Identifiers from string

Author: whitemerry

src/Identifier/Identifier.php

@@ -39,4 +39,4 @@ public function __toString()
      * @return string
      */
     abstract protected function generate();
-}
+}

src/Identifier/SpanIdentifier.php

@@ -9,6 +9,20 @@
  */
 class SpanIdentifier extends Identifier
 {
+    /**
+     * @inheritdoc
+     *
+     * @param $fromString string Optional, creates identifier from string
+     */
+    public function __construct($fromString = null)
+    {
+        if ($fromString && is_zipkin_span_identifier($fromString)) {
+            $this->value = $fromString;
+        } else {
+            parent::__construct();
+        }
+    }
+
     /**
      * Generates 128-bit hex-encoded identifier
      * http://zipkin.io/pages/instrumenting.html#trace-identifiers

src/Identifier/TraceIdentifier.php

@@ -9,6 +9,20 @@
  */
 class TraceIdentifier extends Identifier
 {
+    /**
+     * @inheritdoc
+     *
+     * @param $fromString string Optional, creates identifier from string
+     */
+    public function __construct($fromString = null)
+    {
+        if ($fromString && is_zipkin_trace_identifier($fromString)) {
+            $this->value = $fromString;
+        } else {
+            parent::__construct();
+        }
+    }
+
     /**
      * Generates 128-bit hex-encoded identifier
      * http://zipkin.io/pages/instrumenting.html#trace-identifiers

src/functions.php

@@ -25,3 +25,29 @@ function is_zipkin_timestamp($timestamp)
         return ctype_digit((string) $timestamp) && strlen($timestamp) === 16;
     }
 }
+
+if (!function_exists('is_zipkin_trace_identifier')) {
+    /**
+     * Is zipkin trace identifier
+     *
+     * @param $identifier string|\whitemerry\phpkin\Identifier\Identifier
+     *
+     * @return bool
+     */
+    function is_zipkin_trace_identifier($identifier) {
+        return ctype_xdigit((string) $identifier) && strlen((string) $identifier) === 32;
+    }
+}
+
+if (!function_exists('is_zipkin_span_identifier')) {
+    /**
+     * Is zipkin span identifier
+     *
+     * @param $identifier string|\whitemerry\phpkin\Identifier\Identifier
+     *
+     * @return bool
+     */
+    function is_zipkin_span_identifier($identifier) {
+        return ctype_xdigit((string) $identifier) && strlen((string) $identifier) === 16;
+    }
+}