[Offline pages] Adding ArchiveManager to abstract offline archives management

components/offline_pages/archive_manager.cc

Index: components/offline_pages/archive_manager.cc
diff --git a/components/offline_pages/archive_manager.cc b/components/offline_pages/archive_manager.cc
new file mode 100644
index 0000000000000000000000000000000000000000..019dcc50a7d7658157a0dd4e82809f08c1355f54
--- /dev/null
+++ b/components/offline_pages/archive_manager.cc
@@ -0,0 +1,76 @@
+// Copyright 2016 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 "base/bind.h"
+#include "base/callback.h"
+#include "base/files/file_util.h"
+#include "base/location.h"
+#include "base/logging.h"
+#include "components/offline_pages/archive_manager.h"
+
+namespace offline_pages {
+
+namespace {
+
+void EnsureArchivesDirCreatedImpl(const base::FilePath& archives_dir) {
+  CHECK(base::CreateDirectory(archives_dir));
+}
+
+void ExistsArchiveImpl(const base::FilePath& file_path, bool* exists) {
+  DCHECK(exists);
+  *exists = base::PathExists(file_path);
+}
+
+void DeleteArchivesImpl(const std::vector<base::FilePath>& file_paths,
+                        bool* result) {
+  DCHECK(result);
+  for (const auto& file_path : file_paths) {
+    // Make sure delete happens on the left of || so that it is always executed.
+    *result = base::DeleteFile(file_path, false) || *result;
+  }
+}
+
+void CompleteBooleanCallback(const base::Callback<void(bool)>& callback,
+                             bool* exists) {
+  callback.Run(*exists);
+}
+}  // namespace
+
+ArchiveManager::ArchiveManager(
+    const base::FilePath& archives_dir,
+    const scoped_refptr<base::SequencedTaskRunner>& task_runner)
+    : archives_dir_(archives_dir), task_runner_(task_runner) {}
+
+ArchiveManager::~ArchiveManager() {}
+
+void ArchiveManager::EnsureArchivesDirCreated(const base::Closure& callback) {
+  task_runner_->PostTaskAndReply(
+      FROM_HERE, base::Bind(EnsureArchivesDirCreatedImpl, archives_dir_),
+      callback);
+}
+
+void ArchiveManager::ExistsArchive(const base::FilePath& archive_path,
+                                   const base::Callback<void(bool)>& callback) {
+  bool* result = new bool(false);
+  task_runner_->PostTaskAndReply(
+      FROM_HERE, base::Bind(ExistsArchiveImpl, archive_path, result),
+      base::Bind(CompleteBooleanCallback, callback, base::Owned(result)));
+}
+
+void ArchiveManager::DeleteArchive(const base::FilePath& archive_path,
+                                   const base::Callback<void(bool)>& callback) {
+  std::vector<base::FilePath> archive_paths = {archive_path};
+  DeleteMultipleArchives(archive_paths, callback);
+}
+
+void ArchiveManager::DeleteMultipleArchives(
+    const std::vector<base::FilePath>& archive_paths,
+    const base::Callback<void(bool)>& callback) {
+  bool* result = new bool(false);
+  task_runner_->PostTaskAndReply(
+      FROM_HERE, base::Bind(DeleteArchivesImpl, archive_paths, result),
+      base::Bind(CompleteBooleanCallback, callback, base::Owned(result)));
+}
+
+}  // namespace offline_pages