1 files changed, 314 insertions, 0 deletions
diff --git a/sql/sp_cache.cc b/sql/sp_cache.cc
new file mode 100644
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--- /dev/null
+++ b/sql/sp_cache.cc
@@ -0,0 +1,314 @@
+/* Copyright (c) 2002, 2012, 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 */
+
+#include "mariadb.h"
+#include "sql_priv.h"
+#include "unireg.h"
+#ifdef USE_PRAGMA_IMPLEMENTATION
+#pragma implementation
+#endif
+#include "sp_cache.h"
+#include "sp_head.h"
+
+static mysql_mutex_t Cversion_lock;
+static ulong volatile Cversion= 1;
+
+
+/*
+  Cache of stored routines.
+*/
+
+class sp_cache
+{
+public:
+  sp_cache();
+  ~sp_cache();
+
+  /**
+   Inserts a sp_head object into a hash table.
+
+   @returns Success status
+     @return TRUE Failure
+     @return FALSE Success
+  */
+  inline bool insert(sp_head *sp)
+  {
+    return my_hash_insert(&m_hashtable, (const uchar *)sp);
+  }
+
+  inline sp_head *lookup(char *name, size_t namelen)
+  {
+    return (sp_head *) my_hash_search(&m_hashtable, (const uchar *)name,
+                                      namelen);
+  }
+
+  inline void remove(sp_head *sp)
+  {
+    my_hash_delete(&m_hashtable, (uchar *)sp);
+  }
+
+  /**
+    Remove all elements from a stored routine cache if the current
+    number of elements exceeds the argument value.
+
+    @param[in] upper_limit_for_elements  Soft upper limit of elements that
+                                         can be stored in the cache.
+  */
+  void enforce_limit(ulong upper_limit_for_elements)
+  {
+    if (m_hashtable.records > upper_limit_for_elements)
+      my_hash_reset(&m_hashtable);
+  }
+
+private:
+  void init();
+  void cleanup();
+
+  /* All routines in this cache */
+  HASH m_hashtable;
+}; // class sp_cache
+
+#ifdef HAVE_PSI_INTERFACE
+static PSI_mutex_key key_Cversion_lock;
+
+static PSI_mutex_info all_sp_cache_mutexes[]=
+{
+  { &key_Cversion_lock, "Cversion_lock", PSI_FLAG_GLOBAL}
+};
+
+static void init_sp_cache_psi_keys(void)
+{
+  const char* category= "sql";
+  int count;
+
+  if (PSI_server == NULL)
+    return;
+
+  count= array_elements(all_sp_cache_mutexes);
+  PSI_server->register_mutex(category, all_sp_cache_mutexes, count);
+}
+#endif
+
+/* Initialize the SP caching once at startup */
+
+void sp_cache_init()
+{
+#ifdef HAVE_PSI_INTERFACE
+  init_sp_cache_psi_keys();
+#endif
+
+  mysql_mutex_init(key_Cversion_lock, &Cversion_lock, MY_MUTEX_INIT_FAST);
+}
+
+
+/*
+  Clear the cache *cp and set *cp to NULL.
+
+  SYNOPSIS
+    sp_cache_clear()
+    cp  Pointer to cache to clear
+
+  NOTE
+    This function doesn't invalidate other caches.
+*/
+
+void sp_cache_clear(sp_cache **cp)
+{
+  sp_cache *c= *cp;
+
+  if (c)
+  {
+    delete c;
+    *cp= NULL;
+  }
+}
+
+
+void sp_cache_end()
+{
+  mysql_mutex_destroy(&Cversion_lock);
+}
+
+
+/*
+  Insert a routine into the cache.
+
+  SYNOPSIS
+    sp_cache_insert()
+     cp  The cache to put routine into
+     sp  Routine to insert.
+
+  TODO: Perhaps it will be more straightforward if in case we returned an
+        error from this function when we couldn't allocate sp_cache. (right
+        now failure to put routine into cache will cause a 'SP not found'
+        error to be reported at some later time)
+*/
+
+void sp_cache_insert(sp_cache **cp, sp_head *sp)
+{
+  sp_cache *c;
+
+  if (!(c= *cp))
+  {
+    if (!(c= new sp_cache()))
+      return;                                   // End of memory error
+  }
+  /* Reading a ulong variable with no lock. */
+  sp->set_sp_cache_version(Cversion);
+  DBUG_PRINT("info",("sp_cache: inserting: %s", ErrConvDQName(sp).ptr()));
+  c->insert(sp);
+  *cp= c;                                       // Update *cp if it was NULL
+}
+
+
+/*
+  Look up a routine in the cache.
+  SYNOPSIS
+    sp_cache_lookup()
+      cp    Cache to look into
+      name  Name of rutine to find
+
+  NOTE
+    An obsolete (but not more obsolete then since last
+    sp_cache_flush_obsolete call) routine may be returned.
+
+  RETURN
+    The routine or
+    NULL if the routine not found.
+*/
+
+sp_head *sp_cache_lookup(sp_cache **cp, const Database_qualified_name *name)
+{
+  char buf[NAME_LEN * 2 + 2];
+  sp_cache *c= *cp;
+  if (! c)
+    return NULL;
+  return c->lookup(buf, name->make_qname(buf, sizeof(buf)));
+}
+
+
+/*
+  Invalidate all routines in all caches.
+
+  SYNOPSIS
+    sp_cache_invalidate()
+
+  NOTE
+    This is called when a VIEW definition is created or modified (and in some
+    other contexts). We can't destroy sp_head objects here as one may modify
+    VIEW definitions from prelocking-free SPs.
+*/
+
+void sp_cache_invalidate()
+{
+  DBUG_PRINT("info",("sp_cache: invalidating"));
+  thread_safe_increment(Cversion, &Cversion_lock);
+}
+
+
+/**
+  Remove an out-of-date SP from the cache.
+
+  @param[in] cp  Cache to flush
+  @param[in] sp  SP to remove.
+
+  @note This invalidates pointers to sp_head objects this thread
+  uses. In practice that means don't call this function when
+  inside SP'.
+*/
+
+void sp_cache_flush_obsolete(sp_cache **cp, sp_head **sp)
+{
+  if ((*sp)->sp_cache_version() < Cversion && !(*sp)->is_invoked())
+  {
+    (*cp)->remove(*sp);
+    *sp= NULL;
+  }
+}
+
+/**
+  Return the current global version of the cache.
+*/
+
+ulong sp_cache_version()
+{
+  return Cversion;
+}
+
+
+/**
+  Enforce that the current number of elements in the cache don't exceed
+  the argument value by flushing the cache if necessary.
+
+  @param[in] c  Cache to check
+  @param[in] upper_limit_for_elements  Soft upper limit for number of sp_head
+                                       objects that can be stored in the cache.
+*/
+void
+sp_cache_enforce_limit(sp_cache *c, ulong upper_limit_for_elements)
+{
+ if (c)
+   c->enforce_limit(upper_limit_for_elements);
+}
+
+/*************************************************************************
+  Internal functions
+ *************************************************************************/
+
+extern "C" uchar *hash_get_key_for_sp_head(const uchar *ptr, size_t *plen,
+                                           my_bool first);
+extern "C" void hash_free_sp_head(void *p);
+
+uchar *hash_get_key_for_sp_head(const uchar *ptr, size_t *plen,
+                                my_bool first)
+{
+  sp_head *sp= (sp_head *)ptr;
+  *plen= sp->m_qname.length;
+  return (uchar*) sp->m_qname.str;
+}
+
+
+void hash_free_sp_head(void *p)
+{
+  sp_head *sp= (sp_head *)p;
+  sp_head::destroy(sp);
+}
+
+
+sp_cache::sp_cache()
+{
+  init();
+}
+
+
+sp_cache::~sp_cache()
+{
+  my_hash_free(&m_hashtable);
+}
+
+
+void
+sp_cache::init()
+{
+  my_hash_init(key_memory_sp_cache, &m_hashtable, system_charset_info, 0, 0, 0,
+               hash_get_key_for_sp_head, hash_free_sp_head, 0);
+}
+
+
+void
+sp_cache::cleanup()
+{
+  my_hash_free(&m_hashtable);
+}