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postgresql/src/backend/utils/adt/varchar.c

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/*-------------------------------------------------------------------------
*
* varchar.c
* Functions for the built-in types char(n) and varchar(n).
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/adt/varchar.c,v 1.74 2001/02/10 02:31:27 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/hash.h"
#include "catalog/pg_type.h"
#include "miscadmin.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#ifdef MULTIBYTE
#include "mb/pg_wchar.h"
#endif
/*
* CHAR() and VARCHAR() types are part of the ANSI SQL standard. CHAR()
* is for blank-padded string whose length is specified in CREATE TABLE.
* VARCHAR is for storing string whose length is at most the length specified
* at CREATE TABLE time.
*
* It's hard to implement these types because we cannot figure out
* the length of the type from the type itself. I change (hopefully all) the
* fmgr calls that invoke input functions of a data type to supply the
* length also. (eg. in INSERTs, we have the tupleDescriptor which contains
* the length of the attributes and hence the exact length of the char() or
* varchar(). We pass this to bpcharin() or varcharin().) In the case where
* we cannot determine the length, we pass in -1 instead and the input string
* must be null-terminated.
*
* We actually implement this as a varlena so that we don't have to pass in
* the length for the comparison functions. (The difference between these
* types and "text" is that we truncate and possibly blank-pad the string
* at insertion time.)
*
* - ay 6/95
*/
/*****************************************************************************
* bpchar - char() *
*****************************************************************************/
/*
* bpcharin -
* converts a string of char() type to the internal representation.
* len is the length specified in () plus VARHDRSZ bytes.
*/
Datum
bpcharin(PG_FUNCTION_ARGS)
{
char *s = PG_GETARG_CSTRING(0);
#ifdef NOT_USED
Oid typelem = PG_GETARG_OID(1);
#endif
int32 atttypmod = PG_GETARG_INT32(2);
BpChar *result;
char *r;
int len;
int i;
if (atttypmod < (int32) VARHDRSZ)
{
/* If typmod is -1 (or invalid), use the actual string length */
len = strlen(s);
atttypmod = len + VARHDRSZ;
}
else
#ifdef MULTIBYTE
{
/*
* truncate multi-byte string preserving multi-byte
* boundary
*/
len = pg_mbcliplen(s, atttypmod - VARHDRSZ, atttypmod - VARHDRSZ);
}
#else
len = atttypmod - VARHDRSZ;
#endif
result = (BpChar *) palloc(atttypmod);
VARATT_SIZEP(result) = atttypmod;
r = VARDATA(result);
for (i = 0; i < len; i++, r++, s++)
{
*r = *s;
if (*r == '\0')
break;
}
#ifdef CYR_RECODE
convertstr(VARDATA(result), len, 0);
#endif
/* blank pad the string if necessary */
#ifdef MULTIBYTE
for (; i < atttypmod - VARHDRSZ; i++)
#else
for (; i < len; i++)
#endif
*r++ = ' ';
PG_RETURN_BPCHAR_P(result);
}
Datum
bpcharout(PG_FUNCTION_ARGS)
{
BpChar *s = PG_GETARG_BPCHAR_P(0);
char *result;
int len;
/* copy and add null term */
len = VARSIZE(s) - VARHDRSZ;
result = (char *) palloc(len + 1);
memcpy(result, VARDATA(s), len);
result[len] = '\0';
#ifdef CYR_RECODE
convertstr(result, len, 1);
#endif
PG_RETURN_CSTRING(result);
}
/* bpchar()
* Converts a char() type to a specific internal length.
* len is the length specified in () plus VARHDRSZ bytes.
*/
Datum
bpchar(PG_FUNCTION_ARGS)
{
BpChar *str = PG_GETARG_BPCHAR_P(0);
int32 len = PG_GETARG_INT32(1);
BpChar *result;
char *r,
*s;
int rlen,
slen;
int i;
/* No work if typmod is invalid or supplied data matches it already */
if (len < (int32) VARHDRSZ || len == VARSIZE(str))
PG_RETURN_BPCHAR_P(str);
rlen = len - VARHDRSZ;
#ifdef STRINGDEBUG
printf("bpchar- convert string length %d (%d) ->%d (%d)\n",
VARSIZE(str) - VARHDRSZ, VARSIZE(str), rlen, len);
#endif
result = (BpChar *) palloc(len);
VARATT_SIZEP(result) = len;
r = VARDATA(result);
#ifdef MULTIBYTE
/*
* truncate multi-byte string in a way not to break multi-byte
* boundary
*/
if (VARSIZE(str) > len)
slen = pg_mbcliplen(VARDATA(str), VARSIZE(str) - VARHDRSZ, rlen);
else
slen = VARSIZE(str) - VARHDRSZ;
#else
slen = VARSIZE(str) - VARHDRSZ;
#endif
s = VARDATA(str);
#ifdef STRINGDEBUG
printf("bpchar- string is '");
#endif
for (i = 0; (i < rlen) && (i < slen); i++)
{
#ifdef STRINGDEBUG
printf("%c", *s);
#endif
*r++ = *s++;
}
#ifdef STRINGDEBUG
printf("'\n");
#endif
/* blank pad the string if necessary */
for (; i < rlen; i++)
*r++ = ' ';
PG_RETURN_BPCHAR_P(result);
}
/* _bpchar()
* Converts an array of char() elements to a specific internal length.
* len is the length specified in () plus VARHDRSZ bytes.
*/
Datum
_bpchar(PG_FUNCTION_ARGS)
{
ArrayType *v = (ArrayType *) PG_GETARG_VARLENA_P(0);
int32 len = PG_GETARG_INT32(1);
FunctionCallInfoData locfcinfo;
/*
* Since bpchar() is a built-in function, we should only need to
* look it up once per run.
*/
static FmgrInfo bpchar_finfo;
if (bpchar_finfo.fn_oid == InvalidOid)
fmgr_info(F_BPCHAR, &bpchar_finfo);
MemSet(&locfcinfo, 0, sizeof(locfcinfo));
locfcinfo.flinfo = &bpchar_finfo;
locfcinfo.nargs = 2;
/* We assume we are "strict" and need not worry about null inputs */
locfcinfo.arg[0] = PointerGetDatum(v);
locfcinfo.arg[1] = Int32GetDatum(len);
return array_map(&locfcinfo, BPCHAROID, BPCHAROID);
}
/* bpchar_char()
* Convert bpchar(1) to char.
*
* If input is multiple chars, only the first is returned.
*/
Datum
bpchar_char(PG_FUNCTION_ARGS)
{
BpChar *s = PG_GETARG_BPCHAR_P(0);
PG_RETURN_CHAR(*VARDATA(s));
}
/* char_bpchar()
* Convert char to bpchar(1).
*/
Datum
char_bpchar(PG_FUNCTION_ARGS)
{
char c = PG_GETARG_CHAR(0);
BpChar *result;
result = (BpChar *) palloc(VARHDRSZ + 1);
VARATT_SIZEP(result) = VARHDRSZ + 1;
*(VARDATA(result)) = c;
PG_RETURN_BPCHAR_P(result);
}
/* bpchar_name()
* Converts a bpchar() type to a NameData type.
*/
Datum
bpchar_name(PG_FUNCTION_ARGS)
{
BpChar *s = PG_GETARG_BPCHAR_P(0);
Name result;
int len;
len = VARSIZE(s) - VARHDRSZ;
/* Truncate to max length for a Name */
if (len >= NAMEDATALEN)
len = NAMEDATALEN-1;
/* Remove trailing blanks */
while (len > 0)
{
if (*(VARDATA(s) + len - 1) != ' ')
break;
len--;
}
result = (NameData *) palloc(NAMEDATALEN);
memcpy(NameStr(*result), VARDATA(s), len);
/* Now null pad to full length... */
while (len < NAMEDATALEN)
{
*(NameStr(*result) + len) = '\0';
len++;
}
PG_RETURN_NAME(result);
}
/* name_bpchar()
* Converts a NameData type to a bpchar type.
*/
Datum
name_bpchar(PG_FUNCTION_ARGS)
{
Name s = PG_GETARG_NAME(0);
BpChar *result;
int len;
len = strlen(NameStr(*s));
result = (BpChar *) palloc(VARHDRSZ + len);
memcpy(VARDATA(result), NameStr(*s), len);
VARATT_SIZEP(result) = len + VARHDRSZ;
PG_RETURN_BPCHAR_P(result);
}
/*****************************************************************************
* varchar - varchar() *
*****************************************************************************/
/*
* varcharin -
* converts a string of varchar() type to the internal representation.
* len is the length specified in () plus VARHDRSZ bytes.
*/
Datum
varcharin(PG_FUNCTION_ARGS)
{
char *s = PG_GETARG_CSTRING(0);
#ifdef NOT_USED
Oid typelem = PG_GETARG_OID(1);
#endif
int32 atttypmod = PG_GETARG_INT32(2);
VarChar *result;
int len;
len = strlen(s) + VARHDRSZ;
if (atttypmod >= (int32) VARHDRSZ && len > atttypmod)
#ifdef MULTIBYTE
len = pg_mbcliplen(s, len - VARHDRSZ, atttypmod - VARHDRSZ) + VARHDRSZ;
#else
len = atttypmod; /* clip the string at max length */
#endif
result = (VarChar *) palloc(len);
VARATT_SIZEP(result) = len;
memcpy(VARDATA(result), s, len - VARHDRSZ);
#ifdef CYR_RECODE
convertstr(VARDATA(result), len, 0);
#endif
PG_RETURN_VARCHAR_P(result);
}
Datum
varcharout(PG_FUNCTION_ARGS)
{
VarChar *s = PG_GETARG_VARCHAR_P(0);
char *result;
int len;
/* copy and add null term */
len = VARSIZE(s) - VARHDRSZ;
result = (char *) palloc(len + 1);
memcpy(result, VARDATA(s), len);
result[len] = '\0';
#ifdef CYR_RECODE
convertstr(result, len, 1);
#endif
PG_RETURN_CSTRING(result);
}
/* varchar()
* Converts a varchar() type to the specified size.
* slen is the length specified in () plus VARHDRSZ bytes.
*/
Datum
varchar(PG_FUNCTION_ARGS)
{
VarChar *s = PG_GETARG_VARCHAR_P(0);
int32 slen = PG_GETARG_INT32(1);
VarChar *result;
int len;
len = VARSIZE(s);
if (slen < (int32) VARHDRSZ || len <= slen)
PG_RETURN_VARCHAR_P(s);
/* only reach here if we need to truncate string... */
#ifdef MULTIBYTE
/*
* truncate multi-byte string preserving multi-byte
* boundary
*/
len = pg_mbcliplen(VARDATA(s), slen - VARHDRSZ, slen - VARHDRSZ);
slen = len + VARHDRSZ;
#else
len = slen - VARHDRSZ;
#endif
result = (VarChar *) palloc(slen);
VARATT_SIZEP(result) = slen;
memcpy(VARDATA(result), VARDATA(s), len);
PG_RETURN_VARCHAR_P(result);
}
/* _varchar()
* Converts an array of varchar() elements to the specified size.
* len is the length specified in () plus VARHDRSZ bytes.
*/
Datum
_varchar(PG_FUNCTION_ARGS)
{
ArrayType *v = (ArrayType *) PG_GETARG_VARLENA_P(0);
int32 len = PG_GETARG_INT32(1);
FunctionCallInfoData locfcinfo;
/*
* Since varchar() is a built-in function, we should only need to
* look it up once per run.
*/
static FmgrInfo varchar_finfo;
if (varchar_finfo.fn_oid == InvalidOid)
fmgr_info(F_VARCHAR, &varchar_finfo);
MemSet(&locfcinfo, 0, sizeof(locfcinfo));
locfcinfo.flinfo = &varchar_finfo;
locfcinfo.nargs = 2;
/* We assume we are "strict" and need not worry about null inputs */
locfcinfo.arg[0] = PointerGetDatum(v);
locfcinfo.arg[1] = Int32GetDatum(len);
return array_map(&locfcinfo, VARCHAROID, VARCHAROID);
}
/* "True" length (not counting trailing blanks) of a BpChar */
static int
bcTruelen(BpChar *arg)
{
char *s = VARDATA(arg);
int i;
int len;
len = VARSIZE(arg) - VARHDRSZ;
for (i = len - 1; i >= 0; i--)
{
if (s[i] != ' ')
break;
}
return i + 1;
}
Datum
bpcharlen(PG_FUNCTION_ARGS)
{
BpChar *arg = PG_GETARG_BPCHAR_P(0);
#ifdef MULTIBYTE
unsigned char *s;
int len,
l,
wl;
l = VARSIZE(arg) - VARHDRSZ;
len = 0;
s = VARDATA(arg);
while (l > 0)
{
wl = pg_mblen(s);
l -= wl;
s += wl;
len++;
}
PG_RETURN_INT32(len);
#else
PG_RETURN_INT32(VARSIZE(arg) - VARHDRSZ);
#endif
}
Datum
bpcharoctetlen(PG_FUNCTION_ARGS)
{
BpChar *arg = PG_GETARG_BPCHAR_P(0);
PG_RETURN_INT32(VARSIZE(arg) - VARHDRSZ);
}
/*****************************************************************************
* Comparison Functions used for bpchar
*
* 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
bpchareq(PG_FUNCTION_ARGS)
{
BpChar *arg1 = PG_GETARG_BPCHAR_P(0);
BpChar *arg2 = PG_GETARG_BPCHAR_P(1);
int len1,
len2;
bool result;
len1 = bcTruelen(arg1);
len2 = bcTruelen(arg2);
if (len1 != len2)
result = false;
else
result = (strncmp(VARDATA(arg1), VARDATA(arg2), len1) == 0);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result);
}
Datum
bpcharne(PG_FUNCTION_ARGS)
{
BpChar *arg1 = PG_GETARG_BPCHAR_P(0);
BpChar *arg2 = PG_GETARG_BPCHAR_P(1);
int len1,
len2;
bool result;
len1 = bcTruelen(arg1);
len2 = bcTruelen(arg2);
if (len1 != len2)
result = true;
else
result = (strncmp(VARDATA(arg1), VARDATA(arg2), len1) != 0);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result);
}
Datum
bpcharlt(PG_FUNCTION_ARGS)
{
BpChar *arg1 = PG_GETARG_BPCHAR_P(0);
BpChar *arg2 = PG_GETARG_BPCHAR_P(1);
int len1,
len2;
int cmp;
len1 = bcTruelen(arg1);
len2 = bcTruelen(arg2);
cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(cmp < 0);
}
Datum
bpcharle(PG_FUNCTION_ARGS)
{
BpChar *arg1 = PG_GETARG_BPCHAR_P(0);
BpChar *arg2 = PG_GETARG_BPCHAR_P(1);
int len1,
len2;
int cmp;
len1 = bcTruelen(arg1);
len2 = bcTruelen(arg2);
cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(cmp <= 0);
}
Datum
bpchargt(PG_FUNCTION_ARGS)
{
BpChar *arg1 = PG_GETARG_BPCHAR_P(0);
BpChar *arg2 = PG_GETARG_BPCHAR_P(1);
int len1,
len2;
int cmp;
len1 = bcTruelen(arg1);
len2 = bcTruelen(arg2);
cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(cmp > 0);
}
Datum
bpcharge(PG_FUNCTION_ARGS)
{
BpChar *arg1 = PG_GETARG_BPCHAR_P(0);
BpChar *arg2 = PG_GETARG_BPCHAR_P(1);
int len1,
len2;
int cmp;
len1 = bcTruelen(arg1);
len2 = bcTruelen(arg2);
cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(cmp >= 0);
}
Datum
bpcharcmp(PG_FUNCTION_ARGS)
{
BpChar *arg1 = PG_GETARG_BPCHAR_P(0);
BpChar *arg2 = PG_GETARG_BPCHAR_P(1);
int len1,
len2;
int cmp;
len1 = bcTruelen(arg1);
len2 = bcTruelen(arg2);
cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_INT32(cmp);
}
/*
* bpchar needs a specialized hash function because we want to ignore
* trailing blanks in comparisons. (varchar can use plain hashvarlena.)
*/
Datum
hashbpchar(PG_FUNCTION_ARGS)
{
BpChar *key = PG_GETARG_BPCHAR_P(0);
char *keydata;
int keylen;
Datum result;
keydata = VARDATA(key);
keylen = bcTruelen(key);
result = hash_any(keydata, keylen);
/* Avoid leaking memory for toasted inputs */
PG_FREE_IF_COPY(key, 0);
return result;
}
/*****************************************************************************
* Functions used for varchar
*****************************************************************************/
Datum
varcharlen(PG_FUNCTION_ARGS)
{
VarChar *arg = PG_GETARG_VARCHAR_P(0);
#ifdef MULTIBYTE
unsigned char *s;
int len,
l,
wl;
len = 0;
s = VARDATA(arg);
l = VARSIZE(arg) - VARHDRSZ;
while (l > 0)
{
wl = pg_mblen(s);
l -= wl;
s += wl;
len++;
}
PG_RETURN_INT32(len);
#else
PG_RETURN_INT32(VARSIZE(arg) - VARHDRSZ);
#endif
}
Datum
varcharoctetlen(PG_FUNCTION_ARGS)
{
VarChar *arg = PG_GETARG_VARCHAR_P(0);
PG_RETURN_INT32(VARSIZE(arg) - VARHDRSZ);
}
/*****************************************************************************
* Comparison Functions used for varchar
*
* 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
varchareq(PG_FUNCTION_ARGS)
{
VarChar *arg1 = PG_GETARG_VARCHAR_P(0);
VarChar *arg2 = PG_GETARG_VARCHAR_P(1);
int len1,
len2;
bool result;
len1 = VARSIZE(arg1) - VARHDRSZ;
len2 = VARSIZE(arg2) - VARHDRSZ;
if (len1 != len2)
result = false;
else
result = (strncmp(VARDATA(arg1), VARDATA(arg2), len1) == 0);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result);
}
Datum
varcharne(PG_FUNCTION_ARGS)
{
VarChar *arg1 = PG_GETARG_VARCHAR_P(0);
VarChar *arg2 = PG_GETARG_VARCHAR_P(1);
int len1,
len2;
bool result;
len1 = VARSIZE(arg1) - VARHDRSZ;
len2 = VARSIZE(arg2) - VARHDRSZ;
if (len1 != len2)
result = true;
else
result = (strncmp(VARDATA(arg1), VARDATA(arg2), len1) != 0);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result);
}
Datum
varcharlt(PG_FUNCTION_ARGS)
{
VarChar *arg1 = PG_GETARG_VARCHAR_P(0);
VarChar *arg2 = PG_GETARG_VARCHAR_P(1);
int len1,
len2;
int cmp;
len1 = VARSIZE(arg1) - VARHDRSZ;
len2 = VARSIZE(arg2) - VARHDRSZ;
cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(cmp < 0);
}
Datum
varcharle(PG_FUNCTION_ARGS)
{
VarChar *arg1 = PG_GETARG_VARCHAR_P(0);
VarChar *arg2 = PG_GETARG_VARCHAR_P(1);
int len1,
len2;
int cmp;
len1 = VARSIZE(arg1) - VARHDRSZ;
len2 = VARSIZE(arg2) - VARHDRSZ;
cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(cmp <= 0);
}
Datum
varchargt(PG_FUNCTION_ARGS)
{
VarChar *arg1 = PG_GETARG_VARCHAR_P(0);
VarChar *arg2 = PG_GETARG_VARCHAR_P(1);
int len1,
len2;
int cmp;
len1 = VARSIZE(arg1) - VARHDRSZ;
len2 = VARSIZE(arg2) - VARHDRSZ;
cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(cmp > 0);
}
Datum
varcharge(PG_FUNCTION_ARGS)
{
VarChar *arg1 = PG_GETARG_VARCHAR_P(0);
VarChar *arg2 = PG_GETARG_VARCHAR_P(1);
int len1,
len2;
int cmp;
len1 = VARSIZE(arg1) - VARHDRSZ;
len2 = VARSIZE(arg2) - VARHDRSZ;
cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(cmp >= 0);
}
Datum
varcharcmp(PG_FUNCTION_ARGS)
{
VarChar *arg1 = PG_GETARG_VARCHAR_P(0);
VarChar *arg2 = PG_GETARG_VARCHAR_P(1);
int len1,
len2;
int cmp;
len1 = VARSIZE(arg1) - VARHDRSZ;
len2 = VARSIZE(arg2) - VARHDRSZ;
cmp = varstr_cmp(VARDATA(arg1), len1, VARDATA(arg2), len2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_INT32(cmp);
}
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