Initial Commit

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

@@ -0,0 +1,96 @@
+<?php
+
+namespace WP_Ultimo\Dependencies\Amp\ByteStream;
+
+use WP_Ultimo\Dependencies\Amp\Promise;
+use function WP_Ultimo\Dependencies\Amp\call;
+/**
+ * Allows decompression of input streams using Zlib.
+ */
+final class ZlibInputStream implements InputStream
+{
+    /** @var InputStream|null */
+    private $source;
+    /** @var int */
+    private $encoding;
+    /** @var array */
+    private $options;
+    /** @var resource|null */
+    private $resource;
+    /**
+     * @param InputStream $source Input stream to read compressed data from.
+     * @param int         $encoding Compression algorithm used, see `inflate_init()`.
+     * @param array       $options Algorithm options, see `inflate_init()`.
+     *
+     * @throws StreamException
+     * @throws \Error
+     *
+     * @see http://php.net/manual/en/function.inflate-init.php
+     */
+    public function __construct(InputStream $source, int $encoding, array $options = [])
+    {
+        $this->source = $source;
+        $this->encoding = $encoding;
+        $this->options = $options;
+        $this->resource = @\inflate_init($encoding, $options);
+        if ($this->resource === \false) {
+            throw new StreamException("Failed initializing deflate context");
+        }
+    }
+    /** @inheritdoc */
+    public function read() : Promise
+    {
+        return call(function () {
+            if ($this->resource === null) {
+                return null;
+            }
+            \assert($this->source !== null);
+            $data = (yield $this->source->read());
+            // Needs a double guard, as stream might have been closed while reading
+            /** @psalm-suppress ParadoxicalCondition */
+            if ($this->resource === null) {
+                return null;
+            }
+            if ($data === null) {
+                $decompressed = @\inflate_add($this->resource, "", \ZLIB_FINISH);
+                if ($decompressed === \false) {
+                    throw new StreamException("Failed adding data to deflate context");
+                }
+                $this->close();
+                return $decompressed;
+            }
+            $decompressed = @\inflate_add($this->resource, $data, \ZLIB_SYNC_FLUSH);
+            if ($decompressed === \false) {
+                throw new StreamException("Failed adding data to deflate context");
+            }
+            return $decompressed;
+        });
+    }
+    /**
+     * @internal
+     * @return void
+     */
+    private function close()
+    {
+        $this->resource = null;
+        $this->source = 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;
+    }
+}