diff options
Diffstat (limited to 'sql/sql_cache.cc')
| -rw-r--r-- | sql/sql_cache.cc | 40 |
1 files changed, 34 insertions, 6 deletions
diff --git a/sql/sql_cache.cc b/sql/sql_cache.cc index 8631a13eae7..98d98c1696e 100644 --- a/sql/sql_cache.cc +++ b/sql/sql_cache.cc @@ -1,4 +1,5 @@ -/* Copyright 2000-2008 MySQL AB, 2008 Sun Microsystems, Inc. +/* + Copyright (c) 2000, 2010, Oracle and/or its affiliates. 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 @@ -11,7 +12,8 @@ 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +*/ /* Description of the query cache: @@ -1471,7 +1473,8 @@ def_week_frmt: %lu, in_trans: %d, autocommit: %d", /* Key is query + database + flag */ if (thd->db_length) { - memcpy((char*) (query + query_length + 1), thd->db, thd->db_length); + memcpy((char*) (query + query_length + 1 + sizeof(size_t)), thd->db, + thd->db_length); DBUG_PRINT("qcache", ("database: %s length: %u", thd->db, (unsigned) thd->db_length)); } @@ -1479,7 +1482,7 @@ def_week_frmt: %lu, in_trans: %d, autocommit: %d", { DBUG_PRINT("qcache", ("No active database")); } - tot_length= query_length + thd->db_length + 1 + + tot_length= query_length + thd->db_length + 1 + sizeof(size_t) + QUERY_CACHE_FLAGS_SIZE; /* We should only copy structure (don't use it location directly) @@ -1740,7 +1743,29 @@ Query_cache::send_result_to_client(THD *thd, char *org_sql, uint query_length) DBUG_PRINT("qcache", ("The statement has a SQL_NO_CACHE directive")); goto err; } + { + /* + We have allocated buffer space (in alloc_query) to hold the + SQL statement(s) + the current database name + a flags struct. + If the database name has changed during execution, which might + happen if there are multiple statements, we need to make + sure the new current database has a name with the same length + as the previous one. + */ + size_t db_len; + memcpy((char *) &db_len, (sql + query_length + 1), sizeof(size_t)); + if (thd->db_length != db_len) + { + /* + We should probably reallocate the buffer in this case, + but for now we just leave it uncached + */ + DBUG_PRINT("qcache", + ("Current database has changed since start of query")); + goto err; + } + } /* Try to obtain an exclusive lock on the query cache. If the cache is disabled or if a full cache flush is in progress, the attempt to @@ -1774,10 +1799,13 @@ Query_cache::send_result_to_client(THD *thd, char *org_sql, uint query_length) thd->base_query.set(sql, query_length, system_charset_info); } - tot_length= query_length + thd->db_length + 1 + QUERY_CACHE_FLAGS_SIZE; + tot_length= query_length + 1 + sizeof(size_t) + + thd->db_length + QUERY_CACHE_FLAGS_SIZE; + if (thd->db_length) { - memcpy((char*) (sql+query_length+1), thd->db, thd->db_length); + memcpy((char*) (sql+query_length+1+ sizeof(size_t)), thd->db, + thd->db_length); DBUG_PRINT("qcache", ("database: '%s' length: %u", thd->db, (unsigned)thd->db_length)); } |