MDEV-7145: Delayed replication, intermediate commit.

Initial merge of delayed replication from MySQL git.

The code from the initial push into MySQL is merged, and the
associated test case passes. A number of tasks are still pending:

1. Check full test suite run for any regressions or .result file updates.

2. Extend the feature to also work for parallel replication.

3. There are some todo-comments about future refactoring left from
MySQL, these should be located and merged on top.

4. There are some later related MySQL commits, these should be checked
and merged. These include:
    e134b9362ba0b750d6ac1b444780019622d14aa5
    b38f0f7857c073edfcc0a64675b7f7ede04be00f
    fd2b210383358fe7697f201e19ac9779879ba72a
    afc397376ec50e96b2918ee64e48baf4dda0d37d

5. The testcase from MySQL relies heavily on sleep and timing for
testing, and seems likely to sporadically fail on heavily loaded test
servers in buildbot or distro build farms.

Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

1 files changed, 95 insertions, 53 deletions

diff --git a/sql/sql_binlog.cc b/sql/sql_binlog.cc
index f0465cdf5bf..a7beb42c315 100644
--- a/sql/sql_binlog.cc
+++ b/sql/sql_binlog.cc
@@ -17,18 +17,96 @@
 #include <my_global.h>
 #include "sql_priv.h"
 #include "sql_binlog.h"
-#include "sql_parse.h"                          // check_global_access
-#include "sql_acl.h"                            // *_ACL
+#include "sql_parse.h"
+#include "sql_acl.h"
 #include "rpl_rli.h"
 #include "base64.h"
-#include "slave.h"                              // apply_event_and_update_pos
-#include "log_event.h"                          // Format_description_log_event,
-                                                // EVENT_LEN_OFFSET,
-                                                // EVENT_TYPE_OFFSET,
-                                                // FORMAT_DESCRIPTION_LOG_EVENT,
-                                                // START_EVENT_V3,
-                                                // Log_event_type,
-                                                // Log_event
+#include "slave.h"
+#include "log_event.h"
+
+
+/**
+  Check if the event type is allowed in a BINLOG statement.
+
+  @retval 0 if the event type is ok.
+  @retval 1 if the event type is not ok.
+*/
+static int check_event_type(int type, Relay_log_info *rli)
+{
+  Format_description_log_event *fd_event=
+    rli->relay_log.description_event_for_exec;
+
+  /*
+    Convert event type id of certain old versions (see comment in
+    Format_description_log_event::Format_description_log_event(char*,...)).
+  */
+  if (fd_event && fd_event->event_type_permutation)
+  {
+    IF_DBUG({
+        int new_type= fd_event->event_type_permutation[type];
+        DBUG_PRINT("info",
+                   ("converting event type %d to %d (%s)",
+                    type, new_type,
+                    Log_event::get_type_str((Log_event_type)new_type)));
+      },
+      (void)0);
+    type= fd_event->event_type_permutation[type];
+  }
+
+  switch (type)
+  {
+  case START_EVENT_V3:
+  case FORMAT_DESCRIPTION_EVENT:
+    /*
+      We need a preliminary FD event in order to parse the FD event,
+      if we don't already have one.
+    */
+    if (!fd_event)
+      if (!(rli->relay_log.description_event_for_exec=
+            new Format_description_log_event(4)))
+      {
+        my_error(ER_OUTOFMEMORY, MYF(0), 1);
+        return 1;
+      }
+
+    /* It is always allowed to execute FD events. */
+    return 0;
+    
+  case TABLE_MAP_EVENT:
+  case WRITE_ROWS_EVENT:
+  case UPDATE_ROWS_EVENT:
+  case DELETE_ROWS_EVENT:
+  case PRE_GA_WRITE_ROWS_EVENT:
+  case PRE_GA_UPDATE_ROWS_EVENT:
+  case PRE_GA_DELETE_ROWS_EVENT:
+    /*
+      Row events are only allowed if a Format_description_event has
+      already been seen.
+    */
+    if (fd_event)
+      return 0;
+    else
+    {
+      my_error(ER_NO_FORMAT_DESCRIPTION_EVENT_BEFORE_BINLOG_STATEMENT,
+               MYF(0), Log_event::get_type_str((Log_event_type)type));
+      return 1;
+    }
+    break;
+
+  default:
+    /*
+      It is not meaningful to execute other events than row-events and
+      FD events. It would even be dangerous to execute Stop_log_event
+      and Rotate_log_event since they call flush_relay_log_info, which
+      is not allowed to call by other threads than the slave SQL
+      thread when the slave SQL thread is running.
+    */
+    my_error(ER_ONLY_FD_AND_RBR_EVENTS_ALLOWED_IN_BINLOG_STATEMENT,
+             MYF(0), Log_event::get_type_str((Log_event_type)type));
+    return 1;
+  }
+}
+
 /**
   Execute a BINLOG statement.
 
@@ -73,31 +151,13 @@ void mysql_client_binlog_statement(THD* thd)
     Allocation
   */
 
-  /*
-    If we do not have a Format_description_event, we create a dummy
-    one here.  In this case, the first event we read must be a
-    Format_description_event.
-  */
-  my_bool have_fd_event= TRUE;
   int err;
   Relay_log_info *rli;
   rpl_group_info *rgi;
 
   rli= thd->rli_fake;
-  if (!rli)
-  {
-    rli= thd->rli_fake= new Relay_log_info(FALSE);
-#ifdef HAVE_valgrind
-    rli->is_fake= TRUE;
-#endif
-    have_fd_event= FALSE;
-  }
-  if (rli && !rli->relay_log.description_event_for_exec)
-  {
-    rli->relay_log.description_event_for_exec=
-      new Format_description_log_event(4);
-    have_fd_event= FALSE;
-  }
+  if (!rli && (rli= thd->rli_fake= new Relay_log_info(FALSE)))
+    rli->sql_driver_thd= thd;
   if (!(rgi= thd->rgi_fake))
     rgi= thd->rgi_fake= new rpl_group_info(rli);
   rgi->thd= thd;
@@ -109,16 +169,13 @@ void mysql_client_binlog_statement(THD* thd)
   /*
     Out of memory check
   */
-  if (!(rli &&
-        rli->relay_log.description_event_for_exec &&
-        buf))
+  if (!(rli && buf))
   {
     my_error(ER_OUTOFMEMORY, MYF(ME_FATALERROR), 1);  /* needed 1 bytes */
     goto end;
   }
 
-  rli->sql_driver_thd= thd;
-  rli->no_storage= TRUE;
+  DBUG_ASSERT(rli->belongs_to_client());
 
   for (char const *strptr= thd->lex->comment.str ;
        strptr < thd->lex->comment.str + thd->lex->comment.length ; )
@@ -185,23 +242,8 @@ void mysql_client_binlog_statement(THD* thd)
       DBUG_PRINT("info", ("event_len=%lu, bytes_decoded=%d",
                           event_len, bytes_decoded));
 
-      /*
-        If we have not seen any Format_description_event, then we must
-        see one; it is the only statement that can be read in base64
-        without a prior Format_description_event.
-      */
-      if (!have_fd_event)
-      {
-        int type = (uchar)bufptr[EVENT_TYPE_OFFSET];
-        if (type == FORMAT_DESCRIPTION_EVENT || type == START_EVENT_V3)
-          have_fd_event= TRUE;
-        else
-        {
-          my_error(ER_NO_FORMAT_DESCRIPTION_EVENT_BEFORE_BINLOG_STATEMENT,
-                   MYF(0), Log_event::get_type_str((Log_event_type)type));
-          goto end;
-        }
-      }
+      if (check_event_type(bufptr[EVENT_TYPE_OFFSET], rli))
+        goto end;
 
       ev= Log_event::read_log_event(bufptr, event_len, &error,
                                     rli->relay_log.description_event_for_exec,
@@ -212,7 +254,7 @@ void mysql_client_binlog_statement(THD* thd)
       {
         /*
           This could actually be an out-of-memory, but it is more likely
-          causes by a bad statement
+          caused by a bad statement
         */
         my_error(ER_SYNTAX_ERROR, MYF(0));
         goto end;