silverstripe-textextraction/code/extensions/FileTextCache.php
2015-11-18 17:07:31 +13:00

113 lines
2.6 KiB
PHP

<?php
interface FileTextCache
{
/**
* Save extracted content for a given File entity
*
* @param File $file
* @param string $content
*/
public function save(File $file, $content);
/**
* Return any cached extracted content for a given file entity
*
* @param File $file
*/
public function load(File $file);
/**
* Invalidate the cache for a given file.
* Invoked in onBeforeWrite on the file
*
* @param File $file
*/
public function invalidate(File $file);
}
/**
* Caches the extracted content on the record for the file.
* Limits the stored file content by default to avoid hitting query size limits.
*/
class FileTextCache_Database implements FileTextCache
{
public function load(File $file)
{
return $file->FileContentCache;
}
public function save(File $file, $content)
{
$maxLength = Config::inst()->get('FileTextCache_Database', 'max_content_length');
$file->FileContentCache = ($maxLength) ? substr($content, 0, $maxLength) : $content;
$file->write();
}
public function invalidate(File $file)
{
// To prevent writing to the cache from invalidating it
if (!$file->isChanged('FileContentCache')) {
$file->FileContentCache = '';
}
}
}
/**
* Uses SS_Cache with a lifetime to cache extracted content
*/
class FileTextCache_SSCache implements FileTextCache, Flushable
{
/**
* Lifetime of cache in seconds
* Null is indefinite
*
* @var int|null
* @config
*/
private static $lifetime = null;
/**
* @return SS_Cache
*/
protected static function get_cache()
{
$lifetime = Config::inst()->get(__CLASS__, 'lifetime');
$cache = SS_Cache::factory(__CLASS__);
$cache->setLifetime($lifetime);
return $cache;
}
protected function getKey(File $file)
{
return md5($file->getFullPath());
}
public function load(File $file)
{
$key = $this->getKey($file);
$cache = self::get_cache();
return $cache->load($key);
}
public function save(File $file, $content)
{
$key = $this->getKey($file);
$cache = self::get_cache();
return $cache->save($content, $key);
}
public static function flush()
{
$cache = self::get_cache();
$cache->clean();
}
public function invalidate(File $file)
{
$key = $this->getKey($file);
$cache = self::get_cache();
return $cache->remove($key);
}
}