Support Redis; fixes #13

backend-php/include/config.php

@@ -1,5 +1,21 @@
 <?php const CONFIG = array(
 
+// The type of storage backend Hauk will use. Valid values include:
+// MEMCACHED, REDIS
+//
+// For MEMCACHED, you need either the `memcached` or `memcache` extensions
+// enabled in PHP.
+//
+// For REDIS, you need `redis` extension enabled. Note that `redis` depends on
+// `igbinary`, so if you get an error that a redis extension was not found, even
+// though you enabled `redis`, you may have to also install and enable
+// `igbinary` in PHP.
+"storage_backend"       => REDIS,
+
+/*----------------------------------------------------------------------------*\
+|  MEMCACHED SPECIFIC SETTINGS                                                 |
+\*----------------------------------------------------------------------------*/
+
 // Connection to memcached for data storage. To connect via UNIX socket instead
 // of TCP, set host to 'unix:///path/to/memcached.sock' and port to 0.
 "memcached_host"        => 'localhost',
@@ -18,6 +34,28 @@
 // shared memcached instance or run multiple instances of Hauk.
 "memcached_prefix"  => 'hauk',
 
+/*----------------------------------------------------------------------------*\
+|  REDIS SPECIFIC SETTINGS                                                     |
+\*----------------------------------------------------------------------------*/
+
+// Connection to Redis for data storage. To connect via UNIX socket instead of
+// TCP, set host to '/path/to/redis.sock'.
+"redis_host"            => 'localhost',
+"redis_port"            => 6379,
+
+// If you use password authentication in Redis, set `redis_use_auth` to true and
+// enter the password in `redis_auth`.
+"redis_use_auth"        => false,
+"redis_auth"            => '',
+
+// A prefix to use for all variables sent to Redis. Useful if you have a shared
+// Redis instance or run multiple instances of Hauk.
+"redis_prefix"          => 'hauk',
+
+/*----------------------------------------------------------------------------*\
+|  GENERAL SETTINGS                                                            |
+\*----------------------------------------------------------------------------*/
+
 // A hashed password that is required for creating sessions and posting location
 // data to Hauk. To generate this value on the terminal:
 //   - MD5 (insecure!):     openssl passwd -1

backend-php/include/inc.php

@@ -21,6 +21,9 @@ const LINK_ID_RAND_BYTES = 32;
 const GROUP_PIN_MIN = 100000;
 const GROUP_PIN_MAX = 999999;
 
+const MEMCACHED = 0;
+const REDIS = 1;
+
 const KILOMETERS_PER_HOUR = array(
     // Relative distance per second multiplied by number of seconds per hour.
     "mpsMultiplier" => 3.6,
@@ -42,6 +45,7 @@ const DEFAULTS = array(
     // This is the default config. This file is used as a fallback for missing
     // options in config.php.
 
+    "storage_backend"       => MEMCACHED,
     "memcached_host"        => 'localhost',
     "memcached_port"        => 11211,
     "memcached_binary"      => false,
@@ -49,6 +53,11 @@ const DEFAULTS = array(
     "memcached_sasl_user"   => "",
     "memcached_sasl_pass"   => "",
     "memcached_prefix"      => 'hauk',
+    "redis_host"            => 'localhost',
+    "redis_port"            => 6379,
+    "redis_use_auth"        => false,
+    "redis_auth"            => '',
+    "redis_prefix"          => 'hauk',
     "password_hash"         => '$2y$10$4ZP1iY8A3dZygXoPgsXYV.S3gHzBbiT9nSfONjhWrvMxVPkcFq1Ka',
     "map_tile_uri"          => 'https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png',
     "map_attribution"       => 'Map data &copy; <a href="https://www.openstreetmap.org/">OpenStreetMap</a> contributors, <a href="https://creativecommons.org/licenses/by-sa/2.0/">CC-BY-SA</a>',
@@ -91,9 +100,9 @@ function getConfig($item) {
     if (array_key_exists($item, DEFAULTS)) return DEFAULTS[$item];
 }
 
-define("PREFIX_SESSION", getConfig("memcached_prefix")."-session-");
-define("PREFIX_LOCDATA", getConfig("memcached_prefix")."-locdata-");
-define("PREFIX_GROUPID", getConfig("memcached_prefix")."-groupid-");
+define("PREFIX_SESSION", "-session-");
+define("PREFIX_LOCDATA", "-locdata-");
+define("PREFIX_GROUPID", "-groupid-");
 
 // A base class for location shares. Shares contain a reference to all sessions
 // that broadcasts location data to the share, but does not contain the location
@@ -555,16 +564,30 @@ function requirePOST(...$args) {
 // Hauk maintains compatibility with both `memcache` and `memcached`, meaning we
 // need an abstraction layer between Hauk and the extensions to ensure a unified
 // interface for both. This code loads the correct memcache wrapper.
-if (extension_loaded("memcached")) {
-    include_once(__DIR__."/wrapper/memcached.php");
-} else if (extension_loaded("memcache")) {
-    include_once(__DIR__."/wrapper/memcache.php");
-} else {
-    die("No compatible memcached extension (memcache or memcached) is enabled in your PHP config!\n");
+
+switch (getConfig("storage_backend")) {
+    case MEMCACHED:
+        if (extension_loaded("memcached")) {
+            include_once(__DIR__."/wrapper/memcached.php");
+        } else if (extension_loaded("memcache")) {
+            include_once(__DIR__."/wrapper/memcache.php");
+        } else {
+            die("No compatible memcached extension (memcache or memcached) is enabled in your PHP config!\n");
+        }
+        break;
+    case REDIS:
+        if (extension_loaded("redis")) {
+            include_once(__DIR__."/wrapper/redis.php");
+        } else {
+            die("No compatible redis extension (redis) is enabled in your PHP config!\n");
+        }
+        break;
+    default:
+        die("You have set an invalid storage_backend in Hauk!");
 }
 
+
 // Returns a memcached instance.
 function memConnect() {
-    $memcache = new MemWrapper(getConfig("memcached_host"), getConfig("memcached_port"));
-    return $memcache;
+    return new MemWrapper();
 }

backend-php/include/wrapper/memcache.php

@@ -8,28 +8,24 @@
 class MemWrapper {
     private $memcache = null;
 
-    function __construct($host, $port) {
+    function __construct() {
         $this->memcache = new Memcache();
         $this->memcache->connect(getConfig("memcached_host"), getConfig("memcached_port"))
                    or die ("Server could not connect to memcached!\n");
     }
 
     function get($key) {
-        $data = $this->memcache->get($key);
+        $data = $this->memcache->get(getConfig("memcached_prefix").$key);
         if ($data === false) return false;
         return json_decode($data, true);
     }
 
     function set($key, $data, $expire) {
-        $this->memcache->set($key, json_encode($data), 0, $expire);
-    }
-
-    function replace($key, $data, $expire) {
-        $this->memcache->replace($key, json_encode($data), 0, $expire);
+        $this->memcache->set(getConfig("memcached_prefix").$key, json_encode($data), 0, $expire);
     }
 
     function delete($key) {
-        $this->memcache->delete($key);
+        $this->memcache->delete(getConfig("memcached_prefix").$key);
     }
 }
 

backend-php/include/wrapper/memcached.php

@@ -8,7 +8,7 @@
 class MemWrapper {
     private $memcache = null;
 
-    function __construct($host, $port) {
+    function __construct() {
         // If the hostname starts with "unix://", this is a UNIX socket.
         // The `memcached` extension only needs the full pathname and not the
         // unix scheme, so we strip the scheme from the path.
@@ -27,21 +27,17 @@ class MemWrapper {
     }
 
     function get($key) {
-        $data = $this->memcache->get($key);
+        $data = $this->memcache->get(getConfig("memcached_prefix").$key);
         if ($data === false) return false;
         return json_decode($data, true);
     }
 
     function set($key, $data, $expire) {
-        $this->memcache->set($key, json_encode($data), $expire);
-    }
-
-    function replace($key, $data) {
-        $this->memcache->replace($key, json_encode($data), $expire);
+        $this->memcache->set(getConfig("memcached_prefix").$key, json_encode($data), $expire);
     }
 
     function delete($key) {
-        $this->memcache->delete($key);
+        $this->memcache->delete(getConfig("memcached_prefix").$key);
     }
 }
 

backend-php/include/wrapper/redis.php

@@ -0,0 +1,34 @@
+<?php
+
+// This class is a wrapper class for the `redis` extension in PHP, for
+// communication with Redis backends.
+
+class MemWrapper {
+    private $redis = null;
+
+    function __construct() {
+        $this->redis = new Redis();
+        if (getConfig("redis_use_auth")) {
+            $this->redis->auth(getConfig("redis_auth"))
+                or die("Incorrect Redis authentication!");
+        }
+        $this->redis->connect(getConfig("redis_host"), getConfig("redis_port"))
+                   or die ("Server could not connect to Redis!\n");
+    }
+
+    function get($key) {
+        $data = $this->redis->get(getConfig("redis_prefix").$key);
+        if ($data === false) return false;
+        return json_decode($data, true);
+    }
+
+    function set($key, $data, $expire) {
+        $this->redis->setEx(getConfig("redis_prefix").$key, $expire - time(), json_encode($data));
+    }
+
+    function delete($key) {
+        $this->redis->del(getConfig("redis_prefix").$key);
+    }
+}
+
+?>