Added support for histogram. (#6)

* Added support for histogram

src/Client.php

@@ -261,17 +261,17 @@ public function getLastMessage()
      *
      * @param string|string[] $metrics    Metric(s) to increment
      * @param int             $delta      Value to decrement the metric by
-     * @param int             $sampleRate Sample rate of metric
+     * @param float           $sampleRate Sample rate of metric
      * @param string[]        $tags       List of tags for this metric
      *
      * @return Client This instance
      */
-    public function increment($metrics, $delta = 1, $sampleRate = 1, array $tags = [])
+    public function increment($metrics, $delta = 1, $sampleRate = 1.0, array $tags = [])
     {
         $metrics = is_array($metrics) ? $metrics : [$metrics];
 
         $data = [];
-        if ($sampleRate < 1) {
+        if ($sampleRate < 1.0) {
             foreach ($metrics as $metric) {
                 if ((mt_rand() / mt_getrandmax()) <= $sampleRate) {
                     $data[$metric] = $delta . '|c|@' . $sampleRate;
@@ -356,6 +356,30 @@ public function gauge($metric, $value, array $tags = [])
         );
     }
 
+    /**
+     * Histogram
+     *
+     * @param string   $metric     Metric to send
+     * @param float    $value      Value to send
+     * @param float    $sampleRate Sample rate of metric
+     * @param string[] $tags       List of tags for this metric
+     *
+     * @return Client This instance
+     */
+    public function histogram($metric, $value, $sampleRate = 1.0, array $tags = [])
+    {
+        $data = [];
+        if ($sampleRate < 1.0) {
+            if ((mt_rand() / mt_getrandmax()) <= $sampleRate) {
+                $data[$metric] = $value . '|h|@' . $sampleRate;
+            }
+        } else {
+            $data[$metric] = $value . '|h';
+        }
+
+        return $this->send($data, $tags);
+    }
+
     /**
      * Sets - count the number of unique elements for a group
      *

tests/unit/HistogramTest.php

@@ -0,0 +1,51 @@
+<?php
+/**
+ * This file is part of graze/dog-statsd
+ *
+ * Copyright (c) 2016 Nature Delivered Ltd. <https://www.graze.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ *
+ * @license https://github.com/graze/dog-statsd/blob/master/LICENSE.md
+ * @link    https://github.com/graze/dog-statsd
+ */
+
+namespace Graze\DogStatsD\Test\Unit;
+
+use Graze\DogStatsD\Test\TestCase;
+
+class HistogramTest extends TestCase
+{
+    public function testHistogram()
+    {
+        $this->client->histogram('test_metric', 10);
+        $this->assertEquals('test_metric:10|h', $this->client->getLastMessage());
+
+        $this->client->histogram('test_metric', 1.2);
+        $this->assertEquals('test_metric:1.2|h', $this->client->getLastMessage());
+    }
+
+    public function testHistogramSample()
+    {
+        while ($this->client->getLastMessage() === '') {
+            $this->client->histogram('test_metric', 5, 0.75);
+        }
+        $this->assertEquals('test_metric:5|h|@0.75', $this->client->getLastMessage());
+    }
+
+    public function testHistogramTags()
+    {
+        $this->client->histogram('test_metric', 10, 1.0, []);
+        $this->assertEquals('test_metric:10|h', $this->client->getLastMessage());
+
+        $this->client->histogram('test_metric', 10, 1.0, ['tag1']);
+        $this->assertEquals('test_metric:10|h|#tag1', $this->client->getLastMessage());
+
+        $this->client->histogram('test_metric', 10, 1.0, ['tag1', 'tag2']);
+        $this->assertEquals('test_metric:10|h|#tag1,tag2', $this->client->getLastMessage());
+
+        $this->client->histogram('test_metric', 10, 1.0, ['tag1', 'tag1']);
+        $this->assertEquals('test_metric:10|h|#tag1,tag1', $this->client->getLastMessage());
+    }
+}