spaces.php

aws/Aws/HashingStream.php

@@ -0,0 +1,60 @@
+<?php
+namespace Aws;
+
+use GuzzleHttp\Psr7\StreamDecoratorTrait;
+use Psr\Http\Message\StreamInterface;
+
+/**
+ * Stream decorator that calculates a rolling hash of the stream as it is read.
+ */
+class HashingStream implements StreamInterface
+{
+    use StreamDecoratorTrait;
+
+    /** @var HashInterface */
+    private $hash;
+
+    /** @var callable|null */
+    private $callback;
+
+    /**
+     * @param StreamInterface $stream     Stream that is being read.
+     * @param HashInterface   $hash       Hash used to calculate checksum.
+     * @param callable        $onComplete Optional function invoked when the
+     *                                    hash calculation is completed.
+     */
+    public function __construct(
+        StreamInterface $stream,
+        HashInterface $hash,
+        callable $onComplete = null
+    ) {
+        $this->stream = $stream;
+        $this->hash = $hash;
+        $this->callback = $onComplete;
+    }
+
+    public function read($length)
+    {
+        $data = $this->stream->read($length);
+        $this->hash->update($data);
+        if ($this->eof()) {
+            $result = $this->hash->complete();
+            if ($this->callback) {
+                call_user_func($this->callback, $result);
+            }
+        }
+
+        return $data;
+    }
+
+    public function seek($offset, $whence = SEEK_SET)
+    {
+        if ($offset === 0) {
+            $this->hash->reset();
+            return $this->stream->seek($offset);
+        } else {
+            // Seeking arbitrarily is not supported.
+            return false;
+        }
+    }
+}