Pre-resolve all aliases

Resolve aliases during instantiation, and remove need for function call
in each of `get()`, `has()`, and `build()` as a result.

No measureable impact on test execution time and resource usage.

Author: weierophinney

src/ServiceManager.php

@@ -85,6 +85,11 @@ class ServiceManager implements ServiceLocatorInterface
      */
     private $lazyServicesDelegator;
 
+    /**
+     * @var string[]
+     */
+    private $resolvedAliases = [];
+
     /**
      * A list of already loaded services (this act as a local cache)
      *
@@ -152,7 +157,7 @@ public function withConfig(array $config)
      */
     public function get($name)
     {
-        $name = $this->resolveAlias($name);
+        $name = isset($this->resolvedAliases[$name]) ? $this->resolvedAliases[$name] : $name;
 
         // We start by checking if the service is cached (this is the fastest method).
         if (isset($this->services[$name])) {
@@ -175,15 +180,16 @@ public function get($name)
     public function build($name, array $options = null)
     {
         // We never cache when using "build"
-        return $this->doCreate($this->resolveAlias($name), $options);
+        $name  = isset($this->resolvedAliases[$name]) ? $this->resolvedAliases[$name] : $name;
+        return $this->doCreate($name, $options);
     }
 
     /**
      * {@inheritDoc}
      */
     public function has($name, $checkAbstractFactories = false)
     {
-        $name  = $this->resolveAlias($name);
+        $name  = isset($this->resolvedAliases[$name]) ? $this->resolvedAliases[$name] : $name;
         $found = isset($this->services[$name]) || isset($this->factories[$name]);
 
         if ($found || !$checkAbstractFactories) {
@@ -296,6 +302,8 @@ protected function configure(array $config)
                 ));
             }
         }
+
+        $this->resolveAliases();
     }
 
     /**
@@ -316,6 +324,16 @@ private function resolveAlias($alias)
         return $name;
     }
 
+    /**
+     * Resolve all aliases to their canonical service names.
+     */
+    private function resolveAliases()
+    {
+        foreach ($this->aliases as $alias => $service) {
+            $this->resolvedAliases[$alias] = $this->resolveAlias($alias);
+        }
+    }
+
     /**
      * Get a factory for the given service name
      *