Files
2021-09-13 06:53:04 -04:00

353 lines
8.1 KiB
PHP

<?php
/**
* This file is part of the CodeIgniter 4 framework.
*
* (c) CodeIgniter Foundation <admin@codeigniter.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace CodeIgniter\Cache\Handlers;
use CodeIgniter\Exceptions\CriticalError;
use Config\Cache;
use Redis;
use RedisException;
/**
* Redis cache handler
*/
class RedisHandler extends BaseHandler
{
/**
* Default config
*
* @var array
*/
protected $config = [
'host' => '127.0.0.1',
'password' => null,
'port' => 6379,
'timeout' => 0,
'database' => 0,
];
/**
* Redis connection
*
* @var Redis
*/
protected $redis;
//--------------------------------------------------------------------
/**
* Constructor.
*
* @param Cache $config
*/
public function __construct(Cache $config)
{
$this->prefix = $config->prefix;
if (! empty($config))
{
$this->config = array_merge($this->config, $config->redis);
}
}
/**
* Class destructor
*
* Closes the connection to Redis if present.
*/
public function __destruct()
{
if (isset($this->redis))
{
$this->redis->close();
}
}
//--------------------------------------------------------------------
/**
* Takes care of any handler-specific setup that must be done.
*/
public function initialize()
{
$config = $this->config;
$this->redis = new Redis();
// Try to connect to Redis, if an issue occurs throw a CriticalError exception,
// so that the CacheFactory can attempt to initiate the next cache handler.
try
{
// Note:: If Redis is your primary cache choice, and it is "offline", every page load will end up been delayed by the timeout duration.
// I feel like some sort of temporary flag should be set, to indicate that we think Redis is "offline", allowing us to bypass the timeout for a set period of time.
if (! $this->redis->connect($config['host'], ($config['host'][0] === '/' ? 0 : $config['port']), $config['timeout']))
{
// Note:: I'm unsure if log_message() is necessary, however I'm not 100% comfortable removing it.
log_message('error', 'Cache: Redis connection failed. Check your configuration.');
throw new CriticalError('Cache: Redis connection failed. Check your configuration.');
}
if (isset($config['password']) && ! $this->redis->auth($config['password']))
{
log_message('error', 'Cache: Redis authentication failed.');
throw new CriticalError('Cache: Redis authentication failed.');
}
if (isset($config['database']) && ! $this->redis->select($config['database']))
{
log_message('error', 'Cache: Redis select database failed.');
throw new CriticalError('Cache: Redis select database failed.');
}
}
catch (RedisException $e)
{
// $this->redis->connect() can sometimes throw a RedisException.
// We need to convert the exception into a CriticalError exception and throw it.
throw new CriticalError('Cache: RedisException occurred with message (' . $e->getMessage() . ').');
}
}
//--------------------------------------------------------------------
/**
* Attempts to fetch an item from the cache store.
*
* @param string $key Cache item name
*
* @return mixed
*/
public function get(string $key)
{
$key = static::validateKey($key, $this->prefix);
$data = $this->redis->hMGet($key, ['__ci_type', '__ci_value']);
if (! isset($data['__ci_type'], $data['__ci_value']) || $data['__ci_value'] === false)
{
return null;
}
switch ($data['__ci_type'])
{
case 'array':
case 'object':
return unserialize($data['__ci_value']);
case 'boolean':
case 'integer':
case 'double': // Yes, 'double' is returned and NOT 'float'
case 'string':
case 'NULL':
return settype($data['__ci_value'], $data['__ci_type']) ? $data['__ci_value'] : null;
case 'resource':
default:
return null;
}
}
//--------------------------------------------------------------------
/**
* Saves an item to the cache store.
*
* @param string $key Cache item name
* @param mixed $value The data to save
* @param integer $ttl Time To Live, in seconds (default 60)
*
* @return boolean Success or failure
*/
public function save(string $key, $value, int $ttl = 60)
{
$key = static::validateKey($key, $this->prefix);
switch ($dataType = gettype($value))
{
case 'array':
case 'object':
$value = serialize($value);
break;
case 'boolean':
case 'integer':
case 'double': // Yes, 'double' is returned and NOT 'float'
case 'string':
case 'NULL':
break;
case 'resource':
default:
return false;
}
if (! $this->redis->hMSet($key, ['__ci_type' => $dataType, '__ci_value' => $value]))
{
return false;
}
if ($ttl)
{
$this->redis->expireAt($key, time() + $ttl);
}
return true;
}
//--------------------------------------------------------------------
/**
* Deletes a specific item from the cache store.
*
* @param string $key Cache item name
*
* @return boolean Success or failure
*/
public function delete(string $key)
{
$key = static::validateKey($key, $this->prefix);
return $this->redis->del($key) === 1;
}
//--------------------------------------------------------------------
/**
* Deletes items from the cache store matching a given pattern.
*
* @param string $pattern Cache items glob-style pattern
*
* @return integer The number of deleted items
*/
public function deleteMatching(string $pattern)
{
$matchedKeys = [];
$iterator = null;
do
{
// Scan for some keys
$keys = $this->redis->scan($iterator, $pattern);
// Redis may return empty results, so protect against that
if ($keys !== false)
{
foreach ($keys as $key)
{
$matchedKeys[] = $key;
}
}
}
while ($iterator > 0);
return $this->redis->del($matchedKeys);
}
//--------------------------------------------------------------------
/**
* Performs atomic incrementation of a raw stored value.
*
* @param string $key Cache ID
* @param integer $offset Step/value to increase by
*
* @return integer
*/
public function increment(string $key, int $offset = 1)
{
$key = static::validateKey($key, $this->prefix);
return $this->redis->hIncrBy($key, 'data', $offset);
}
//--------------------------------------------------------------------
/**
* Performs atomic decrementation of a raw stored value.
*
* @param string $key Cache ID
* @param integer $offset Step/value to increase by
*
* @return integer
*/
public function decrement(string $key, int $offset = 1)
{
$key = static::validateKey($key, $this->prefix);
return $this->redis->hIncrBy($key, 'data', -$offset);
}
//--------------------------------------------------------------------
/**
* Will delete all items in the entire cache.
*
* @return boolean Success or failure
*/
public function clean()
{
return $this->redis->flushDB();
}
//--------------------------------------------------------------------
/**
* Returns information on the entire cache.
*
* The information returned and the structure of the data
* varies depending on the handler.
*
* @return array
*/
public function getCacheInfo()
{
return $this->redis->info();
}
//--------------------------------------------------------------------
/**
* Returns detailed information about the specific item in the cache.
*
* @param string $key Cache item name.
*
* @return array|null
* Returns null if the item does not exist, otherwise array<string, mixed>
* with at least the 'expire' key for absolute epoch expiry (or null).
*/
public function getMetaData(string $key)
{
$key = static::validateKey($key, $this->prefix);
$value = $this->get($key);
if ($value !== null)
{
$time = time();
$ttl = $this->redis->ttl($key);
return [
'expire' => $ttl > 0 ? time() + $ttl : null,
'mtime' => $time,
'data' => $value,
];
}
return null;
}
//--------------------------------------------------------------------
/**
* Determines if the driver is supported on this system.
*
* @return boolean
*/
public function isSupported(): bool
{
return extension_loaded('redis');
}
}