1 files changed, 146 insertions, 0 deletions
diff --git a/src/backend/tsearch/ts_utils.c b/src/backend/tsearch/ts_utils.c
new file mode 100644
index 0000000..ed16a2e
--- /dev/null
+++ b/src/backend/tsearch/ts_utils.c
@@ -0,0 +1,146 @@
+/*-------------------------------------------------------------------------
+ *
+ * ts_utils.c
+ *		various support functions
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/tsearch/ts_utils.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include <ctype.h>
+
+#include "miscadmin.h"
+#include "tsearch/ts_locale.h"
+#include "tsearch/ts_utils.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 *))
+{
+	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 && !t_isspace(pbuf))
+				pbuf += pg_mblen(pbuf);
+			*pbuf = '\0';
+
+			/* Skip empty lines */
+			if (*line == '\0')
+			{
+				pfree(line);
+				continue;
+			}
+
+			if (s->len >= reallen)
+			{
+				if (reallen == 0)
+				{
+					reallen = 64;
+					stop = (char **) palloc(sizeof(char *) * reallen);
+				}
+				else
+				{
+					reallen *= 2;
+					stop = (char **) repalloc((void *) stop,
+											  sizeof(char *) * reallen);
+				}
+			}
+
+			if (wordop)
+			{
+				stop[s->len] = wordop(line);
+				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)) ? true : false;
+}