between
* padding space characters and "real" space characters.
*/
result = 0;
goto done;
}
if (sss->bpchar)
{
/* Get true number of bytes, ignoring trailing spaces */
len1 = bpchartruelen(a1p, len1);
len2 = bpchartruelen(a2p, len2);
}
if (len1 >= sss->buflen1)
{
pfree(sss->buf1);
sss->buflen1 = Max(len1 + 1, Min(sss->buflen1 * 2, MaxAllocSize));
sss->buf1 = MemoryContextAlloc(ssup->ssup_cxt, sss->buflen1);
}
if (len2 >= sss->buflen2)
{
pfree(sss->buf2);
sss->buflen2 = Max(len2 + 1, Min(sss->buflen2 * 2, MaxAllocSize));
sss->buf2 = MemoryContextAlloc(ssup->ssup_cxt, sss->buflen2);
}
/*
* We're likely to be asked to compare the same strings repeatedly, and
* memcmp() is so much cheaper than strcoll() that it pays to try to cache
* comparisons, even though in general there is no reason to think that
* that will work out (every string datum may be unique). Caching does
* not slow things down measurably when it doesn't work out, and can speed
* things up by rather a lot when it does. In part, this is because the
* memcmp() compares data from cachelines that are needed in L1 cache even
* when the last comparison's result cannot be reused.
*/
arg1_match = true;
if (len1 != sss->last_len1 || memcmp(sss->buf1, a1p, len1) != 0)
{
arg1_match = false;
memcpy(sss->buf1, a1p, len1);
sss->buf1[len1] = '\0';
sss->last_len1 = len1;
}
/*
* If we're comparing the same two strings as last time, we can return the
* same answer without calling strcoll() again. This is more likely than
* it seems (at least with moderate to low cardinality sets), because
* quicksort compares the same pivot against many values.
*/
if (len2 != sss->last_len2 || memcmp(sss->buf2, a2p, len2) != 0)
{
memcpy(sss->buf2, a2p, len2);
sss->buf2[len2] = '\0';
sss->last_len2 = len2;
}
else if (arg1_match && !sss->cache_blob)
{
/* Use result cached following last actual strcoll() call */
result = sss->last_returned;
goto done;
}
if (sss->locale)
{
if (sss->locale->provider == COLLPROVIDER_ICU)
{
#ifdef USE_ICU
#ifdef HAVE_UCOL_STRCOLLUTF8
if (GetDatabaseEncoding() == PG_UTF8)
{
UErrorCode status;
status = U_ZERO_ERROR;
result = ucol_strcollUTF8(sss->locale->info.icu.ucol,
a1p, len1,
a2p, len2,
&status);
if (U_FAILURE(status))
ereport(ERROR,
(errmsg("collation failed: %s", u_errorName(status))));
}
else
#endif
{
int32_t ulen1,
ulen2;
UChar *uchar1,
*uchar2;
ulen1 = icu_to_uchar(&uchar1, a1p, len1);
ulen2 = icu_to_uchar(&uchar2, a2p, len2);
result = ucol_strcoll(sss->locale->info.icu.ucol,
uchar1, ulen1,
uchar2, ulen2);
pfree(uchar1);
pfree(uchar2);
}
#else /* not USE_ICU */
/* shouldn't happen */
elog(ERROR, "unsupported collprovider: %c", sss->locale->provider);
#endif /* not USE_ICU */
}
else
{
#ifdef HAVE_LOCALE_T
result = strcoll_l(sss->buf1, sss->buf2, sss->locale->info.lt);
#else
/* shouldn't happen */
elog(ERROR, "unsupported collprovider: %c", sss->locale->provider);
#endif
}
}
else
result = strcoll(sss->buf1, sss->buf2);
/*
* In some locales strcoll() can claim that nonidentical strings are
* equal. Believing that would be bad news for a number of reasons, so we
* follow Perl's lead and sort "equal" strings according to strcmp().
*/
if (result == 0)
result = strcmp(sss->buf1, sss->buf2);
/* Cache result, perhaps saving an expensive strcoll() call next time */
sss->cache_blob = false;
sss->last_returned = result;
done:
/* We can't afford to leak memory here. */
if (PointerGetDatum(arg1) != x)
pfree(arg1);
if (PointerGetDatum(arg2) != y)
pfree(arg2);
return result;
}
/*
* Abbreviated key comparison func
*/
static int
varstrcmp_abbrev(Datum x, Datum y, SortSupport ssup)
{
/*
* When 0 is returned, the core system will call varstrfastcmp_c()
* (bpcharfastcmp_c() in BpChar case) or varstrfastcmp_locale(). Even a
* strcmp() on two non-truncated strxfrm() blobs cannot indicate *equality*
* authoritatively, for the same reason that there is a strcoll()
* tie-breaker call to strcmp() in varstr_cmp().
*/
if (x > y)
return 1;
else if (x == y)
return 0;
else
return -1;
}
/*
* Conversion routine for sortsupport. Converts original to abbreviated key
* representation. Our encoding strategy is simple -- pack the first 8 bytes
* of a strxfrm() blob into a Datum (on little-endian machines, the 8 bytes are
* stored in reverse order), and treat it as an unsigned integer. When the "C"
* locale is used, or in case of bytea, just memcpy() from original instead.
*/
static Datum
varstr_abbrev_convert(Datum original, SortSupport ssup)
{
VarStringSortSupport *sss = (VarStringSortSupport *) ssup->ssup_extra;
VarString *authoritative = DatumGetVarStringPP(original);
char *authoritative_data = VARDATA_ANY(authoritative);
/* working state */
Datum res;
char *pres;
int len;
uint32 hash;
pres = (char *) &res;
/* memset(), so any non-overwritten bytes are NUL */
memset(pres, 0, sizeof(Datum));
len = VARSIZE_ANY_EXHDR(authoritative);
/* Get number of bytes, ignoring trailing spaces */
if (sss->bpchar)
len = bpchartruelen(authoritative_data, len);
/*
* If we're using the C collation, use memcpy(), rather than strxfrm(), to
* abbreviate keys. The full comparator for the C locale is always
* memcmp(). It would be incorrect to allow bytea callers (callers that
* always force the C collation -- bytea isn't a collatable type, but this
* approach is convenient) to use strxfrm(). This is because bytea
* strings may contain NUL bytes. Besides, this should be faster, too.
*
* More generally, it's okay that bytea callers can have NUL bytes in
* strings because varstrcmp_abbrev() need not make a distinction between
* terminating NUL bytes, and NUL bytes representing actual NULs in the
* authoritative representation. Hopefully a comparison at or past one
* abbreviated key's terminating NUL byte will resolve the comparison
* without consulting the authoritative representation; specifically, some
* later non-NUL byte in the longer string can resolve the comparison
* against a subsequent terminating NUL in the shorter string. There will
* usually be what is effectively a "length-wise" resolution there and
* then.
*
* If that doesn't work out -- if all bytes in the longer string
* positioned at or past the offset of the smaller string's (first)
* terminating NUL are actually representative of NUL bytes in the
* authoritative binary string (perhaps with some *terminating* NUL bytes
* towards the end of the longer string iff it happens to still be small)
* -- then an authoritative tie-breaker will happen, and do the right
* thing: explicitly consider string length.
*/
if (sss->collate_c)
memcpy(pres, authoritative_data, Min(len, sizeof(Datum)));
else
{
Size bsize;
#ifdef USE_ICU
int32_t ulen = -1;
UChar *uchar = NULL;
#endif
/*
* We're not using the C collation, so fall back on strxfrm or ICU
* analogs.
*/
/* By convention, we use buffer 1 to store and NUL-terminate */
if (len >= sss->buflen1)
{
pfree(sss->buf1);
sss->buflen1 = Max(len + 1, Min(sss->buflen1 * 2, MaxAllocSize));
sss->buf1 = palloc(sss->buflen1);
}
/* Might be able to reuse strxfrm() blob from last call */
if (sss->last_len1 == len && sss->cache_blob &&
memcmp(sss->buf1, authoritative_data, len) == 0)
{
memcpy(pres, sss->buf2, Min(sizeof(Datum), sss->last_len2));
/* No change affecting cardinality, so no hashing required */
goto done;
}
memcpy(sss->buf1, authoritative_data, len);
/*
* Just like strcoll(), strxfrm() expects a NUL-terminated string. Not
* necessary for ICU, but doesn't hurt.
*/
sss->buf1[len] = '\0';
sss->last_len1 = len;
#ifdef USE_ICU
/* When using ICU and not UTF8, convert string to UChar. */
if (sss->locale && sss->locale->provider == COLLPROVIDER_ICU &&
GetDatabaseEncoding() != PG_UTF8)
ulen = icu_to_uchar(&uchar, sss->buf1, len);
#endif
/*
* Loop: Call strxfrm() or ucol_getSortKey(), possibly enlarge buffer,
* and try again. Both of these functions have the result buffer
* content undefined if the result did not fit, so we need to retry
* until everything fits, even though we only need the first few bytes
* in the end. When using ucol_nextSortKeyPart(), however, we only
* ask for as many bytes as we actually need.
*/
for (;;)
{
#ifdef USE_ICU
if (sss->locale && sss->locale->provider == COLLPROVIDER_ICU)
{
/*
* When using UTF8, use the iteration interface so we only
* need to produce as many bytes as we actually need.
*/
if (GetDatabaseEncoding() == PG_UTF8)
{
UCharIterator iter;
uint32_t state[2];
UErrorCode status;
uiter_setUTF8(&iter, sss->buf1, len);
state[0] = state[1] = 0; /* won't need that again */
status = U_ZERO_ERROR;
bsize = ucol_nextSortKeyPart(sss->locale->info.icu.ucol,
&iter,
state,
(uint8_t *) sss->buf2,
Min(sizeof(Datum), sss->buflen2),
&status);
if (U_FAILURE(status))
ereport(ERROR,
(errmsg("sort key generation failed: %s",
u_errorName(status))));
}
else
bsize = ucol_getSortKey(sss->locale->info.icu.ucol,
uchar, ulen,
(uint8_t *) sss->buf2, sss->buflen2);
}
else
#endif
#ifdef HAVE_LOCALE_T
if (sss->locale && sss->locale->provider == COLLPROVIDER_LIBC)
bsize = strxfrm_l(sss->buf2, sss->buf1,
sss->buflen2, sss->locale->info.lt);
else
#endif
bsize = strxfrm(sss->buf2, sss->buf1, sss->buflen2);
sss->last_len2 = bsize;
if (bsize < sss->buflen2)
break;
/*
* Grow buffer and retry.
*/
pfree(sss->buf2);
sss->buflen2 = Max(bsize + 1,
Min(sss->buflen2 * 2, MaxAllocSize));
sss->buf2 = palloc(sss->buflen2);
}
/*
* Every Datum byte is always compared. This is safe because the
* strxfrm() blob is itself NUL terminated, leaving no danger of
* misinterpreting any NUL bytes not intended to be interpreted as
* logically representing termination.
*
* (Actually, even if there were NUL bytes in the blob it would be
* okay. See remarks on bytea case above.)
*/
memcpy(pres, sss->buf2, Min(sizeof(Datum), bsize));
#ifdef USE_ICU
if (uchar)
pfree(uchar);
#endif
}
/*
* Maintain approximate cardinality of both abbreviated keys and original,
* authoritative keys using HyperLogLog. Used as cheap insurance against
* the worst case, where we do many string transformations for no saving
* in full strcoll()-based comparisons. These statistics are used by
* varstr_abbrev_abort().
*
* First, Hash key proper, or a significant fraction of it. Mix in length
* in order to compensate for cases where differences are past
* PG_CACHE_LINE_SIZE bytes, so as to limit the overhead of hashing.
*/
hash = DatumGetUInt32(hash_any((unsigned char *) authoritative_data,
Min(len, PG_CACHE_LINE_SIZE)));
if (len > PG_CACHE_LINE_SIZE)
hash ^= DatumGetUInt32(hash_uint32((uint32) len));
addHyperLogLog(&sss->full_card, hash);
/* Hash abbreviated key */
#if SIZEOF_DATUM == 8
{
uint32 lohalf,
hihalf;
lohalf = (uint32) res;
hihalf = (uint32) (res >> 32);
hash = DatumGetUInt32(hash_uint32(lohalf ^ hihalf));
}
#else /* SIZEOF_DATUM != 8 */
hash = DatumGetUInt32(hash_uint32((uint32) res));
#endif
addHyperLogLog(&sss->abbr_card, hash);
/* Cache result, perhaps saving an expensive strxfrm() call next time */
sss->cache_blob = true;
done:
/*
* Byteswap on little-endian machines.
*
* This is needed so that varstrcmp_abbrev() (an unsigned integer 3-way
* comparator) works correctly on all platforms. If we didn't do this,
* the comparator would have to call memcmp() with a pair of pointers to
* the first byte of each abbreviated key, which is slower.
*/
res = DatumBigEndianToNative(res);
/* Don't leak memory here */
if (PointerGetDatum(authoritative) != original)
pfree(authoritative);
return res;
}
/*
* Callback for estimating effectiveness of abbreviated key optimization, using
* heuristic rules. Returns value indicating if the abbreviation optimization
* should be aborted, based on its projected effectiveness.
*/
static bool
varstr_abbrev_abort(int memtupcount, SortSupport ssup)
{
VarStringSortSupport *sss = (VarStringSortSupport *) ssup->ssup_extra;
double abbrev_distinct,
key_distinct;
Assert(ssup->abbreviate);
/* Have a little patience */
if (memtupcount < 100)
return false;
abbrev_distinct = estimateHyperLogLog(&sss->abbr_card);
key_distinct = estimateHyperLogLog(&sss->full_card);
/*
* Clamp cardinality estimates to at least one distinct value. While
* NULLs are generally disregarded, if only NULL values were seen so far,
* that might misrepresent costs if we failed to clamp.
*/
if (abbrev_distinct <= 1.0)
abbrev_distinct = 1.0;
if (key_distinct <= 1.0)
key_distinct = 1.0;
/*
* In the worst case all abbreviated keys are identical, while at the same
* time there are differences within full key strings not captured in
* abbreviations.
*/
#ifdef TRACE_SORT
if (trace_sort)
{
double norm_abbrev_card = abbrev_distinct / (double) memtupcount;
elog(LOG, "varstr_abbrev: abbrev_distinct after %d: %f "
"(key_distinct: %f, norm_abbrev_card: %f, prop_card: %f)",
memtupcount, abbrev_distinct, key_distinct, norm_abbrev_card,
sss->prop_card);
}
#endif
/*
* If the number of distinct abbreviated keys approximately matches the
* number of distinct authoritative original keys, that's reason enough to
* proceed. We can win even with a very low cardinality set if most
* tie-breakers only memcmp(). This is by far the most important
* consideration.
*
* While comparisons that are resolved at the abbreviated key level are
* considerably cheaper than tie-breakers resolved with memcmp(), both of
* those two outcomes are so much cheaper than a full strcoll() once
* sorting is underway that it doesn't seem worth it to weigh abbreviated
* cardinality against the overall size of the set in order to more
* accurately model costs. Assume that an abbreviated comparison, and an
* abbreviated comparison with a cheap memcmp()-based authoritative
* resolution are equivalent.
*/
if (abbrev_distinct > key_distinct * sss->prop_card)
{
/*
* When we have exceeded 10,000 tuples, decay required cardinality
* aggressively for next call.
*
* This is useful because the number of comparisons required on
* average increases at a linearithmic rate, and at roughly 10,000
* tuples that factor will start to dominate over the linear costs of
* string transformation (this is a conservative estimate). The decay
* rate is chosen to be a little less aggressive than halving -- which
* (since we're called at points at which memtupcount has doubled)
* would never see the cost model actually abort past the first call
* following a decay. This decay rate is mostly a precaution against
* a sudden, violent swing in how well abbreviated cardinality tracks
* full key cardinality. The decay also serves to prevent a marginal
* case from being aborted too late, when too much has already been
* invested in string transformation.
*
* It's possible for sets of several million distinct strings with
* mere tens of thousands of distinct abbreviated keys to still
* benefit very significantly. This will generally occur provided
* each abbreviated key is a proxy for a roughly uniform number of the
* set's full keys. If it isn't so, we hope to catch that early and
* abort. If it isn't caught early, by the time the problem is
* apparent it's probably not worth aborting.
*/
if (memtupcount > 10000)
sss->prop_card *= 0.65;
return false;
}
/*
* Abort abbreviation strategy.
*
* The worst case, where all abbreviated keys are identical while all
* original strings differ will typically only see a regression of about
* 10% in execution time for small to medium sized lists of strings.
* Whereas on modern CPUs where cache stalls are the dominant cost, we can
* often expect very large improvements, particularly with sets of strings
* of moderately high to high abbreviated cardinality. There is little to
* lose but much to gain, which our strategy reflects.
*/
#ifdef TRACE_SORT
if (trace_sort)
elog(LOG, "varstr_abbrev: aborted abbreviation at %d "
"(abbrev_distinct: %f, key_distinct: %f, prop_card: %f)",
memtupcount, abbrev_distinct, key_distinct, sss->prop_card);
#endif
return true;
}
Datum
text_larger(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_PP(0);
text *arg2 = PG_GETARG_TEXT_PP(1);
text *result;
result = ((text_cmp(arg1, arg2, PG_GET_COLLATION()) > 0) ? arg1 : arg2);
PG_RETURN_TEXT_P(result);
}
Datum
text_smaller(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_PP(0);
text *arg2 = PG_GETARG_TEXT_PP(1);
text *result;
result = ((text_cmp(arg1, arg2, PG_GET_COLLATION()) < 0) ? arg1 : arg2);
PG_RETURN_TEXT_P(result);
}
/*
* The following operators support character-by-character comparison
* of text datums, to allow building indexes suitable for LIKE clauses.
* Note that the regular texteq/textne comparison operators, and regular
* support functions 1 and 2 with "C" collation are assumed to be
* compatible with these!
*/
static int
internal_text_pattern_compare(text *arg1, text *arg2)
{
int result;
int len1,
len2;
len1 = VARSIZE_ANY_EXHDR(arg1);
len2 = VARSIZE_ANY_EXHDR(arg2);
result = memcmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), Min(len1, len2));
if (result != 0)
return result;
else if (len1 < len2)
return -1;
else if (len1 > len2)
return 1;
else
return 0;
}
Datum
text_pattern_lt(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_PP(0);
text *arg2 = PG_GETARG_TEXT_PP(1);
int result;
result = internal_text_pattern_compare(arg1, arg2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result < 0);
}
Datum
text_pattern_le(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_PP(0);
text *arg2 = PG_GETARG_TEXT_PP(1);
int result;
result = internal_text_pattern_compare(arg1, arg2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result <= 0);
}
Datum
text_pattern_ge(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_PP(0);
text *arg2 = PG_GETARG_TEXT_PP(1);
int result;
result = internal_text_pattern_compare(arg1, arg2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result >= 0);
}
Datum
text_pattern_gt(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_PP(0);
text *arg2 = PG_GETARG_TEXT_PP(1);
int result;
result = internal_text_pattern_compare(arg1, arg2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result > 0);
}
Datum
bttext_pattern_cmp(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_PP(0);
text *arg2 = PG_GETARG_TEXT_PP(1);
int result;
result = internal_text_pattern_compare(arg1, arg2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_INT32(result);
}
Datum
bttext_pattern_sortsupport(PG_FUNCTION_ARGS)
{
SortSupport ssup = (SortSupport) PG_GETARG_POINTER(0);
MemoryContext oldcontext;
oldcontext = MemoryContextSwitchTo(ssup->ssup_cxt);
/* Use generic string SortSupport, forcing "C" collation */
varstr_sortsupport(ssup, C_COLLATION_OID, false);
MemoryContextSwitchTo(oldcontext);
PG_RETURN_VOID();
}
/*-------------------------------------------------------------
* byteaoctetlen
*
* get the number of bytes contained in an instance of type 'bytea'
*-------------------------------------------------------------
*/
Datum
byteaoctetlen(PG_FUNCTION_ARGS)
{
Datum str = PG_GETARG_DATUM(0);
/* We need not detoast the input at all */
PG_RETURN_INT32(toast_raw_datum_size(str) - VARHDRSZ);
}
/*
* byteacat -
* takes two bytea* and returns a bytea* that is the concatenation of
* the two.
*
* Cloned from textcat and modified as required.
*/
Datum
byteacat(PG_FUNCTION_ARGS)
{
bytea *t1 = PG_GETARG_BYTEA_PP(0);
bytea *t2 = PG_GETARG_BYTEA_PP(1);
PG_RETURN_BYTEA_P(bytea_catenate(t1, t2));
}
/*
* bytea_catenate
* Guts of byteacat(), broken out so it can be used by other functions
*
* Arguments can be in short-header form, but not compressed or out-of-line
*/
static bytea *
bytea_catenate(bytea *t1, bytea *t2)
{
bytea *result;
int len1,
len2,
len;
char *ptr;
len1 = VARSIZE_ANY_EXHDR(t1);
len2 = VARSIZE_ANY_EXHDR(t2);
/* paranoia ... probably should throw error instead? */
if (len1 < 0)
len1 = 0;
if (len2 < 0)
len2 = 0;
len = len1 + len2 + VARHDRSZ;
result = (bytea *) palloc(len);
/* Set size of result string... */
SET_VARSIZE(result, len);
/* Fill data field of result string... */
ptr = VARDATA(result);
if (len1 > 0)
memcpy(ptr, VARDATA_ANY(t1), len1);
if (len2 > 0)
memcpy(ptr + len1, VARDATA_ANY(t2), len2);
return result;
}
#define PG_STR_GET_BYTEA(str_) \
DatumGetByteaPP(DirectFunctionCall1(byteain, CStringGetDatum(str_)))
/*
* bytea_substr()
* Return a substring starting at the specified position.
* Cloned from text_substr and modified as required.
*
* Input:
* - string
* - starting position (is one-based)
* - string length (optional)
*
* If the starting position is zero or less, then return from the start of the string
* adjusting the length to be consistent with the "negative start" per SQL.
* If the length is less than zero, an ERROR is thrown. If no third argument
* (length) is provided, the length to the end of the string is assumed.
*/
Datum
bytea_substr(PG_FUNCTION_ARGS)
{
PG_RETURN_BYTEA_P(bytea_substring(PG_GETARG_DATUM(0),
PG_GETARG_INT32(1),
PG_GETARG_INT32(2),
false));
}
/*
* bytea_substr_no_len -
* Wrapper to avoid opr_sanity failure due to
* one function accepting a different number of args.
*/
Datum
bytea_substr_no_len(PG_FUNCTION_ARGS)
{
PG_RETURN_BYTEA_P(bytea_substring(PG_GETARG_DATUM(0),
PG_GETARG_INT32(1),
-1,
true));
}
static bytea *
bytea_substring(Datum str,
int S,
int L,
bool length_not_specified)
{
int S1; /* adjusted start position */
int L1; /* adjusted substring length */
S1 = Max(S, 1);
if (length_not_specified)
{
/*
* Not passed a length - DatumGetByteaPSlice() grabs everything to the
* end of the string if we pass it a negative value for length.
*/
L1 = -1;
}
else
{
/* end position */
int E = S + L;
/*
* A negative value for L is the only way for the end position to be
* before the start. SQL99 says to throw an error.
*/
if (E < S)
ereport(ERROR,
(errcode(ERRCODE_SUBSTRING_ERROR),
errmsg("negative substring length not allowed")));
/*
* A zero or negative value for the end position can happen if the
* start was negative or one. SQL99 says to return a zero-length
* string.
*/
if (E < 1)
return PG_STR_GET_BYTEA("");
L1 = E - S1;
}
/*
* If the start position is past the end of the string, SQL99 says to
* return a zero-length string -- DatumGetByteaPSlice() will do that for
* us. Convert to zero-based starting position
*/
return DatumGetByteaPSlice(str, S1 - 1, L1);
}
/*
* byteaoverlay
* Replace specified substring of first string with second
*
* The SQL standard defines OVERLAY() in terms of substring and concatenation.
* This code is a direct implementation of what the standard says.
*/
Datum
byteaoverlay(PG_FUNCTION_ARGS)
{
bytea *t1 = PG_GETARG_BYTEA_PP(0);
bytea *t2 = PG_GETARG_BYTEA_PP(1);
int sp = PG_GETARG_INT32(2); /* substring start position */
int sl = PG_GETARG_INT32(3); /* substring length */
PG_RETURN_BYTEA_P(bytea_overlay(t1, t2, sp, sl));
}
Datum
byteaoverlay_no_len(PG_FUNCTION_ARGS)
{
bytea *t1 = PG_GETARG_BYTEA_PP(0);
bytea *t2 = PG_GETARG_BYTEA_PP(1);
int sp = PG_GETARG_INT32(2); /* substring start position */
int sl;
sl = VARSIZE_ANY_EXHDR(t2); /* defaults to length(t2) */
PG_RETURN_BYTEA_P(bytea_overlay(t1, t2, sp, sl));
}
static bytea *
bytea_overlay(bytea *t1, bytea *t2, int sp, int sl)
{
bytea *result;
bytea *s1;
bytea *s2;
int sp_pl_sl;
/*
* Check for possible integer-overflow cases. For negative sp, throw a
* "substring length" error because that's what should be expected
* according to the spec's definition of OVERLAY().
*/
if (sp <= 0)
ereport(ERROR,
(errcode(ERRCODE_SUBSTRING_ERROR),
errmsg("negative substring length not allowed")));
if (pg_add_s32_overflow(sp, sl, &sp_pl_sl))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
s1 = bytea_substring(PointerGetDatum(t1), 1, sp - 1, false);
s2 = bytea_substring(PointerGetDatum(t1), sp_pl_sl, -1, true);
result = bytea_catenate(s1, t2);
result = bytea_catenate(result, s2);
return result;
}
/*
* byteapos -
* Return the position of the specified substring.
* Implements the SQL POSITION() function.
* Cloned from textpos and modified as required.
*/
Datum
byteapos(PG_FUNCTION_ARGS)
{
bytea *t1 = PG_GETARG_BYTEA_PP(0);
bytea *t2 = PG_GETARG_BYTEA_PP(1);
int pos;
int px,
p;
int len1,
len2;
char *p1,
*p2;
len1 = VARSIZE_ANY_EXHDR(t1);
len2 = VARSIZE_ANY_EXHDR(t2);
if (len2 <= 0)
PG_RETURN_INT32(1); /* result for empty pattern */
p1 = VARDATA_ANY(t1);
p2 = VARDATA_ANY(t2);
pos = 0;
px = (len1 - len2);
for (p = 0; p <= px; p++)
{
if ((*p2 == *p1) && (memcmp(p1, p2, len2) == 0))
{
pos = p + 1;
break;
};
p1++;
};
PG_RETURN_INT32(pos);
}
/*-------------------------------------------------------------
* byteaGetByte
*
* this routine treats "bytea" as an array of bytes.
* It returns the Nth byte (a number between 0 and 255).
*-------------------------------------------------------------
*/
Datum
byteaGetByte(PG_FUNCTION_ARGS)
{
bytea *v = PG_GETARG_BYTEA_PP(0);
int32 n = PG_GETARG_INT32(1);
int len;
int byte;
len = VARSIZE_ANY_EXHDR(v);
if (n < 0 || n >= len)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("index %d out of valid range, 0..%d",
n, len - 1)));
byte = ((unsigned char *) VARDATA_ANY(v))[n];
PG_RETURN_INT32(byte);
}
/*-------------------------------------------------------------
* byteaGetBit
*
* This routine treats a "bytea" type like an array of bits.
* It returns the value of the Nth bit (0 or 1).
*
*-------------------------------------------------------------
*/
Datum
byteaGetBit(PG_FUNCTION_ARGS)
{
bytea *v = PG_GETARG_BYTEA_PP(0);
int32 n = PG_GETARG_INT32(1);
int byteNo,
bitNo;
int len;
int byte;
len = VARSIZE_ANY_EXHDR(v);
if (n < 0 || n >= len * 8)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("index %d out of valid range, 0..%d",
n, len * 8 - 1)));
byteNo = n / 8;
bitNo = n % 8;
byte = ((unsigned char *) VARDATA_ANY(v))[byteNo];
if (byte & (1 << bitNo))
PG_RETURN_INT32(1);
else
PG_RETURN_INT32(0);
}
/*-------------------------------------------------------------
* byteaSetByte
*
* Given an instance of type 'bytea' creates a new one with
* the Nth byte set to the given value.
*
*-------------------------------------------------------------
*/
Datum
byteaSetByte(PG_FUNCTION_ARGS)
{
bytea *res = PG_GETARG_BYTEA_P_COPY(0);
int32 n = PG_GETARG_INT32(1);
int32 newByte = PG_GETARG_INT32(2);
int len;
len = VARSIZE(res) - VARHDRSZ;
if (n < 0 || n >= len)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("index %d out of valid range, 0..%d",
n, len - 1)));
/*
* Now set the byte.
*/
((unsigned char *) VARDATA(res))[n] = newByte;
PG_RETURN_BYTEA_P(res);
}
/*-------------------------------------------------------------
* byteaSetBit
*
* Given an instance of type 'bytea' creates a new one with
* the Nth bit set to the given value.
*
*-------------------------------------------------------------
*/
Datum
byteaSetBit(PG_FUNCTION_ARGS)
{
bytea *res = PG_GETARG_BYTEA_P_COPY(0);
int32 n = PG_GETARG_INT32(1);
int32 newBit = PG_GETARG_INT32(2);
int len;
int oldByte,
newByte;
int byteNo,
bitNo;
len = VARSIZE(res) - VARHDRSZ;
if (n < 0 || n >= len * 8)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("index %d out of valid range, 0..%d",
n, len * 8 - 1)));
byteNo = n / 8;
bitNo = n % 8;
/*
* sanity check!
*/
if (newBit != 0 && newBit != 1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("new bit must be 0 or 1")));
/*
* Update the byte.
*/
oldByte = ((unsigned char *) VARDATA(res))[byteNo];
if (newBit == 0)
newByte = oldByte & (~(1 << bitNo));
else
newByte = oldByte | (1 << bitNo);
((unsigned char *) VARDATA(res))[byteNo] = newByte;
PG_RETURN_BYTEA_P(res);
}
/* text_name()
* Converts a text type to a Name type.
*/
Datum
text_name(PG_FUNCTION_ARGS)
{
text *s = PG_GETARG_TEXT_PP(0);
Name result;
int len;
len = VARSIZE_ANY_EXHDR(s);
/* Truncate oversize input */
if (len >= NAMEDATALEN)
len = pg_mbcliplen(VARDATA_ANY(s), len, NAMEDATALEN - 1);
/* We use palloc0 here to ensure result is zero-padded */
result = (Name) palloc0(NAMEDATALEN);
memcpy(NameStr(*result), VARDATA_ANY(s), len);
PG_RETURN_NAME(result);
}
/* name_text()
* Converts a Name type to a text type.
*/
Datum
name_text(PG_FUNCTION_ARGS)
{
Name s = PG_GETARG_NAME(0);
PG_RETURN_TEXT_P(cstring_to_text(NameStr(*s)));
}
/*
* textToQualifiedNameList - convert a text object to list of names
*
* This implements the input parsing needed by nextval() and other
* functions that take a text parameter representing a qualified name.
* We split the name at dots, downcase if not double-quoted, and
* truncate names if they're too long.
*/
List *
textToQualifiedNameList(text *textval)
{
char *rawname;
List *result = NIL;
List *namelist;
ListCell *l;
/* Convert to C string (handles possible detoasting). */
/* Note we rely on being able to modify rawname below. */
rawname = text_to_cstring(textval);
if (!SplitIdentifierString(rawname, '.', &namelist))
ereport(ERROR,
(errcode(ERRCODE_INVALID_NAME),
errmsg("invalid name syntax")));
if (namelist == NIL)
ereport(ERROR,
(errcode(ERRCODE_INVALID_NAME),
errmsg("invalid name syntax")));
foreach(l, namelist)
{
char *curname = (char *) lfirst(l);
result = lappend(result, makeString(pstrdup(curname)));
}
pfree(rawname);
list_free(namelist);
return result;
}
/*
* SplitIdentifierString --- parse a string containing identifiers
*
* This is the guts of textToQualifiedNameList, and is exported for use in
* other situations such as parsing GUC variables. In the GUC case, it's
* important to avoid memory leaks, so the API is designed to minimize the
* amount of stuff that needs to be allocated and freed.
*
* Inputs:
* rawstring: the input string; must be overwritable! On return, it's
* been modified to contain the separated identifiers.
* separator: the separator punctuation expected between identifiers
* (typically '.' or ','). Whitespace may also appear around
* identifiers.
* Outputs:
* namelist: filled with a palloc'd list of pointers to identifiers within
* rawstring. Caller should list_free() this even on error return.
*
* Returns true if okay, false if there is a syntax error in the string.
*
* Note that an empty string is considered okay here, though not in
* textToQualifiedNameList.
*/
bool
SplitIdentifierString(char *rawstring, char separator,
List **namelist)
{
char *nextp = rawstring;
bool done = false;
*namelist = NIL;
while (scanner_isspace(*nextp))
nextp++; /* skip leading whitespace */
if (*nextp == '\0')
return true; /* allow empty string */
/* At the top of the loop, we are at start of a new identifier. */
do
{
char *curname;
char *endp;
if (*nextp == '"')
{
/* Quoted name --- collapse quote-quote pairs, no downcasing */
curname = nextp + 1;
for (;;)
{
endp = strchr(nextp + 1, '"');
if (endp == NULL)
return false; /* mismatched quotes */
if (endp[1] != '"')
break; /* found end of quoted name */
/* Collapse adjacent quotes into one quote, and look again */
memmove(endp, endp + 1, strlen(endp));
nextp = endp;
}
/* endp now points at the terminating quote */
nextp = endp + 1;
}
else
{
/* Unquoted name --- extends to separator or whitespace */
char *downname;
int len;
curname = nextp;
while (*nextp && *nextp != separator &&
!scanner_isspace(*nextp))
nextp++;
endp = nextp;
if (curname == nextp)
return false; /* empty unquoted name not allowed */
/*
* Downcase the identifier, using same code as main lexer does.
*
* XXX because we want to overwrite the input in-place, we cannot
* support a downcasing transformation that increases the string
* length. This is not a problem given the current implementation
* of downcase_truncate_identifier, but we'll probably have to do
* something about this someday.
*/
len = endp - curname;
downname = downcase_truncate_identifier(curname, len, false);
Assert(strlen(downname) <= len);
strncpy(curname, downname, len); /* strncpy is required here */
pfree(downname);
}
while (scanner_isspace(*nextp))
nextp++; /* skip trailing whitespace */
if (*nextp == separator)
{
nextp++;
while (scanner_isspace(*nextp))
nextp++; /* skip leading whitespace for next */
/* we expect another name, so done remains false */
}
else if (*nextp == '\0')
done = true;
else
return false; /* invalid syntax */
/* Now safe to overwrite separator with a null */
*endp = '\0';
/* Truncate name if it's overlength */
truncate_identifier(curname, strlen(curname), false);
/*
* Finished isolating current name --- add it to list
*/
*namelist = lappend(*namelist, curname);
/* Loop back if we didn't reach end of string */
} while (!done);
return true;
}
/*
* SplitDirectoriesString --- parse a string containing file/directory names
*
* This works fine on file names too; the function name is historical.
*
* This is similar to SplitIdentifierString, except that the parsing
* rules are meant to handle pathnames instead of identifiers: there is
* no downcasing, embedded spaces are allowed, the max length is MAXPGPATH-1,
* and we apply canonicalize_path() to each extracted string. Because of the
* last, the returned strings are separately palloc'd rather than being
* pointers into rawstring --- but we still scribble on rawstring.
*
* Inputs:
* rawstring: the input string; must be modifiable!
* separator: the separator punctuation expected between directories
* (typically ',' or ';'). Whitespace may also appear around
* directories.
* Outputs:
* namelist: filled with a palloc'd list of directory names.
* Caller should list_free_deep() this even on error return.
*
* Returns true if okay, false if there is a syntax error in the string.
*
* Note that an empty string is considered okay here.
*/
bool
SplitDirectoriesString(char *rawstring, char separator,
List **namelist)
{
char *nextp = rawstring;
bool done = false;
*namelist = NIL;
while (scanner_isspace(*nextp))
nextp++; /* skip leading whitespace */
if (*nextp == '\0')
return true; /* allow empty string */
/* At the top of the loop, we are at start of a new directory. */
do
{
char *curname;
char *endp;
if (*nextp == '"')
{
/* Quoted name --- collapse quote-quote pairs */
curname = nextp + 1;
for (;;)
{
endp = strchr(nextp + 1, '"');
if (endp == NULL)
return false; /* mismatched quotes */
if (endp[1] != '"')
break; /* found end of quoted name */
/* Collapse adjacent quotes into one quote, and look again */
memmove(endp, endp + 1, strlen(endp));
nextp = endp;
}
/* endp now points at the terminating quote */
nextp = endp + 1;
}
else
{
/* Unquoted name --- extends to separator or end of string */
curname = endp = nextp;
while (*nextp && *nextp != separator)
{
/* trailing whitespace should not be included in name */
if (!scanner_isspace(*nextp))
endp = nextp + 1;
nextp++;
}
if (curname == endp)
return false; /* empty unquoted name not allowed */
}
while (scanner_isspace(*nextp))
nextp++; /* skip trailing whitespace */
if (*nextp == separator)
{
nextp++;
while (scanner_isspace(*nextp))
nextp++; /* skip leading whitespace for next */
/* we expect another name, so done remains false */
}
else if (*nextp == '\0')
done = true;
else
return false; /* invalid syntax */
/* Now safe to overwrite separator with a null */
*endp = '\0';
/* Truncate path if it's overlength */
if (strlen(curname) >= MAXPGPATH)
curname[MAXPGPATH - 1] = '\0';
/*
* Finished isolating current name --- add it to list
*/
curname = pstrdup(curname);
canonicalize_path(curname);
*namelist = lappend(*namelist, curname);
/* Loop back if we didn't reach end of string */
} while (!done);
return true;
}
/*
* SplitGUCList --- parse a string containing identifiers or file names
*
* This is used to split the value of a GUC_LIST_QUOTE GUC variable, without
* presuming whether the elements will be taken as identifiers or file names.
* We assume the input has already been through flatten_set_variable_args(),
* so that we need never downcase (if appropriate, that was done already).
* Nor do we ever truncate, since we don't know the correct max length.
* We disallow embedded whitespace for simplicity (it shouldn't matter,
* because any embedded whitespace should have led to double-quoting).
* Otherwise the API is identical to SplitIdentifierString.
*
* XXX it's annoying to have so many copies of this string-splitting logic.
* However, it's not clear that having one function with a bunch of option
* flags would be much better.
*
* XXX there is a version of this function in src/bin/pg_dump/dumputils.c.
* Be sure to update that if you have to change this.
*
* Inputs:
* rawstring: the input string; must be overwritable! On return, it's
* been modified to contain the separated identifiers.
* separator: the separator punctuation expected between identifiers
* (typically '.' or ','). Whitespace may also appear around
* identifiers.
* Outputs:
* namelist: filled with a palloc'd list of pointers to identifiers within
* rawstring. Caller should list_free() this even on error return.
*
* Returns true if okay, false if there is a syntax error in the string.
*/
bool
SplitGUCList(char *rawstring, char separator,
List **namelist)
{
char *nextp = rawstring;
bool done = false;
*namelist = NIL;
while (scanner_isspace(*nextp))
nextp++; /* skip leading whitespace */
if (*nextp == '\0')
return true; /* allow empty string */
/* At the top of the loop, we are at start of a new identifier. */
do
{
char *curname;
char *endp;
if (*nextp == '"')
{
/* Quoted name --- collapse quote-quote pairs */
curname = nextp + 1;
for (;;)
{
endp = strchr(nextp + 1, '"');
if (endp == NULL)
return false; /* mismatched quotes */
if (endp[1] != '"')
break; /* found end of quoted name */
/* Collapse adjacent quotes into one quote, and look again */
memmove(endp, endp + 1, strlen(endp));
nextp = endp;
}
/* endp now points at the terminating quote */
nextp = endp + 1;
}
else
{
/* Unquoted name --- extends to separator or whitespace */
curname = nextp;
while (*nextp && *nextp != separator &&
!scanner_isspace(*nextp))
nextp++;
endp = nextp;
if (curname == nextp)
return false; /* empty unquoted name not allowed */
}
while (scanner_isspace(*nextp))
nextp++; /* skip trailing whitespace */
if (*nextp == separator)
{
nextp++;
while (scanner_isspace(*nextp))
nextp++; /* skip leading whitespace for next */
/* we expect another name, so done remains false */
}
else if (*nextp == '\0')
done = true;
else
return false; /* invalid syntax */
/* Now safe to overwrite separator with a null */
*endp = '\0';
/*
* Finished isolating current name --- add it to list
*/
*namelist = lappend(*namelist, curname);
/* Loop back if we didn't reach end of string */
} while (!done);
return true;
}
/*****************************************************************************
* Comparison Functions used for bytea
*
* Note: btree indexes need these routines not to leak memory; therefore,
* be careful to free working copies of toasted datums. Most places don't
* need to be so careful.
*****************************************************************************/
Datum
byteaeq(PG_FUNCTION_ARGS)
{
Datum arg1 = PG_GETARG_DATUM(0);
Datum arg2 = PG_GETARG_DATUM(1);
bool result;
Size len1,
len2;
/*
* We can use a fast path for unequal lengths, which might save us from
* having to detoast one or both values.
*/
len1 = toast_raw_datum_size(arg1);
len2 = toast_raw_datum_size(arg2);
if (len1 != len2)
result = false;
else
{
bytea *barg1 = DatumGetByteaPP(arg1);
bytea *barg2 = DatumGetByteaPP(arg2);
result = (memcmp(VARDATA_ANY(barg1), VARDATA_ANY(barg2),
len1 - VARHDRSZ) == 0);
PG_FREE_IF_COPY(barg1, 0);
PG_FREE_IF_COPY(barg2, 1);
}
PG_RETURN_BOOL(result);
}
Datum
byteane(PG_FUNCTION_ARGS)
{
Datum arg1 = PG_GETARG_DATUM(0);
Datum arg2 = PG_GETARG_DATUM(1);
bool result;
Size len1,
len2;
/*
* We can use a fast path for unequal lengths, which might save us from
* having to detoast one or both values.
*/
len1 = toast_raw_datum_size(arg1);
len2 = toast_raw_datum_size(arg2);
if (len1 != len2)
result = true;
else
{
bytea *barg1 = DatumGetByteaPP(arg1);
bytea *barg2 = DatumGetByteaPP(arg2);
result = (memcmp(VARDATA_ANY(barg1), VARDATA_ANY(barg2),
len1 - VARHDRSZ) != 0);
PG_FREE_IF_COPY(barg1, 0);
PG_FREE_IF_COPY(barg2, 1);
}
PG_RETURN_BOOL(result);
}
Datum
bytealt(PG_FUNCTION_ARGS)
{
bytea *arg1 = PG_GETARG_BYTEA_PP(0);
bytea *arg2 = PG_GETARG_BYTEA_PP(1);
int len1,
len2;
int cmp;
len1 = VARSIZE_ANY_EXHDR(arg1);
len2 = VARSIZE_ANY_EXHDR(arg2);
cmp = memcmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), Min(len1, len2));
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL((cmp < 0) || ((cmp == 0) && (len1 < len2)));
}
Datum
byteale(PG_FUNCTION_ARGS)
{
bytea *arg1 = PG_GETARG_BYTEA_PP(0);
bytea *arg2 = PG_GETARG_BYTEA_PP(1);
int len1,
len2;
int cmp;
len1 = VARSIZE_ANY_EXHDR(arg1);
len2 = VARSIZE_ANY_EXHDR(arg2);
cmp = memcmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), Min(len1, len2));
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL((cmp < 0) || ((cmp == 0) && (len1 <= len2)));
}
Datum
byteagt(PG_FUNCTION_ARGS)
{
bytea *arg1 = PG_GETARG_BYTEA_PP(0);
bytea *arg2 = PG_GETARG_BYTEA_PP(1);
int len1,
len2;
int cmp;
len1 = VARSIZE_ANY_EXHDR(arg1);
len2 = VARSIZE_ANY_EXHDR(arg2);
cmp = memcmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), Min(len1, len2));
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL((cmp > 0) || ((cmp == 0) && (len1 > len2)));
}
Datum
byteage(PG_FUNCTION_ARGS)
{
bytea *arg1 = PG_GETARG_BYTEA_PP(0);
bytea *arg2 = PG_GETARG_BYTEA_PP(1);
int len1,
len2;
int cmp;
len1 = VARSIZE_ANY_EXHDR(arg1);
len2 = VARSIZE_ANY_EXHDR(arg2);
cmp = memcmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), Min(len1, len2));
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL((cmp > 0) || ((cmp == 0) && (len1 >= len2)));
}
Datum
byteacmp(PG_FUNCTION_ARGS)
{
bytea *arg1 = PG_GETARG_BYTEA_PP(0);
bytea *arg2 = PG_GETARG_BYTEA_PP(1);
int len1,
len2;
int cmp;
len1 = VARSIZE_ANY_EXHDR(arg1);
len2 = VARSIZE_ANY_EXHDR(arg2);
cmp = memcmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), Min(len1, len2));
if ((cmp == 0) && (len1 != len2))
cmp = (len1 < len2) ? -1 : 1;
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_INT32(cmp);
}
Datum
bytea_sortsupport(PG_FUNCTION_ARGS)
{
SortSupport ssup = (SortSupport) PG_GETARG_POINTER(0);
MemoryContext oldcontext;
oldcontext = MemoryContextSwitchTo(ssup->ssup_cxt);
/* Use generic string SortSupport, forcing "C" collation */
varstr_sortsupport(ssup, C_COLLATION_OID, false);
MemoryContextSwitchTo(oldcontext);
PG_RETURN_VOID();
}
/*
* appendStringInfoText
*
* Append a text to str.
* Like appendStringInfoString(str, text_to_cstring(t)) but faster.
*/
static void
appendStringInfoText(StringInfo str, const text *t)
{
appendBinaryStringInfo(str, VARDATA_ANY(t), VARSIZE_ANY_EXHDR(t));
}
/*
* replace_text
* replace all occurrences of 'old_sub_str' in 'orig_str'
* with 'new_sub_str' to form 'new_str'
*
* returns 'orig_str' if 'old_sub_str' == '' or 'orig_str' == ''
* otherwise returns 'new_str'
*/
Datum
replace_text(PG_FUNCTION_ARGS)
{
text *src_text = PG_GETARG_TEXT_PP(0);
text *from_sub_text = PG_GETARG_TEXT_PP(1);
text *to_sub_text = PG_GETARG_TEXT_PP(2);
int src_text_len;
int from_sub_text_len;
TextPositionState state;
text *ret_text;
int start_posn;
int curr_posn;
int chunk_len;
char *start_ptr;
StringInfoData str;
text_position_setup(src_text, from_sub_text, &state);
/*
* Note: we check the converted string length, not the original, because
* they could be different if the input contained invalid encoding.
*/
src_text_len = state.len1;
from_sub_text_len = state.len2;
/* Return unmodified source string if empty source or pattern */
if (src_text_len < 1 || from_sub_text_len < 1)
{
text_position_cleanup(&state);
PG_RETURN_TEXT_P(src_text);
}
start_posn = 1;
curr_posn = text_position_next(1, &state);
/* When the from_sub_text is not found, there is nothing to do. */
if (curr_posn == 0)
{
text_position_cleanup(&state);
PG_RETURN_TEXT_P(src_text);
}
/* start_ptr points to the start_posn'th character of src_text */
start_ptr = VARDATA_ANY(src_text);
initStringInfo(&str);
do
{
CHECK_FOR_INTERRUPTS();
/* copy the data skipped over by last text_position_next() */
chunk_len = charlen_to_bytelen(start_ptr, curr_posn - start_posn);
appendBinaryStringInfo(&str, start_ptr, chunk_len);
appendStringInfoText(&str, to_sub_text);
start_posn = curr_posn;
start_ptr += chunk_len;
start_posn += from_sub_text_len;
start_ptr += charlen_to_bytelen(start_ptr, from_sub_text_len);
curr_posn = text_position_next(start_posn, &state);
}
while (curr_posn > 0);
/* copy trailing data */
chunk_len = ((char *) src_text + VARSIZE_ANY(src_text)) - start_ptr;
appendBinaryStringInfo(&str, start_ptr, chunk_len);
text_position_cleanup(&state);
ret_text = cstring_to_text_with_len(str.data, str.len);
pfree(str.data);
PG_RETURN_TEXT_P(ret_text);
}
/*
* check_replace_text_has_escape_char
*
* check whether replace_text contains escape char.
*/
static bool
check_replace_text_has_escape_char(const text *replace_text)
{
const char *p = VARDATA_ANY(replace_text);
const char *p_end = p + VARSIZE_ANY_EXHDR(replace_text);
if (pg_database_encoding_max_length() == 1)
{
for (; p < p_end; p++)
{
if (*p == '\\')
return true;
}
}
else
{
for (; p < p_end; p += pg_mblen(p))
{
if (*p == '\\')
return true;
}
}
return false;
}
/*
* appendStringInfoRegexpSubstr
*
* Append replace_text to str, substituting regexp back references for
* \n escapes. start_ptr is the start of the match in the source string,
* at logical character position data_pos.
*/
static void
appendStringInfoRegexpSubstr(StringInfo str, text *replace_text,
regmatch_t *pmatch,
char *start_ptr, int data_pos)
{
const char *p = VARDATA_ANY(replace_text);
const char *p_end = p + VARSIZE_ANY_EXHDR(replace_text);
int eml = pg_database_encoding_max_length();
for (;;)
{
const char *chunk_start = p;
int so;
int eo;
/* Find next escape char. */
if (eml == 1)
{
for (; p < p_end && *p != '\\'; p++)
/* nothing */ ;
}
else
{
for (; p < p_end && *p != '\\'; p += pg_mblen(p))
/* nothing */ ;
}
/* Copy the text we just scanned over, if any. */
if (p > chunk_start)
appendBinaryStringInfo(str, chunk_start, p - chunk_start);
/* Done if at end of string, else advance over escape char. */
if (p >= p_end)
break;
p++;
if (p >= p_end)
{
/* Escape at very end of input. Treat same as unexpected char */
appendStringInfoChar(str, '\\');
break;
}
if (*p >= '1' && *p <= '9')
{
/* Use the back reference of regexp. */
int idx = *p - '0';
so = pmatch[idx].rm_so;
eo = pmatch[idx].rm_eo;
p++;
}
else if (*p == '&')
{
/* Use the entire matched string. */
so = pmatch[0].rm_so;
eo = pmatch[0].rm_eo;
p++;
}
else if (*p == '\\')
{
/* \\ means transfer one \ to output. */
appendStringInfoChar(str, '\\');
p++;
continue;
}
else
{
/*
* If escape char is not followed by any expected char, just treat
* it as ordinary data to copy. (XXX would it be better to throw
* an error?)
*/
appendStringInfoChar(str, '\\');
continue;
}
if (so != -1 && eo != -1)
{
/*
* Copy the text that is back reference of regexp. Note so and eo
* are counted in characters not bytes.
*/
char *chunk_start;
int chunk_len;
Assert(so >= data_pos);
chunk_start = start_ptr;
chunk_start += charlen_to_bytelen(chunk_start, so - data_pos);
chunk_len = charlen_to_bytelen(chunk_start, eo - so);
appendBinaryStringInfo(str, chunk_start, chunk_len);
}
}
}
#define REGEXP_REPLACE_BACKREF_CNT 10
/*
* replace_text_regexp
*
* replace text that matches to regexp in src_text to replace_text.
*
* Note: to avoid having to include regex.h in builtins.h, we declare
* the regexp argument as void *, but really it's regex_t *.
*/
text *
replace_text_regexp(text *src_text, void *regexp,
text *replace_text, bool glob)
{
text *ret_text;
regex_t *re = (regex_t *) regexp;
int src_text_len = VARSIZE_ANY_EXHDR(src_text);
StringInfoData buf;
regmatch_t pmatch[REGEXP_REPLACE_BACKREF_CNT];
pg_wchar *data;
size_t data_len;
int search_start;
int data_pos;
char *start_ptr;
bool have_escape;
initStringInfo(&buf);
/* Convert data string to wide characters. */
data = (pg_wchar *) palloc((src_text_len + 1) * sizeof(pg_wchar));
data_len = pg_mb2wchar_with_len(VARDATA_ANY(src_text), data, src_text_len);
/* Check whether replace_text has escape char. */
have_escape = check_replace_text_has_escape_char(replace_text);
/* start_ptr points to the data_pos'th character of src_text */
start_ptr = (char *) VARDATA_ANY(src_text);
data_pos = 0;
search_start = 0;
while (search_start <= data_len)
{
int regexec_result;
CHECK_FOR_INTERRUPTS();
regexec_result = pg_regexec(re,
data,
data_len,
search_start,
NULL, /* no details */
REGEXP_REPLACE_BACKREF_CNT,
pmatch,
0);
if (regexec_result == REG_NOMATCH)
break;
if (regexec_result != REG_OKAY)
{
char errMsg[100];
CHECK_FOR_INTERRUPTS();
pg_regerror(regexec_result, re, errMsg, sizeof(errMsg));
ereport(ERROR,
(errcode(ERRCODE_INVALID_REGULAR_EXPRESSION),
errmsg("regular expression failed: %s", errMsg)));
}
/*
* Copy the text to the left of the match position. Note we are given
* character not byte indexes.
*/
if (pmatch[0].rm_so - data_pos > 0)
{
int chunk_len;
chunk_len = charlen_to_bytelen(start_ptr,
pmatch[0].rm_so - data_pos);
appendBinaryStringInfo(&buf, start_ptr, chunk_len);
/*
* Advance start_ptr over that text, to avoid multiple rescans of
* it if the replace_text contains multiple back-references.
*/
start_ptr += chunk_len;
data_pos = pmatch[0].rm_so;
}
/*
* Copy the replace_text. Process back references when the
* replace_text has escape characters.
*/
if (have_escape)
appendStringInfoRegexpSubstr(&buf, replace_text, pmatch,
start_ptr, data_pos);
else
appendStringInfoText(&buf, replace_text);
/* Advance start_ptr and data_pos over the matched text. */
start_ptr += charlen_to_bytelen(start_ptr,
pmatch[0].rm_eo - data_pos);
data_pos = pmatch[0].rm_eo;
/*
* When global option is off, replace the first instance only.
*/
if (!glob)
break;
/*
* Advance search position. Normally we start the next search at the
* end of the previous match; but if the match was of zero length, we
* have to advance by one character, or we'd just find the same match
* again.
*/
search_start = data_pos;
if (pmatch[0].rm_so == pmatch[0].rm_eo)
search_start++;
}
/*
* Copy the text to the right of the last match.
*/
if (data_pos < data_len)
{
int chunk_len;
chunk_len = ((char *) src_text + VARSIZE_ANY(src_text)) - start_ptr;
appendBinaryStringInfo(&buf, start_ptr, chunk_len);
}
ret_text = cstring_to_text_with_len(buf.data, buf.len);
pfree(buf.data);
pfree(data);
return ret_text;
}
/*
* split_text
* parse input string
* return ord item (1 based)
* based on provided field separator
*/
Datum
split_text(PG_FUNCTION_ARGS)
{
text *inputstring = PG_GETARG_TEXT_PP(0);
text *fldsep = PG_GETARG_TEXT_PP(1);
int fldnum = PG_GETARG_INT32(2);
int inputstring_len;
int fldsep_len;
TextPositionState state;
int start_posn;
int end_posn;
text *result_text;
/* field number is 1 based */
if (fldnum < 1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("field position must be greater than zero")));
text_position_setup(inputstring, fldsep, &state);
/*
* Note: we check the converted string length, not the original, because
* they could be different if the input contained invalid encoding.
*/
inputstring_len = state.len1;
fldsep_len = state.len2;
/* return empty string for empty input string */
if (inputstring_len < 1)
{
text_position_cleanup(&state);
PG_RETURN_TEXT_P(cstring_to_text(""));
}
/* empty field separator */
if (fldsep_len < 1)
{
text_position_cleanup(&state);
/* if first field, return input string, else empty string */
if (fldnum == 1)
PG_RETURN_TEXT_P(inputstring);
else
PG_RETURN_TEXT_P(cstring_to_text(""));
}
/* identify bounds of first field */
start_posn = 1;
end_posn = text_position_next(1, &state);
/* special case if fldsep not found at all */
if (end_posn == 0)
{
text_position_cleanup(&state);
/* if field 1 requested, return input string, else empty string */
if (fldnum == 1)
PG_RETURN_TEXT_P(inputstring);
else
PG_RETURN_TEXT_P(cstring_to_text(""));
}
while (end_posn > 0 && --fldnum > 0)
{
/* identify bounds of next field */
start_posn = end_posn + fldsep_len;
end_posn = text_position_next(start_posn, &state);
}
text_position_cleanup(&state);
if (fldnum > 0)
{
/* N'th field separator not found */
/* if last field requested, return it, else empty string */
if (fldnum == 1)
result_text = text_substring(PointerGetDatum(inputstring),
start_posn,
-1,
true);
else
result_text = cstring_to_text("");
}
else
{
/* non-last field requested */
result_text = text_substring(PointerGetDatum(inputstring),
start_posn,
end_posn - start_posn,
false);
}
PG_RETURN_TEXT_P(result_text);
}
/*
* Convenience function to return true when two text params are equal.
*/
static bool
text_isequal(text *txt1, text *txt2)
{
return DatumGetBool(DirectFunctionCall2(texteq,
PointerGetDatum(txt1),
PointerGetDatum(txt2)));
}
/*
* text_to_array
* parse input string and return text array of elements,
* based on provided field separator
*/
Datum
text_to_array(PG_FUNCTION_ARGS)
{
return text_to_array_internal(fcinfo);
}
/*
* text_to_array_null
* parse input string and return text array of elements,
* based on provided field separator and null string
*
* This is a separate entry point only to prevent the regression tests from
* complaining about different argument sets for the same internal function.
*/
Datum
text_to_array_null(PG_FUNCTION_ARGS)
{
return text_to_array_internal(fcinfo);
}
/*
* common code for text_to_array and text_to_array_null functions
*
* These are not strict so we have to test for null inputs explicitly.
*/
static Datum
text_to_array_internal(PG_FUNCTION_ARGS)
{
text *inputstring;
text *fldsep;
text *null_string;
int inputstring_len;
int fldsep_len;
char *start_ptr;
text *result_text;
bool is_null;
ArrayBuildState *astate = NULL;
/* when input string is NULL, then result is NULL too */
if (PG_ARGISNULL(0))
PG_RETURN_NULL();
inputstring = PG_GETARG_TEXT_PP(0);
/* fldsep can be NULL */
if (!PG_ARGISNULL(1))
fldsep = PG_GETARG_TEXT_PP(1);
else
fldsep = NULL;
/* null_string can be NULL or omitted */
if (PG_NARGS() > 2 && !PG_ARGISNULL(2))
null_string = PG_GETARG_TEXT_PP(2);
else
null_string = NULL;
if (fldsep != NULL)
{
/*
* Normal case with non-null fldsep. Use the text_position machinery
* to search for occurrences of fldsep.
*/
TextPositionState state;
int fldnum;
int start_posn;
int end_posn;
int chunk_len;
text_position_setup(inputstring, fldsep, &state);
/*
* Note: we check the converted string length, not the original,
* because they could be different if the input contained invalid
* encoding.
*/
inputstring_len = state.len1;
fldsep_len = state.len2;
/* return empty array for empty input string */
if (inputstring_len < 1)
{
text_position_cleanup(&state);
PG_RETURN_ARRAYTYPE_P(construct_empty_array(TEXTOID));
}
/*
* empty field separator: return the input string as a one-element
* array
*/
if (fldsep_len < 1)
{
Datum elems[1];
bool nulls[1];
int dims[1];
int lbs[1];
text_position_cleanup(&state);
/* single element can be a NULL too */
is_null = null_string ? text_isequal(inputstring, null_string) : false;
elems[0] = PointerGetDatum(inputstring);
nulls[0] = is_null;
dims[0] = 1;
lbs[0] = 1;
/* XXX: this hardcodes assumptions about the text type */
PG_RETURN_ARRAYTYPE_P(construct_md_array(elems, nulls,
1, dims, lbs,
TEXTOID, -1, false, 'i'));
}
start_posn = 1;
/* start_ptr points to the start_posn'th character of inputstring */
start_ptr = VARDATA_ANY(inputstring);
for (fldnum = 1;; fldnum++) /* field number is 1 based */
{
CHECK_FOR_INTERRUPTS();
end_posn = text_position_next(start_posn, &state);
if (end_posn == 0)
{
/* fetch last field */
chunk_len = ((char *) inputstring + VARSIZE_ANY(inputstring)) - start_ptr;
}
else
{
/* fetch non-last field */
chunk_len = charlen_to_bytelen(start_ptr, end_posn - start_posn);
}
/* must build a temp text datum to pass to accumArrayResult */
result_text = cstring_to_text_with_len(start_ptr, chunk_len);
is_null = null_string ? text_isequal(result_text, null_string) : false;
/* stash away this field */
astate = accumArrayResult(astate,
PointerGetDatum(result_text),
is_null,
TEXTOID,
CurrentMemoryContext);
pfree(result_text);
if (end_posn == 0)
break;
start_posn = end_posn;
start_ptr += chunk_len;
start_posn += fldsep_len;
start_ptr += charlen_to_bytelen(start_ptr, fldsep_len);
}
text_position_cleanup(&state);
}
else
{
/*
* When fldsep is NULL, each character in the inputstring becomes an
* element in the result array. The separator is effectively the
* space between characters.
*/
inputstring_len = VARSIZE_ANY_EXHDR(inputstring);
/* return empty array for empty input string */
if (inputstring_len < 1)
PG_RETURN_ARRAYTYPE_P(construct_empty_array(TEXTOID));
start_ptr = VARDATA_ANY(inputstring);
while (inputstring_len > 0)
{
int chunk_len = pg_mblen(start_ptr);
CHECK_FOR_INTERRUPTS();
/* must build a temp text datum to pass to accumArrayResult */
result_text = cstring_to_text_with_len(start_ptr, chunk_len);
is_null = null_string ? text_isequal(result_text, null_string) : false;
/* stash away this field */
astate = accumArrayResult(astate,
PointerGetDatum(result_text),
is_null,
TEXTOID,
CurrentMemoryContext);
pfree(result_text);
start_ptr += chunk_len;
inputstring_len -= chunk_len;
}
}
PG_RETURN_ARRAYTYPE_P(makeArrayResult(astate,
CurrentMemoryContext));
}
/*
* array_to_text
* concatenate Cstring representation of input array elements
* using provided field separator
*/
Datum
array_to_text(PG_FUNCTION_ARGS)
{
ArrayType *v = PG_GETARG_ARRAYTYPE_P(0);
char *fldsep = text_to_cstring(PG_GETARG_TEXT_PP(1));
PG_RETURN_TEXT_P(array_to_text_internal(fcinfo, v, fldsep, NULL));
}
/*
* array_to_text_null
* concatenate Cstring representation of input array elements
* using provided field separator and null string
*
* This version is not strict so we have to test for null inputs explicitly.
*/
Datum
array_to_text_null(PG_FUNCTION_ARGS)
{
ArrayType *v;
char *fldsep;
char *null_string;
/* returns NULL when first or second parameter is NULL */
if (PG_ARGISNULL(0) || PG_ARGISNULL(1))
PG_RETURN_NULL();
v = PG_GETARG_ARRAYTYPE_P(0);
fldsep = text_to_cstring(PG_GETARG_TEXT_PP(1));
/* NULL null string is passed through as a null pointer */
if (!PG_ARGISNULL(2))
null_string = text_to_cstring(PG_GETARG_TEXT_PP(2));
else
null_string = NULL;
PG_RETURN_TEXT_P(array_to_text_internal(fcinfo, v, fldsep, null_string));
}
/*
* common code for array_to_text and array_to_text_null functions
*/
static text *
array_to_text_internal(FunctionCallInfo fcinfo, ArrayType *v,
const char *fldsep, const char *null_string)
{
text *result;
int nitems,
*dims,
ndims;
Oid element_type;
int typlen;
bool typbyval;
char typalign;
StringInfoData buf;
bool printed = false;
char *p;
bits8 *bitmap;
int bitmask;
int i;
ArrayMetaState *my_extra;
ndims = ARR_NDIM(v);
dims = ARR_DIMS(v);
nitems = ArrayGetNItems(ndims, dims);
/* if there are no elements, return an empty string */
if (nitems == 0)
return cstring_to_text_with_len("", 0);
element_type = ARR_ELEMTYPE(v);
initStringInfo(&buf);
/*
* We arrange to look up info about element type, including its output
* conversion proc, only once per series of calls, assuming the element
* type doesn't change underneath us.
*/
my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
if (my_extra == NULL)
{
fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
sizeof(ArrayMetaState));
my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
my_extra->element_type = ~element_type;
}
if (my_extra->element_type != element_type)
{
/*
* Get info about element type, including its output conversion proc
*/
get_type_io_data(element_type, IOFunc_output,
&my_extra->typlen, &my_extra->typbyval,
&my_extra->typalign, &my_extra->typdelim,
&my_extra->typioparam, &my_extra->typiofunc);
fmgr_info_cxt(my_extra->typiofunc, &my_extra->proc,
fcinfo->flinfo->fn_mcxt);
my_extra->element_type = element_type;
}
typlen = my_extra->typlen;
typbyval = my_extra->typbyval;
typalign = my_extra->typalign;
p = ARR_DATA_PTR(v);
bitmap = ARR_NULLBITMAP(v);
bitmask = 1;
for (i = 0; i < nitems; i++)
{
Datum itemvalue;
char *value;
/* Get source element, checking for NULL */
if (bitmap && (*bitmap & bitmask) == 0)
{
/* if null_string is NULL, we just ignore null elements */
if (null_string != NULL)
{
if (printed)
appendStringInfo(&buf, "%s%s", fldsep, null_string);
else
appendStringInfoString(&buf, null_string);
printed = true;
}
}
else
{
itemvalue = fetch_att(p, typbyval, typlen);
value = OutputFunctionCall(&my_extra->proc, itemvalue);
if (printed)
appendStringInfo(&buf, "%s%s", fldsep, value);
else
appendStringInfoString(&buf, value);
printed = true;
p = att_addlength_pointer(p, typlen, p);
p = (char *) att_align_nominal(p, typalign);
}
/* advance bitmap pointer if any */
if (bitmap)
{
bitmask <<= 1;
if (bitmask == 0x100)
{
bitmap++;
bitmask = 1;
}
}
}
result = cstring_to_text_with_len(buf.data, buf.len);
pfree(buf.data);
return result;
}
#define HEXBASE 16
/*
* Convert an int32 to a string containing a base 16 (hex) representation of
* the number.
*/
Datum
to_hex32(PG_FUNCTION_ARGS)
{
uint32 value = (uint32) PG_GETARG_INT32(0);
char *ptr;
const char *digits = "0123456789abcdef";
char buf[32]; /* bigger than needed, but reasonable */
ptr = buf + sizeof(buf) - 1;
*ptr = '\0';
do
{
*--ptr = digits[value % HEXBASE];
value /= HEXBASE;
} while (ptr > buf && value);
PG_RETURN_TEXT_P(cstring_to_text(ptr));
}
/*
* Convert an int64 to a string containing a base 16 (hex) representation of
* the number.
*/
Datum
to_hex64(PG_FUNCTION_ARGS)
{
uint64 value = (uint64) PG_GETARG_INT64(0);
char *ptr;
const char *digits = "0123456789abcdef";
char buf[32]; /* bigger than needed, but reasonable */
ptr = buf + sizeof(buf) - 1;
*ptr = '\0';
do
{
*--ptr = digits[value % HEXBASE];
value /= HEXBASE;
} while (ptr > buf && value);
PG_RETURN_TEXT_P(cstring_to_text(ptr));
}
/*
* Return the size of a datum, possibly compressed
*
* Works on any data type
*/
Datum
pg_column_size(PG_FUNCTION_ARGS)
{
Datum value = PG_GETARG_DATUM(0);
int32 result;
int typlen;
/* On first call, get the input type's typlen, and save at *fn_extra */
if (fcinfo->flinfo->fn_extra == NULL)
{
/* Lookup the datatype of the supplied argument */
Oid argtypeid = get_fn_expr_argtype(fcinfo->flinfo, 0);
typlen = get_typlen(argtypeid);
if (typlen == 0) /* should not happen */
elog(ERROR, "cache lookup failed for type %u", argtypeid);
fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
sizeof(int));
*((int *) fcinfo->flinfo->fn_extra) = typlen;
}
else
typlen = *((int *) fcinfo->flinfo->fn_extra);
if (typlen == -1)
{
/* varlena type, possibly toasted */
result = toast_datum_size(value);
}
else if (typlen == -2)
{
/* cstring */
result = strlen(DatumGetCString(value)) + 1;
}
else
{
/* ordinary fixed-width type */
result = typlen;
}
PG_RETURN_INT32(result);
}
/*
* string_agg - Concatenates values and returns string.
*
* Syntax: string_agg(value text, delimiter text) RETURNS text
*
* Note: Any NULL values are ignored. The first-call delimiter isn't
* actually used at all, and on subsequent calls the delimiter precedes
* the associated value.
*/
/* subroutine to initialize state */
static StringInfo
makeStringAggState(FunctionCallInfo fcinfo)
{
StringInfo state;
MemoryContext aggcontext;
MemoryContext oldcontext;
if (!AggCheckCallContext(fcinfo, &aggcontext))
{
/* cannot be called directly because of internal-type argument */
elog(ERROR, "string_agg_transfn called in non-aggregate context");
}
/*
* Create state in aggregate context. It'll stay there across subsequent
* calls.
*/
oldcontext = MemoryContextSwitchTo(aggcontext);
state = makeStringInfo();
MemoryContextSwitchTo(oldcontext);
return state;
}
Datum
string_agg_transfn(PG_FUNCTION_ARGS)
{
StringInfo state;
state = PG_ARGISNULL(0) ? NULL : (StringInfo) PG_GETARG_POINTER(0);
/* Append the value unless null. */
if (!PG_ARGISNULL(1))
{
/* On the first time through, we ignore the delimiter. */
if (state == NULL)
state = makeStringAggState(fcinfo);
else if (!PG_ARGISNULL(2))
appendStringInfoText(state, PG_GETARG_TEXT_PP(2)); /* delimiter */
appendStringInfoText(state, PG_GETARG_TEXT_PP(1)); /* value */
}
/*
* The transition type for string_agg() is declared to be "internal",
* which is a pass-by-value type the same size as a pointer.
*/
PG_RETURN_POINTER(state);
}
Datum
string_agg_finalfn(PG_FUNCTION_ARGS)
{
StringInfo state;
/* cannot be called directly because of internal-type argument */
Assert(AggCheckCallContext(fcinfo, NULL));
state = PG_ARGISNULL(0) ? NULL : (StringInfo) PG_GETARG_POINTER(0);
if (state != NULL)
PG_RETURN_TEXT_P(cstring_to_text_with_len(state->data, state->len));
else
PG_RETURN_NULL();
}
/*
* Prepare cache with fmgr info for the output functions of the datatypes of
* the arguments of a concat-like function, beginning with argument "argidx".
* (Arguments before that will have corresponding slots in the resulting
* FmgrInfo array, but we don't fill those slots.)
*/
static FmgrInfo *
build_concat_foutcache(FunctionCallInfo fcinfo, int argidx)
{
FmgrInfo *foutcache;
int i;
/* We keep the info in fn_mcxt so it survives across calls */
foutcache = (FmgrInfo *) MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
PG_NARGS() * sizeof(FmgrInfo));
for (i = argidx; i < PG_NARGS(); i++)
{
Oid valtype;
Oid typOutput;
bool typIsVarlena;
valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
if (!OidIsValid(valtype))
elog(ERROR, "could not determine data type of concat() input");
getTypeOutputInfo(valtype, &typOutput, &typIsVarlena);
fmgr_info_cxt(typOutput, &foutcache[i], fcinfo->flinfo->fn_mcxt);
}
fcinfo->flinfo->fn_extra = foutcache;
return foutcache;
}
/*
* Implementation of both concat() and concat_ws().
*
* sepstr is the separator string to place between values.
* argidx identifies the first argument to concatenate (counting from zero);
* note that this must be constant across any one series of calls.
*
* Returns NULL if result should be NULL, else text value.
*/
static text *
concat_internal(const char *sepstr, int argidx,
FunctionCallInfo fcinfo)
{
text *result;
StringInfoData str;
FmgrInfo *foutcache;
bool first_arg = true;
int i;
/*
* concat(VARIADIC some-array) is essentially equivalent to
* array_to_text(), ie concat the array elements with the given separator.
* So we just pass the case off to that code.
*/
if (get_fn_expr_variadic(fcinfo->flinfo))
{
ArrayType *arr;
/* Should have just the one argument */
Assert(argidx == PG_NARGS() - 1);
/* concat(VARIADIC NULL) is defined as NULL */
if (PG_ARGISNULL(argidx))
return NULL;
/*
* Non-null argument had better be an array. We assume that any call
* context that could let get_fn_expr_variadic return true will have
* checked that a VARIADIC-labeled parameter actually is an array. So
* it should be okay to just Assert that it's an array rather than
* doing a full-fledged error check.
*/
Assert(OidIsValid(get_base_element_type(get_fn_expr_argtype(fcinfo->flinfo, argidx))));
/* OK, safe to fetch the array value */
arr = PG_GETARG_ARRAYTYPE_P(argidx);
/*
* And serialize the array. We tell array_to_text to ignore null
* elements, which matches the behavior of the loop below.
*/
return array_to_text_internal(fcinfo, arr, sepstr, NULL);
}
/* Normal case without explicit VARIADIC marker */
initStringInfo(&str);
/* Get output function info, building it if first time through */
foutcache = (FmgrInfo *) fcinfo->flinfo->fn_extra;
if (foutcache == NULL)
foutcache = build_concat_foutcache(fcinfo, argidx);
for (i = argidx; i < PG_NARGS(); i++)
{
if (!PG_ARGISNULL(i))
{
Datum value = PG_GETARG_DATUM(i);
/* add separator if appropriate */
if (first_arg)
first_arg = false;
else
appendStringInfoString(&str, sepstr);
/* call the appropriate type output function, append the result */
appendStringInfoString(&str,
OutputFunctionCall(&foutcache[i], value));
}
}
result = cstring_to_text_with_len(str.data, str.len);
pfree(str.data);
return result;
}
/*
* Concatenate all arguments. NULL arguments are ignored.
*/
Datum
text_concat(PG_FUNCTION_ARGS)
{
text *result;
result = concat_internal("", 0, fcinfo);
if (result == NULL)
PG_RETURN_NULL();
PG_RETURN_TEXT_P(result);
}
/*
* Concatenate all but first argument value with separators. The first
* parameter is used as the separator. NULL arguments are ignored.
*/
Datum
text_concat_ws(PG_FUNCTION_ARGS)
{
char *sep;
text *result;
/* return NULL when separator is NULL */
if (PG_ARGISNULL(0))
PG_RETURN_NULL();
sep = text_to_cstring(PG_GETARG_TEXT_PP(0));
result = concat_internal(sep, 1, fcinfo);
if (result == NULL)
PG_RETURN_NULL();
PG_RETURN_TEXT_P(result);
}
/*
* Return first n characters in the string. When n is negative,
* return all but last |n| characters.
*/
Datum
text_left(PG_FUNCTION_ARGS)
{
text *str = PG_GETARG_TEXT_PP(0);
const char *p = VARDATA_ANY(str);
int len = VARSIZE_ANY_EXHDR(str);
int n = PG_GETARG_INT32(1);
int rlen;
if (n < 0)
n = pg_mbstrlen_with_len(p, len) + n;
rlen = pg_mbcharcliplen(p, len, n);
PG_RETURN_TEXT_P(cstring_to_text_with_len(p, rlen));
}
/*
* Return last n characters in the string. When n is negative,
* return all but first |n| characters.
*/
Datum
text_right(PG_FUNCTION_ARGS)
{
text *str = PG_GETARG_TEXT_PP(0);
const char *p = VARDATA_ANY(str);
int len = VARSIZE_ANY_EXHDR(str);
int n = PG_GETARG_INT32(1);
int off;
if (n < 0)
n = -n;
else
n = pg_mbstrlen_with_len(p, len) - n;
off = pg_mbcharcliplen(p, len, n);
PG_RETURN_TEXT_P(cstring_to_text_with_len(p + off, len - off));
}
/*
* Return reversed string
*/
Datum
text_reverse(PG_FUNCTION_ARGS)
{
text *str = PG_GETARG_TEXT_PP(0);
const char *p = VARDATA_ANY(str);
int len = VARSIZE_ANY_EXHDR(str);
const char *endp = p + len;
text *result;
char *dst;
result = palloc(len + VARHDRSZ);
dst = (char *) VARDATA(result) + len;
SET_VARSIZE(result, len + VARHDRSZ);
if (pg_database_encoding_max_length() > 1)
{
/* multibyte version */
while (p < endp)
{
int sz;
sz = pg_mblen(p);
dst -= sz;
memcpy(dst, p, sz);
p += sz;
}
}
else
{
/* single byte version */
while (p < endp)
*(--dst) = *p++;
}
PG_RETURN_TEXT_P(result);
}
/*
* Support macros for text_format()
*/
#define TEXT_FORMAT_FLAG_MINUS 0x0001 /* is minus flag present? */
#define ADVANCE_PARSE_POINTER(ptr,end_ptr) \
do { \
if (++(ptr) >= (end_ptr)) \
ereport(ERROR, \
(errcode(ERRCODE_INVALID_PARAMETER_VALUE), \
errmsg("unterminated format() type specifier"), \
errhint("For a single \"%%\" use \"%%%%\"."))); \
} while (0)
/*
* Returns a formatted string
*/
Datum
text_format(PG_FUNCTION_ARGS)
{
text *fmt;
StringInfoData str;
const char *cp;
const char *start_ptr;
const char *end_ptr;
text *result;
int arg;
bool funcvariadic;
int nargs;
Datum *elements = NULL;
bool *nulls = NULL;
Oid element_type = InvalidOid;
Oid prev_type = InvalidOid;
Oid prev_width_type = InvalidOid;
FmgrInfo typoutputfinfo;
FmgrInfo typoutputinfo_width;
/* When format string is null, immediately return null */
if (PG_ARGISNULL(0))
PG_RETURN_NULL();
/* If argument is marked VARIADIC, expand array into elements */
if (get_fn_expr_variadic(fcinfo->flinfo))
{
ArrayType *arr;
int16 elmlen;
bool elmbyval;
char elmalign;
int nitems;
/* Should have just the one argument */
Assert(PG_NARGS() == 2);
/* If argument is NULL, we treat it as zero-length array */
if (PG_ARGISNULL(1))
nitems = 0;
else
{
/*
* Non-null argument had better be an array. We assume that any
* call context that could let get_fn_expr_variadic return true
* will have checked that a VARIADIC-labeled parameter actually is
* an array. So it should be okay to just Assert that it's an
* array rather than doing a full-fledged error check.
*/
Assert(OidIsValid(get_base_element_type(get_fn_expr_argtype(fcinfo->flinfo, 1))));
/* OK, safe to fetch the array value */
arr = PG_GETARG_ARRAYTYPE_P(1);
/* Get info about array element type */
element_type = ARR_ELEMTYPE(arr);
get_typlenbyvalalign(element_type,
&elmlen, &elmbyval, &elmalign);
/* Extract all array elements */
deconstruct_array(arr, element_type, elmlen, elmbyval, elmalign,
&elements, &nulls, &nitems);
}
nargs = nitems + 1;
funcvariadic = true;
}
else
{
/* Non-variadic case, we'll process the arguments individually */
nargs = PG_NARGS();
funcvariadic = false;
}
/* Setup for main loop. */
fmt = PG_GETARG_TEXT_PP(0);
start_ptr = VARDATA_ANY(fmt);
end_ptr = start_ptr + VARSIZE_ANY_EXHDR(fmt);
initStringInfo(&str);
arg = 1; /* next argument position to print */
/* Scan format string, looking for conversion specifiers. */
for (cp = start_ptr; cp < end_ptr; cp++)
{
int argpos;
int widthpos;
int flags;
int width;
Datum value;
bool isNull;
Oid typid;
/*
* If it's not the start of a conversion specifier, just copy it to
* the output buffer.
*/
if (*cp != '%')
{
appendStringInfoCharMacro(&str, *cp);
continue;
}
ADVANCE_PARSE_POINTER(cp, end_ptr);
/* Easy case: %% outputs a single % */
if (*cp == '%')
{
appendStringInfoCharMacro(&str, *cp);
continue;
}
/* Parse the optional portions of the format specifier */
cp = text_format_parse_format(cp, end_ptr,
&argpos, &widthpos,
&flags, &width);
/*
* Next we should see the main conversion specifier. Whether or not
* an argument position was present, it's known that at least one
* character remains in the string at this point. Experience suggests
* that it's worth checking that that character is one of the expected
* ones before we try to fetch arguments, so as to produce the least
* confusing response to a mis-formatted specifier.
*/
if (strchr("sIL", *cp) == NULL)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized format() type specifier \"%c\"",
*cp),
errhint("For a single \"%%\" use \"%%%%\".")));
/* If indirect width was specified, get its value */
if (widthpos >= 0)
{
/* Collect the specified or next argument position */
if (widthpos > 0)
arg = widthpos;
if (arg >= nargs)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("too few arguments for format()")));
/* Get the value and type of the selected argument */
if (!funcvariadic)
{
value = PG_GETARG_DATUM(arg);
isNull = PG_ARGISNULL(arg);
typid = get_fn_expr_argtype(fcinfo->flinfo, arg);
}
else
{
value = elements[arg - 1];
isNull = nulls[arg - 1];
typid = element_type;
}
if (!OidIsValid(typid))
elog(ERROR, "could not determine data type of format() input");
arg++;
/* We can treat NULL width the same as zero */
if (isNull)
width = 0;
else if (typid == INT4OID)
width = DatumGetInt32(value);
else if (typid == INT2OID)
width = DatumGetInt16(value);
else
{
/* For less-usual datatypes, convert to text then to int */
char *str;
if (typid != prev_width_type)
{
Oid typoutputfunc;
bool typIsVarlena;
getTypeOutputInfo(typid, &typoutputfunc, &typIsVarlena);
fmgr_info(typoutputfunc, &typoutputinfo_width);
prev_width_type = typid;
}
str = OutputFunctionCall(&typoutputinfo_width, value);
/* pg_atoi will complain about bad data or overflow */
width = pg_atoi(str, sizeof(int), '\0');
pfree(str);
}
}
/* Collect the specified or next argument position */
if (argpos > 0)
arg = argpos;
if (arg >= nargs)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("too few arguments for format()")));
/* Get the value and type of the selected argument */
if (!funcvariadic)
{
value = PG_GETARG_DATUM(arg);
isNull = PG_ARGISNULL(arg);
typid = get_fn_expr_argtype(fcinfo->flinfo, arg);
}
else
{
value = elements[arg - 1];
isNull = nulls[arg - 1];
typid = element_type;
}
if (!OidIsValid(typid))
elog(ERROR, "could not determine data type of format() input");
arg++;
/*
* Get the appropriate typOutput function, reusing previous one if
* same type as previous argument. That's particularly useful in the
* variadic-array case, but often saves work even for ordinary calls.
*/
if (typid != prev_type)
{
Oid typoutputfunc;
bool typIsVarlena;
getTypeOutputInfo(typid, &typoutputfunc, &typIsVarlena);
fmgr_info(typoutputfunc, &typoutputfinfo);
prev_type = typid;
}
/*
* And now we can format the value.
*/
switch (*cp)
{
case 's':
case 'I':
case 'L':
text_format_string_conversion(&str, *cp, &typoutputfinfo,
value, isNull,
flags, width);
break;
default:
/* should not get here, because of previous check */
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized format() type specifier \"%c\"",
*cp),
errhint("For a single \"%%\" use \"%%%%\".")));
break;
}
}
/* Don't need deconstruct_array results anymore. */
if (elements != NULL)
pfree(elements);
if (nulls != NULL)
pfree(nulls);
/* Generate results. */
result = cstring_to_text_with_len(str.data, str.len);
pfree(str.data);
PG_RETURN_TEXT_P(result);
}
/*
* Parse contiguous digits as a decimal number.
*
* Returns true if some digits could be parsed.
* The value is returned into *value, and *ptr is advanced to the next
* character to be parsed.
*
* Note parsing invariant: at least one character is known available before
* string end (end_ptr) at entry, and this is still true at exit.
*/
static bool
text_format_parse_digits(const char **ptr, const char *end_ptr, int *value)
{
bool found = false;
const char *cp = *ptr;
int val = 0;
while (*cp >= '0' && *cp <= '9')
{
int8 digit = (*cp - '0');
if (unlikely(pg_mul_s32_overflow(val, 10, &val)) ||
unlikely(pg_add_s32_overflow(val, digit, &val)))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("number is out of range")));
ADVANCE_PARSE_POINTER(cp, end_ptr);
found = true;
}
*ptr = cp;
*value = val;
return found;
}
/*
* Parse a format specifier (generally following the SUS printf spec).
*
* We have already advanced over the initial '%', and we are looking for
* [argpos][flags][width]type (but the type character is not consumed here).
*
* Inputs are start_ptr (the position after '%') and end_ptr (string end + 1).
* Output parameters:
* argpos: argument position for value to be printed. -1 means unspecified.
* widthpos: argument position for width. Zero means the argument position
* was unspecified (ie, take the next arg) and -1 means no width
* argument (width was omitted or specified as a constant).
* flags: bitmask of flags.
* width: directly-specified width value. Zero means the width was omitted
* (note it's not necessary to distinguish this case from an explicit
* zero width value).
*
* The function result is the next character position to be parsed, ie, the
* location where the type character is/should be.
*
* Note parsing invariant: at least one character is known available before
* string end (end_ptr) at entry, and this is still true at exit.
*/
static const char *
text_format_parse_format(const char *start_ptr, const char *end_ptr,
int *argpos, int *widthpos,
int *flags, int *width)
{
const char *cp = start_ptr;
int n;
/* set defaults for output parameters */
*argpos = -1;
*widthpos = -1;
*flags = 0;
*width = 0;
/* try to identify first number */
if (text_format_parse_digits(&cp, end_ptr, &n))
{
if (*cp != '$')
{
/* Must be just a width and a type, so we're done */
*width = n;
return cp;
}
/* The number was argument position */
*argpos = n;
/* Explicit 0 for argument index is immediately refused */
if (n == 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("format specifies argument 0, but arguments are numbered from 1")));
ADVANCE_PARSE_POINTER(cp, end_ptr);
}
/* Handle flags (only minus is supported now) */
while (*cp == '-')
{
*flags |= TEXT_FORMAT_FLAG_MINUS;
ADVANCE_PARSE_POINTER(cp, end_ptr);
}
if (*cp == '*')
{
/* Handle indirect width */
ADVANCE_PARSE_POINTER(cp, end_ptr);
if (text_format_parse_digits(&cp, end_ptr, &n))
{
/* number in this position must be closed by $ */
if (*cp != '$')
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("width argument position must be ended by \"$\"")));
/* The number was width argument position */
*widthpos = n;
/* Explicit 0 for argument index is immediately refused */
if (n == 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("format specifies argument 0, but arguments are numbered from 1")));
ADVANCE_PARSE_POINTER(cp, end_ptr);
}
else
*widthpos = 0; /* width's argument position is unspecified */
}
else
{
/* Check for direct width specification */
if (text_format_parse_digits(&cp, end_ptr, &n))
*width = n;
}
/* cp should now be pointing at type character */
return cp;
}
/*
* Format a %s, %I, or %L conversion
*/
static void
text_format_string_conversion(StringInfo buf, char conversion,
FmgrInfo *typOutputInfo,
Datum value, bool isNull,
int flags, int width)
{
char *str;
/* Handle NULL arguments before trying to stringify the value. */
if (isNull)
{
if (conversion == 's')
text_format_append_string(buf, "", flags, width);
else if (conversion == 'L')
text_format_append_string(buf, "NULL", flags, width);
else if (conversion == 'I')
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
errmsg("null values cannot be formatted as an SQL identifier")));
return;
}
/* Stringify. */
str = OutputFunctionCall(typOutputInfo, value);
/* Escape. */
if (conversion == 'I')
{
/* quote_identifier may or may not allocate a new string. */
text_format_append_string(buf, quote_identifier(str), flags, width);
}
else if (conversion == 'L')
{
char *qstr = quote_literal_cstr(str);
text_format_append_string(buf, qstr, flags, width);
/* quote_literal_cstr() always allocates a new string */
pfree(qstr);
}
else
text_format_append_string(buf, str, flags, width);
/* Cleanup. */
pfree(str);
}
/*
* Append str to buf, padding as directed by flags/width
*/
static void
text_format_append_string(StringInfo buf, const char *str,
int flags, int width)
{
bool align_to_left = false;
int len;
/* fast path for typical easy case */
if (width == 0)
{
appendStringInfoString(buf, str);
return;
}
if (width < 0)
{
/* Negative width: implicit '-' flag, then take absolute value */
align_to_left = true;
/* -INT_MIN is undefined */
if (width <= INT_MIN)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("number is out of range")));
width = -width;
}
else if (flags & TEXT_FORMAT_FLAG_MINUS)
align_to_left = true;
len = pg_mbstrlen(str);
if (align_to_left)
{
/* left justify */
appendStringInfoString(buf, str);
if (len < width)
appendStringInfoSpaces(buf, width - len);
}
else
{
/* right justify */
if (len < width)
appendStringInfoSpaces(buf, width - len);
appendStringInfoString(buf, str);
}
}
/*
* text_format_nv - nonvariadic wrapper for text_format function.
*
* note: this wrapper is necessary to pass the sanity check in opr_sanity,
* which checks that all built-in functions that share the implementing C
* function take the same number of arguments.
*/
Datum
text_format_nv(PG_FUNCTION_ARGS)
{
return text_format(fcinfo);
}
/*
* Helper function for Levenshtein distance functions. Faster than memcmp(),
* for this use case.
*/
static inline bool
rest_of_char_same(const char *s1, const char *s2, int len)
{
while (len > 0)
{
len--;
if (s1[len] != s2[len])
return false;
}
return true;
}
/* Expand each Levenshtein distance variant */
#include "levenshtein.c"
#define LEVENSHTEIN_LESS_EQUAL
#include "levenshtein.c"