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-rw-r--r--classes/Memcached_DataObject.php201
1 files changed, 144 insertions, 57 deletions
diff --git a/classes/Memcached_DataObject.php b/classes/Memcached_DataObject.php
index be8137573..400b05f97 100644
--- a/classes/Memcached_DataObject.php
+++ b/classes/Memcached_DataObject.php
@@ -19,8 +19,6 @@
if (!defined('STATUSNET') && !defined('LACONICA')) { exit(1); }
-require_once INSTALLDIR.'/classes/Memcached_DataObject.php';
-
class Memcached_DataObject extends DB_DataObject
{
/**
@@ -38,6 +36,41 @@ class Memcached_DataObject extends DB_DataObject
}
/**
+ * Magic function called at serialize() time.
+ *
+ * We use this to drop a couple process-specific references
+ * from DB_DataObject which can cause trouble in future
+ * processes.
+ *
+ * @return array of variable names to include in serialization.
+ */
+ function __sleep()
+ {
+ $vars = array_keys(get_object_vars($this));
+ $skip = array('_DB_resultid', '_link_loaded');
+ return array_diff($vars, $skip);
+ }
+
+ /**
+ * Magic function called at unserialize() time.
+ *
+ * Clean out some process-specific variables which might
+ * be floating around from a previous process's cached
+ * objects.
+ *
+ * Old cached objects may still have them.
+ */
+ function __wakeup()
+ {
+ // Refers to global state info from a previous process.
+ // Clear this out so we don't accidentally break global
+ // state in *this* process.
+ $this->_DB_resultid = null;
+ // We don't have any local DBO refs, so clear these out.
+ $this->_link_loaded = false;
+ }
+
+ /**
* Wrapper for DB_DataObject's static lookup using memcached
* as backing instead of an in-process cache array.
*
@@ -57,31 +90,42 @@ class Memcached_DataObject extends DB_DataObject
unset($i);
}
$i = Memcached_DataObject::getcached($cls, $k, $v);
- if ($i) {
- return $i;
- } else {
- $i = DB_DataObject::staticGet($cls, $k, $v);
- if ($i) {
- // DB_DataObject's in-process lookup cache interferes with GC
- // to cause massive memory leaks in long-running processes.
- if (php_sapi_name() == 'cli') {
- $i->_clear_cache();
- }
-
- // Now store it into the shared memcached, if present...
+ if ($i === false) { // false == cache miss
+ $i = DB_DataObject::factory($cls);
+ if (empty($i)) {
+ $i = false;
+ return $i;
+ }
+ $result = $i->get($k, $v);
+ if ($result) {
+ // Hit!
$i->encache();
+ } else {
+ // save the fact that no such row exists
+ $c = self::memcache();
+ if (!empty($c)) {
+ $ck = self::cachekey($cls, $k, $v);
+ $c->set($ck, null);
+ }
+ $i = false;
}
- return $i;
}
+ return $i;
}
- function &pkeyGet($cls, $kv)
+ /**
+ * @fixme Should this return false on lookup fail to match staticGet?
+ */
+ function pkeyGet($cls, $kv)
{
$i = Memcached_DataObject::multicache($cls, $kv);
- if ($i) {
+ if ($i !== false) { // false == cache miss
return $i;
} else {
- $i = new $cls();
+ $i = DB_DataObject::factory($cls);
+ if (empty($i)) {
+ return false;
+ }
foreach ($kv as $k => $v) {
$i->$k = $v;
}
@@ -89,6 +133,11 @@ class Memcached_DataObject extends DB_DataObject
$i->encache();
} else {
$i = null;
+ $c = self::memcache();
+ if (!empty($c)) {
+ $ck = self::multicacheKey($cls, $kv);
+ $c->set($ck, null);
+ }
}
return $i;
}
@@ -97,6 +146,9 @@ class Memcached_DataObject extends DB_DataObject
function insert()
{
$result = parent::insert();
+ if ($result) {
+ $this->encache(); // in case of cached negative lookups
+ }
return $result;
}
@@ -123,7 +175,7 @@ class Memcached_DataObject extends DB_DataObject
}
static function cacheKey($cls, $k, $v) {
- if (is_object($cls) || is_object($j) || is_object($v)) {
+ if (is_object($cls) || is_object($k) || is_object($v)) {
$e = new Exception();
common_log(LOG_ERR, __METHOD__ . ' object in param: ' .
str_replace("\n", " ", $e->getTraceAsString()));
@@ -142,6 +194,17 @@ class Memcached_DataObject extends DB_DataObject
function keyTypes()
{
+ // ini-based classes return number-indexed arrays. handbuilt
+ // classes return column => keytype. Make this uniform.
+
+ $keys = $this->keys();
+
+ $keyskeys = array_keys($keys);
+
+ if (is_string($keyskeys[0])) {
+ return $keys;
+ }
+
global $_DB_DATAOBJECT;
if (!isset($_DB_DATAOBJECT['INI'][$this->_database][$this->__table."__keys"])) {
$this->databaseStructure();
@@ -153,67 +216,90 @@ class Memcached_DataObject extends DB_DataObject
function encache()
{
$c = $this->memcache();
+
if (!$c) {
return false;
- } else {
- $pkey = array();
- $pval = array();
- $types = $this->keyTypes();
- ksort($types);
- foreach ($types as $key => $type) {
- if ($type == 'K') {
- $pkey[] = $key;
- $pval[] = $this->$key;
- } else {
- $c->set($this->cacheKey($this->tableName(), $key, $this->$key), $this);
- }
- }
- # XXX: should work for both compound and scalar pkeys
- $pvals = implode(',', $pval);
- $pkeys = implode(',', $pkey);
- $c->set($this->cacheKey($this->tableName(), $pkeys, $pvals), $this);
+ }
+
+ $keys = $this->_allCacheKeys();
+
+ foreach ($keys as $key) {
+ $c->set($key, $this);
}
}
function decache()
{
$c = $this->memcache();
+
if (!$c) {
return false;
- } else {
- $pkey = array();
- $pval = array();
- $types = $this->keyTypes();
- ksort($types);
- foreach ($types as $key => $type) {
- if ($type == 'K') {
- $pkey[] = $key;
- $pval[] = $this->$key;
- } else {
- $c->delete($this->cacheKey($this->tableName(), $key, $this->$key));
+ }
+
+ $keys = $this->_allCacheKeys();
+
+ foreach ($keys as $key) {
+ $c->delete($key, $this);
+ }
+ }
+
+ function _allCacheKeys()
+ {
+ $ckeys = array();
+
+ $types = $this->keyTypes();
+ ksort($types);
+
+ $pkey = array();
+ $pval = array();
+
+ foreach ($types as $key => $type) {
+
+ assert(!empty($key));
+
+ if ($type == 'U') {
+ if (empty($this->$key)) {
+ continue;
}
+ $ckeys[] = $this->cacheKey($this->tableName(), $key, $this->$key);
+ } else if ($type == 'K' || $type == 'N') {
+ $pkey[] = $key;
+ $pval[] = $this->$key;
+ } else {
+ throw new Exception("Unknown key type $key => $type for " . $this->tableName());
}
- # should work for both compound and scalar pkeys
- # XXX: comma works for now but may not be safe separator for future keys
- $pvals = implode(',', $pval);
- $pkeys = implode(',', $pkey);
- $c->delete($this->cacheKey($this->tableName(), $pkeys, $pvals));
}
+
+ assert(count($pkey) > 0);
+
+ // XXX: should work for both compound and scalar pkeys
+ $pvals = implode(',', $pval);
+ $pkeys = implode(',', $pkey);
+
+ $ckeys[] = $this->cacheKey($this->tableName(), $pkeys, $pvals);
+
+ return $ckeys;
}
function multicache($cls, $kv)
{
ksort($kv);
- $c = Memcached_DataObject::memcache();
+ $c = self::memcache();
if (!$c) {
return false;
} else {
- $pkeys = implode(',', array_keys($kv));
- $pvals = implode(',', array_values($kv));
- return $c->get(Memcached_DataObject::cacheKey($cls, $pkeys, $pvals));
+ return $c->get(self::multicacheKey($cls, $kv));
}
}
+ static function multicacheKey($cls, $kv)
+ {
+ ksort($kv);
+ $pkeys = implode(',', array_keys($kv));
+ $pvals = implode(',', array_values($kv));
+ return self::cacheKey($cls, $pkeys, $pvals);
+ }
+
function getSearchEngine($table)
{
require_once INSTALLDIR.'/lib/search_engines.php';
@@ -248,7 +334,8 @@ class Memcached_DataObject extends DB_DataObject
$key_part = common_keyize($cls).':'.md5($qry);
$ckey = common_cache_key($key_part);
$stored = $c->get($ckey);
- if ($stored) {
+
+ if ($stored !== false) {
return new ArrayWrapper($stored);
}