Implement the ConfigDirPolicyProvider based on the AsyncPolicyLoader

chrome/browser/policy/config_dir_policy_loader.h

+// Copyright (c) 2012 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.
+
+#ifndef CHROME_BROWSER_POLICY_CONFIG_DIR_POLICY_LOADER_H_
+#define CHROME_BROWSER_POLICY_CONFIG_DIR_POLICY_LOADER_H_
+#pragma once
+
+#include "base/file_path.h"
+#include "base/files/file_path_watcher.h"
+#include "chrome/browser/policy/async_policy_loader.h"
+#include "chrome/browser/policy/policy_constants.h"
+
+namespace base {
+class Value;
+}
+
+namespace policy {
+
+struct PolicyDefinitionList;
+
+// A policy loader implementation backed by a set of files in a given
+// directory. The files should contain JSON-formatted policy settings. They are
+// merged together and the result is returned in a PolicyBundle.
+// The files are consulted in lexicographic file name order, so the
+// last value read takes precedence in case of policy key collisions.
+class ConfigDirPolicyLoader : public AsyncPolicyLoader {
+ public:
+  ConfigDirPolicyLoader(const FilePath& config_dir, PolicyScope scope);
+  virtual ~ConfigDirPolicyLoader();
+
+  // AsyncPolicyLoader implementation.
+  virtual void InitOnFile() OVERRIDE;
+  virtual scoped_ptr<PolicyBundle> Load() OVERRIDE;
+  virtual base::Time LastModificationTime() OVERRIDE;
+
+ private:
+  // Loads the policy files at |path| into the |bundle|, with the given |level|.
+  void LoadFromPath(const FilePath& path,
+                    PolicyLevel level,
+                    PolicyBundle* bundle);
+
+  // Merges the 3rd party |policies| into the |bundle|, with the given |level|.
+  void Merge3rdPartyPolicy(const base::Value* policies,
+                           PolicyLevel level,
+                           PolicyBundle* bundle);
+
+  // Callback for the FilePathWatchers.
+  void OnFileUpdated(const FilePath& path, bool error);
+
+  // The directory containing the policy files.
+  FilePath config_dir_;
+
+  // Policies loaded by this provider will have this scope.
+  PolicyScope scope_;
+
+  // Watchers for events on the mandatory and recommended subdirectories of
+  // |config_dir_|.
+  base::files::FilePathWatcher mandatory_watcher_;
+  base::files::FilePathWatcher recommended_watcher_;
+
+  DISALLOW_COPY_AND_ASSIGN(ConfigDirPolicyLoader);
+};
+
+}  // namespace policy
+
+#endif  // CHROME_BROWSER_POLICY_CONFIG_DIR_POLICY_LOADER_H_