silverstripe-framework/filesystem/flysystem/FlysystemAssetStore.php
2015-09-24 12:57:28 +12:00

372 lines
10 KiB
PHP

<?php
namespace SilverStripe\Filesystem\Flysystem;
use Config;
use Injector;
use InvalidArgumentException;
use League\Flysystem\Exception;
use League\Flysystem\Filesystem;
use League\Flysystem\Util;
use SilverStripe\Filesystem\Storage\AssetNameGenerator;
use SilverStripe\Filesystem\Storage\AssetStore;
/**
* Asset store based on flysystem Filesystem as a backend
*
* @package framework
* @subpackage filesystem
*/
class FlysystemAssetStore implements AssetStore {
/**
* @var Filesystem
*/
private $filesystem = null;
/**
* Enable to use legacy filename behaviour (omits hash)
*
* @config
* @var bool
*/
private static $legacy_filenames = false;
/**
* Assign new flysystem backend
*
* @param Filesystem $filesystem
* @return $this
*/
public function setFilesystem(Filesystem $filesystem) {
$this->filesystem = $filesystem;
return $this;
}
/**
* Get the currently assigned flysystem backend
*
* @return Filesystem
*/
public function getFilesystem() {
return $this->filesystem;
}
public function getAsStream($hash, $filename, $variant = null) {
$fileID = $this->getFileID($hash, $filename, $variant);
return $this->getFilesystem()->readStream($fileID);
}
public function getAsString($hash, $filename, $variant = null) {
$fileID = $this->getFileID($hash, $filename, $variant);
return $this->getFilesystem()->read($fileID);
}
public function getAsURL($hash, $filename, $variant = null) {
$fileID = $this->getFileID($hash, $filename, $variant);
return $this->getFilesystem()->getPublicUrl($fileID);
}
public function setFromLocalFile($path, $filename = null, $conflictResolution = null) {
// Validate this file exists
if(!file_exists($path)) {
throw new InvalidArgumentException("$path does not exist");
}
// Get filename to save to
if(empty($filename)) {
$filename = basename($path);
}
// Callback for saving content
$filesystem = $this->getFilesystem();
$callback = function($fileID) use ($filesystem, $path) {
// Read contents as string into flysystem
$handle = fopen($path, 'r');
if($handle === false) {
throw new InvalidArgumentException("$path could not be opened for reading");
}
$result = $filesystem->putStream($fileID, $handle);
fclose($handle);
return $result;
};
// Submit to conflict check
$hash = sha1_file($path);
return $this->writeWithCallback($callback, $hash, $filename, $conflictResolution);
}
public function setFromString($data, $filename, $conflictResolution = null) {
// Callback for saving content
$filesystem = $this->getFilesystem();
$callback = function($fileID) use ($filesystem, $data) {
return $filesystem->put($fileID, $data);
};
// Submit to conflict check
$hash = sha1($data);
return $this->writeWithCallback($callback, $hash, $filename, $conflictResolution);
}
public function setFromStream($stream, $filename, $conflictResolution = null) {
// If the stream isn't rewindable, write to a temporary filename
if(!$this->isSeekableStream($stream)) {
$path = $this->getStreamAsFile($stream);
$result = $this->setFromLocalFile($path, $filename, $conflictResolution);
unlink($path);
return $result;
}
// Callback for saving content
$filesystem = $this->getFilesystem();
$callback = function($fileID) use ($filesystem, $stream) {
return $filesystem->putStream($fileID, $stream);
};
// Submit to conflict check
$hash = $this->getStreamSHA1($stream);
return $this->writeWithCallback($callback, $hash, $filename, $conflictResolution);
}
/**
* get sha1 hash from stream
*
* @param resource $stream
* @return string str1 hash
*/
protected function getStreamSHA1($stream) {
Util::rewindStream($stream);
$context = hash_init('sha1');
hash_update_stream($context, $stream);
return hash_final($context);
}
/**
* Get stream as a file
*
* @param resource $stream
* @return string Filename of resulting stream content
*/
protected function getStreamAsFile($stream) {
// Get temporary file and name
$file = tempnam(sys_get_temp_dir(), 'ssflysystem');
$buffer = fopen($file, 'w');
if (!$buffer) {
throw new Exception("Could not create temporary file");
}
// Transfer from given stream
Util::rewindStream($stream);
stream_copy_to_stream($stream, $buffer);
if (! fclose($buffer)) {
throw new Exception("Could not write stream to temporary file");
}
return $file;
}
/**
* Determine if this stream is seekable
*
* @param resource $stream
* @return bool True if this stream is seekable
*/
protected function isSeekableStream($stream) {
return Util::isSeekableStream($stream);
}
/**
* Invokes the conflict resolution scheme on the given content, and invokes a callback if
* the storage request is approved.
*
* @param callable $callback Will be invoked and passed a fileID if the file should be stored
* @param string $hash SHA1 of the file content
* @param string $filename Name for the resulting file
* @param string $conflictResolution {@see AssetStore}. Will default to one chosen by the backend
* @return array Tuple associative array (Filename, Hash, Variant)
* @throws Exception
*/
protected function writeWithCallback($callback, $hash, $filename, $conflictResolution = null) {
$filename = $this->cleanFilename($filename);
$fileID = $this->getFileID($hash, $filename);
// Check conflict resolution scheme
$resolvedID = $this->resolveConflicts($conflictResolution, $fileID);
if($resolvedID === false) {
// If defering to the existing file, return the sha of the existing file
$stream = $this
->getFilesystem()
->readStream($fileID);
$hash = $this->getStreamSHA1($stream);
} else {
// Submit and validate result
$result = $callback($resolvedID);
if(!$result) {
throw new Exception("Could not save {$filename}");
}
// in case conflict resolution renamed the file, return the renamed
$filename = $this->getOriginalFilename($resolvedID);
}
return array(
'Hash' => $hash,
'Filename' => $filename,
'Variant' => ''
);
}
public function getMetadata($hash, $filename, $variant = null) {
$fileID = $this->getFileID($hash, $filename, $variant);
return $this->getFilesystem()->getMetadata($fileID);
}
public function getMimeType($hash, $filename, $variant = null) {
$fileID = $this->getFileID($hash, $filename, $variant);
return $this->getFilesystem()->getMimetype($fileID);
}
/**
* Determine the path that should be written to, given the conflict resolution scheme
*
* @param string $conflictResolution
* @param string $fileID
* @return string|false Safe filename to write to. If false, then don't write.
* @throws Exception
*/
protected function resolveConflicts($conflictResolution, $fileID) {
// If overwrite is requested, simply put
if($conflictResolution === AssetStore::CONFLICT_OVERWRITE) {
return $fileID;
}
// Otherwise, check if this exists
$exists = $this->getFilesystem()->has($fileID);
if(!$exists) {
return $fileID;
}
// Flysystem defaults to use_existing
switch($conflictResolution) {
// Throw tantrum
case AssetStore::CONFLICT_EXCEPTION: {
throw new \InvalidArgumentException("File already exists at path {$fileID}");
}
// Rename
case AssetStore::CONFLICT_RENAME: {
foreach($this->fileGeneratorFor($fileID) as $candidate) {
// @todo better infinite loop breaking
if(!$this->getFilesystem()->has($candidate)) {
return $candidate;
}
}
throw new \InvalidArgumentException("File could not be renamed with path {$fileID}");
}
// Default to use existing file
case AssetStore::CONFLICT_USE_EXISTING:
default: {
return false;
}
}
}
/**
* Get an asset renamer for the given filename.
*
* @param string $fileID Adaptor specific identifier for this file/version
* @return AssetNameGenerator
*/
protected function fileGeneratorFor($fileID){
return Injector::inst()->createWithArgs('AssetNameGenerator', array($fileID));
}
/**
* Performs filename cleanup before sending it back.
*
* This name should not contain hash or variants.
*
* @param string $filename
* @return string
*/
protected function cleanFilename($filename) {
// Since we use double underscore to delimit variants, eradicate them from filename
return preg_replace('/_{2,}/', '_', $filename);
}
/**
* Given a FileID, map this back to the original filename, trimming variant
*
* @param string $fileID Adaptor specific identifier for this file/version
* @param string $variant Out parameter for any found variant
* @return string
*/
protected function getOriginalFilename($fileID, &$variant = '') {
// Remove variant
$original = $fileID;
$variant = '';
if(preg_match('/^(?<before>((?<!__).)+)__(?<variant>[^\\.]+)(?<after>.*)$/', $fileID, $matches)) {
$original = $matches['before'].$matches['after'];
$variant = $matches['variant'];
}
// Remove hash
return preg_replace(
'/(?<hash>[a-zA-Z0-9]{10}\\/)(?<name>[^\\/]+)$/',
'$2',
$original
);
}
/**
* Map file tuple (hash, name, variant) to a filename to be used by flysystem
*
* The resulting file will look something like my/directory/EA775CB4D4/filename__variant.jpg
*
* @param string $hash
* @param string $filename Name of file
* @param string $variant (if given)
* @return string Adaptor specific identifier for this file/version
*/
protected function getFileID($hash, $filename, $variant = null) {
// Since we use double underscore to delimit variants, eradicate them from filename
$filename = $this->cleanFilename($filename);
$name = basename($filename);
// Split extension
$extension = null;
if(($pos = strpos($name, '.')) !== false) {
$extension = substr($name, $pos);
$name = substr($name, 0, $pos);
}
// Unless in legacy mode, inject hash just prior to the filename
if(Config::inst()->get(__CLASS__, 'legacy_filenames')) {
$fileID = $name;
} else {
$fileID = substr($hash, 0, 10) . '/' . $name;
}
// Add directory
$dirname = ltrim(dirname($filename), '.');
if($dirname) {
$fileID = $dirname . '/' . $fileID;
}
// Add variant
if($variant) {
$fileID .= '__' . $variant;
}
// Add extension
if($extension) {
$fileID .= $extension;
}
return $fileID;
}
}