PHP 5.3 support

.travis.yml

@@ -1,6 +1,7 @@
 language: php
 php:
   - 5.6
+  - 5.3
 
 services:
   - redis-server

composer.json

@@ -7,12 +7,14 @@
         }
     ],
     "require": {
-        "php": ">=5.6.0",
+        "php": ">=5.3.3",
         "ext-redis": "*"
     },
     "require-dev": {
-        "phpunit/phpunit": "5.4.6",
-        "guzzlehttp/guzzle": "~6.0"
+        "phpunit/phpunit": "4.1.0"
+    },
+    "suggest": {
+        "guzzlehttp/guzzle": "~6.0 for running the blackbox tests."
     },
     "autoload": {
         "psr-0": {

src/Prometheus/RedisAdapter.php

@@ -18,19 +18,19 @@ class RedisAdapter
     const PROMETHEUS_SAMPLE_LABEL_VALUES_SUFFIX = '_LABEL_VALUES';
     const PROMETHEUS_SAMPLE_NAME_SUFFIX = '_NAME';
 
-    const METRIC_TYPES = [
-        Gauge::TYPE,
-        Counter::TYPE,
-        Histogram::TYPE,
-    ];
-
     private $hostname;
     private $redis;
+    private $metricTypes;
 
     public function __construct($hostname)
     {
         $this->hostname = $hostname;
         $this->redis = new \Redis();
+        $this->metricTypes = array(
+            Gauge::TYPE,
+            Counter::TYPE,
+            Histogram::TYPE,
+        );
     }
 
     public function flushRedis()
@@ -54,7 +54,7 @@ public function fetchMetrics()
     {
         $this->openConnection();
         $metrics = array();
-        foreach (self::METRIC_TYPES as $metricType) {
+        foreach ($this->metricTypes as $metricType) {
             $metrics = array_merge($metrics, $this->fetchMetricsByType($metricType));
         }
         return $metrics;

src/Prometheus/RenderTextFormat.php

@@ -30,7 +30,8 @@ public function render(array $metrics)
     private function renderSample(Sample $sample)
     {
         $escapedLabels = array();
-        if (!empty($sample->getLabels())) {
+        $labels = $sample->getLabels();
+        if (!empty($labels)) {
             foreach ($sample->getLabels() as $labelName => $labelValue) {
                 $escapedLabels[] = $labelName . '="' . $this->escapeLabelValue($labelValue) . '"';
             }