[MDEV-6877] Added a bitmap compare function for binlog_row_image

The function compares bitmaps according to the binlog_row_image variable
setting.

sql/log_event.h

@@ -4264,9 +4264,58 @@ public:
   virtual int get_data_size();
 
   MY_BITMAP const *get_cols() const { return &m_cols; }
+  MY_BITMAP const *get_cols_ai() const { return &m_cols_ai; }
   size_t get_width() const          { return m_width; }
   ulong get_table_id() const        { return m_table_id; }
 
+#if defined(MYSQL_SERVER)
+  /*
+    This member function compares the table's read/write_set
+    with this event's m_cols and m_cols_ai. Comparison takes
+    into account what type of rows event is this: Delete, Write or
+    Update, therefore it uses the correct m_cols[_ai] according
+    to the event type code.
+
+    Note that this member function should only be called for the
+    following events:
+    - Delete_rows_log_event
+    - Write_rows_log_event
+    - Update_rows_log_event
+
+    @param[IN] table The table to compare this events bitmaps
+                     against.
+
+    @return TRUE if sets match, FALSE otherwise. (following
+                 bitmap_cmp return logic).
+
+   */
+  virtual bool read_write_bitmaps_cmp(TABLE *table)
+  {
+    bool res= FALSE;
+
+    switch (get_general_type_code())
+    {
+      case DELETE_ROWS_EVENT:
+        res= bitmap_cmp(get_cols(), table->read_set);
+        break;
+      case UPDATE_ROWS_EVENT:
+        res= (bitmap_cmp(get_cols(), table->read_set) &&
+              bitmap_cmp(get_cols_ai(), table->write_set));
+        break;
+      case WRITE_ROWS_EVENT:
+        res= bitmap_cmp(get_cols(), table->write_set);
+        break;
+      default:
+        /*
+          We should just compare bitmaps for Delete, Write
+          or Update rows events.
+        */
+        DBUG_ASSERT(0);
+    }
+    return res;
+  }
+#endif
+
 #ifdef MYSQL_SERVER
   virtual bool write_data_header(IO_CACHE *file);
   virtual bool write_data_body(IO_CACHE *file);