From fb1ce8cbc16b09725d79c41f745c8d65df75d61f Mon Sep 17 00:00:00 2001
From: Christopher Vagnetoft <cvagnetoft@gmail.com>
Date: Sat, 24 Feb 2024 20:44:06 +0100
Subject: [PATCH] Initial commit

---
 .gitignore                        |   3 +
 README.md                         |  10 +
 composer.json                     |  25 +++
 phpstan.neon                      |  12 ++
 phpunit.xml                       |  23 +++
 src/Header/HeaderBag.php          |  27 +++
 src/Header/HeaderPacker.php       | 155 ++++++++++++++++
 src/Huffman/Codec.php             |  50 +++++
 src/Huffman/Dictionary.php        | 296 ++++++++++++++++++++++++++++++
 tests/Header/HeaderPackerTest.php |  30 +++
 tests/Huffman/CodecTest.php       |  38 ++++
 11 files changed, 669 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 README.md
 create mode 100644 composer.json
 create mode 100644 phpstan.neon
 create mode 100644 phpunit.xml
 create mode 100644 src/Header/HeaderBag.php
 create mode 100644 src/Header/HeaderPacker.php
 create mode 100644 src/Huffman/Codec.php
 create mode 100644 src/Huffman/Dictionary.php
 create mode 100644 tests/Header/HeaderPackerTest.php
 create mode 100644 tests/Huffman/CodecTest.php

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..235a653
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+/vendor/
+/composer.lock
+/.phpunit.*
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..002acc1
--- /dev/null
+++ b/README.md
@@ -0,0 +1,10 @@
+# HTTP/2 Support for ReactPHP
+
+This is a project that is exploring the feasability and practicality of bringing HTTP/2 to ReactPHP while staying true to the ReactPHP philosophy. The main rationale for this is to eventually enable native support for gRPC.
+
+## Status
+
+Currently implemented:
+
+* Huffman encoding (for compressed headers)
+* Header parsing (including dictionary)
diff --git a/composer.json b/composer.json
new file mode 100644
index 0000000..339ba97
--- /dev/null
+++ b/composer.json
@@ -0,0 +1,25 @@
+{
+    "name": "noccylabs/react-http2",
+    "description": "Native ReactPHP HTTP2 implementation",
+    "type": "library",
+    "license": "GPL-3.0-or-later",
+    "keywords": [ "reactphp", "websockets" ],
+    "autoload": {
+        "psr-4": {
+            "NoccyLabs\\React\\Http2\\": "src/"
+        }
+    },
+    "authors": [
+        {
+            "name": "NoccyLabs",
+            "email": "labs@noccy.com"
+        }
+    ],
+    "require": {
+        "react/http": "^1.9.0"
+    },
+    "require-dev": {
+        "phpunit/phpunit": "^11.0",
+        "phpstan/phpstan": "^1.10"
+    }
+}
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..e68bade
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,12 @@
+parameters:
+  level: 5
+    
+  excludePaths:
+    - doc
+    - vendor
+    - tests
+
+  # Paths to include in the analysis
+  paths:
+    - src
+
diff --git a/phpunit.xml b/phpunit.xml
new file mode 100644
index 0000000..0e66c06
--- /dev/null
+++ b/phpunit.xml
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/11.0/phpunit.xsd"
+         bootstrap="vendor/autoload.php"
+         cacheDirectory=".phpunit.cache"
+         executionOrder="depends,defects"
+         requireCoverageMetadata="true"
+         beStrictAboutCoverageMetadata="true"
+         beStrictAboutOutputDuringTests="true"
+         failOnRisky="true"
+         failOnWarning="true">
+    <testsuites>
+        <testsuite name="default">
+            <directory>tests</directory>
+        </testsuite>
+    </testsuites>
+
+    <source restrictDeprecations="true" restrictNotices="true" restrictWarnings="true">
+        <include>
+            <directory>src</directory>
+        </include>
+    </source>
+</phpunit>
diff --git a/src/Header/HeaderBag.php b/src/Header/HeaderBag.php
new file mode 100644
index 0000000..7d723dd
--- /dev/null
+++ b/src/Header/HeaderBag.php
@@ -0,0 +1,27 @@
+<?php
+
+namespace NoccyLabs\React\Http2\Header;
+
+use NoccyLabs\React\Http2\Huffman\Codec;
+use NoccyLabs\React\Http2\Huffman\Dictionary;
+
+/**
+ * An ordered list of HTTP/2 headers
+ * 
+ * 
+ */
+class HeaderBag
+{
+
+    private array $headers = [];
+
+    public function __construct(array $headers = [])
+    {
+        foreach ($headers as $name=>$value) $this->append($name, $value);
+    }
+
+    public function append(string $name, string $value)
+    {
+        $this->headers[] = [ $name, $value ];
+    }
+}
\ No newline at end of file
diff --git a/src/Header/HeaderPacker.php b/src/Header/HeaderPacker.php
new file mode 100644
index 0000000..ef44a8e
--- /dev/null
+++ b/src/Header/HeaderPacker.php
@@ -0,0 +1,155 @@
+<?php
+
+namespace NoccyLabs\React\Http2\Header;
+
+use NoccyLabs\React\Http2\Huffman\Codec;
+use NoccyLabs\React\Http2\Huffman\Dictionary;
+
+/**
+ * Per-connection header packer, implements HPACK for HTTP/2 as per RFC7541
+ * 
+ */
+class HeaderPacker
+{
+    /** @var Codec $huffman The codec and dictionary is static and shared */
+    private static ?Codec $huffman = null;
+
+    private static $staticTable = [
+        1     => [ ':authority', null],
+        2     => [ ':method', 'GET' ],
+        3     => [ ':method', 'POST'],
+        4     => [ ':path', '/'],
+        5     => [ ':path', '/index.html'],
+        6     => [ ':scheme', 'http'],
+        7     => [ ':scheme', 'https'],
+        8     => [ ':status', '200'],
+        9     => [ ':status', '204'],
+        10    => [ ':status', '206'],
+        11    => [ ':status', '304'],
+        12    => [ ':status', '400'],
+        13    => [ ':status', '404'],
+        14    => [ ':status', '500'],
+        15    => [ 'accept-charset', null],
+        16    => [ 'accept-encoding', 'gzip, deflate'],
+        17    => [ 'accept-language', null],
+        18    => [ 'accept-ranges', null],
+        19    => [ 'accept', null ],
+        20    => [ 'access-control-allow-origin', null],
+        21    => [ 'age', null],
+        22    => [ 'allow', null],
+        23    => [ 'authorization', null],
+        24    => [ 'cache-control', null],
+        25    => [ 'content-disposition', null],
+        26    => [ 'content-encoding', null],
+        27    => [ 'content-language', null],
+        28    => [ 'content-length', null],
+        29    => [ 'content-location', null],
+        30    => [ 'content-range', null],
+        31    => [ 'content-type', null],
+        32    => [ 'cookie', null],
+        33    => [ 'date', null],
+        34    => [ 'etag', null],
+        35    => [ 'expect', null],
+        36    => [ 'expires', null],
+        37    => [ 'from', null],
+        38    => [ 'host', null],
+        39    => [ 'if-match', null],
+        40    => [ 'if-modified-since', null],
+        41    => [ 'if-none-match', null],
+        42    => [ 'if-range', null],
+        43    => [ 'if-unmodified-since', null],
+        44    => [ 'last-modified', null],
+        45    => [ 'link', null],
+        46    => [ 'location', null],
+        47    => [ 'max-forwards', null],
+        48    => [ 'proxy-authenticate', null],
+        49    => [ 'proxy-authorization', null],
+        50    => [ 'range', null],
+        51    => [ 'referer', null],
+        52    => [ 'refresh', null],
+        53    => [ 'retry-after', null],
+        54    => [ 'server', null],
+        55    => [ 'set-cookie', null],
+        56    => [ 'strict-transport-security', null],
+        57    => [ 'transfer-encoding', null],
+        58    => [ 'user-agent', null],
+        59    => [ 'vary', null],
+        60    => [ 'via', null],
+        61    => [ 'www-authenticate', null],
+    ];
+    private const STATIC_TABLE_SIZE = 62; // considering unused index 0
+
+    public function __construct()
+    {
+        if (!self::$huffman) self::$huffman = new Codec(Dictionary::createRfc7541Dictionary());
+    }
+
+    public function packHeaders(HeaderBag $headers): string
+    {
+        $packed = '';
+
+
+        return $packed;
+    }
+
+    public function unpackHeaders(string $raw): HeaderBag
+    {
+        $headers = new HeaderBag();
+        $bytes = array_map("ord", str_split($raw));
+
+        while (count($bytes) > 0) {
+            $head = array_shift($bytes);
+            if ($head & 0x80) {
+                // Indexed field
+                [$header,$value] = $this->getIndexedHeader($head & 0x7F);
+                $headers->append($header,$value);
+            } elseif ($head & 0x40) {
+                // Indexed with literal
+                [$header,$value] = $this->getIndexedHeader($head & 0x3F);
+                $valueHead = array_shift($bytes);
+                $encoded = (bool)($valueHead & 0x80);
+                $length = ($valueHead & 0x7F);
+                while ($length-- > 0) {
+                    $value .= chr(array_shift($bytes));
+                }
+                if ($encoded) {
+                    $value = self::$huffman->decode($value);
+                }
+                $headers->append($header,$value);
+            } else {
+                // Literal field
+                $valueHead = array_shift($bytes);
+                $encoded = (bool)($valueHead & 0x80);
+                $length = ($valueHead & 0x7F);
+                $header = '';
+                while ($length-- > 0) {
+                    $header .= chr(array_shift($bytes));
+                }
+                if ($encoded) {
+                    $header = self::$huffman->decode($header);
+                }
+
+                $valueHead = array_shift($bytes);
+                $encoded = (bool)($valueHead & 0x80);
+                $length = ($valueHead & 0x7F);
+                $value = '';
+                while ($length-- > 0) {
+                    $value .= chr(array_shift($bytes));
+                }
+                if ($encoded) {
+                    $value = self::$huffman->decode($value);
+                }
+
+                $headers->append($header,$value);
+            }
+        }
+
+        return $headers;
+    }
+
+    private function getIndexedHeader(int $index): array
+    {
+        return self::$staticTable[$index];
+    }
+
+}
\ No newline at end of file
diff --git a/src/Huffman/Codec.php b/src/Huffman/Codec.php
new file mode 100644
index 0000000..de2a873
--- /dev/null
+++ b/src/Huffman/Codec.php
@@ -0,0 +1,50 @@
+<?php
+
+namespace NoccyLabs\React\Http2\Huffman;
+
+class Codec
+{
+    private Dictionary $dictionary;
+
+    const CODE_EOS = 256;
+
+    public function __construct(Dictionary $dictionary)
+    {
+        $this->dictionary = $dictionary;
+    }
+
+    public function decode(string $data): ?string
+    {
+        $in = array_map("ord", str_split($data));
+        $out = [];
+        $bits = '';
+        for ($ch = 0; $ch < count($in); $ch++) {
+            $bits .= str_pad(decbin($in[$ch]), 8, "0", STR_PAD_LEFT);
+            while (($code = $this->dictionary->match($bits)) !== null) {
+                if ($code === self::CODE_EOS) break(2);
+                $out[] = $code;
+            }
+        }
+        return join("", array_map("chr", $out));
+    }
+
+    public function encode(string $data): ?string
+    {
+        $in = array_map("ord", str_split($data));
+        //$in[] = self::CODE_EOS;
+        $out = [];
+        $bits = '';
+        for ($ch = 0; $ch < count($in); $ch++) {
+            $bits .= $this->dictionary->pattern($in[$ch]);
+            while (strlen($bits) >= 8) {
+                $out[] = bindec(substr($bits, 0, 8));
+                $bits = substr($bits, 8);
+            }
+        }
+        if (strlen($bits) > 0) {
+            $out[] = bindec(str_pad($bits, 8, "1", STR_PAD_RIGHT));
+        }
+        return join("", array_map("chr", $out));
+    }
+
+}
\ No newline at end of file
diff --git a/src/Huffman/Dictionary.php b/src/Huffman/Dictionary.php
new file mode 100644
index 0000000..ed313b8
--- /dev/null
+++ b/src/Huffman/Dictionary.php
@@ -0,0 +1,296 @@
+<?php
+
+namespace NoccyLabs\React\Http2\Huffman;
+
+class Dictionary
+{
+    private array $codes;
+
+    private array $patterns;
+
+    public function __construct(?array $codes = [])
+    {
+        $this->codes = $codes;
+        $this->patterns = array_flip($codes);
+    }
+
+    public function match(string &$pattern): ?int
+    {
+        for ($l = 1; $l <= strlen($pattern); $l++) {
+            $t = substr($pattern, 0, $l);
+            if (array_key_exists($t, $this->patterns)) {
+                $pattern = substr($pattern, strlen($t));
+                return $this->patterns[$t];
+            }
+        }
+        return null;
+    }
+
+    public function pattern(int $code): string
+    {
+        return $this->codes[$code];
+    }
+
+    public static function createRfc7541Dictionary(): Dictionary
+    {
+        return new Dictionary(array (
+            0 => '1111111111000',
+            1 => '11111111111111111011000',
+            2 => '1111111111111111111111100010',
+            3 => '1111111111111111111111100011',
+            4 => '1111111111111111111111100100',
+            5 => '1111111111111111111111100101',
+            6 => '1111111111111111111111100110',
+            7 => '1111111111111111111111100111',
+            8 => '1111111111111111111111101000',
+            9 => '111111111111111111101010',
+            10 => '111111111111111111111111111100',
+            11 => '1111111111111111111111101001',
+            12 => '1111111111111111111111101010',
+            13 => '111111111111111111111111111101',
+            14 => '1111111111111111111111101011',
+            15 => '1111111111111111111111101100',
+            16 => '1111111111111111111111101101',
+            17 => '1111111111111111111111101110',
+            18 => '1111111111111111111111101111',
+            19 => '1111111111111111111111110000',
+            20 => '1111111111111111111111110001',
+            21 => '1111111111111111111111110010',
+            22 => '111111111111111111111111111110',
+            23 => '1111111111111111111111110011',
+            24 => '1111111111111111111111110100',
+            25 => '1111111111111111111111110101',
+            26 => '1111111111111111111111110110',
+            27 => '1111111111111111111111110111',
+            28 => '1111111111111111111111111000',
+            29 => '1111111111111111111111111001',
+            30 => '1111111111111111111111111010',
+            31 => '1111111111111111111111111011',
+            32 => '010100',
+            33 => '1111111000',
+            34 => '1111111001',
+            35 => '111111111010',
+            36 => '1111111111001',
+            37 => '010101',
+            38 => '11111000',
+            39 => '11111111010',
+            40 => '1111111010',
+            41 => '1111111011',
+            42 => '11111001',
+            43 => '11111111011',
+            44 => '11111010',
+            45 => '010110',
+            46 => '010111',
+            47 => '011000',
+            48 => '00000',
+            49 => '00001',
+            50 => '00010',
+            51 => '011001',
+            52 => '011010',
+            53 => '011011',
+            54 => '011100',
+            55 => '011101',
+            56 => '011110',
+            57 => '011111',
+            58 => '1011100',
+            59 => '11111011',
+            60 => '111111111111100',
+            61 => '100000',
+            62 => '111111111011',
+            63 => '1111111100',
+            64 => '1111111111010',
+            65 => '100001',
+            66 => '1011101',
+            67 => '1011110',
+            68 => '1011111',
+            69 => '1100000',
+            70 => '1100001',
+            71 => '1100010',
+            72 => '1100011',
+            73 => '1100100',
+            74 => '1100101',
+            75 => '1100110',
+            76 => '1100111',
+            77 => '1101000',
+            78 => '1101001',
+            79 => '1101010',
+            80 => '1101011',
+            81 => '1101100',
+            82 => '1101101',
+            83 => '1101110',
+            84 => '1101111',
+            85 => '1110000',
+            86 => '1110001',
+            87 => '1110010',
+            88 => '11111100',
+            89 => '1110011',
+            90 => '11111101',
+            91 => '1111111111011',
+            92 => '1111111111111110000',
+            93 => '1111111111100',
+            94 => '11111111111100',
+            95 => '100010',
+            96 => '111111111111101',
+            97 => '00011',
+            98 => '100011',
+            99 => '00100',
+            100 => '100100',
+            101 => '00101',
+            102 => '100101',
+            103 => '100110',
+            104 => '100111',
+            105 => '00110',
+            106 => '1110100',
+            107 => '1110101',
+            108 => '101000',
+            109 => '101001',
+            110 => '101010',
+            111 => '00111',
+            112 => '101011',
+            113 => '1110110',
+            114 => '101100',
+            115 => '01000',
+            116 => '01001',
+            117 => '101101',
+            118 => '1110111',
+            119 => '1111000',
+            120 => '1111001',
+            121 => '1111010',
+            122 => '1111011',
+            123 => '111111111111110',
+            124 => '11111111100',
+            125 => '11111111111101',
+            126 => '1111111111101',
+            127 => '1111111111111111111111111100',
+            128 => '11111111111111100110',
+            129 => '1111111111111111010010',
+            130 => '11111111111111100111',
+            131 => '11111111111111101000',
+            132 => '1111111111111111010011',
+            133 => '1111111111111111010100',
+            134 => '1111111111111111010101',
+            135 => '11111111111111111011001',
+            136 => '1111111111111111010110',
+            137 => '11111111111111111011010',
+            138 => '11111111111111111011011',
+            139 => '11111111111111111011100',
+            140 => '11111111111111111011101',
+            141 => '11111111111111111011110',
+            142 => '111111111111111111101011',
+            143 => '11111111111111111011111',
+            144 => '111111111111111111101100',
+            145 => '111111111111111111101101',
+            146 => '1111111111111111010111',
+            147 => '11111111111111111100000',
+            148 => '111111111111111111101110',
+            149 => '11111111111111111100001',
+            150 => '11111111111111111100010',
+            151 => '11111111111111111100011',
+            152 => '11111111111111111100100',
+            153 => '111111111111111011100',
+            154 => '1111111111111111011000',
+            155 => '11111111111111111100101',
+            156 => '1111111111111111011001',
+            157 => '11111111111111111100110',
+            158 => '11111111111111111100111',
+            159 => '111111111111111111101111',
+            160 => '1111111111111111011010',
+            161 => '111111111111111011101',
+            162 => '11111111111111101001',
+            163 => '1111111111111111011011',
+            164 => '1111111111111111011100',
+            165 => '11111111111111111101000',
+            166 => '11111111111111111101001',
+            167 => '111111111111111011110',
+            168 => '11111111111111111101010',
+            169 => '1111111111111111011101',
+            170 => '1111111111111111011110',
+            171 => '111111111111111111110000',
+            172 => '111111111111111011111',
+            173 => '1111111111111111011111',
+            174 => '11111111111111111101011',
+            175 => '11111111111111111101100',
+            176 => '111111111111111100000',
+            177 => '111111111111111100001',
+            178 => '1111111111111111100000',
+            179 => '111111111111111100010',
+            180 => '11111111111111111101101',
+            181 => '1111111111111111100001',
+            182 => '11111111111111111101110',
+            183 => '11111111111111111101111',
+            184 => '11111111111111101010',
+            185 => '1111111111111111100010',
+            186 => '1111111111111111100011',
+            187 => '1111111111111111100100',
+            188 => '11111111111111111110000',
+            189 => '1111111111111111100101',
+            190 => '1111111111111111100110',
+            191 => '11111111111111111110001',
+            192 => '11111111111111111111100000',
+            193 => '11111111111111111111100001',
+            194 => '11111111111111101011',
+            195 => '1111111111111110001',
+            196 => '1111111111111111100111',
+            197 => '11111111111111111110010',
+            198 => '1111111111111111101000',
+            199 => '1111111111111111111101100',
+            200 => '11111111111111111111100010',
+            201 => '11111111111111111111100011',
+            202 => '11111111111111111111100100',
+            203 => '111111111111111111111011110',
+            204 => '111111111111111111111011111',
+            205 => '11111111111111111111100101',
+            206 => '111111111111111111110001',
+            207 => '1111111111111111111101101',
+            208 => '1111111111111110010',
+            209 => '111111111111111100011',
+            210 => '11111111111111111111100110',
+            211 => '111111111111111111111100000',
+            212 => '111111111111111111111100001',
+            213 => '11111111111111111111100111',
+            214 => '111111111111111111111100010',
+            215 => '111111111111111111110010',
+            216 => '111111111111111100100',
+            217 => '111111111111111100101',
+            218 => '11111111111111111111101000',
+            219 => '11111111111111111111101001',
+            220 => '1111111111111111111111111101',
+            221 => '111111111111111111111100011',
+            222 => '111111111111111111111100100',
+            223 => '111111111111111111111100101',
+            224 => '11111111111111101100',
+            225 => '111111111111111111110011',
+            226 => '11111111111111101101',
+            227 => '111111111111111100110',
+            228 => '1111111111111111101001',
+            229 => '111111111111111100111',
+            230 => '111111111111111101000',
+            231 => '11111111111111111110011',
+            232 => '1111111111111111101010',
+            233 => '1111111111111111101011',
+            234 => '1111111111111111111101110',
+            235 => '1111111111111111111101111',
+            236 => '111111111111111111110100',
+            237 => '111111111111111111110101',
+            238 => '11111111111111111111101010',
+            239 => '11111111111111111110100',
+            240 => '11111111111111111111101011',
+            241 => '111111111111111111111100110',
+            242 => '11111111111111111111101100',
+            243 => '11111111111111111111101101',
+            244 => '111111111111111111111100111',
+            245 => '111111111111111111111101000',
+            246 => '111111111111111111111101001',
+            247 => '111111111111111111111101010',
+            248 => '111111111111111111111101011',
+            249 => '1111111111111111111111111110',
+            250 => '111111111111111111111101100',
+            251 => '111111111111111111111101101',
+            252 => '111111111111111111111101110',
+            253 => '111111111111111111111101111',
+            254 => '111111111111111111111110000',
+            255 => '11111111111111111111101110',
+            256 => '111111111111111111111111111111',
+        ));
+    }
+}
\ No newline at end of file
diff --git a/tests/Header/HeaderPackerTest.php b/tests/Header/HeaderPackerTest.php
new file mode 100644
index 0000000..dc66449
--- /dev/null
+++ b/tests/Header/HeaderPackerTest.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace NoccyLabs\React\Http2\Header;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+
+#[CoversClass(HeaderBag::class)]
+#[CoversClass(HeaderPacker::class)]
+class HeaderPackerTest extends \PHPUnit\Framework\TestCase
+{
+
+    public function testUnpackingExamplesFromRfc7541()
+    {
+        $packer = new HeaderPacker();
+
+        $in = "\x82\x86\x84\x41\x8c\xf1\xe3\xc2\xe5\xf2\x3a\x6b\xa0\xab\x90\xf4\xff";
+        $expect = new HeaderBag([
+            ':method' => 'GET',
+            ':scheme' => 'http',
+            ':path' => '/',
+            ':authority' => 'www.example.com'
+        ]);
+        $out = $packer->unpackHeaders($in);
+
+        $this->assertEquals($expect, $out);
+
+    }
+
+
+}
\ No newline at end of file
diff --git a/tests/Huffman/CodecTest.php b/tests/Huffman/CodecTest.php
new file mode 100644
index 0000000..3e31f6f
--- /dev/null
+++ b/tests/Huffman/CodecTest.php
@@ -0,0 +1,38 @@
+<?php
+
+namespace NoccyLabs\React\Http2\Huffman;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+
+#[CoversClass(Codec::class)]
+#[CoversClass(Dictionary::class)]
+class CodecTest extends \PHPUnit\Framework\TestCase
+{
+
+    public function testDecodingExamplesFromRfc7541()
+    {
+        $dict = Dictionary::createRfc7541Dictionary();
+        $huff = new Codec($dict);
+
+        $in = "\xf1\xe3\xc2\xe5\xf2\x3a\x6b\xa0\xab\x90\xf4\xff";
+        $expect = "www.example.com";
+        $out = $huff->decode($in);
+
+        $this->assertEquals($expect, $out);
+
+    }
+
+    public function testEncodingExamplesFromRfc7541()
+    {
+        $dict = Dictionary::createRfc7541Dictionary();
+        $huff = new Codec($dict);
+
+        $in = "www.example.com";
+        $expect = "\xf1\xe3\xc2\xe5\xf2\x3a\x6b\xa0\xab\x90\xf4\xff";
+        $out = $huff->encode($in);
+
+        $this->assertEquals($expect, $out);
+
+    }
+
+}
\ No newline at end of file