Merge branch 'master' into php-units-of-measure-issue-62

PhpUnitsOfMeasure · Jul 26, 2017 · a0fe8e0 · a0fe8e0
2 parents 45b8b96 + 212a332
commit a0fe8e0
Show file tree

Hide file tree

Showing 3 changed files with 107 additions and 1 deletion.
diff --git a/source/AbstractPhysicalQuantity.php b/source/AbstractPhysicalQuantity.php
@@ -12,6 +12,23 @@ abstract class AbstractPhysicalQuantity implements PhysicalQuantityInterface
      */
     // protected static $unitDefinitions;
 
+    /**
+     * Static cache for unit lookups.
+     *
+     * @var UnitOfMeasureInterface[]
+     */
+    private static $unitCache = [];
+
+    /**
+     * Create a cache key for the unit lookup cache.
+     *
+     * @var UnitOfMeasureInterface[]
+     */
+    private static function buildUnitCacheKey($unit)
+    {
+        return get_called_class() . '#' . $unit;
+    }
+
     /**
      * Register a new unit of measure for all instances of this this physical quantity.
      *
@@ -47,9 +64,14 @@ public static function getUnit($unit)
             static::initialize();
         }
 
+        $key = static::buildUnitCacheKey($unit);
+        if (isset(self::$unitCache[$key])) {
+            return self::$unitCache[$key];
+        }
+
         foreach (static::$unitDefinitions as $unitOfMeasure) {
             if ($unit === $unitOfMeasure->getName() || $unitOfMeasure->isAliasOf($unit)) {
-                return $unitOfMeasure;
+                return self::$unitCache[$key] = $unitOfMeasure;
             }
         }
 

diff --git a/source/PhysicalQuantity/Power.php b/source/PhysicalQuantity/Power.php
@@ -0,0 +1,32 @@
+<?php
+namespace PhpUnitsOfMeasure\PhysicalQuantity;
+
+use PhpUnitsOfMeasure\AbstractPhysicalQuantity;
+use PhpUnitsOfMeasure\UnitOfMeasure;
+use PhpUnitsOfMeasure\HasSIUnitsTrait;
+
+class Power extends AbstractPhysicalQuantity
+{
+    use HasSIUnitsTrait;
+
+    protected static $unitDefinitions;
+
+    protected static function initialize()
+    {
+        // Watt
+        $watt = UnitOfMeasure::nativeUnitFactory('W');
+        $watt->addAlias('watt');
+        $watt->addAlias('watts');
+        static::addUnit($watt);
+
+        static::addMissingSIPrefixedUnits(
+            $watt,
+            1,
+            '%pW',
+            [
+                '%Pwatt',
+                '%Pwatts',
+            ]
+        );
+    }
+}
diff --git a/tests/PhysicalQuantity/PowerTest.php b/tests/PhysicalQuantity/PowerTest.php
@@ -0,0 +1,52 @@
+<?php
+
+namespace PhpUnitsOfMeasureTest\PhysicalQuantity;
+
+use PhpUnitsOfMeasure\PhysicalQuantity\Power;
+
+class PowerTest extends AbstractPhysicalQuantityTestCase
+{
+    protected $supportedUnitsWithAliases = [
+        'W',
+        'watt',
+        'watts',
+        'µW',
+        'microwatt',
+        'microwatts',
+        'mW',
+        'milliwatt',
+        'milliwatts',
+        'kW',
+        'kilowatt',
+        'kilowatts',
+        'MW',
+        'megawatt',
+        'megawatts',
+        'GW',
+        'gigawatt',
+        'gigawatts',
+        'TW',
+        'terawatt',
+        'terawatts',
+        'PW',
+        'petawatt',
+        'petawatts',
+    ];
+
+    protected function instantiateTestQuantity()
+    {
+        return new Power(1, 'W');
+    }
+
+    public function testToKilowatt()
+    {
+        $quantity = new Power(1000, 'W');
+        $this->assertEquals(1, $quantity->toUnit('kW'));
+    }
+
+    public function testToWatt()
+    {
+        $quantity = new Power(1, 'kW');
+        $this->assertEquals(1000, $quantity->toUnit('W'));
+    }
+}