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libphutil/src/cache/PhutilMemcacheKeyValueCache.php
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PhutilMemcacheKeyValueCache.php
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<?php
/**
* @task memcache Managing Memcache
*/
final class PhutilMemcacheKeyValueCache extends PhutilKeyValueCache {
private $servers = array();
private $connections = array();
/* -( Key-Value Cache Implementation )------------------------------------- */
public function isAvailable() {
return function_exists('memcache_pconnect');
}
public function getKeys(array $keys) {
$buckets = $this->bucketKeys($keys);
$results = array();
foreach ($buckets as $bucket => $bucket_keys) {
$conn = $this->getConnection($bucket);
$result = $conn->get($bucket_keys);
if (!$result) {
// If the call fails, treat it as a miss on all keys.
$result = array();
}
$results += $result;
}
return $results;
}
public function setKeys(array $keys, $ttl = null) {
$buckets = $this->bucketKeys(array_keys($keys));
// Memcache interprets TTLs as:
//
// - Seconds from now, for values from 1 to 2592000 (30 days).
// - Epoch timestamp, for values larger than 2592000.
//
// We support only relative TTLs, so convert excessively large relative
// TTLs into epoch TTLs.
if ($ttl > 2592000) {
$effective_ttl = time() + $ttl;
} else {
$effective_ttl = $ttl;
}
foreach ($buckets as $bucket => $bucket_keys) {
$conn = $this->getConnection($bucket);
foreach ($bucket_keys as $key) {
$conn->set($key, $keys[$key], 0, $effective_ttl);
}
}
return $this;
}
public function deleteKeys(array $keys) {
$buckets = $this->bucketKeys($keys);
foreach ($buckets as $bucket => $bucket_keys) {
$conn = $this->getConnection($bucket);
foreach ($bucket_keys as $key) {
$conn->delete($key);
}
}
return $this;
}
public function destroyCache() {
foreach ($this->servers as $key => $spec) {
$this->getConnection($key)->flush();
}
return $this;
}
/* -( Managing Memcache )-------------------------------------------------- */
/**
* Set available memcache servers. For example:
*
* $cache->setServers(
* array(
* array(
* 'host' => '10.0.0.20',
* 'port' => 11211,
* ),
* array(
* 'host' => '10.0.0.21',
* 'port' => 11211,
* ),
* ));
*
* @param list<dict> List of server specifications.
* @return this
* @task memcache
*/
public function setServers(array $servers) {
$this->servers = array_values($servers);
return $this;
}
private function bucketKeys(array $keys) {
$buckets = array();
$n = count($this->servers);
if (!$n) {
throw new PhutilInvalidStateException('setServers');
}
foreach ($keys as $key) {
$bucket = (int)((crc32($key) & 0x7FFFFFFF) % $n);
$buckets[$bucket][] = $key;
}
return $buckets;
}
/**
* @phutil-external-symbol function memcache_pconnect
*/
private function getConnection($server) {
if (empty($this->connections[$server])) {
$spec = $this->servers[$server];
$host = $spec['host'];
$port = $spec['port'];
$conn = memcache_pconnect($host, $spec['port']);
if (!$conn) {
throw new Exception(
pht(
'Unable to connect to memcache server (%s:%d)!',
$host,
$port));
}
$this->connections[$server] = $conn;
}
return $this->connections[$server];
}
}
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