feature #13981 [Translation] merge all fallback catalogues messages i…

…nto current catalo... (aitboudad)

This PR was merged into the 2.7 branch.

Discussion
----------

[Translation] merge all fallback catalogues messages into current catalo...

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Fixed tickets  | ~
| Tests pass?   | yes
| License       | MIT

The amount of reduced memory depend on number of defined fallbacks and the size of messages.
For example if we defined 2 fallbacks and we have a large file like ~20 mb we save (~40 mb)
![selection_004](https://cloud.githubusercontent.com/assets/1753742/6737082/3af85be2-ce61-11e4-8104-4330944070cc.png)

Commits
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6eb5e73 [Translation] merge all fallback catalogues messages into current catalogue.

src/Symfony/Component/Translation/Translator.php

@@ -346,7 +346,7 @@ protected function initializeCatalogue($locale)
 
     /**
      * @param string $locale
-     * @param bool $forceRefresh
+     * @param bool   $forceRefresh
      */
     private function initializeCacheCatalogue($locale, $forceRefresh = false)
     {
@@ -358,29 +358,7 @@ private function initializeCacheCatalogue($locale, $forceRefresh = false)
         $cache = new ConfigCache($this->cacheDir.'/catalogue.'.$locale.'.php', $this->debug);
         if ($forceRefresh || !$cache->isFresh()) {
             $this->initializeCatalogue($locale);
-
-            $fallbackContent = '';
-            $current = '';
-            $replacementPattern = '/[^a-z0-9_]/i';
-            foreach ($this->computeFallbackLocales($locale) as $fallback) {
-                $fallbackSuffix = ucfirst(preg_replace($replacementPattern, '_', $fallback));
-                $currentSuffix = ucfirst(preg_replace($replacementPattern, '_', $current));
-
-                $fallbackContent .= sprintf(<<<EOF
-\$catalogue%s = new MessageCatalogue('%s', %s);
-\$catalogue%s->addFallbackCatalogue(\$catalogue%s);
-
-
-EOF
-                    ,
-                    $fallbackSuffix,
-                    $fallback,
-                    var_export($this->catalogues[$fallback]->all(), true),
-                    $currentSuffix,
-                    $fallbackSuffix
-                );
-                $current = $fallback;
-            }
+            $fallbackContent = $this->getFallbackContent($this->catalogues[$locale]);
 
             $content = sprintf(<<<EOF
 <?php
@@ -408,7 +386,7 @@ private function initializeCacheCatalogue($locale, $forceRefresh = false)
 
         $catalogue = include $cache;
 
-        /**
+        /*
          * Old cache returns only the catalogue, without resourcesHash
          */
         $resourcesHash = null;
@@ -423,6 +401,51 @@ private function initializeCacheCatalogue($locale, $forceRefresh = false)
         $this->catalogues[$locale] = $catalogue;
     }
 
+    private function getFallbackContent(MessageCatalogue $catalogue)
+    {
+        if (!$this->debug) {
+            // merge all fallback catalogues messages into $catalogue
+            $fallbackCatalogue = $catalogue->getFallbackCatalogue();
+            $messages = $catalogue->all();
+            while ($fallbackCatalogue) {
+                $messages = array_replace_recursive($fallbackCatalogue->all(), $messages);
+                $fallbackCatalogue = $fallbackCatalogue->getFallbackCatalogue();
+            }
+            foreach ($messages as $domain => $domainMessages) {
+                $catalogue->add($domainMessages, $domain);
+            }
+
+            return '';
+        }
+
+        $fallbackContent = '';
+        $current = '';
+        $replacementPattern = '/[^a-z0-9_]/i';
+        $fallbackCatalogue = $catalogue->getFallbackCatalogue();
+        while ($fallbackCatalogue) {
+            $fallback = $fallbackCatalogue->getLocale();
+            $fallbackSuffix = ucfirst(preg_replace($replacementPattern, '_', $fallback));
+            $currentSuffix = ucfirst(preg_replace($replacementPattern, '_', $current));
+
+            $fallbackContent .= sprintf(<<<EOF
+\$catalogue%s = new MessageCatalogue('%s', %s);
+\$catalogue%s->addFallbackCatalogue(\$catalogue%s);
+
+EOF
+                ,
+                $fallbackSuffix,
+                $fallback,
+                var_export($fallbackCatalogue->all(), true),
+                $currentSuffix,
+                $fallbackSuffix
+            );
+            $current = $fallbackCatalogue->getLocale();
+            $fallbackCatalogue = $fallbackCatalogue->getFallbackCatalogue();
+        }
+
+        return $fallbackContent;
+    }
+
     private function getResourcesHash($locale)
     {
         if (!isset($this->resources[$locale])) {