From a1fc4ef300a36700397ea5ce221d2586081616de Mon Sep 17 00:00:00 2001
From: Ben Ramsey <ben@moontoast.com>
Date: Wed, 18 Jul 2012 20:13:37 -0500
Subject: [PATCH] Implemented compareTo() and equals()

---
 src/Rhumsaa/Uuid/Uuid.php       | 43 +++++++++++++++++++++++++++++++-
 tests/Rhumsaa/Uuid/UuidTest.php | 44 +++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+), 1 deletion(-)

diff --git a/src/Rhumsaa/Uuid/Uuid.php b/src/Rhumsaa/Uuid/Uuid.php
index 75030d6..1565842 100644
--- a/src/Rhumsaa/Uuid/Uuid.php
+++ b/src/Rhumsaa/Uuid/Uuid.php
@@ -113,12 +113,53 @@ final class Uuid
         return $this->toString();
     }
 
+    /**
+     * Compares this UUID with the specified UUID.
+     *
+     * The first of two UUIDs is greater than the second if the most
+     * significant field in which the UUIDs differ is greater for the first
+     * UUID.
+     *
+     * @param Uuid $uuid UUID to which this UUID is to be compared
+     * @return int -1, 0 or 1 as this UUID is less than, equal to, or greater than $uuid
+     */
     public function compareTo(Uuid $uuid)
     {
+        $comparison = null;
+
+        if ($this->getMostSignificantBits() < $uuid->getMostSignificantBits()) {
+            $comparison = -1;
+        } elseif ($this->getMostSignificantBits() > $uuid->getMostSignificantBits()) {
+            $comparison = 1;
+        } elseif ($this->getLeastSignificantBits() < $uuid->getLeastSignificantBits()) {
+            $comparison = -1;
+        } elseif ($this->getLeastSignificantBits() > $uuid->getLeastSignificantBits()) {
+            $comparison = 1;
+        } else {
+            $comparison = 0;
+        }
+
+        return $comparison;
     }
 
-    public function equals(Uuid $uuid)
+    /**
+     * Compares this object to the specified object.
+     *
+     * The result is true if and only if the argument is not null, is a UUID
+     * object, has the same variant, and contains the same value, bit for bit,
+     * as this UUID.
+     *
+     * @param object $obj
+     * @returns bool
+     */
+    public function equals($obj)
     {
+        if (!($obj instanceof Uuid)) {
+            return false;
+        }
+
+        return ($this->getMostSignificantBits() == $obj->getMostSignificantBits()
+            && $this->getLeastSignificantBits() == $obj->getLeastSignificantBits());
     }
 
     /**
diff --git a/tests/Rhumsaa/Uuid/UuidTest.php b/tests/Rhumsaa/Uuid/UuidTest.php
index 1f63d60..83e2e0d 100644
--- a/tests/Rhumsaa/Uuid/UuidTest.php
+++ b/tests/Rhumsaa/Uuid/UuidTest.php
@@ -484,6 +484,50 @@ class UuidTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals(2, $uuid->getVariant());
         $this->assertEquals(5, $uuid->getVersion());
     }
+
+    /**
+     * @covers Rhumsaa\Uuid\Uuid::compareTo
+     */
+    public function testCompareTo()
+    {
+        // $uuid1 and $uuid2 are identical
+        $uuid1 = Uuid::fromString('ff6f8cb0-c57d-11e1-9b21-0800200c9a66');
+        $uuid2 = Uuid::fromString('ff6f8cb0-c57d-11e1-9b21-0800200c9a66');
+
+        // The next three UUIDs are used for comparing msb and lsb in
+        // the compareTo() method
+
+        // msb are greater than $uuid4, lsb are greater than $uuid5
+        $uuid3 = Uuid::fromString('44cca71e-d13d-11e1-a959-c8bcc8a476f4');
+
+        // msb are less than in $uuid3, lsb are equal to those in $uuid3
+        $uuid4 = Uuid::fromString('44cca71e-d13d-11e2-a959-c8bcc8a476f4');
+
+        // msb are equal to those in $uuid3, lsb are less than in $uuid3
+        $uuid5 = Uuid::fromString('44cca71e-d13d-11e1-a959-c8bcc8a476f3');
+
+        $this->assertEquals(0, $uuid1->compareTo($uuid2));
+        $this->assertEquals(0, $uuid2->compareTo($uuid1));
+        $this->assertEquals(-1, $uuid3->compareTo($uuid4));
+        $this->assertEquals(1, $uuid4->compareTo($uuid3));
+        $this->assertEquals(-1, $uuid5->compareTo($uuid3));
+        $this->assertEquals(1, $uuid3->compareto($uuid5));
+    }
+
+    /**
+     * @covers Rhumsaa\Uuid\Uuid::equals
+     */
+    public function testEquals()
+    {
+        $uuid1 = Uuid::uuid5(Uuid::NAMESPACE_DNS, 'python.org');
+        $uuid2 = Uuid::uuid5(Uuid::NAMESPACE_DNS, 'python.org');
+        $uuid3 = Uuid::uuid5(Uuid::NAMESPACE_DNS, 'php.net');
+
+        $this->assertTrue($uuid1->equals($uuid2));
+        $this->assertFalse($uuid1->equals($uuid3));
+        $this->assertFalse($uuid1->equals(null));
+        $this->assertFalse($uuid1->equals(new \stdClass()));
+    }
 }
 
 /**