runff 1.0 commit

lib/aws/GuzzleHttp/Psr7/LazyOpenStream.php

@@ -0,0 +1,39 @@
+<?php
+namespace GuzzleHttp\Psr7;
+
+use Psr\Http\Message\StreamInterface;
+
+/**
+ * Lazily reads or writes to a file that is opened only after an IO operation
+ * take place on the stream.
+ */
+class LazyOpenStream implements StreamInterface
+{
+    use StreamDecoratorTrait;
+
+    /** @var string File to open */
+    private $filename;
+
+    /** @var string $mode */
+    private $mode;
+
+    /**
+     * @param string $filename File to lazily open
+     * @param string $mode     fopen mode to use when opening the stream
+     */
+    public function __construct($filename, $mode)
+    {
+        $this->filename = $filename;
+        $this->mode = $mode;
+    }
+
+    /**
+     * Creates the underlying stream lazily when required.
+     *
+     * @return StreamInterface
+     */
+    protected function createStream()
+    {
+        return stream_for(try_fopen($this->filename, $this->mode));
+    }
+}