Initial Commit

dependencies/amphp/byte-stream/lib/ZlibOutputStream.php

@@ -0,0 +1,101 @@
+<?php
+
+namespace WP_Ultimo\Dependencies\Amp\ByteStream;
+
+use WP_Ultimo\Dependencies\Amp\Promise;
+/**
+ * Allows compression of output streams using Zlib.
+ */
+final class ZlibOutputStream implements OutputStream
+{
+    /** @var OutputStream|null */
+    private $destination;
+    /** @var int */
+    private $encoding;
+    /** @var array */
+    private $options;
+    /** @var resource|null */
+    private $resource;
+    /**
+     * @param OutputStream $destination Output stream to write the compressed data to.
+     * @param int          $encoding Compression encoding to use, see `deflate_init()`.
+     * @param array        $options Compression options to use, see `deflate_init()`.
+     *
+     * @throws StreamException If an invalid encoding or invalid options have been passed.
+     *
+     * @see http://php.net/manual/en/function.deflate-init.php
+     */
+    public function __construct(OutputStream $destination, int $encoding, array $options = [])
+    {
+        $this->destination = $destination;
+        $this->encoding = $encoding;
+        $this->options = $options;
+        $this->resource = @\deflate_init($encoding, $options);
+        if ($this->resource === \false) {
+            throw new StreamException("Failed initializing deflate context");
+        }
+    }
+    /** @inheritdoc */
+    public function write(string $data) : Promise
+    {
+        if ($this->resource === null) {
+            throw new ClosedException("The stream has already been closed");
+        }
+        \assert($this->destination !== null);
+        $compressed = \deflate_add($this->resource, $data, \ZLIB_SYNC_FLUSH);
+        if ($compressed === \false) {
+            throw new StreamException("Failed adding data to deflate context");
+        }
+        $promise = $this->destination->write($compressed);
+        $promise->onResolve(function ($error) {
+            if ($error) {
+                $this->close();
+            }
+        });
+        return $promise;
+    }
+    /** @inheritdoc */
+    public function end(string $finalData = "") : Promise
+    {
+        if ($this->resource === null) {
+            throw new ClosedException("The stream has already been closed");
+        }
+        \assert($this->destination !== null);
+        $compressed = \deflate_add($this->resource, $finalData, \ZLIB_FINISH);
+        if ($compressed === \false) {
+            throw new StreamException("Failed adding data to deflate context");
+        }
+        $promise = $this->destination->end($compressed);
+        $promise->onResolve(function () {
+            $this->close();
+        });
+        return $promise;
+    }
+    /**
+     * @internal
+     * @return void
+     */
+    private function close()
+    {
+        $this->resource = null;
+        $this->destination = null;
+    }
+    /**
+     * Gets the used compression encoding.
+     *
+     * @return int Encoding specified on construction time.
+     */
+    public function getEncoding() : int
+    {
+        return $this->encoding;
+    }
+    /**
+     * Gets the used compression options.
+     *
+     * @return array Options array passed on construction time.
+     */
+    public function getOptions() : array
+    {
+        return $this->options;
+    }
+}