Issue #1956914 by chaby, pounard: Use a single cache_get_multiple() call per...

Issue #1956914 by chaby, pounard: Use a single cache_get_multiple() call per region instead of a cache_get() per block in _block_render_blocks().

modules/block/block.module

@@ -840,15 +840,37 @@ function _block_render_blocks($region_blocks) {
   // preserve the submission of forms in blocks, by fetching from cache only
   // if the request method is 'GET' (or 'HEAD').
   $cacheable = !count(module_implements('node_grants')) && ($_SERVER['REQUEST_METHOD'] == 'GET' || $_SERVER['REQUEST_METHOD'] == 'HEAD');
+
+  // Proceed to a loop over all blocks in order to compute their respective
+  // cache identifiers, this allows us to do one single cache_get_multiple()
+  // call instead of doing one cache_get() call per block.
+  $cached_blocks = array();
+  if ($cacheable) {
+
+    $cids = array();
+    foreach ($region_blocks as $key => $block) {
+      if (!isset($block->content)) {
+        if (($cid = _block_get_cache_id($block))) {
+          $cids[] = $cid;
+        }
+      }
+    }
+
+    if ($cids) {
+      $cached_blocks = cache_get_multiple($cids, 'cache_block');
+    }
+  }
+
   foreach ($region_blocks as $key => $block) {
     // Render the block content if it has not been created already.
     if (!isset($block->content)) {
       // Erase the block from the static array - we'll put it back if it has
       // content.
       unset($region_blocks[$key]);
-      // Try fetching the block from cache.
-      if ($cacheable && ($cid = _block_get_cache_id($block)) && ($cache = cache_get($cid, 'cache_block'))) {
-        $array = $cache->data;
+
+      // Try fetching the block from the previously loaded cache entries.
+      if (($cid = _block_get_cache_id($block)) && isset($cached_blocks[$cid])) {
+        $array = $cached_blocks[$cid]->data;
       }
       else {
         $array = module_invoke($block->module, 'block_view', $block->delta);