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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:00:34 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:00:34 +0000 |
commit | 3f619478f796eddbba6e39502fe941b285dd97b1 (patch) | |
tree | e2c7b5777f728320e5b5542b6213fd3591ba51e2 /sql/rpl_tblmap.h | |
parent | Initial commit. (diff) | |
download | mariadb-upstream.tar.xz mariadb-upstream.zip |
Adding upstream version 1:10.11.6.upstream/1%10.11.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'sql/rpl_tblmap.h')
-rw-r--r-- | sql/rpl_tblmap.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/sql/rpl_tblmap.h b/sql/rpl_tblmap.h new file mode 100644 index 00000000..63bac5e6 --- /dev/null +++ b/sql/rpl_tblmap.h @@ -0,0 +1,112 @@ +/* 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 |