Scanner performance improvements

Use flex flags -CF.  Pass the to-be-scanned string around as StringInfo
type, to avoid querying the length repeatedly.  Clean up some code and
remove lex-compatibility cruft.  Escape backslash sequences inline.  Use
flex-provided yy_scan_buffer() function to set up input, rather than using
myinput().

1 files changed, 4 insertions, 14 deletions

diff --git a/src/backend/parser/parser.c b/src/backend/parser/parser.c
index f83d04e69cc..4eadbef5f44 100644
--- a/src/backend/parser/parser.c
+++ b/src/backend/parser/parser.c
@@ -14,7 +14,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parser.c,v 1.51 2001/11/05 17:46:26 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parser.c,v 1.52 2002/04/20 21:56:14 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -28,12 +28,6 @@
 #include "parser/parse_expr.h"
 
 
-#if defined(FLEX_SCANNER)
-extern void DeleteBuffer(void);
-#endif   /* FLEX_SCANNER */
-
-char	   *parseString;		/* the char* which holds the string to be
-								 * parsed */
 List	   *parsetree;			/* result of parsing is left here */
 
 static int	lookahead_token;	/* one-token lookahead */
@@ -48,24 +42,20 @@ static bool have_lookahead;		/* lookahead_token set? */
  * Returns a list of raw (un-analyzed) parse trees.
  */
 List *
-parser(char *str, Oid *typev, int nargs)
+parser(StringInfo str, Oid *typev, int nargs)
 {
 	int			yyresult;
 
-	parseString = str;
 	parsetree = NIL;			/* in case parser forgets to set it */
 	have_lookahead = false;
 
-	scanner_init();
+	scanner_init(str);
 	parser_init(typev, nargs);
 	parse_expr_init();
 
 	yyresult = yyparse();
 
-#if defined(FLEX_SCANNER)
-	DeleteBuffer();
-#endif   /* FLEX_SCANNER */
-
+	scanner_finish();
 	clearerr(stdin);
 
 	if (yyresult)				/* error */