metrics importer implemented

src/Metrics/Importer/PrometheusImporter.php

@@ -0,0 +1,63 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Basis\Telemetry\Metrics\Importer;
+
+use Basis\Telemetry\Metrics\Info;
+use Basis\Telemetry\Metrics\Registry;
+
+class PrometheusImporter
+{
+    public function __construct(private Registry $registry, private Info $info)
+    {
+    }
+
+    public function fromString(string $string, string $prefix = ''): self
+    {
+        $info = [];
+        $values = [];
+
+        foreach (explode(PHP_EOL, $string) as $line) {
+            if (substr($line, 0, 1) == '#') {
+                [$_, $type, $nick, $value] = explode(' ', $line, 4);
+                if ($prefix && strpos($nick, $prefix) === 0) {
+                    $nick = substr($nick, strlen($prefix));
+                }
+                if (!array_key_exists($nick, $info)) {
+                    $info[$nick] = compact('nick');
+                }
+                $info[$nick][strtolower($type)] = $value;
+            } else {
+                $labels = [];
+                [$nick, $value] = explode(' ', $line);
+                if ($prefix && strpos($nick, $prefix) === 0) {
+                    $nick = substr($nick, strlen($prefix));
+                }
+                if (strpos($nick, '{') !== false) {
+                    [$nick, $postfix] = explode('{', trim($nick, '}'), 2);
+                    foreach (explode(',', $postfix) as $chunk) {
+                        [$k, $v] = explode('=', $chunk, 2);
+                        $labels[$k] = trim($v, '"');
+                    }
+                }
+                if ("" . intval($value) == $value) {
+                    $value = intval($value);
+                } else {
+                    $value = floatval($value);
+                }
+                $values[] = compact('nick', 'labels', 'value');
+            }
+        }
+
+        foreach ($info as $row) {
+            $this->info->set($row['nick'], $row['help'], $row['type']);
+        }
+
+        foreach ($values as $row) {
+            $this->registry->set($row['nick'], $row['value'], $row['labels']);
+        }
+
+        return $this;
+    }
+}

tests/Metrics/ImporterTest.php

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+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Metrics;
+
+use Basis\Telemetry\Metrics\Exporter;
+use Basis\Telemetry\Metrics\Exporter\PrometheusExporter;
+use Basis\Telemetry\Metrics\Importer\PrometheusImporter;
+use Basis\Telemetry\Metrics\Info;
+use Basis\Telemetry\Metrics\Registry;
+use Basis\Telemetry\Metrics\Type;
+use DomainException;
+use PHPUnit\Framework\TestCase;
+
+class ImporterTest extends TestCase
+{
+    public function test(): void
+    {
+        $registry = new Registry();
+        $registry->set('memory_usage', memory_get_usage(true));
+        $registry->set('request_counter', 1, ['user' => '1']);
+        $registry->set('request_counter', 2, ['user' => '2']);
+        $registry->set('uptime', 30);
+
+        $info = new Info();
+        $info->set('memory_usage', 'Memory usage');
+        $info->set('request_counter', 'Request Counter', Type::COUNTER);
+        $info->set('uptime', 'Uptime', Type::COUNTER);
+
+        $exporter = new PrometheusExporter($registry, $info);
+
+        $registry2 = new Registry();
+        $info2 = new Info();
+        $importer = new PrometheusImporter($registry2, $info2);
+        $importer->fromString($exporter->toString('tester_'), 'tester_');
+
+        $keys = [
+            ['memory_usage', []],
+            ['request_counter', ['user' => '1']],
+            ['request_counter', ['user' => '2']],
+            ['uptime'],
+        ];
+
+        foreach ($keys as $key) {
+            $this->assertSame($registry->get(...$key), $registry2->get(...$key));
+            $this->assertSame($info->get($key[0]), $info2->get($key[0]));
+        }
+    }
+}