Introduce ExtensionsService. Load extensions on startup from a directory in

the profile if a command-line flag is present.

Please carefully scrutinize the threading/ref-counting schenanigans.

Review URL: http://codereview.chromium.org/12876

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@6403 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 106 insertions, 0 deletions

diff --git a/chrome/browser/extensions/extensions_service.h b/chrome/browser/extensions/extensions_service.h
new file mode 100644
index 0000000..17f25b7
--- /dev/null
+++ b/chrome/browser/extensions/extensions_service.h
@@ -0,0 +1,106 @@
+// Copyright (c) 2006-2008 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_EXTENSIONS_EXTENSIONS_SERVICE_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSIONS_SERVICE_H_
+
+#include <vector>
+
+#include "base/file_path.h"
+#include "base/message_loop.h"
+#include "base/ref_counted.h"
+#include "base/task.h"
+#include "chrome/browser/extensions/extension.h"
+
+typedef std::vector<Extension*> ExtensionList;
+class ExtensionsServiceBackend;
+
+// Interface for the frontend to implement. Typically, this will be
+// ExtensionsService, but it can also be a test harness.
+class ExtensionsServiceFrontendInterface
+    : public base::RefCountedThreadSafe<ExtensionsServiceFrontendInterface> {
+ public:
+  virtual ~ExtensionsServiceFrontendInterface(){}
+
+  // The message loop to invoke the frontend's methods on.
+  virtual MessageLoop* GetMessageLoop() = 0;
+
+  // Called when loading an extension fails.
+  virtual void OnExtensionLoadError(const std::wstring& message) = 0;
+
+  // Called with results from LoadExtensionsFromDirectory(). The frontend
+  // takes ownership of the list.
+  virtual void OnExtensionsLoadedFromDirectory(ExtensionList* extensions) = 0;
+};
+
+
+// Manages installed and running Chromium extensions.
+class ExtensionsService : public ExtensionsServiceFrontendInterface {
+ public:
+  ExtensionsService(const FilePath& profile_directory);
+  ~ExtensionsService();
+
+  // Gets the list of currently installed extensions.
+  const ExtensionList* extensions() const {
+    return &extensions_;
+  }
+
+  // Initialize and start all installed extensions.
+  bool Init();
+
+  // ExtensionsServiceFrontendInterface
+  virtual MessageLoop* GetMessageLoop();
+  virtual void OnExtensionLoadError(const std::wstring& message);
+  virtual void OnExtensionsLoadedFromDirectory(ExtensionList* extensions);
+
+ private:
+  // The name of the directory inside the profile where extensions are
+  // installed to.
+  static const FilePath::CharType* kInstallDirectoryName;
+
+  // The message loop for the thread the ExtensionsService is running on.
+  MessageLoop* message_loop_;
+
+  // The backend that will do IO on behalf of this instance.
+  scoped_refptr<ExtensionsServiceBackend> backend_;
+
+  // The current list of installed extensions.
+  ExtensionList extensions_;
+
+  // The full path to the directory where extensions are installed.
+  FilePath install_directory_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionsService);
+};
+
+// Implements IO for the ExtensionsService.
+// TODO(aa): Extract an interface out of this for testing the frontend, once the
+// frontend has significant logic to test.
+class ExtensionsServiceBackend
+    : public base::RefCountedThreadSafe<ExtensionsServiceBackend> {
+ public:
+  ExtensionsServiceBackend(){};
+
+  // Loads extensions from a directory. The extensions are assumed to be
+  // unpacked in directories that are direct children of the specified path.
+  // Errors are reported through OnExtensionLoadError(). On completion,
+  // OnExtensionsLoadedFromDirectory() is called with any successfully loaded
+  // extensions.
+  bool LoadExtensionsFromDirectory(
+      const FilePath &path,
+      scoped_refptr<ExtensionsServiceFrontendInterface> frontend);
+
+ private:
+  // Notify a frontend that there was an error loading an extension.
+  void ReportExtensionLoadError(ExtensionsServiceFrontendInterface* frontend,
+                                const std::wstring& error);
+
+  // Notify a frontend that extensions were loaded.
+  void ReportExtensionsLoaded(ExtensionsServiceFrontendInterface* frontend,
+                              ExtensionList* extensions);
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionsServiceBackend);
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSIONS_SERVICE_H_