1 files changed, 103 insertions, 1 deletions

diff --git a/src/backend/tsearch/ts_locale.c b/src/backend/tsearch/ts_locale.c
index dacf7325c6e..73d8ed51de7 100644
--- a/src/backend/tsearch/ts_locale.c
+++ b/src/backend/tsearch/ts_locale.c
@@ -7,15 +7,18 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tsearch/ts_locale.c,v 1.7 2008/01/01 19:45:52 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tsearch/ts_locale.c,v 1.7.2.1 2008/06/18 20:55:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
 
+#include "storage/fd.h"
 #include "tsearch/ts_locale.h"
 #include "tsearch/ts_public.h"
 
+static void tsearch_readline_callback(void *arg);
+
 
 #ifdef TS_USE_WIDE
 
@@ -194,9 +197,108 @@ t_isprint(const char *ptr)
 
 
 /*
+ * Set up to read a file using tsearch_readline().  This facility is
+ * better than just reading the file directly because it provides error
+ * context pointing to the specific line where a problem is detected.
+ *
+ * Expected usage is:
+ *
+ *		tsearch_readline_state trst;
+ *
+ *		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)
+ *			process line;
+ *		tsearch_readline_end(&trst);
+ *
+ * Note that the caller supplies the ereport() for file open failure;
+ * this is so that a custom message can be provided.  The filename string
+ * passed to tsearch_readline_begin() must remain valid through
+ * tsearch_readline_end().
+ */
+bool
+tsearch_readline_begin(tsearch_readline_state *stp,
+					   const char *filename)
+{
+	if ((stp->fp = AllocateFile(filename, "r")) == NULL)
+		return false;
+	stp->filename = filename;
+	stp->lineno = 0;
+	stp->curline = NULL;
+	/* Setup error traceback support for ereport() */
+	stp->cb.callback = tsearch_readline_callback;
+	stp->cb.arg = (void *) stp;
+	stp->cb.previous = error_context_stack;
+	error_context_stack = &stp->cb;
+	return true;
+}
+
+/*
+ * Read the next line from a tsearch data file (expected to be in UTF-8), and
+ * convert it to database encoding if needed. The returned string is palloc'd.
+ * NULL return means EOF.
+ */
+char *
+tsearch_readline(tsearch_readline_state *stp)
+{
+	char	   *result;
+
+	stp->lineno++;
+	stp->curline = NULL;
+	result = t_readline(stp->fp);
+	stp->curline = result;
+	return result;
+}
+
+/*
+ * Close down after reading a file with tsearch_readline()
+ */
+void
+tsearch_readline_end(tsearch_readline_state *stp)
+{
+	FreeFile(stp->fp);
+	/* Pop the error context stack */
+	error_context_stack = stp->cb.previous;
+}
+
+/*
+ * Error context callback for errors occurring while reading a tsearch
+ * configuration file.
+ */
+static void
+tsearch_readline_callback(void *arg)
+{
+	tsearch_readline_state *stp = (tsearch_readline_state *) arg;
+
+	/*
+	 * We can't include the text of the config line for errors that occur
+	 * during t_readline() itself.  This is only partly a consequence of
+	 * our arms-length use of that routine: the major cause of such
+	 * errors is encoding violations, and we daren't try to print error
+	 * messages containing badly-encoded data.
+	 */
+	if (stp->curline)
+		errcontext("line %d of configuration file \"%s\": \"%s\"",
+				   stp->lineno,
+				   stp->filename,
+				   stp->curline);
+	else
+		errcontext("line %d of configuration file \"%s\"",
+				   stp->lineno,
+				   stp->filename);
+}
+
+
+/*
  * Read the next line from a tsearch data file (expected to be in UTF-8), and
  * convert it to database encoding if needed. The returned string is palloc'd.
  * NULL return means EOF.
+ *
+ * Note: direct use of this function is now deprecated.  Go through
+ * tsearch_readline() to provide better error reporting.
  */
 char *
 t_readline(FILE *fp)