From f0886a4d9dfc36e92f7254c958ec73476704c4d4 Mon Sep 17 00:00:00 2001
From: Luis Soares <luis.soares@sun.com>
Date: Tue, 29 Sep 2009 00:04:20 +0100
Subject: BUG#28777, WL#4293: SHOW BINLOG EVENTS does not work on relay log
 files

NOTE: this is the backport to next-mr.

SHOW BINLOG EVENTS does not work with relay log files. If issuing
"SHOW BINLOG EVENTS IN 'relay-log.000001'" in a non-empty relay
log file (relay-log.000001), mysql reports empty set.

This patch addresses this issue by extending the SHOW command
with RELAYLOG. Events in relay log files can now be inspected by
issuing SHOW RELAYLOG EVENTS [IN 'log_name'] [FROM pos] [LIMIT
[offset,] row_count].

mysql-test/extra/rpl_tests/rpl_show_relaylog_events.inc:
  Shared part of the test case.
mysql-test/include/show_binlog_events.inc:
  Added options $binary_log_file, $binary_log_limit_row,
  $binary_log_limit_offset so that show_binlog_events can take
  same parameters as SHOW BINLOG EVENTS does.
mysql-test/include/show_relaylog_events.inc:
  Clone of show_binlog_events for relaylog events.
mysql-test/suite/rpl/t/rpl_row_show_relaylog_events.test:
  Test case for row based replication.
mysql-test/suite/rpl/t/rpl_stm_mix_show_relaylog_events.test:
  Test case for statement and mixed mode replication.
sql/lex.h:
  Added RELAYLOG symbol.
sql/mysqld.cc:
  Added "show_relaylog_events" to status_vars.
sql/sp_head.cc:
  Set SQLCOM_SHOW_RELAYLOG_EVENTS to return flags=
  sp_head::MULTI_RESULTS; in sp_get_flags_for_command as
  SQLCOM_SHOW_BINLOG_EVENTS does.
sql/sql_lex.h:
  Added sql_command SQLCOM_SHOW_RELAYLOG_EVENTS to lex enum_sql_command.
sql/sql_parse.cc:
  Added handling of SQLCOM_SHOW_RELAYLOG_EVENTS.
sql/sql_repl.cc:
  mysql_show_binlog_events set to choose the log file to use based on
  the command issued (SHOW BINLOG|RELAYLOG EVENTS).
sql/sql_yacc.yy:
  Added RELAYLOG to the grammar.
---
 sql/sql_repl.cc | 37 +++++++++++++++++++++++++++----------
 1 file changed, 27 insertions(+), 10 deletions(-)

(limited to 'sql/sql_repl.cc')

diff --git a/sql/sql_repl.cc b/sql/sql_repl.cc
index 0ec8d91214c..4d9b7410b88 100644
--- a/sql/sql_repl.cc
+++ b/sql/sql_repl.cc
@@ -1401,6 +1401,7 @@ bool mysql_show_binlog_events(THD* thd)
   bool ret = TRUE;
   IO_CACHE log;
   File file = -1;
+  MYSQL_BIN_LOG *binary_log= NULL;
   DBUG_ENTER("mysql_show_binlog_events");
 
   Log_event::init_show_field_list(&field_list);
@@ -1411,14 +1412,30 @@ bool mysql_show_binlog_events(THD* thd)
   Format_description_log_event *description_event= new
     Format_description_log_event(3); /* MySQL 4.0 by default */
 
-  /*
-    Wait for handlers to insert any pending information
-    into the binlog.  For e.g. ndb which updates the binlog asynchronously
-    this is needed so that the uses sees all its own commands in the binlog
-  */
-  ha_binlog_wait(thd);
+  DBUG_ASSERT(thd->lex->sql_command == SQLCOM_SHOW_BINLOG_EVENTS ||
+              thd->lex->sql_command == SQLCOM_SHOW_RELAYLOG_EVENTS);
 
-  if (mysql_bin_log.is_open())
+  /* select wich binary log to use: binlog or relay */
+  if ( thd->lex->sql_command == SQLCOM_SHOW_BINLOG_EVENTS )
+  {
+    /*
+      Wait for handlers to insert any pending information
+      into the binlog.  For e.g. ndb which updates the binlog asynchronously
+      this is needed so that the uses sees all its own commands in the binlog
+    */
+    ha_binlog_wait(thd);
+
+    binary_log= &mysql_bin_log;
+  }
+  else  /* showing relay log contents */
+  {
+    if (!active_mi)
+      DBUG_RETURN(TRUE);
+
+    binary_log= &(active_mi->rli.relay_log);
+  }
+
+  if (binary_log->is_open())
   {
     LEX_MASTER_INFO *lex_mi= &thd->lex->mi;
     SELECT_LEX_UNIT *unit= &thd->lex->unit;
@@ -1426,7 +1443,7 @@ bool mysql_show_binlog_events(THD* thd)
     my_off_t pos = max(BIN_LOG_HEADER_SIZE, lex_mi->pos); // user-friendly
     char search_file_name[FN_REFLEN], *name;
     const char *log_file_name = lex_mi->log_file_name;
-    pthread_mutex_t *log_lock = mysql_bin_log.get_log_lock();
+    pthread_mutex_t *log_lock = binary_log->get_log_lock();
     LOG_INFO linfo;
     Log_event* ev;
 
@@ -1436,13 +1453,13 @@ bool mysql_show_binlog_events(THD* thd)
 
     name= search_file_name;
     if (log_file_name)
-      mysql_bin_log.make_log_name(search_file_name, log_file_name);
+      binary_log->make_log_name(search_file_name, log_file_name);
     else
       name=0;					// Find first log
 
     linfo.index_file_offset = 0;
 
-    if (mysql_bin_log.find_log_pos(&linfo, name, 1))
+    if (binary_log->find_log_pos(&linfo, name, 1))
     {
       errmsg = "Could not find target log";
       goto err;
-- 
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