pgpool2.git / summary / log / commit / refs

commit    062c2de1f916b19eff266b197787fe5e89aa6083
Author:   Tatsuo Ishii <ishii@sraoss.co.jp>
Date:     Wed Apr 17 13:11:00 2019 +0000

    Fix "not enough space in buffer" error.
    
    The error occurred while processing error message returned from
    backend and the cause is that the query string in question is too
    big. Problem is, the buffer is in fixed size (8192 bytes). From the
    programming point of view there's absolutely no need to use fixed size
    buffer. So eliminate the fixed size buffer and use palloced buffer
    instead. This also saves some memory copy work.
    
    Per bug 499.


 src/protocol/pool_process_query.c | 59 ++++++++++++++-------------------------
 1 file changed, 21 insertions(+), 38 deletions(-)

diff --git a/src/protocol/pool_process_query.c b/src/protocol/pool_process_query.c
index cfa0e2103..32c49cb55 100644
--- a/src/protocol/pool_process_query.c
+++ b/src/protocol/pool_process_query.c
@@ -4216,26 +4216,20 @@ detect_idle_in_transaction_sesion_timeout_error(POOL_CONNECTION * backend, int m
 
 /*
  * extract_message: extract specified error by an error code.
- * returns 0 in case of sucess or 1 in case of specified error.
- * throws an ereport for all other errors.
+ * returns 0 in case of success or 1 in case of specified error.
+ * throw an ereport for all other errors.
  */
 static int
 extract_message(POOL_CONNECTION * backend, char *error_code, int major, char class, bool unread)
 {
 	int			is_error = 0;
 	char		kind;
-	int			readlen = 0,
-				len;
-	static char buf[8192];		/* memory space is large enough */
-	char	   *p,
-			   *str;
+	int			len;
+	int			nlen = 0;
+	char		*str = NULL;
 
 	if (pool_read(backend, &kind, sizeof(kind)))
 		return -1;
-	readlen += sizeof(kind);
-	p = buf;
-	memcpy(p, &kind, sizeof(kind));
-	p += sizeof(kind);
 
 	ereport(DEBUG5,
 			(errmsg("extract_message: kind: %c", kind)));
@@ -4249,28 +4243,16 @@ extract_message(POOL_CONNECTION * backend, char *error_code, int major, char cla
 		{
 			char	   *e;
 
-			if (pool_read(backend, &len, sizeof(len)) < 0)
+			if (pool_read(backend, &nlen, sizeof(nlen)) < 0)
 				return -1;
-			readlen += sizeof(len);
-			memcpy(p, &len, sizeof(len));
-			p += sizeof(len);
 
-			len = ntohl(len) - 4;
+			len = ntohl(nlen) - 4;
 			str = palloc(len);
-
 			pool_read(backend, str, len);
-			readlen += len;
-
-			if (readlen >= sizeof(buf))
-				ereport(ERROR,
-						(errmsg("unable to extract message"),
-						 errdetail("not enough space in buffer")));
-
-			memcpy(p, str, len);
 
 			/*
-			 * Checks error code which is formatted 'Cxxxxxx' (xxxxxx is error
-			 * code).
+			 * Check error code which is formatted 'Cxxxxxx' (xxxxxx is the
+			 * error code).
 			 */
 			e = str;
 			while (*e)
@@ -4283,27 +4265,28 @@ extract_message(POOL_CONNECTION * backend, char *error_code, int major, char cla
 				else
 					e = e + strlen(e) + 1;
 			}
-			pfree(str);
 		}
 		else
 		{
 			str = pool_read_string(backend, &len, 0);
-			readlen += len;
-
-			if (readlen >= sizeof(buf))
-				ereport(ERROR,
-						(errmsg("unable to extract message"),
-						 errdetail("not enough space in buffer")));
-
-			memcpy(p, str, len);
 		}
 	}
+
 	if (unread || !is_error)
 	{
-		/* put a message to read buffer */
-		pool_unread(backend, buf, readlen);
+		/* put back  message to read buffer */
+		if (str)
+		{
+			pool_unread(backend, str, len);
+		}
+		if (nlen != 0)
+			pool_unread(backend, &nlen, sizeof(nlen));
+		pool_unread(backend, &kind, sizeof(kind));
 	}
 
+	if (str)
+		pfree(str);
+
 	return is_error;
 }
 


[parent: daa530a75b8a]