Merge pull request #31 from async-interop/registry

Add loop bound state registry

Author: bwoebi

composer.json

@@ -6,9 +6,17 @@
     "require": {
         "php": ">=5.5.0"
     },
+    "require-dev": {
+        "phpunit/phpunit": "^4|^5"
+    },
     "autoload": {
         "psr-4": {
             "Interop\\Async\\": "src"
         }
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "Interop\\Async\\": "test"
+        }
     }
 }

phpunit.xml

@@ -0,0 +1,12 @@
+<phpunit bootstrap="./vendor/autoload.php" colors="true">
+    <testsuites>
+        <testsuite name="Tests">
+            <directory>./test</directory>
+        </testsuite>
+    </testsuites>
+    <filter>
+        <whitelist addUncoveredFilesFromWhitelist="true">
+            <directory>./src</directory>
+        </whitelist>
+    </filter>
+</phpunit>

src/Loop.php

@@ -4,6 +4,8 @@
 
 final class Loop
 {
+    use Registry;
+
     /**
      * @var LoopDriver
      */
@@ -20,15 +22,18 @@ final class Loop
     public static function execute(callable $callback, LoopDriver $driver)
     {
         $previousDriver = self::$driver;
+        $previousRegistry = self::$registry;
 
         self::$driver = $driver;
+        self::$registry = [];
 
         try {
             $callback();
 
             self::$driver->run();
         } finally {
             self::$driver = $previousDriver;
+            self::$registry = $previousRegistry;
         }
     }
 

src/Registry.php

@@ -0,0 +1,58 @@
+<?php
+
+namespace Interop\Async;
+
+trait Registry
+{
+    /**
+     * @var array
+     */
+    private static $registry = null;
+
+    /**
+     * Stores information in the loop bound registry. This can be used to store
+     * loop bound information. Stored information is package private.
+     * Packages MUST NOT retrieve the stored state of other packages.
+     *
+     * Therefore packages SHOULD use the following prefix to keys:
+     * `vendor.package.`
+     *
+     * @param string $key namespaced storage key
+     * @param mixed $value the value to be stored
+     *
+     * @return void
+     */
+    public static function storeState($key, $value)
+    {
+        if (self::$registry === null) {
+            throw new \RuntimeException('Not within the scope of an event loop driver');
+        }
+
+        if ($value === null) {
+            unset(self::$registry[$key]);
+        } else {
+            self::$registry[$key] = $value;
+        }
+    }
+
+    /**
+     * Fetches information stored bound to the loop. Stored information is
+     * package private. Packages MUST NOT retrieve the stored state of
+     * other packages.
+     *
+     * Therefore packages SHOULD use the following prefix to keys:
+     * `vendor.package.`
+     *
+     * @param string $key namespaced storage key
+     *
+     * @return mixed previously stored value or null if it doesn't exist
+     */
+    public static function fetchState($key)
+    {
+        if (self::$registry === null) {
+            throw new \RuntimeException('Not within the scope of an event loop driver');
+        }
+
+        return isset(self::$registry[$key]) ? self::$registry[$key] : null;
+    }
+}

src/UnsupportedFeatureException.php

@@ -6,4 +6,7 @@
  * Must be thrown if an optional feature is not supported by the current driver
  * or system.
  */
-class UnsupportedFeatureException extends \RuntimeException { }
+class UnsupportedFeatureException extends \RuntimeException
+{
+
+}

test/RegistryTest.php

@@ -0,0 +1,67 @@
+<?php
+
+namespace Interop\Async;
+
+class RegistryTest extends \PHPUnit_Framework_TestCase
+{
+    use Registry;
+
+    protected function setUp()
+    {
+        self::$registry = null;
+    }
+
+    /**
+     * @test
+     * @expectedException \RuntimeException
+     */
+    public function fetchfailsOutsideOfLoop()
+    {
+        self::fetchState("foobar");
+    }
+
+    /**
+     * @test
+     * @expectedException \RuntimeException
+     */
+    public function storefailsOutsideOfLoop()
+    {
+        self::fetchState("store");
+    }
+
+    /** @test */
+    public function defaultsToNull()
+    {
+        // emulate we're in an event loop…
+        self::$registry = [];
+        $this->assertNull(self::fetchState("foobar"));
+    }
+
+    /**
+     * @test
+     * @dataProvider provideValues
+     */
+    public function fetchesStoredValue($value)
+    {
+        // emulate we're in an event loop…
+        self::$registry = [];
+
+        $this->assertNull(self::fetchState("foobar"));
+        self::storeState("foobar", $value);
+
+        $this->assertSame($value, self::fetchState("foobar"));
+    }
+
+    public function provideValues()
+    {
+        return [
+            ["string"],
+            [42],
+            [1.001],
+            [true],
+            [false],
+            [null],
+            [new \StdClass],
+        ];
+    }
+}