Limit cache data size to avoid database errors

pull/194/head
Thomas Bruederli 11 years ago
parent bb57fca320
commit 5793309478

@ -45,6 +45,7 @@ class rcube_cache
private $cache = array();
private $cache_changes = array();
private $cache_sums = array();
private $max_packet = -1;
/**
@ -319,7 +320,7 @@ class rcube_cache
* Writes single cache record into DB.
*
* @param string $key Cache key name
* @param mxied $data Serialized cache data
* @param mixed $data Serialized cache data
*
* @param boolean True on success, False on failure
*/
@ -329,6 +330,12 @@ class rcube_cache
return false;
}
// don't attempt to write too big data sets
if (strlen($data) > $this->max_packet_size()) {
trigger_error("rcube_cache: max_packet_size ($this->max_packet) exceeded for key $key. Tried to write " . strlen($data) . " bytes", E_USER_WARNING);
return false;
}
if ($this->type == 'memcache' || $this->type == 'apc') {
return $this->add_record($this->ckey($key), $data);
}
@ -591,4 +598,30 @@ class rcube_cache
return $this->packed ? @unserialize($data) : $data;
}
/**
* Determine the maximum size for cache data to be written
*/
private function max_packet_size()
{
if ($this->max_packet < 0) {
$this->max_packet = 2097152; // default/max is 2 MB
if ($this->type == 'db') {
$value = $this->db->get_variable('max_allowed_packet', 1048500);
$this->max_packet = min($value, $this->max_packet) - 2000;
}
else if ($this->type == 'memcache') {
$stats = $this->db->getStats();
$remaining = $stats['limit_maxbytes'] - $stats['bytes'];
$this->max_packet = min($remaining / 5, $this->max_packet);
}
else if ($this->type == 'apc' && function_exists('apc_sma_info')) {
$stats = apc_sma_info();
$this->max_packet = min($stats['avail_mem'] / 5, $this->max_packet);
}
}
return $this->max_packet;
}
}

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