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+/* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
+
+#ifndef TABLE_MAPPING_H
+#define TABLE_MAPPING_H
+
+/* Forward declarations */
+#ifndef MYSQL_CLIENT
+struct TABLE;
+#else
+class Table_map_log_event;
+typedef Table_map_log_event TABLE;
+void free_table_map_log_event(TABLE *table);
+#endif
+
+
+/*
+ CLASS table_mapping
+
+ RESPONSIBILITIES
+ The table mapping is used to map table id's to table pointers
+
+ COLLABORATION
+ RELAY_LOG For mapping table id:s to tables when receiving events.
+ */
+
+/*
+ Guilhem to Mats:
+ in the table_mapping class, the memory is allocated and never freed (until
+ destruction). So this is a good candidate for allocating inside a MEM_ROOT:
+ it gives the efficient allocation in chunks (like in expand()). So I have
+ introduced a MEM_ROOT.
+
+ Note that inheriting from Sql_alloc had no effect: it has effects only when
+ "ptr= new table_mapping" is called, and this is never called. And it would
+ then allocate from thd->mem_root which is a highly volatile object (reset
+ from example after executing each query, see dispatch_command(), it has a
+ free_root() at end); as the table_mapping object is supposed to live longer
+ than a query, it was dangerous.
+ A dedicated MEM_ROOT needs to be used, see below.
+*/
+
+#include "hash.h" /* HASH */
+
+class table_mapping {
+
+private:
+ MEM_ROOT m_mem_root;
+
+public:
+
+ enum enum_error {
+ ERR_NO_ERROR = 0,
+ ERR_LIMIT_EXCEEDED,
+ ERR_MEMORY_ALLOCATION
+ };
+
+ table_mapping();
+ ~table_mapping();
+
+ TABLE* get_table(ulonglong table_id);
+
+ int set_table(ulonglong table_id, TABLE* table);
+ int remove_table(ulonglong table_id);
+ void clear_tables();
+ ulong count() const { return m_table_ids.records; }
+
+private:
+ /*
+ This is a POD (Plain Old Data). Keep it that way (we apply offsetof() to
+ it, which only works for PODs)
+ */
+ struct entry {
+ ulonglong table_id;
+ union {
+ TABLE *table;
+ entry *next;
+ };
+ };
+
+ entry *find_entry(ulonglong table_id)
+ {
+ return (entry *) my_hash_search(&m_table_ids,
+ (uchar*)&table_id,
+ sizeof(table_id));
+ }
+ int expand();
+
+ /*
+ Head of the list of free entries; "free" in the sense that it's an
+ allocated entry free for use, NOT in the sense that it's freed
+ memory.
+ */
+ entry *m_free;
+
+ /* Correspondance between an id (a number) and a TABLE object */
+ HASH m_table_ids;
+};
+
+#endif