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

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/*-------------------------------------------------------------------------
*
* tsvector.c
* I/O functions for tsvector
*
* Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
*
*
* IDENTIFICATION
* src/backend/utils/adt/tsvector.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "common/int.h"
#include "libpq/pqformat.h"
#include "nodes/miscnodes.h"
#include "tsearch/ts_locale.h"
#include "tsearch/ts_utils.h"
#include "utils/builtins.h"
#include "utils/memutils.h"
#include "varatt.h"
typedef struct
{
WordEntry entry; /* must be first! */
WordEntryPos *pos;
int poslen; /* number of elements in pos */
} WordEntryIN;
/* Compare two WordEntryPos values for qsort */
int
compareWordEntryPos(const void *a, const void *b)
{
int apos = WEP_GETPOS(*(const WordEntryPos *) a);
int bpos = WEP_GETPOS(*(const WordEntryPos *) b);
return pg_cmp_s32(apos, bpos);
}
/*
* Removes duplicate pos entries. If there's two entries with same pos but
* different weight, the higher weight is retained, so we can't use
* qunique here.
*
* Returns new length.
*/
static int
uniquePos(WordEntryPos *a, int l)
{
WordEntryPos *ptr,
*res;
if (l <= 1)
return l;
qsort(a, l, sizeof(WordEntryPos), compareWordEntryPos);
res = a;
ptr = a + 1;
while (ptr - a < l)
{
if (WEP_GETPOS(*ptr) != WEP_GETPOS(*res))
{
res++;
*res = *ptr;
if (res - a >= MAXNUMPOS - 1 ||
WEP_GETPOS(*res) == MAXENTRYPOS - 1)
break;
}
else if (WEP_GETWEIGHT(*ptr) > WEP_GETWEIGHT(*res))
WEP_SETWEIGHT(*res, WEP_GETWEIGHT(*ptr));
ptr++;
}
return res + 1 - a;
}
/* Compare two WordEntryIN values for qsort */
static int
compareentry(const void *va, const void *vb, void *arg)
{
const WordEntryIN *a = (const WordEntryIN *) va;
const WordEntryIN *b = (const WordEntryIN *) vb;
char *BufferStr = (char *) arg;
return tsCompareString(&BufferStr[a->entry.pos], a->entry.len,
&BufferStr[b->entry.pos], b->entry.len,
false);
}
/*
* Sort an array of WordEntryIN, remove duplicates.
* *outbuflen receives the amount of space needed for strings and positions.
*/
static int
uniqueentry(WordEntryIN *a, int l, char *buf, int *outbuflen)
{
int buflen;
WordEntryIN *ptr,
*res;
Assert(l >= 1);
if (l > 1)
qsort_arg(a, l, sizeof(WordEntryIN), compareentry, buf);
buflen = 0;
res = a;
ptr = a + 1;
while (ptr - a < l)
{
if (!(ptr->entry.len == res->entry.len &&
strncmp(&buf[ptr->entry.pos], &buf[res->entry.pos],
res->entry.len) == 0))
{
/* done accumulating data into *res, count space needed */
buflen += res->entry.len;
if (res->entry.haspos)
{
res->poslen = uniquePos(res->pos, res->poslen);
buflen = SHORTALIGN(buflen);
buflen += res->poslen * sizeof(WordEntryPos) + sizeof(uint16);
}
res++;
if (res != ptr)
memcpy(res, ptr, sizeof(WordEntryIN));
}
else if (ptr->entry.haspos)
{
if (res->entry.haspos)
{
/* append ptr's positions to res's positions */
int newlen = ptr->poslen + res->poslen;
res->pos = (WordEntryPos *)
repalloc(res->pos, newlen * sizeof(WordEntryPos));
memcpy(&res->pos[res->poslen], ptr->pos,
ptr->poslen * sizeof(WordEntryPos));
res->poslen = newlen;
pfree(ptr->pos);
}
else
{
/* just give ptr's positions to pos */
res->entry.haspos = 1;
res->pos = ptr->pos;
res->poslen = ptr->poslen;
}
}
ptr++;
}
/* count space needed for last item */
buflen += res->entry.len;
if (res->entry.haspos)
{
res->poslen = uniquePos(res->pos, res->poslen);
buflen = SHORTALIGN(buflen);
buflen += res->poslen * sizeof(WordEntryPos) + sizeof(uint16);
}
*outbuflen = buflen;
return res + 1 - a;
}
static int
WordEntryCMP(WordEntry *a, WordEntry *b, char *buf)
{
return compareentry(a, b, buf);
}
Datum
tsvectorin(PG_FUNCTION_ARGS)
{
char *buf = PG_GETARG_CSTRING(0);
Node *escontext = fcinfo->context;
TSVectorParseState state;
WordEntryIN *arr;
int totallen;
int arrlen; /* allocated size of arr */
WordEntry *inarr;
int len = 0;
TSVector in;
int i;
char *token;
int toklen;
WordEntryPos *pos;
int poslen;
char *strbuf;
int stroff;
/*
* Tokens are appended to tmpbuf, cur is a pointer to the end of used
* space in tmpbuf.
*/
char *tmpbuf;
char *cur;
int buflen = 256; /* allocated size of tmpbuf */
state = init_tsvector_parser(buf, 0, escontext);
arrlen = 64;
arr = (WordEntryIN *) palloc(sizeof(WordEntryIN) * arrlen);
cur = tmpbuf = (char *) palloc(buflen);
while (gettoken_tsvector(state, &token, &toklen, &pos, &poslen, NULL))
{
if (toklen >= MAXSTRLEN)
ereturn(escontext, (Datum) 0,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("word is too long (%ld bytes, max %ld bytes)",
(long) toklen,
(long) (MAXSTRLEN - 1))));
if (cur - tmpbuf > MAXSTRPOS)
ereturn(escontext, (Datum) 0,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("string is too long for tsvector (%ld bytes, max %ld bytes)",
(long) (cur - tmpbuf), (long) MAXSTRPOS)));
/*
* Enlarge buffers if needed
*/
if (len >= arrlen)
{
arrlen *= 2;
arr = (WordEntryIN *)
repalloc(arr, sizeof(WordEntryIN) * arrlen);
}
while ((cur - tmpbuf) + toklen >= buflen)
{
int dist = cur - tmpbuf;
buflen *= 2;
tmpbuf = (char *) repalloc(tmpbuf, buflen);
cur = tmpbuf + dist;
}
arr[len].entry.len = toklen;
arr[len].entry.pos = cur - tmpbuf;
memcpy(cur, token, toklen);
cur += toklen;
if (poslen != 0)
{
arr[len].entry.haspos = 1;
arr[len].pos = pos;
arr[len].poslen = poslen;
}
else
{
arr[len].entry.haspos = 0;
arr[len].pos = NULL;
arr[len].poslen = 0;
}
len++;
}
close_tsvector_parser(state);
/* Did gettoken_tsvector fail? */
if (SOFT_ERROR_OCCURRED(escontext))
PG_RETURN_NULL();
if (len > 0)
len = uniqueentry(arr, len, tmpbuf, &buflen);
else
buflen = 0;
if (buflen > MAXSTRPOS)
ereturn(escontext, (Datum) 0,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("string is too long for tsvector (%d bytes, max %d bytes)", buflen, MAXSTRPOS)));
totallen = CALCDATASIZE(len, buflen);
in = (TSVector) palloc0(totallen);
SET_VARSIZE(in, totallen);
in->size = len;
inarr = ARRPTR(in);
strbuf = STRPTR(in);
stroff = 0;
for (i = 0; i < len; i++)
{
memcpy(strbuf + stroff, &tmpbuf[arr[i].entry.pos], arr[i].entry.len);
arr[i].entry.pos = stroff;
stroff += arr[i].entry.len;
if (arr[i].entry.haspos)
{
/* This should be unreachable because of MAXNUMPOS restrictions */
if (arr[i].poslen > 0xFFFF)
elog(ERROR, "positions array too long");
/* Copy number of positions */
stroff = SHORTALIGN(stroff);
*(uint16 *) (strbuf + stroff) = (uint16) arr[i].poslen;
stroff += sizeof(uint16);
/* Copy positions */
memcpy(strbuf + stroff, arr[i].pos, arr[i].poslen * sizeof(WordEntryPos));
stroff += arr[i].poslen * sizeof(WordEntryPos);
pfree(arr[i].pos);
}
inarr[i] = arr[i].entry;
}
Assert((strbuf + stroff - (char *) in) == totallen);
PG_RETURN_TSVECTOR(in);
}
Datum
tsvectorout(PG_FUNCTION_ARGS)
{
TSVector out = PG_GETARG_TSVECTOR(0);
char *outbuf;
int32 i,
lenbuf = 0,
pp;
WordEntry *ptr = ARRPTR(out);
char *curbegin,
*curin,
*curout;
lenbuf = out->size * 2 /* '' */ + out->size - 1 /* space */ + 2 /* \0 */ ;
for (i = 0; i < out->size; i++)
{
lenbuf += ptr[i].len * 2 * pg_database_encoding_max_length() /* for escape */ ;
if (ptr[i].haspos)
lenbuf += 1 /* : */ + 7 /* int2 + , + weight */ * POSDATALEN(out, &(ptr[i]));
}
curout = outbuf = (char *) palloc(lenbuf);
for (i = 0; i < out->size; i++)
{
curbegin = curin = STRPTR(out) + ptr->pos;
if (i != 0)
*curout++ = ' ';
*curout++ = '\'';
while (curin - curbegin < ptr->len)
{
int len = pg_mblen(curin);
if (t_iseq(curin, '\''))
*curout++ = '\'';
else if (t_iseq(curin, '\\'))
*curout++ = '\\';
while (len--)
*curout++ = *curin++;
}
*curout++ = '\'';
if ((pp = POSDATALEN(out, ptr)) != 0)
{
WordEntryPos *wptr;
*curout++ = ':';
wptr = POSDATAPTR(out, ptr);
while (pp)
{
curout += sprintf(curout, "%d", WEP_GETPOS(*wptr));
switch (WEP_GETWEIGHT(*wptr))
{
case 3:
*curout++ = 'A';
break;
case 2:
*curout++ = 'B';
break;
case 1:
*curout++ = 'C';
break;
case 0:
default:
break;
}
if (pp > 1)
*curout++ = ',';
pp--;
wptr++;
}
}
ptr++;
}
*curout = '\0';
PG_FREE_IF_COPY(out, 0);
PG_RETURN_CSTRING(outbuf);
}
/*
* Binary Input / Output functions. The binary format is as follows:
*
* uint32 number of lexemes
*
* for each lexeme:
* lexeme text in client encoding, null-terminated
* uint16 number of positions
* for each position:
* uint16 WordEntryPos
*/
Datum
tsvectorsend(PG_FUNCTION_ARGS)
{
TSVector vec = PG_GETARG_TSVECTOR(0);
StringInfoData buf;
int i,
j;
WordEntry *weptr = ARRPTR(vec);
pq_begintypsend(&buf);
pq_sendint32(&buf, vec->size);
for (i = 0; i < vec->size; i++)
{
uint16 npos;
/*
* the strings in the TSVector array are not null-terminated, so we
* have to send the null-terminator separately
*/
pq_sendtext(&buf, STRPTR(vec) + weptr->pos, weptr->len);
pq_sendbyte(&buf, '\0');
npos = POSDATALEN(vec, weptr);
pq_sendint16(&buf, npos);
if (npos > 0)
{
WordEntryPos *wepptr = POSDATAPTR(vec, weptr);
for (j = 0; j < npos; j++)
pq_sendint16(&buf, wepptr[j]);
}
weptr++;
}
PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
}
Datum
tsvectorrecv(PG_FUNCTION_ARGS)
{
StringInfo buf = (StringInfo) PG_GETARG_POINTER(0);
TSVector vec;
int i;
int32 nentries;
int datalen; /* number of bytes used in the variable size
* area after fixed size TSVector header and
* WordEntries */
Size hdrlen;
Size len; /* allocated size of vec */
bool needSort = false;
nentries = pq_getmsgint(buf, sizeof(int32));
if (nentries < 0 || nentries > (MaxAllocSize / sizeof(WordEntry)))
elog(ERROR, "invalid size of tsvector");
hdrlen = DATAHDRSIZE + sizeof(WordEntry) * nentries;
len = hdrlen * 2; /* times two to make room for lexemes */
vec = (TSVector) palloc0(len);
vec->size = nentries;
datalen = 0;
for (i = 0; i < nentries; i++)
{
const char *lexeme;
uint16 npos;
size_t lex_len;
lexeme = pq_getmsgstring(buf);
npos = (uint16) pq_getmsgint(buf, sizeof(uint16));
/* sanity checks */
lex_len = strlen(lexeme);
if (lex_len > MAXSTRLEN)
elog(ERROR, "invalid tsvector: lexeme too long");
if (datalen > MAXSTRPOS)
elog(ERROR, "invalid tsvector: maximum total lexeme length exceeded");
if (npos > MAXNUMPOS)
elog(ERROR, "unexpected number of tsvector positions");
/*
* Looks valid. Fill the WordEntry struct, and copy lexeme.
*
* But make sure the buffer is large enough first.
*/
while (hdrlen + SHORTALIGN(datalen + lex_len) +
sizeof(uint16) + npos * sizeof(WordEntryPos) >= len)
{
len *= 2;
vec = (TSVector) repalloc(vec, len);
}
vec->entries[i].haspos = (npos > 0) ? 1 : 0;
vec->entries[i].len = lex_len;
vec->entries[i].pos = datalen;
memcpy(STRPTR(vec) + datalen, lexeme, lex_len);
datalen += lex_len;
if (i > 0 && WordEntryCMP(&vec->entries[i],
&vec->entries[i - 1],
STRPTR(vec)) <= 0)
needSort = true;
/* Receive positions */
if (npos > 0)
{
uint16 j;
WordEntryPos *wepptr;
/*
* Pad to 2-byte alignment if necessary. Though we used palloc0
* for the initial allocation, subsequent repalloc'd memory areas
* are not initialized to zero.
*/
if (datalen != SHORTALIGN(datalen))
{
*(STRPTR(vec) + datalen) = '\0';
datalen = SHORTALIGN(datalen);
}
memcpy(STRPTR(vec) + datalen, &npos, sizeof(uint16));
wepptr = POSDATAPTR(vec, &vec->entries[i]);
for (j = 0; j < npos; j++)
{
wepptr[j] = (WordEntryPos) pq_getmsgint(buf, sizeof(WordEntryPos));
if (j > 0 && WEP_GETPOS(wepptr[j]) <= WEP_GETPOS(wepptr[j - 1]))
elog(ERROR, "position information is misordered");
}
datalen += sizeof(uint16) + npos * sizeof(WordEntryPos);
}
}
SET_VARSIZE(vec, hdrlen + datalen);
if (needSort)
qsort_arg(ARRPTR(vec), vec->size, sizeof(WordEntry),
compareentry, STRPTR(vec));
PG_RETURN_TSVECTOR(vec);
}
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