diff options
| author | Robert Haas | 2013-04-11 19:20:24 +0000 |
|---|---|---|
| committer | Robert Haas | 2013-04-11 19:20:24 +0000 |
| commit | ef5409534ea854748a04388905334ae958ae0e66 (patch) | |
| tree | 2804afa2b40c79900c61b18aacb1df13e3aa8178 | |
| parent | 8cbbdddac18d5aaf9546342291fa9a20de4deee8 (diff) | |
Avoid PG_TRY/PG_CATCH overhead if stringinfo is already large enough.copy_hack
| -rw-r--r-- | src/backend/libpq/pqcomm.c | 25 | ||||
| -rw-r--r-- | src/include/lib/stringinfo.h | 7 |
2 files changed, 21 insertions, 11 deletions
diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c index d9dda21d93..b0406bba46 100644 --- a/src/backend/libpq/pqcomm.c +++ b/src/backend/libpq/pqcomm.c @@ -1131,19 +1131,22 @@ pq_getmessage(StringInfo s, int maxlen) * large message), we will elog(ERROR), but we want to discard the * message body so as not to lose communication sync. */ - PG_TRY(); + if (!isStringInfoLargeEnough(s, len)) { - enlargeStringInfo(s, len); - } - PG_CATCH(); - { - if (pq_discardbytes(len) == EOF) - ereport(COMMERROR, - (errcode(ERRCODE_PROTOCOL_VIOLATION), - errmsg("incomplete message from client"))); - PG_RE_THROW(); + PG_TRY(); + { + enlargeStringInfo(s, len); + } + PG_CATCH(); + { + if (pq_discardbytes(len) == EOF) + ereport(COMMERROR, + (errcode(ERRCODE_PROTOCOL_VIOLATION), + errmsg("incomplete message from client"))); + PG_RE_THROW(); + } + PG_END_TRY(); } - PG_END_TRY(); /* And grab the message */ if (pq_getbytes(s->data, len) == EOF) diff --git a/src/include/lib/stringinfo.h b/src/include/lib/stringinfo.h index ecb693fcc2..f795680777 100644 --- a/src/include/lib/stringinfo.h +++ b/src/include/lib/stringinfo.h @@ -153,4 +153,11 @@ extern void appendBinaryStringInfo(StringInfo str, */ extern void enlargeStringInfo(StringInfo str, int needed); +/*------------------------ + * isStringInfoLargeEnough + * Test whether a StringInfo's buffer can hold at least 'needed' more bytes. + */ +#define isStringInfoLargeEnough(str,needed) \ + ((needed) < (str)->maxlen - ((str)->len + 1)) + #endif /* STRINGINFO_H */ |