BUG#31581: 5.1-telco-6.1 -> 5.1.22. Slave crashes during starting

This patch has two purposes:
(1) To refactor the code so that
   {Write|Update|Delete}_rows_log_event_old does not use code from
   {Write|Update|Delete}_rows_log_event. Before refactoring there
   was the following problem: whenever we modifed the code for new
   events, it affected the old events. This is bad, as it makes
   maintainance difficult. After refactoring, we can safely edit the
   new code without affecting old events. So, if we for instance
   modify the binary format of new events, we no longer need to worry
   about how the new code reads old events.
(2) To fix BUG#31581.

These two objectives are reached by the following changes:
 - Merged Rows_log_event into Old_rows_log_event and
   {Write|Update|Delete}_rows_log_event into
   {Write|Update|Delete}_rows_log_event_old.
 - Fixed the bug by replacing {WRITE|UPDATE|DELETE}_ROWS_EVENT by
   PRE_GA_{WRITE|UPDATE|DELETE}_ROWS_EVENT.
 - Added comments to log_event_old.h

(This patch is identical to the previously committed patch which was
a collapse of three changesets, except that it adds assert(0) to
constructors for old types of row log events that should never be
called.)


sql/log_event_old.cc:
  Merged Rows_log_event into Old_rows_log_event and
  {Write|Update|Delete}_rows_log_event into
  {Write|Update|Delete}_rows_log_event_old. Also fixed the bug by
  replacing {WRITE|UPDATE|DELETE}_ROWS_EVENT by
  PRE_GA_{WRITE|UPDATE|DELETE}_ROWS_EVENT.
sql/log_event_old.h:
  Merged Rows_log_event into Old_rows_log_event and
  {Write|Update|Delete}_rows_log_event into
  {Write|Update|Delete}_rows_log_event_old. Also added comment
  explaining what the file contains and what the classes do.

1 files changed, 406 insertions, 61 deletions

diff --git a/sql/log_event_old.h b/sql/log_event_old.h
index 81e55097905..efb2be29ee4 100644
--- a/sql/log_event_old.h
+++ b/sql/log_event_old.h
@@ -20,18 +20,269 @@
   Need to include this file at the proper position of log_event.h
  */
 
+
+/**
+  @file
+
+  @brief This file contains classes handling old formats of row-based
+  binlog events.
+*/
+/*
+  Around 2007-10-31, I made these classes completely separated from
+  the new classes (before, there was a complex class hierarchy
+  involving multiple inheritance; see BUG#31581), by simply copying
+  and pasting the entire contents of Rows_log_event into
+  Old_rows_log_event and the entire contents of
+  {Write|Update|Delete}_rows_log_event into
+  {Write|Update|Delete}_rows_log_event_old.  For clarity, I will keep
+  the comments marking which code was cut-and-pasted for some time.
+  With the classes collapsed into one, there is probably some
+  redundancy (maybe some methods can be simplified and/or removed),
+  but we keep them this way for now.  /Sven
+*/
+
+
+/**
+  @class Old_rows_log_event
   
-class Old_rows_log_event
+  Base class for the three types of row-based events
+  {Write|Update|Delete}_row_log_event_old, with event type codes
+  PRE_GA_{WRITE|UPDATE|DELETE}_ROWS_EVENT.  These events are never
+  created any more, except when reading a relay log created by an old
+  server.
+*/
+class Old_rows_log_event : public Log_event
 {
- public:
- 
-  virtual ~Old_rows_log_event() {}
+  /********** BEGIN CUT & PASTE FROM Rows_log_event **********/
+public:
+  /**
+     Enumeration of the errors that can be returned.
+   */
+  enum enum_error
+  {
+    ERR_OPEN_FAILURE = -1,               /**< Failure to open table */
+    ERR_OK = 0,                                 /**< No error */
+    ERR_TABLE_LIMIT_EXCEEDED = 1,      /**< No more room for tables */
+    ERR_OUT_OF_MEM = 2,                         /**< Out of memory */
+    ERR_BAD_TABLE_DEF = 3,     /**< Table definition does not match */
+    ERR_RBR_TO_SBR = 4  /**< daisy-chanining RBR to SBR not allowed */
+  };
+
+  /*
+    These definitions allow you to combine the flags into an
+    appropriate flag set using the normal bitwise operators.  The
+    implicit conversion from an enum-constant to an integer is
+    accepted by the compiler, which is then used to set the real set
+    of flags.
+  */
+  enum enum_flag
+  {
+    /* Last event of a statement */
+    STMT_END_F = (1U << 0),
+
+    /* Value of the OPTION_NO_FOREIGN_KEY_CHECKS flag in thd->options */
+    NO_FOREIGN_KEY_CHECKS_F = (1U << 1),
+
+    /* Value of the OPTION_RELAXED_UNIQUE_CHECKS flag in thd->options */
+    RELAXED_UNIQUE_CHECKS_F = (1U << 2),
+
+    /** 
+      Indicates that rows in this event are complete, that is contain
+      values for all columns of the table.
+     */
+    COMPLETE_ROWS_F = (1U << 3)
+  };
+
+  typedef uint16 flag_set;
+
+  /* Special constants representing sets of flags */
+  enum 
+  {
+      RLE_NO_FLAGS = 0U
+  };
+
+  virtual ~Old_rows_log_event();
+
+  void set_flags(flag_set flags_arg) { m_flags |= flags_arg; }
+  void clear_flags(flag_set flags_arg) { m_flags &= ~flags_arg; }
+  flag_set get_flags(flag_set flags_arg) const { return m_flags & flags_arg; }
+
+#if !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION)
+  virtual void pack_info(Protocol *protocol);
+#endif
+
+#ifdef MYSQL_CLIENT
+  /* not for direct call, each derived has its own ::print() */
+  virtual void print(FILE *file, PRINT_EVENT_INFO *print_event_info)= 0;
+#endif
+
+#ifndef MYSQL_CLIENT
+  int add_row_data(uchar *data, size_t length)
+  {
+    return do_add_row_data(data,length); 
+  }
+#endif
+
+  /* Member functions to implement superclass interface */
+  virtual int get_data_size();
+
+  MY_BITMAP const *get_cols() const { return &m_cols; }
+  size_t get_width() const          { return m_width; }
+  ulong get_table_id() const        { return m_table_id; }
+
+#ifndef MYSQL_CLIENT
+  virtual bool write_data_header(IO_CACHE *file);
+  virtual bool write_data_body(IO_CACHE *file);
+  virtual const char *get_db() { return m_table->s->db.str; }
+#endif
+  /*
+    Check that malloc() succeeded in allocating memory for the rows
+    buffer and the COLS vector. Checking that an Update_rows_log_event_old
+    is valid is done in the Update_rows_log_event_old::is_valid()
+    function.
+  */
+  virtual bool is_valid() const
+  {
+    return m_rows_buf && m_cols.bitmap;
+  }
+
+  uint     m_row_count;         /* The number of rows added to the event */
+
+protected:
+  /* 
+     The constructors are protected since you're supposed to inherit
+     this class, not create instances of this class.
+  */
+#ifndef MYSQL_CLIENT
+  Old_rows_log_event(THD*, TABLE*, ulong table_id,
+                     MY_BITMAP const *cols, bool is_transactional);
+#endif
+  Old_rows_log_event(const char *row_data, uint event_len,
+                     Log_event_type event_type,
+                     const Format_description_log_event *description_event);
+
+#ifdef MYSQL_CLIENT
+  void print_helper(FILE *, PRINT_EVENT_INFO *, char const *const name);
+#endif
 
+#ifndef MYSQL_CLIENT
+  virtual int do_add_row_data(uchar *data, size_t length);
+#endif
+
+#ifndef MYSQL_CLIENT
+  TABLE *m_table;		/* The table the rows belong to */
+#endif
+  ulong       m_table_id;	/* Table ID */
+  MY_BITMAP   m_cols;		/* Bitmap denoting columns available */
+  ulong       m_width;          /* The width of the columns bitmap */
+  /*
+    Bitmap for columns available in the after image, if present. These
+    fields are only available for Update_rows events. Observe that the
+    width of both the before image COLS vector and the after image
+    COLS vector is the same: the number of columns of the table on the
+    master.
+  */
+  MY_BITMAP   m_cols_ai;
+
+  ulong       m_master_reclength; /* Length of record on master side */
+
+  /* Bit buffers in the same memory as the class */
+  uint32    m_bitbuf[128/(sizeof(uint32)*8)];
+  uint32    m_bitbuf_ai[128/(sizeof(uint32)*8)];
+
+  uchar    *m_rows_buf;		/* The rows in packed format */
+  uchar    *m_rows_cur;		/* One-after the end of the data */
+  uchar    *m_rows_end;		/* One-after the end of the allocated space */
+
+  flag_set m_flags;		/* Flags for row-level events */
+
+  /* helper functions */
+
+#if !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION)
+  const uchar *m_curr_row;     /* Start of the row being processed */
+  const uchar *m_curr_row_end; /* One-after the end of the current row */
+  uchar    *m_key;      /* Buffer to keep key value during searches */
+
+  int find_row(const Relay_log_info *const);
+  int write_row(const Relay_log_info *const, const bool);
+
+  // Unpack the current row into m_table->record[0]
+  int unpack_current_row(const Relay_log_info *const rli)
+  { 
+    DBUG_ASSERT(m_table);
+    ASSERT_OR_RETURN_ERROR(m_curr_row < m_rows_end, HA_ERR_CORRUPT_EVENT);
+    int const result= ::unpack_row(rli, m_table, m_width, m_curr_row, &m_cols,
+                                   &m_curr_row_end, &m_master_reclength);
+    ASSERT_OR_RETURN_ERROR(m_curr_row_end <= m_rows_end, HA_ERR_CORRUPT_EVENT);
+    return result;
+  }
+#endif
+
+private:
+
+#if !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION)
+  virtual int do_apply_event(Relay_log_info const *rli);
+  virtual int do_update_pos(Relay_log_info *rli);
+  virtual enum_skip_reason do_shall_skip(Relay_log_info *rli);
+
+  /*
+    Primitive to prepare for a sequence of row executions.
+
+    DESCRIPTION
+
+      Before doing a sequence of do_prepare_row() and do_exec_row()
+      calls, this member function should be called to prepare for the
+      entire sequence. Typically, this member function will allocate
+      space for any buffers that are needed for the two member
+      functions mentioned above.
+
+    RETURN VALUE
+
+      The member function will return 0 if all went OK, or a non-zero
+      error code otherwise.
+  */
+  virtual 
+  int do_before_row_operations(const Slave_reporting_capability *const log) = 0;
+
+  /*
+    Primitive to clean up after a sequence of row executions.
+
+    DESCRIPTION
+    
+      After doing a sequence of do_prepare_row() and do_exec_row(),
+      this member function should be called to clean up and release
+      any allocated buffers.
+      
+      The error argument, if non-zero, indicates an error which happened during
+      row processing before this function was called. In this case, even if 
+      function is successful, it should return the error code given in the argument.
+  */
+  virtual 
+  int do_after_row_operations(const Slave_reporting_capability *const log,
+                              int error) = 0;
+
+  /*
+    Primitive to do the actual execution necessary for a row.
+
+    DESCRIPTION
+      The member function will do the actual execution needed to handle a row.
+      The row is located at m_curr_row. When the function returns, 
+      m_curr_row_end should point at the next row (one byte after the end
+      of the current row).    
+
+    RETURN VALUE
+      0 if execution succeeded, 1 if execution failed.
+      
+  */
+  virtual int do_exec_row(const Relay_log_info *const rli) = 0;
+#endif /* !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION) */
+
+  /********** END OF CUT & PASTE FROM Rows_log_event **********/
  protected:
   
 #if !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION)
 
-  int do_apply_event(Rows_log_event*,const Relay_log_info*);
+  int do_apply_event(Old_rows_log_event*,const Relay_log_info*);
 
   /*
     Primitive to prepare for a sequence of row executions.
@@ -100,33 +351,61 @@ class Old_rows_log_event
 };
 
 
-class Write_rows_log_event_old 
- : public Write_rows_log_event, public Old_rows_log_event
-{
+/**
+  @class Write_rows_log_event_old
 
+  Old class for binlog events that write new rows to a table (event
+  type code PRE_GA_WRITE_ROWS_EVENT).  Such events are never produced
+  by this version of the server, but they may be read from a relay log
+  created by an old server.  New servers create events of class
+  Write_rows_log_event (event type code WRITE_ROWS_EVENT) instead.
+*/
+class Write_rows_log_event_old : public Old_rows_log_event
+{
+  /********** BEGIN CUT & PASTE FROM Write_rows_log_event **********/
 public:
-  enum
-  {
-    /* Support interface to THD::binlog_prepare_pending_rows_event */
-    TYPE_CODE = PRE_GA_WRITE_ROWS_EVENT
-  };
-
 #if !defined(MYSQL_CLIENT)
-  Write_rows_log_event_old(THD *thd, TABLE *table, ulong table_id,
-                           MY_BITMAP const *cols, bool is_transactional)
-    : Write_rows_log_event(thd, table, table_id, cols, is_transactional)
-  {
-  }
+  Write_rows_log_event_old(THD*, TABLE*, ulong table_id,
+                           MY_BITMAP const *cols, bool is_transactional);
 #endif
-#if defined(HAVE_REPLICATION)
+#ifdef HAVE_REPLICATION
   Write_rows_log_event_old(const char *buf, uint event_len,
-                           const Format_description_log_event *descr)
-    : Write_rows_log_event(buf, event_len, descr)
+                           const Format_description_log_event *description_event);
+#endif
+#if !defined(MYSQL_CLIENT) 
+  static bool binlog_row_logging_function(THD *thd, TABLE *table,
+                                          bool is_transactional,
+                                          MY_BITMAP *cols,
+                                          uint fields,
+                                          const uchar *before_record
+                                          __attribute__((unused)),
+                                          const uchar *after_record)
   {
+    return thd->binlog_write_row(table, is_transactional,
+                                 cols, fields, after_record);
   }
 #endif
 
 private:
+#ifdef MYSQL_CLIENT
+  void print(FILE *file, PRINT_EVENT_INFO *print_event_info);
+#endif
+
+#if !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION)
+  virtual int do_before_row_operations(const Slave_reporting_capability *const);
+  virtual int do_after_row_operations(const Slave_reporting_capability *const,int);
+  virtual int do_exec_row(const Relay_log_info *const);
+#endif
+  /********** END OF CUT & PASTE FROM Write_rows_log_event **********/
+
+public:
+  enum
+  {
+    /* Support interface to THD::binlog_prepare_pending_rows_event */
+    TYPE_CODE = PRE_GA_WRITE_ROWS_EVENT
+  };
+
+private:
   virtual Log_event_type get_type_code() { return (Log_event_type)TYPE_CODE; }
 
 #if !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION)
@@ -145,35 +424,74 @@ private:
 };
 
 
-class Update_rows_log_event_old 
-  : public Update_rows_log_event, public Old_rows_log_event
+/**
+  @class Update_rows_log_event_old
+
+  Old class for binlog events that modify existing rows to a table
+  (event type code PRE_GA_UPDATE_ROWS_EVENT).  Such events are never
+  produced by this version of the server, but they may be read from a
+  relay log created by an old server.  New servers create events of
+  class Update_rows_log_event (event type code UPDATE_ROWS_EVENT)
+  instead.
+*/
+class Update_rows_log_event_old : public Old_rows_log_event
 {
-  uchar *m_after_image, *m_memory;
-  
+  /********** BEGIN CUT & PASTE FROM Update_rows_log_event **********/
 public:
-  enum 
-  {
-    /* Support interface to THD::binlog_prepare_pending_rows_event */
-    TYPE_CODE = PRE_GA_UPDATE_ROWS_EVENT
-  };
+#ifndef MYSQL_CLIENT
+  Update_rows_log_event_old(THD*, TABLE*, ulong table_id,
+                            MY_BITMAP const *cols,
+                            bool is_transactional);
 
-#if !defined(MYSQL_CLIENT)
-  Update_rows_log_event_old(THD *thd, TABLE *table, ulong table_id,
-                           MY_BITMAP const *cols, bool is_transactional)
-    : Update_rows_log_event(thd, table, table_id, cols, is_transactional),
-      m_after_image(NULL), m_memory(NULL)
+  void init(MY_BITMAP const *cols);
+#endif
+
+  virtual ~Update_rows_log_event_old();
+
+#ifdef HAVE_REPLICATION
+  Update_rows_log_event_old(const char *buf, uint event_len,
+                            const Format_description_log_event *description_event);
+#endif
+
+#if !defined(MYSQL_CLIENT) 
+  static bool binlog_row_logging_function(THD *thd, TABLE *table,
+                                          bool is_transactional,
+                                          MY_BITMAP *cols,
+                                          uint fields,
+                                          const uchar *before_record,
+                                          const uchar *after_record)
   {
+    return thd->binlog_update_row(table, is_transactional,
+                                  cols, fields, before_record, after_record);
   }
 #endif
-#if defined(HAVE_REPLICATION)
-  Update_rows_log_event_old(const char *buf, uint event_len, 
-                            const Format_description_log_event *descr)
-    : Update_rows_log_event(buf, event_len, descr),
-      m_after_image(NULL), m_memory(NULL)
+
+  virtual bool is_valid() const
   {
+    return Old_rows_log_event::is_valid() && m_cols_ai.bitmap;
   }
+
+protected:
+#ifdef MYSQL_CLIENT
+  void print(FILE *file, PRINT_EVENT_INFO *print_event_info);
 #endif
 
+#if !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION)
+  virtual int do_before_row_operations(const Slave_reporting_capability *const);
+  virtual int do_after_row_operations(const Slave_reporting_capability *const,int);
+  virtual int do_exec_row(const Relay_log_info *const);
+#endif /* !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION) */
+  /********** END OF CUT & PASTE FROM Update_rows_log_event **********/
+
+  uchar *m_after_image, *m_memory;
+  
+public:
+  enum 
+  {
+    /* Support interface to THD::binlog_prepare_pending_rows_event */
+    TYPE_CODE = PRE_GA_UPDATE_ROWS_EVENT
+  };
+
 private:
   virtual Log_event_type get_type_code() { return (Log_event_type)TYPE_CODE; }
 
@@ -192,9 +510,54 @@ private:
 };
 
 
-class Delete_rows_log_event_old 
-  : public Delete_rows_log_event, public Old_rows_log_event
+/**
+  @class Delete_rows_log_event_old
+
+  Old class for binlog events that delete existing rows from a table
+  (event type code PRE_GA_DELETE_ROWS_EVENT).  Such events are never
+  produced by this version of the server, but they may be read from a
+  relay log created by an old server.  New servers create events of
+  class Delete_rows_log_event (event type code DELETE_ROWS_EVENT)
+  instead.
+*/
+class Delete_rows_log_event_old : public Old_rows_log_event
 {
+  /********** BEGIN CUT & PASTE FROM Update_rows_log_event **********/
+public:
+#ifndef MYSQL_CLIENT
+  Delete_rows_log_event_old(THD*, TABLE*, ulong,
+                            MY_BITMAP const *cols, bool is_transactional);
+#endif
+#ifdef HAVE_REPLICATION
+  Delete_rows_log_event_old(const char *buf, uint event_len,
+                            const Format_description_log_event *description_event);
+#endif
+#if !defined(MYSQL_CLIENT) 
+  static bool binlog_row_logging_function(THD *thd, TABLE *table,
+                                          bool is_transactional,
+                                          MY_BITMAP *cols,
+                                          uint fields,
+                                          const uchar *before_record,
+                                          const uchar *after_record
+                                          __attribute__((unused)))
+  {
+    return thd->binlog_delete_row(table, is_transactional,
+                                  cols, fields, before_record);
+  }
+#endif
+  
+protected:
+#ifdef MYSQL_CLIENT
+  void print(FILE *file, PRINT_EVENT_INFO *print_event_info);
+#endif
+
+#if !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION)
+  virtual int do_before_row_operations(const Slave_reporting_capability *const);
+  virtual int do_after_row_operations(const Slave_reporting_capability *const,int);
+  virtual int do_exec_row(const Relay_log_info *const);
+#endif
+  /********** END CUT & PASTE FROM Delete_rows_log_event **********/
+
   uchar *m_after_image, *m_memory;
  
 public:
@@ -204,23 +567,6 @@ public:
     TYPE_CODE = PRE_GA_DELETE_ROWS_EVENT
   };
 
-#if !defined(MYSQL_CLIENT)
-  Delete_rows_log_event_old(THD *thd, TABLE *table, ulong table_id,
-                           MY_BITMAP const *cols, bool is_transactional)
-    : Delete_rows_log_event(thd, table, table_id, cols, is_transactional),
-      m_after_image(NULL), m_memory(NULL)
-  {
-  }
-#endif
-#if defined(HAVE_REPLICATION)
-  Delete_rows_log_event_old(const char *buf, uint event_len,
-                            const Format_description_log_event *descr)
-    : Delete_rows_log_event(buf, event_len, descr),
-      m_after_image(NULL), m_memory(NULL)
-  {
-  }
-#endif
-
 private:
   virtual Log_event_type get_type_code() { return (Log_event_type)TYPE_CODE; }
 
@@ -240,4 +586,3 @@ private:
 
 
 #endif
-