1 files changed, 164 insertions, 0 deletions
diff --git a/storage/maria/ma_keycache.c b/storage/maria/ma_keycache.c
new file mode 100644
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--- /dev/null
+++ b/storage/maria/ma_keycache.c
@@ -0,0 +1,164 @@
+/* Copyright (C) 2006 MySQL AB
+
+   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 Street, Fifth Floor, Boston, MA 02110-1335 USA */
+
+/*
+  Key cache assignments
+*/
+
+#include "maria_def.h"
+
+/*
+  Assign pages of the index file for a table to a key cache
+
+  SYNOPSIS
+    maria_assign_to_pagecache()
+      info          open table
+      key_map       map of indexes to assign to the key cache
+      pagecache_ptr pointer to the key cache handle
+      assign_lock   Mutex to lock during assignment
+
+  PREREQUESTS
+    One must have a READ lock or a WRITE lock on the table when calling
+    the function to ensure that there is no other writers to it.
+
+    The caller must also ensure that one doesn't call this function from
+    two different threads with the same table.
+
+  NOTES
+    At present pages for all indexes must be assigned to the same key cache.
+    In future only pages for indexes specified in the key_map parameter
+    of the table will be assigned to the specified key cache.
+
+  RETURN VALUE
+    0  If a success
+    #  Error code
+*/
+
+int maria_assign_to_pagecache(MARIA_HA *info,
+                              ulonglong key_map __attribute__((unused)),
+                              PAGECACHE *pagecache)
+{
+  int error= 0;
+  MARIA_SHARE* share= info->s;
+  DBUG_ENTER("maria_assign_to_pagecache");
+  DBUG_PRINT("enter",
+             ("old_pagecache_handle:%p  new_pagecache_handle:%p",
+             share->pagecache, pagecache));
+
+  /*
+    Skip operation if we didn't change key cache. This can happen if we
+    call this for all open instances of the same table
+  */
+  if (share->pagecache == pagecache)
+    DBUG_RETURN(0);
+
+  /*
+    First flush all blocks for the table in the old key cache.
+    This is to ensure that the disk is consistent with the data pages
+    in memory (which may not be the case if the table uses delayed_key_write)
+
+    Note that some other read thread may still fill in the key cache with
+    new blocks during this call and after, but this doesn't matter as
+    all threads will start using the new key cache for their next call to
+    maria library and we know that there will not be any changed blocks
+    in the old key cache.
+  */
+
+  if (flush_pagecache_blocks(share->pagecache, &share->kfile, FLUSH_RELEASE))
+  {
+    error= my_errno;
+    /* Mark that table must be checked */
+    _ma_set_fatal_error(info, error);
+  }
+
+  /*
+    Flush the new key cache for this file.  This is needed to ensure
+    that there is no old blocks (with outdated data) left in the new key
+    cache from an earlier assign_to_keycache operation
+
+    (This can never fail as there is never any not written data in the
+    new key cache)
+  */
+  (void) flush_pagecache_blocks(pagecache, &share->kfile, FLUSH_RELEASE);
+
+  /*
+    ensure that setting the key cache and changing the multi_pagecache
+    is done atomicly
+  */
+  mysql_mutex_lock(&share->intern_lock);
+  /*
+    Tell all threads to use the new key cache
+    This should be seen at the lastes for the next call to an maria function.
+  */
+  share->pagecache= pagecache;
+
+  /* store the key cache in the global hash structure for future opens */
+  if (multi_pagecache_set((uchar*) share->unique_file_name.str,
+                          (uint)share->unique_file_name.length,
+			  share->pagecache))
+    error= my_errno;
+  mysql_mutex_unlock(&share->intern_lock);
+  DBUG_RETURN(error);
+}
+
+
+/*
+  Change all MARIA entries that uses one key cache to another key cache
+
+  SYNOPSIS
+    maria_change_pagecache()
+    old_pagecache	Old key cache
+    new_pagecache	New key cache
+
+  NOTES
+    This is used when we delete one key cache.
+
+    To handle the case where some other threads tries to open an MARIA
+    table associated with the to-be-deleted key cache while this operation
+    is running, we have to call 'multi_pagecache_change()' from this
+    function while we have a lock on the MARIA table list structure.
+
+    This is safe as long as it's only MARIA that is using this specific
+    key cache.
+*/
+
+
+void maria_change_pagecache(PAGECACHE *old_pagecache,
+                            PAGECACHE *new_pagecache)
+{
+  LIST *pos;
+  DBUG_ENTER("maria_change_pagecache");
+
+  /*
+    Lock list to ensure that no one can close the table while we manipulate it
+  */
+  mysql_mutex_lock(&THR_LOCK_maria);
+  for (pos=maria_open_list ; pos ; pos=pos->next)
+  {
+    MARIA_HA *info= (MARIA_HA*) pos->data;
+    MARIA_SHARE *share= info->s;
+    if (share->pagecache == old_pagecache)
+      maria_assign_to_pagecache(info, (ulonglong) ~0, new_pagecache);
+  }
+
+  /*
+    We have to do the following call while we have the lock on the
+    MARIA list structure to ensure that another thread is not trying to
+    open a new table that will be associted with the old key cache
+  */
+  multi_pagecache_change(old_pagecache, new_pagecache);
+  mysql_mutex_unlock(&THR_LOCK_maria);
+  DBUG_VOID_RETURN;
+}