From 94e926acdf13fba15c0a1cfe19ea195093e71324 Mon Sep 17 00:00:00 2001
From: "heikki@hundin.mysql.fi" <>
Date: Sat, 22 Jun 2002 20:05:30 +0300
Subject: [PATCH] log.cc, handler.cc: Add BEGIN andd COMMIT around
transactions in the binlog
---
sql/handler.cc | 31 +++++++++++++++++++++++++++++++
sql/log.cc | 40 ++++++++++++++++++++++++++++++++++++----
2 files changed, 67 insertions(+), 4 deletions(-)
diff --git a/sql/handler.cc b/sql/handler.cc
index 098c3130de..564d91aa88 100644
--- a/sql/handler.cc
+++ b/sql/handler.cc
@@ -251,6 +251,7 @@ int ha_autocommit_or_rollback(THD *thd, int error)
}
else
(void) ha_rollback_stmt(thd);
+
thd->tx_isolation=thd->session_tx_isolation;
}
#endif
@@ -309,6 +310,36 @@ int ha_commit_trans(THD *thd, THD_TRANS* trans)
if (trans == &thd->transaction.all && mysql_bin_log.is_open() &&
my_b_tell(&thd->transaction.trans_log))
{
+ /* We write the command "COMMIT" as the last SQL command in the
+ binlog segment cached for this transaction */
+
+ int save_query_length = thd->query_length;
+
+ thd->query_length = 6; /* length of 'COMMIT'; note that we may come
+ here because a DROP TABLE, for instance,
+ makes an implicit commit, and then
+ thd->query is not 'COMMIT'! */
+
+ Query_log_event qinfo(thd, "COMMIT", TRUE);
+
+ /* When we come here, and the user wrapped the transaction into
+ BEGIN and COMMIT, then qinfo got above the field cache_stmt
+ erroneously set to 0. Let us set it to 1: */
+
+ qinfo.cache_stmt = 1;
+
+ /* Write the 'COMMIT' entry to the cache */
+
+ if (mysql_bin_log.write(&qinfo)) {
+ my_error(ER_ERROR_DURING_COMMIT, MYF(0), 5000);
+ error=1;
+ }
+
+ thd->query_length = save_query_length;
+
+ /* Now we write the binlog segment cached for this transaction to
+ the real binlog */
+
mysql_bin_log.write(thd, &thd->transaction.trans_log);
reinit_io_cache(&thd->transaction.trans_log,
WRITE_CACHE, (my_off_t) 0, 0, 1);
diff --git a/sql/log.cc b/sql/log.cc
index f4284ac6ba..ee5818fc59 100644
--- a/sql/log.cc
+++ b/sql/log.cc
@@ -442,8 +442,8 @@ int MYSQL_LOG::purge_logs(THD* thd, const char* to_log)
#ifdef HAVE_FTRUNCATE
if (ftruncate(index_file,0))
{
- sql_print_error("Could not truncate the binlog index file \
-during log purge for write");
+ sql_print_error(
+"Could not truncate the binlog index file during log purge for write");
error = LOG_INFO_FATAL;
goto err;
}
@@ -455,8 +455,8 @@ during log purge for write");
O_CREAT | O_BINARY | O_RDWR | O_APPEND,
MYF(MY_WME))))
{
- sql_print_error("Could not re-open the binlog index file \
-during log purge for write");
+ sql_print_error(
+"Could not re-open the binlog index file during log purge for write");
error = LOG_INFO_FATAL;
goto err;
}
@@ -661,6 +661,38 @@ bool MYSQL_LOG::write(Query_log_event* event_info)
error=1;
+ if (file == &thd->transaction.trans_log
+ && !my_b_tell(&thd->transaction.trans_log)) {
+
+ /* Add the "BEGIN" and "COMMIT" in the binlog around transactions
+ which may contain more than 1 SQL statement. If we run with
+ AUTOCOMMIT=1, then MySQL immediately writes each SQL statement to
+ the binlog when the statement has been completed. No need to add
+ "BEGIN" ... "COMMIT" around such statements. Otherwise, MySQL uses
+ thd->transaction.trans_log to cache the SQL statements until the
+ explicit commit, and at the commit writes the contents in .trans_log
+ to the binlog.
+
+ We write the "BEGIN" mark first in the buffer (.trans_log) where we
+ store the SQL statements for a transaction. At the transaction commit
+ we will add the "COMMIT mark and write the buffer to the binlog.
+ The function my_b_tell above returns != 0 if there already is data
+ in the buffer. */
+
+ int save_query_length = thd->query_length;
+
+ thd->query_length = 5; /* length of string BEGIN */
+
+ Query_log_event qinfo(thd, "BEGIN", TRUE);
+
+ error = ((&qinfo)->write(file));
+
+ thd->query_length = save_query_length;
+
+ if (error)
+ goto err;
+ }
+
if (thd->last_insert_id_used)
{
Intvar_log_event e((uchar)LAST_INSERT_ID_EVENT, thd->last_insert_id);
--
2.30.9