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

 *

 * ts_utils.c

 *    various support functions

 *

 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group

 *

 *

 * IDENTIFICATION

 *    src/backend/tsearch/ts_utils.c

 *

 *-------------------------------------------------------------------------

 */

#include "postgres.h"

#include <ctype.h>

#include "catalog/pg_collation_d.h"

#include "miscadmin.h"

#include "tsearch/ts_locale.h"

#include "tsearch/ts_public.h"

/*

 * Given the base name and extension of a tsearch config file, return

 * its full path name.  The base name is assumed to be user-supplied,

 * and is checked to prevent pathname attacks.  The extension is assumed

 * to be safe.

 *

 * The result is a palloc'd string.

 */

char *

get_tsearch_config_filename(const char *basename,

              const char *extension)

{

  char    sharepath[MAXPGPATH];

  char     *result;

  /*

   * We limit the basename to contain a-z, 0-9, and underscores.  This may

   * be overly restrictive, but we don't want to allow access to anything

   * outside the tsearch_data directory, so for instance '/' *must* be

   * rejected, and on some platforms '\' and ':' are risky as well. Allowing

   * uppercase might result in incompatible behavior between case-sensitive

   * and case-insensitive filesystems, and non-ASCII characters create other

   * interesting risks, so on the whole a tight policy seems best.

   */

  if (strspn(basename, "abcdefghijklmnopqrstuvwxyz0123456789_") != strlen(basename))

    ereport(ERROR,

        (errcode(ERRCODE_INVALID_PARAMETER_VALUE),

         errmsg("invalid text search configuration file name \"%s\"",

            basename)));

  get_share_path(my_exec_path, sharepath);

  result = palloc(MAXPGPATH);

  snprintf(result, MAXPGPATH, "%s/tsearch_data/%s.%s",

       sharepath, basename, extension);

  return result;

}

/*

 * Reads a stop-word file. Each word is run through 'wordop'

 * function, if given.  wordop may either modify the input in-place,

 * or palloc a new version.

 */

void

readstoplist(const char *fname, StopList *s, char *(*wordop) (const char *, size_t, Oid))

{

  char    **stop = NULL;

  s->len = 0;

  if (fname && *fname)

  {

    char     *filename = get_tsearch_config_filename(fname, "stop");

    tsearch_readline_state trst;

    char     *line;

    int     reallen = 0;

    if (!tsearch_readline_begin(&trst, filename))

      ereport(ERROR,

          (errcode(ERRCODE_CONFIG_FILE_ERROR),

           errmsg("could not open stop-word file \"%s\": %m",

              filename)));

    while ((line = tsearch_readline(&trst)) != NULL)

    {

      char     *pbuf = line;

      /* Trim trailing space */

      while (*pbuf && !isspace((unsigned char) *pbuf))

        pbuf += pg_mblen_cstr(pbuf);

      *pbuf = '\0';

      /* Skip empty lines */

      if (*line == '\0')

      {

        pfree(line);

        continue;

      }

      if (s->len >= reallen)

      {

        if (reallen == 0)

        {

          reallen = 64;

          stop = palloc_array(char *, reallen);

        }

        else

        {

          reallen *= 2;

          stop = repalloc_array(stop, char *, reallen);

        }

      }

      if (wordop)

      {

        stop[s->len] = wordop(line, strlen(line), DEFAULT_COLLATION_OID);

        if (stop[s->len] != line)

          pfree(line);

      }

      else

        stop[s->len] = line;

      (s->len)++;

    }

    tsearch_readline_end(&trst);

    pfree(filename);

  }

  s->stop = stop;

  /* Sort to allow binary searching */

  if (s->stop && s->len > 0)

    qsort(s->stop, s->len, sizeof(char *), pg_qsort_strcmp);

}

bool

searchstoplist(StopList *s, char *key)

{

  return (s->stop && s->len > 0 &&

      bsearch(&key, s->stop, s->len,

          sizeof(char *), pg_qsort_strcmp));

}