/*-------------------------------------------------------------------------

 *

 * tsvector.c

 *    I/O functions for tsvector

 *

 * Portions Copyright (c) 1996-2026, 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/fmgrprotos.h"

#include "utils/memutils.h"

#include "varatt.h"

typedef struct

{

  WordEntry entry;      /* must be first, see compareentry */

  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 WordEntry structs for qsort_arg.  This can also be used on

 * WordEntryIN structs, since those have WordEntry as their first field.

 */

static int

compareentry(const void *va, const void *vb, void *arg)

{

  const WordEntry *a = (const WordEntry *) va;

  const WordEntry *b = (const WordEntry *) vb;

  char     *BufferStr = (char *) arg;

  return tsCompareString(&BufferStr[a->pos], a->len,

               &BufferStr[b->pos], b->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 = repalloc_array(res->pos, WordEntryPos, newlen);

        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;

}

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 = palloc_array(WordEntryIN, arrlen);

  cur = tmpbuf = palloc_array(char, 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 (%d bytes, max %d bytes)",

              toklen,

              MAXSTRLEN)));

    if (cur - tmpbuf > MAXSTRPOS)

      ereturn(escontext, (Datum) 0,

          (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),

           errmsg("string is too long for tsvector (%zu bytes, max %zu bytes)",

              (size_t) (cur - tmpbuf), (size_t) MAXSTRPOS)));

    /*

     * Enlarge buffers if needed

     */

    if (len >= arrlen)

    {

      arrlen *= 2;

      arr = repalloc_array(arr, 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 (%zu bytes, max %zu bytes)",

            (size_t) buflen, (size_t) 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,

        pp;

  size_t    lenbuf;

  WordEntry  *ptr = ARRPTR(out);

  char     *curin,

         *curout;

  const char *curend;

  lenbuf = out->size * 2 /* '' */ + out->size - 1 /* space */ + 2 /* \0 */ ;

  for (i = 0; i < out->size; i++)

  {

    lenbuf += ptr[i].len * 2 /* allow for escapes */ ;

    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++)

  {

    curin = STRPTR(out) + ptr->pos;

    curend = curin + ptr->len;

    if (i != 0)

      *curout++ = ' ';

    *curout++ = '\'';

    while (curin < curend)

    {

      int     len = pg_mblen_range(curin, curend);

      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));

  /* We disallow empty lexemes, so more than MAXSTRPOS of them can't fit */

  if (nentries < 0 || nentries > MAXSTRPOS)

    elog(ERROR, "invalid size of tsvector");

  hdrlen = DATAHDRSIZE + sizeof(WordEntry) * nentries;

  len = hdrlen * 2;     /* times two to make some 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 == 0)

      elog(ERROR, "invalid tsvector: empty 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 && compareentry(&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);

    }

  }

  /*

   * Enforce that datalen is still within MAXSTRPOS, ie the last lexeme

   * didn't go past that.  We could allow that, since no "pos" field

   * overflowed, but tsvectorrecv shouldn't accept values that other

   * tsvector-constructing routines wouldn't.

   */

  if (datalen > MAXSTRPOS)

    elog(ERROR, "invalid tsvector: maximum total lexeme length exceeded");

  SET_VARSIZE(vec, hdrlen + datalen);

  if (needSort)

    qsort_arg(ARRPTR(vec), vec->size, sizeof(WordEntry),

          compareentry, STRPTR(vec));

  PG_RETURN_TSVECTOR(vec);

}