--- a/lib/Protobuf-PHP/library/DrSlump/Protobuf/Codec/Binary/Reader.php
+++ b/lib/Protobuf-PHP/library/DrSlump/Protobuf/Codec/Binary/Reader.php
@@ -1,1 +1,223 @@
-
+<?php
+
+namespace DrSlump\Protobuf\Codec\Binary;
+
+/**
+ * Implements reading primitives for Protobuf binary streams
+ *
+ * Important: There are no checks in place for overflows, so you must
+ * be aware of PHP's integer and floating point limits.
+ *
+ * @note Protobuf uses little-endian order
+ */
+class Reader
+{
+    /** @var resource */
+    protected $_fd;
+
+    /**
+     * Create a new reader from a file descriptor or a string of bytes
+     *
+     * @param resource|string $fdOrString
+     */
+    public function __construct($fdOrString)
+    {
+        if (is_resource($fdOrString)) {
+            $this->_fd = $fdOrString;
+        } else {
+            // @todo Could this be faster by using a custom String wrapper?
+            $this->_fd = fopen('data://text/plain,' . urlencode($fdOrString), 'rb');
+        }
+    }
+
+    public function __destruct()
+    {
+        fclose($this->_fd);
+    }
+
+    /**
+     * Obtain a number of bytes from the string
+     *
+     * @throws \RuntimeException
+     * @param int $length
+     * @return string
+     */
+    public function read($length)
+    {
+        // Protect against 0 byte reads when an EOF
+        if ($length < 1) return '';
+
+        $bytes = fread($this->_fd, $length);
+        if (FALSE === $bytes) {
+            throw new \RuntimeException('Failed to read ' . $length . ' bytes');
+        }
+
+        return $bytes;
+    }
+
+    /**
+     * Check if we have reached the end of the stream
+     *
+     * @return bool
+     */
+    public function eof()
+    {
+        return feof($this->_fd);
+    }
+
+    /**
+     * Obtain the current position in the stream
+     *
+     * @return int
+     */
+    public function pos()
+    {
+        return ftell($this->_fd);
+    }
+
+    /**
+     * Obtain a byte
+     *
+     * @return int
+     */
+    public function byte()
+    {
+        return ord($this->read(1));
+    }
+
+    /**
+     * Decode a varint
+     *
+     * @return int
+     */
+    public function varint()
+    {
+        $result = $shift = 0;
+        do {
+            $byte = $this->byte();
+            $result |= ($byte & 0x7f) << $shift;
+            $shift += 7;
+        } while ($byte > 0x7f);
+
+        return $result;
+    }
+
+    /**
+     * Decodes a zigzag integer of the given bits
+     *
+     * @param int $bits - Either 32 or 64
+     */
+    public function zigzag()
+    {
+        $number = $this->varint();
+        return ($number >> 1) ^ (-($number & 1));
+    }
+
+    /**
+     * Decode a fixed 32bit integer with sign
+     *
+     * @return int
+     */
+    public function sFixed32()
+    {
+        $bytes = $this->read(4);
+        if ($this->isBigEndian()) {
+            $bytes = strrev($bytes);
+        }
+
+        list(, $result) = unpack('l', $bytes);
+        return $result;
+    }
+
+    /**
+     * Decode a fixed 32bit integer without sign
+     *
+     * @return int
+     */
+    public function fixed32()
+    {
+        $bytes = $this->read(4);
+
+        if (PHP_INT_SIZE < 8) {
+            list(, $lo, $hi) = unpack('v*', $bytes);
+            $result = $hi << 16 | $lo;
+        } else {
+            list(, $result) = unpack('V*', $bytes);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Decode a fixed 62bit integer with sign
+     *
+     * @return int
+     */
+    public function sFixed64()
+    {
+        $bytes = $this->read(8);
+
+        list(, $lo0, $lo1, $hi0, $hi1) = unpack('v*', $bytes);
+        return ($hi1 << 16 | $hi0) << 32 | ($lo1 << 16 | $lo0);
+    }
+
+    /**
+     * Decode a fixed 62bit integer without sign
+     *
+     * @return int
+     */
+    public function fixed64()
+    {
+        return $this->sFixed64();
+    }
+
+    /**
+     * Decode a 32bit float
+     *
+     * @return float
+     */
+    public function float()
+    {
+        $bytes = $this->read(4);
+        if ($this->isBigEndian()) {
+            $bytes = strrev($bytes);
+        }
+
+        list(, $result) = unpack('f', $bytes);
+        return $result;
+    }
+
+    /**
+     * Decode a 64bit double
+     *
+     * @return float
+     */
+    public function double()
+    {
+        $bytes = $this->read(8);
+        if ($this->isBigEndian()) {
+            $bytes = strrev($bytes);
+        }
+
+        list(, $result) = unpack('d', $bytes);
+        return $result;
+    }
+
+    /**
+     * Check if the current architecture is Big Endian
+     *
+     * @return bool
+     */
+    public function isBigEndian()
+    {
+        static $endianness;
+
+        if (NULL === $endianness) {
+            list(,$result) = unpack('L', pack('V', 1));
+            $endianness = $result !== 1;
+        }
+
+        return $endianness;
+    }
+}
+