Add a cache to store UUID -> Fedora 4 path mappings (#41)

* First draft of a cache for UUID -> F4 paths in transactions.

* Update interface and implementation methods

* New tests for KeyCache

* Fixing up Redis

* Correct response is +PONG

* PSR-2 compliance and function mocking case-sensitivity.

composer.json

@@ -16,7 +16,8 @@
     },
     "require-dev": {
         "phpunit/phpunit": "^4.8",
-        "squizlabs/php_codesniffer": "^2.0@dev"
+        "squizlabs/php_codesniffer": "^2.0@dev",
+        "mockery/mockery": "^0.9"
     },
     "license": "GPLv3",
     "authors": [

phpunit.xml.dist

@@ -8,5 +8,8 @@
         <testsuite name="uuid">
             <directory>test/UuidGenerator</directory>
         </testsuite>
+        <testsuite name="cache">
+            <directory>test/KeyCache</directory>
+        </testsuite>
     </testsuites>
 </phpunit>

src/KeyCache/IUuidCache.php

@@ -0,0 +1,81 @@
+<?php
+/**
+ * @file
+ * Part of the Chullo service
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Islandora\Chullo\KeyCache;
+
+/**
+ * Interface for key -> value service to store UUID -> Fedora Paths
+ *  not yet indexed into the triplestore (ie. in a transaction)
+ * @author Jared Whiklo <[email protected]>
+ * @since 2016-04-12
+ */
+interface IUuidCache
+{
+
+    /**
+     * Sets the value for the provided key.
+     *
+     * @var string $txID
+     *   The transaction ID.
+     * @var string $uuid
+     *   The UUID.
+     * @var string $path
+     *   The Fedora path.
+     * @var int $expire
+     *   The number of seconds from now to expire. Default to an hour.
+     * @return bool
+     *   Was key set successful.
+     */
+    public function set($txID, $uuid, $path, $expire = 3600);
+
+    /**
+     * Gets the Fedora path for the provided UUID.
+     *
+     * @var string $txID
+     *   The transaction ID.
+     * @var string $uuid
+     *   The UUID
+     * @return string
+     *   The UUID corresponding to the path in the transaction or NULL
+     */
+    public function getByUuid($txID, $uuid);
+
+    /**
+     * Gets the UUID for the provided path.
+     *
+     * @var string $txID
+     *   The transaction ID.
+     * @var string $path
+     *   The key.
+     * @return string
+     *   The UUID corresponding to the path in the transaction or NULL
+     */
+    public function getByPath($txID, $path);
+
+    /**
+     * Delete any pairs related to transaction ID.
+     *
+     * @var string $txID
+      *   The transaction ID.
+     * @return void
+     */
+    public function delete($txID);
+
+    /**
+     * Set/reset the transaction to expire in $seconds seconds.
+     *
+     * @var string $txID
+     *   The transaction ID.
+     * @var int $seconds
+     *   The number of seconds from now to expire.
+     * @return bool
+     *   Whether the expiry was set or not.
+     */
+    public function extend($txID, $seconds);
+}

src/KeyCache/RedisKeyCache.php

@@ -0,0 +1,161 @@
+<?php
+/**
+ * @file
+ * This is part of Chullo service.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Islandora\Chullo\KeyCache;
+
+/**
+ * Implementation of the IKeyCache using Redis and phpredis.
+ *
+ * @author Jared Whiklo <[email protected]>
+ * @since 2016-04-12
+ */
+class RedisKeyCache implements IUuidCache
+{
+
+    /**
+     * @var Redis $redis
+     *   The Redis object.
+     */
+    protected $redis;
+    /**
+     * @var bool $connected
+     *   Are we connected to the Redis server yet.
+     */
+    private $connected = false;
+    /**
+     * @var string $host
+     *   The hostname of the redis server.
+     */
+    private $host;
+    /**
+     * @var int $port
+     *   The port of the redis server.
+     */
+    private $port;
+
+    /**
+     * @param \Redis $instance
+     *   An instance of the Redis client
+     */
+    public function __construct(\Redis $instance, $host, $port)
+    {
+        $this->redis = $instance;
+        $this->redis->host = $host;
+        $this->redis->port = $port;
+    }
+
+    /**
+     *
+     */
+    public function __destruct()
+    {
+        $this->redis->close();
+    }
+
+    /**
+     * Create using a hostname and port.
+     *
+     * @param $host
+     *   The hostname of the redis server
+     * @param $port
+     *   The port of the redis server
+     * @return RedisKeyCache
+     */
+    public static function create($host = "localhost", $port = 6379)
+    {
+        $redis = new \Redis();
+        $redis->connect($host, $port);
+        return new RedisKeyCache($redis, $host, $port);
+    }
+
+    /**
+     * Check if we are connected to the Redis server.
+     *
+     * @return bool Whether we are connected.
+     */
+    private function isConnected()
+    {
+        try {
+            $result = $this->redis->ping();
+            $connected = ($result == "+PONG");
+        } catch (RedisException $e) {
+            error_log("RedisKeyCache: Error communicating with Redis server - " . $e->getMessage());
+            # Try connecting once more.
+            $this->redis->connect($this->host, $this->port);
+            $result = $this->redis->ping();
+            $connected = ($result == "+PONG");
+        }
+        return $connected;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function set($txID, $uuid, $path, $expire = 3600)
+    {
+        if ($this->isConnected()) {
+            $result = $this->redis->hSetNx($txID, $uuid, $path);
+            if ($result) {
+                $this->redis->expire($txID, $expire);
+            }
+            return $result;
+        }
+        /**
+         * TODO: return exceptions??
+         */
+        return false;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getByUuid($txId, $uuid)
+    {
+        if ($this->isConnected()) {
+            return $this->redis->hget($txId, $uuid);
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getByPath($txId, $path)
+    {
+        if ($this->isConnected()) {
+            $hashes = $this->redis->hgetall($txId);
+            if ($hashes !== false) {
+                $flipped = array_flip($hashes);
+                if (array_key_exists($path, $flipped)) {
+                    return $flipped[$path];
+                }
+            }
+        }
+        return false;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function extend($txId, $expire = 3600)
+    {
+        if ($this->isConnected()) {
+            return $this->redis->expire($txId, $expire);
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function delete($txId)
+    {
+        if ($this->isConnected()) {
+            return $this->redis->del($txId);
+        }
+    }
+}

test/KeyCache/UuidCacheTest.php

@@ -0,0 +1,110 @@
+<?php
+
+namespace Islandora\Chullo\KeyCache;
+
+use Islandora\Chullo\Uuid\UuidGenerator;
+use Islandora\Chullo\KeyCache\RedisKeyCache;
+use Mockery\Adapter\Phpunit\MockeryTestCase;
+
+class UuidCacheTest extends \PHPUnit_Framework_TestCase
+{
+
+    protected $redis;
+
+    protected $uuid_gen;
+
+    public function setUp()
+    {
+        $this->redis = \Mockery::mock('\Redis');
+        $this->redis->shouldReceive('expire')->andReturn(1);
+        $this->redis->shouldReceive('ping')->andReturn("+PONG");
+        $this->redis->shouldReceive('close')->andReturn(null);
+
+        $this->uuid_gen = new UuidGenerator();
+    }
+
+    /**
+     * @covers RedisKeyCache::set
+     * @group UnitTest
+     */
+    public function testAddUuidPair()
+    {
+        // Need both to account for OS X and Linux differences.
+        $this->redis->shouldReceive('hSetNx')->andReturn(1);
+        $this->redis->shouldReceive('hsetnx')->andReturn(1);
+        $redis_cache = new RedisKeyCache($this->redis, 'localhost', 6379);
+
+        $transId = "tx:" . $this->uuid_gen->generateV4();
+        $uuid = $this->uuid_gen->generateV4();
+        $path = "http://localhost:8080/fcrepo/rest/object1";
+
+        $this->assertEquals(1, $redis_cache->set($transId, $uuid, $path), "Error setting uuid->path hash");
+    }
+
+    /**
+     * @covers RedisKeyCache::getByUuid
+     * @group UnitTest
+     */
+    public function testGetByUuid()
+    {
+        $txID = $transId = "tx:" . $this->uuid_gen->generateV4();
+        $uuid = $this->uuid_gen->generateV4();
+        $path = "http://localhost:8080/fcrepo/rest/object1";
+
+        // Need both to account for OS X and Linux differences.
+        $this->redis->shouldReceive('hGet')->with($txID, $uuid)->andReturn($path);
+        $this->redis->shouldReceive('hget')->with($txID, $uuid)->andReturn($path);
+
+        $redis_cache = new RedisKeyCache($this->redis, 'localhost', 6379);
+
+        $this->assertEquals($path, $redis_cache->getByUuid($txID, $uuid), "Error getting by Uuid");
+    }
+
+    /**
+     * @covers RedisKeyCache::getByPath
+     * @group UnitTest
+     */
+    public function testGetByPath()
+    {
+        $txID = $transId = "tx:" . $this->uuid_gen->generateV4();
+
+        $uuid1 = $this->uuid_gen->generateV4();
+        $path1 = "http://localhost:8080/fcrepo/rest/object1";
+
+        $uuid2 = $this->uuid_gen->generateV4();
+        $path2 = "http://localhost:8080/fcrepo/rest/object2";
+
+        $hashes = array(
+            $uuid1 => $path1,
+            $uuid2 => $path2,
+        );
+
+        // Need both to account for OS X and Linux differences.
+        $this->redis->shouldReceive('hGetAll')->with($txID)->andReturn($hashes);
+        $this->redis->shouldReceive('hgetall')->with($txID)->andReturn($hashes);
+
+        $redis_cache = new RedisKeyCache($this->redis, 'localhost', 6379);
+
+        $this->assertEquals($uuid2, $redis_cache->getByPath($txID, $path2), "Error getting by Path");
+    }
+
+    /**
+     * @covers RedisKeyCache::delete
+     * @group UnitTest
+     */
+    public function testDelete()
+    {
+        $txID = $transId = "tx:" . $this->uuid_gen->generateV4();
+
+        $this->redis->shouldReceive('del')->with($txID)->andReturn(1);
+
+        $redis_cache = new RedisKeyCache($this->redis, 'localhost', 6379);
+
+        $this->assertEquals(1, $redis_cache->delete($txID), "Error deleting transaction ID.");
+    }
+
+    public function tearDown()
+    {
+        \Mockery::close();
+    }
+}

test/UuidGenerator/UuidTest.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace Islandora\Chullo;
+namespace Islandora\Chullo\Uuid;
 
 use Ramsey\Uuid\Uuid;
 use Islandora\Chullo\Uuid\UuidGenerator;