Using a stream wrapper to access CouchDb attachments with PHP
Join the DZone community and get the full member experience.
Join For FreeIt’s pretty straightforward to create the wrapper. Of course it’s only an approach. We can create more functionality to our stram wrapper but at least this example meets my needs.
namespace Nov\CouchDb\Fs; class StreamWrapper { var $position; var $varname; /** * @var \Nov\CouchDb\Fs\Resource */ var $fs; /** * @param string $path * @return \Nov\CouchDb\Fs */ private static function _getFs($path, $_url) { return \Nov\CouchDb\Fs::factory(FSCDB, $_url['host']); } function stream_open($path, $mode, $options, &$opened_path) { $_url = parse_url($path); $_path = $_url['path']; $fs = self::_getFs($path, $_url); $_type = strtolower(substr($mode, 0, 1)); switch ($_type) { case 'r': $this->fs = $fs->open($_path); break; case 'w': $this->fs = $fs->open($_path, true, true); break; } return true; } function stream_read($count=null) { if (is_null($count)) { return $this->fs->raw(); } else { return $this->fs->raw(0, $count); } } function stream_write($data, $lenght=null) { if (is_null($lenght)) { $this->fs->write($data); } else { $this->fs->write(mb_substr($data, 0, $lenght)); } return strlen($data); } public function unlink($path) { $_url = parse_url($path); $_path = $_url['path']; $fs = self::_getFs($path, $_url)->open($_path); $fs->delete(); } public function url_stat($path , $flags) { $_url = parse_url($path); $_path = $_url['path']; $fs = self::_getFs($path, $_url)->open($_path); //tamaño en bytes $size = $fs->getLenght(); $out[7] = $size; $out['size'] = $size; return $out; }
That’s very simple. It’s almost the same code than the Monkey Patching example.
And now if we want to use it:
use Nov\CouchDb; use Nov\CouchDb\Fs; require_once ("Nov/Loader.php"); Nov\Loader::init(); // I use FSCDB to set up the connection parameters to our couchDb database define('FSCDB', \NovConf::CDB1); stream_wrapper_register("novCouchDb", "Nov\CouchDb\Fs\StreamWrapper") or die("Failed to register protocol"); $file = "novCouchDb://fs/home/gonzalo/new.txt"; $f = fopen($file, 'w+'); fwrite($f, "***12345dkkydd678901"); fclose($f); $f = fopen($file, 'r'); $a = fread($f, filesize($file)); fclose($f); unlink($file); echo $a;
As we can see the URI is:
novCouchDb://fs/home/gonzalo/new.txt.
That’s mean [protocol]://[database]/[path]
The behaviour of this example is exactly the same than Monkey Patching one but I preffer this one. It looks like more “clean” than Monkey Patching approach.
The full source code is available here. And the example: document_root/tests/couchdb/test7.php
Published at DZone with permission of Gonzalo Ayuso, DZone MVB. See the original article here.
Opinions expressed by DZone contributors are their own.
Comments