Add a preClose callback

This is useful in case a callback wants to do something with the stream
right before it gets closed.

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

src/CallbackWrapper.php

@@ -44,6 +44,11 @@ class CallbackWrapper extends Wrapper {
  */
  protected $readDirCallBack;
 
+ /**
+ * @var callable
+ */
+ protected $preCloseCallback;
+
  /**
  * Wraps a stream with the provided callbacks
  *
@@ -56,14 +61,15 @@ class CallbackWrapper extends Wrapper {
  *
  * @throws \BadMethodCallException
  */
- public static function wrap($source, $read = null, $write = null, $close = null, $readDir = null) {
+ public static function wrap($source, $read = null, $write = null, $close = null, $readDir = null, $preClose = null) {
  $context = stream_context_create(array(
  'callback' => array(
  'source' => $source,
  'read' => $read,
  'write' => $write,
  'close' => $close,
- 'readDir' => $readDir
+ 'readDir' => $readDir,
+ 'preClose' => $preClose,
  )
  ));
  return Wrapper::wrapSource($source, $context, 'callback', '\Icewind\Streams\CallbackWrapper');
@@ -76,6 +82,7 @@ protected function open() {
  $this->writeCallback = $context['write'];
  $this->closeCallback = $context['close'];
  $this->readDirCallBack = $context['readDir'];
+ $this->preCloseCallback = $context['preClose'];
  return true;
  }
 
@@ -104,6 +111,11 @@ public function stream_write($data) {
  }
 
  public function stream_close() {
+ if (is_callable($this->preCloseCallback)) {
+ call_user_func($this->preCloseCallback, $this->loadContext('callback')['source']);
+ // prevent further calls by potential PHP 7 GC ghosts
+ $this->preCloseCallback = null;
+ }
  $result = parent::stream_close();
  if (is_callable($this->closeCallback)) {
  call_user_func($this->closeCallback);