Make ServiceWorkerCacheStorage::CacheLoader::LoadCache synchronous

content/browser/service_worker/service_worker_cache_storage.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/service_worker/service_worker_cache_storage.h"
 
 #include <string>
 
 #include "base/files/file_util.h"
 #include "base/files/memory_mapped_file.h"
@@ skipping 39 matching lines @@
 
   CacheLoader(base::SequencedTaskRunner* cache_task_runner,
               net::URLRequestContext* request_context,
               base::WeakPtr<storage::BlobStorageContext> blob_context)
       : cache_task_runner_(cache_task_runner),
         request_context_(request_context),
         blob_context_(blob_context) {}
 
   virtual ~CacheLoader() {}
 
-  // Loads the given cache_name, the cache is NULL if it fails. If the cache
-  // doesn't exist a new one is created.
-  virtual void LoadCache(const std::string& cache_name,
-                         const CacheCallback& callback) = 0;
+  // Creates a ServiceWorkerCache with the given name. It does not attempt to
+  // load the backend, that happens lazily when the cache is used.
+  virtual scoped_ptr<ServiceWorkerCache> CreateServiceWorkerCache(
+      const std::string& cache_name) = 0;
 
   // Deletes any pre-existing cache of the same name and then loads it.
   virtual void CreateCache(const std::string& cache_name,
                            const CacheCallback& callback) = 0;
 
   // After the backend has been deleted, do any extra house keeping such as
   // removing the cache's directory.
   virtual void CleanUpDeletedCache(const std::string& key,
                                    const BoolCallback& callback) = 0;
 
   // Writes the cache names (and sizes) to disk if applicable.
   virtual void WriteIndex(const CacheMap& caches,
                           const BoolCallback& callback) = 0;
 
   // Loads the cache names from disk if applicable.
   virtual void LoadIndex(scoped_ptr<std::vector<std::string> > cache_names,
                          const StringsCallback& callback) = 0;
 
  protected:
-  virtual void LoadCacheImpl(const std::string&) {}
-
   scoped_refptr<base::SequencedTaskRunner> cache_task_runner_;
   net::URLRequestContext* request_context_;
   base::WeakPtr<storage::BlobStorageContext> blob_context_;
 };
 
 class ServiceWorkerCacheStorage::MemoryLoader
     : public ServiceWorkerCacheStorage::CacheLoader {
  public:
   MemoryLoader(base::SequencedTaskRunner* cache_task_runner,
                net::URLRequestContext* request_context,
                base::WeakPtr<storage::BlobStorageContext> blob_context)
       : CacheLoader(cache_task_runner, request_context, blob_context) {}
-  virtual void LoadCache(const std::string& cache_name,
-                         const CacheCallback& callback) OVERRIDE {
-    NOTREACHED();
+
+  virtual scoped_ptr<ServiceWorkerCache> CreateServiceWorkerCache(
+      const std::string& cache_name) OVERRIDE {
+    return ServiceWorkerCache::CreateMemoryCache(request_context_,
+                                                 blob_context_);
   }
 
   virtual void CreateCache(const std::string& cache_name,
                            const CacheCallback& callback) OVERRIDE {
-    scoped_ptr<ServiceWorkerCache> cache =
-        ServiceWorkerCache::CreateMemoryCache(request_context_, blob_context_);
-    callback.Run(cache.Pass());
+    callback.Run(CreateServiceWorkerCache(cache_name).Pass());
   }
 
   virtual void CleanUpDeletedCache(const std::string& cache_name,
                                    const BoolCallback& callback) OVERRIDE {
     callback.Run(true);
   }
 
   virtual void WriteIndex(const CacheMap& caches,
                           const BoolCallback& callback) OVERRIDE {
     callback.Run(false);
@@ skipping 12 matching lines @@
     : public ServiceWorkerCacheStorage::CacheLoader {
  public:
   SimpleCacheLoader(const base::FilePath& origin_path,
                     base::SequencedTaskRunner* cache_task_runner,
                     net::URLRequestContext* request_context,
                     base::WeakPtr<storage::BlobStorageContext> blob_context)
       : CacheLoader(cache_task_runner, request_context, blob_context),
         origin_path_(origin_path),
         weak_ptr_factory_(this) {}
 
-  virtual void LoadCache(const std::string& cache_name,
-                         const CacheCallback& callback) OVERRIDE {
+  virtual scoped_ptr<ServiceWorkerCache> CreateServiceWorkerCache(
+      const std::string& cache_name) OVERRIDE {
     DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
-    // 1. Create the cache's directory if necessary. (LoadCreateDirectoryInPool)
-    // 2. Create the cache object. (LoadDidCreateDirectory)
-
-    cache_task_runner_->PostTask(
-        FROM_HERE,
-        base::Bind(&SimpleCacheLoader::LoadCreateDirectoryInPool,
-                   CreatePersistentCachePath(origin_path_, cache_name),
-                   cache_name,
-                   callback,
-                   weak_ptr_factory_.GetWeakPtr(),
-                   base::MessageLoopProxy::current()));
-  }
-
-  static void LoadCreateDirectoryInPool(
-      const base::FilePath& path,
-      const std::string& cache_name,
-      const CacheCallback& callback,
-      base::WeakPtr<SimpleCacheLoader> loader,
-      const scoped_refptr<base::MessageLoopProxy>& original_loop) {
-    bool rv = base::CreateDirectory(path);
-    original_loop->PostTask(
-        FROM_HERE,
-        base::Bind(&SimpleCacheLoader::LoadDidCreateDirectory,
-                   cache_name,
-                   callback,
-                   loader,
-                   rv));
-  }
-
-  static void LoadDidCreateDirectory(const std::string& cache_name,
-                                     const CacheCallback& callback,
-                                     base::WeakPtr<SimpleCacheLoader> loader,
-                                     bool dir_rv) {
-    DCHECK_CURRENTLY_ON(BrowserThread::IO);
-
-    if (!dir_rv || !loader) {
-      callback.Run(scoped_ptr<ServiceWorkerCache>());
-      return;
-    }
-
-    scoped_ptr<ServiceWorkerCache> cache =
-        ServiceWorkerCache::CreatePersistentCache(
-            CreatePersistentCachePath(loader->origin_path_, cache_name),
-            loader->request_context_,
-            loader->blob_context_);
-    callback.Run(cache.Pass());
+    return ServiceWorkerCache::CreatePersistentCache(
+        CreatePersistentCachePath(origin_path_, cache_name),
+        request_context_,
+        blob_context_);
   }
 
   virtual void CreateCache(const std::string& cache_name,
                            const CacheCallback& callback) OVERRIDE {
     DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
     // 1. Delete the cache's directory if it exists.
     // (CreateCacheDeleteFilesInPool)
     // 2. Load the cache. (LoadCreateDirectoryInPool)
 
     base::FilePath cache_path =
         CreatePersistentCachePath(origin_path_, cache_name);
 
-    cache_task_runner_->PostTask(
+    PostTaskAndReplyWithResult(
+        cache_task_runner_.get(),
         FROM_HERE,
-        base::Bind(&SimpleCacheLoader::CreateCacheDeleteFilesInPool,
-                   cache_path,
+        base::Bind(&SimpleCacheLoader::CreateCachePrepDirInPool, cache_path),
+        base::Bind(&SimpleCacheLoader::CreateCachePreppedDir,
                    cache_name,
                    callback,
-                   weak_ptr_factory_.GetWeakPtr(),
-                   base::MessageLoopProxy::current()));
+                   weak_ptr_factory_.GetWeakPtr()));
   }
 
-  static void CreateCacheDeleteFilesInPool(
-      const base::FilePath& cache_path,
-      const std::string& cache_name,
-      const CacheCallback& callback,
-      base::WeakPtr<SimpleCacheLoader> loader,
-      const scoped_refptr<base::MessageLoopProxy>& original_loop) {
-    base::FilePath path(cache_path);
-    if (base::PathExists(path))
-      base::DeleteFile(path, /* recursive */ true);
+  static bool CreateCachePrepDirInPool(const base::FilePath& cache_path) {
+    if (base::PathExists(cache_path))
+      base::DeleteFile(cache_path, /* recursive */ true);
+    return base::CreateDirectory(cache_path);
+  }
 
-    // Jump straight into LoadCache on the same thread.
-    LoadCreateDirectoryInPool(
-        cache_path, cache_name, callback, loader, original_loop);
+  static void CreateCachePreppedDir(const std::string& cache_name,
+                                    const CacheCallback& callback,
+                                    base::WeakPtr<SimpleCacheLoader> loader,
+                                    bool success) {
+    if (!success || !loader) {
+      callback.Run(scoped_ptr<ServiceWorkerCache>());
+      return;
+    }
+
+    callback.Run(loader->CreateServiceWorkerCache(cache_name));
   }
 
   virtual void CleanUpDeletedCache(const std::string& cache_name,
                                    const BoolCallback& callback) OVERRIDE {
     DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
     // 1. Delete the cache's directory. (CleanUpDeleteCacheDirInPool)
 
     base::FilePath cache_path =
         CreatePersistentCachePath(origin_path_, cache_name);
@@ skipping 299 matching lines @@
       base::Bind(&ServiceWorkerCacheStorage::LazyInitDidLoadIndex,
                  weak_factory_.GetWeakPtr(),
                  callback));
 }
 
 void ServiceWorkerCacheStorage::LazyInitDidLoadIndex(
     const base::Closure& callback,
     scoped_ptr<std::vector<std::string> > indexed_cache_names) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
-  if (indexed_cache_names->empty()) {
-    LazyInitDone();
-    return;
+  for (std::vector<std::string>::iterator it = indexed_cache_names->begin();
+       it != indexed_cache_names->end();
+       ++it) {
+    scoped_ptr<ServiceWorkerCache> cache =
+        cache_loader_->CreateServiceWorkerCache(*it);
+    AddCacheToMaps(*it, cache.Pass());
   }
 
-  std::vector<std::string>::const_iterator iter = indexed_cache_names->begin();
-  std::vector<std::string>::const_iterator iter_next = iter + 1;
-
-  cache_loader_->LoadCache(
-      *iter,
-      base::Bind(&ServiceWorkerCacheStorage::LazyInitIterateAndLoadCacheName,
-                 weak_factory_.GetWeakPtr(),
-                 callback,
-                 base::Passed(indexed_cache_names.Pass()),
-                 iter_next,
-                 *iter));
-}
-
-void ServiceWorkerCacheStorage::LazyInitIterateAndLoadCacheName(
-    const base::Closure& callback,
-    scoped_ptr<std::vector<std::string> > indexed_cache_names,
-    const std::vector<std::string>::const_iterator& iter,
-    const std::string& cache_name,
-    scoped_ptr<ServiceWorkerCache> cache) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-
-  if (cache)
-    AddCacheToMaps(cache_name, cache.Pass());
-
-  if (iter == indexed_cache_names->end()) {
-    LazyInitDone();
-    return;
-  }
-
-  std::vector<std::string>::const_iterator iter_next = iter + 1;
-  cache_loader_->LoadCache(
-      *iter,
-      base::Bind(&ServiceWorkerCacheStorage::LazyInitIterateAndLoadCacheName,
-                 weak_factory_.GetWeakPtr(),
-                 callback,
-                 base::Passed(indexed_cache_names.Pass()),
-                 iter_next,
-                 *iter));
-}
-
-void ServiceWorkerCacheStorage::LazyInitDone() {
   initialized_ = true;
   for (std::vector<base::Closure>::iterator it = init_callbacks_.begin();
        it != init_callbacks_.end();
        ++it) {
     it->Run();
   }
   init_callbacks_.clear();
 }
 
 ServiceWorkerCacheStorage::CacheContext*
@@ skipping 74 matching lines @@
   NameMap::const_iterator name_iter = name_map_.find(cache_name);
   if (name_iter == name_map_.end())
     return NULL;
 
   CacheMap::const_iterator map_iter = cache_map_.find(name_iter->second);
   DCHECK(map_iter != cache_map_.end());
   return map_iter->second;
 }
 
 }  // namespace content