Cleaning Up Extensions When Local Content Removed

chrome/browser/extensions/extension_garbage_collector.cc

+// 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.
+
+#include "chrome/browser/extensions/extension_garbage_collector.h"
+
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/string_util.h"
+#include "chrome/browser/extensions/extension_prefs.h"
+#include "chrome/browser/extensions/extension_service.h"
+#include "content/public/browser/browser_thread.h"
+
+ExtensionGarbageCollector::ExtensionGarbageCollector(
+    ExtensionService* extension_service)
+    : extension_service_(extension_service) {
+}
+
+ExtensionGarbageCollector::~ExtensionGarbageCollector() {
+}
+
+void ExtensionGarbageCollector::GarbageCollectExtensions() {
+  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  ExtensionPrefs* extension_prefs = extension_service_->extension_prefs();
+
+  if (extension_prefs->pref_service()->ReadOnly())
+    return;
+
+  scoped_ptr<ExtensionPrefs::ExtensionsInfo> info(
+      extension_prefs->GetInstalledExtensionsInfo());
+
+  std::map<std::string, FilePath> extension_paths;
+  for (size_t i = 0; i < info->size(); ++i)
+    extension_paths[info->at(i)->extension_id] = info->at(i)->extension_path;
+
+  if (!content::BrowserThread::PostTask(
+          content::BrowserThread::FILE, FROM_HERE,
+          base::Bind(
+               &ExtensionGarbageCollector::CheckExtensionDirectories,
+               this,
+               extension_paths)))
+    NOTREACHED();
+}
+
+void ExtensionGarbageCollector::CheckExtensionDirectories(
+    const std::map<std::string, FilePath>& extension_paths) {
+  DVLOG(1) << "Garbage collecting extensions...";

[Aaron Boodman, 2012/03/31 23:33:33]

Add a CHECK that this is on the file thread.

[Devlin, 2012/04/05 01:58:01]

Done.

+
+  CheckInstalledDirectories(extension_paths);
+
+  // Find any extensions for which the directory is nonexistent; add these to a
+  // list of extensions to be uninstalled.
+  std::vector<std::string> bad_extensions;
+  for (std::map<std::string, FilePath>::const_iterator iter =
+           extension_paths.begin(); iter != extension_paths.end(); ++iter) {
+    if (!file_util::PathExists(iter->second)) {
+      bad_extensions.push_back(iter->first);
+    }
+  }
+
+  if (bad_extensions.size() && !content::BrowserThread::PostTask(
+          content::BrowserThread::UI, FROM_HERE,
+          base::Bind(
+               &ExtensionGarbageCollector::RemoveExtensionsMissingLocalContent,
+               this,
+               bad_extensions)))
+    NOTREACHED();
+}
+
+void ExtensionGarbageCollector::CheckInstalledDirectories(
+    const std::map<std::string, FilePath>& extension_paths) {
+  FilePath install_directory = extension_service_->install_directory();

[Aaron Boodman, 2012/03/31 23:33:33]

Add a CHECK that on the file thread.

[Aaron Boodman, 2012/03/31 23:33:33]

Not safe to access extension_service on a background thread. (in this case, it's
probably fine because this value doesn't change, but it's bad form) and might
confuse future maintainers.

[Devlin, 2012/04/05 01:58:01]

Done.

[Devlin, 2012/04/05 01:58:01]

Done.

+
+  if (!file_util::DirectoryExists(install_directory))
+    return;
+
+  file_util::FileEnumerator enumerator(install_directory,
+                                       false,  // Not recursive.
+                                       file_util::FileEnumerator::DIRECTORIES);
+
+  FilePath extension_path;
+  for (extension_path = enumerator.Next(); !extension_path.value().empty();
+       extension_path = enumerator.Next()) {
+    std::string extension_id;
+    FilePath basename = extension_path.BaseName();
+    if (IsStringASCII(basename.value())) {
+      extension_id = UTF16ToASCII(basename.LossyDisplayName());
+      if (!Extension::IdIsValid(extension_id))
+        extension_id.clear();
+    }
+
+    // Delete directories that aren't valid IDs.
+    if (extension_id.empty()) {
+      DLOG(WARNING) << "Invalid extension ID enecountered in extensions "
+                       "directory: " << basename.value();
+      DVLOG(1) << "Deleting invalid extension directory "
+               << extension_path.value() << ".";
+      file_util::Delete(extension_path, true);  // Recursive.
+      continue;
+    }
+
+    std::map<std::string, FilePath>::const_iterator iter =
+        extension_paths.find(extension_id);
+
+    // If there is no entry in the prefs file, just delete the directory and
+    // move on. This can legitimately happen when an uninstall does not
+    // complete, for example, when a plugin is in use at uninstall time.
+    if (iter == extension_paths.end()) {
+      DVLOG(1) << "Deleting unreferenced install for directory "
+               << extension_path.LossyDisplayName() << ".";
+      file_util::Delete(extension_path, true);  // Recursive.
+      continue;
+    }
+
+    // Clean up old version directories.
+    file_util::FileEnumerator versions_enumerator(
+        extension_path,
+        false,  // Not recursive.
+        file_util::FileEnumerator::DIRECTORIES);
+    for (FilePath version_dir = versions_enumerator.Next();
+         !version_dir.value().empty();
+         version_dir = versions_enumerator.Next()) {
+      if (version_dir.BaseName() != iter->second.BaseName()) {
+        DVLOG(1) << "Deleting old version for directory "
+                 << version_dir.LossyDisplayName() << ".";
+        file_util::Delete(version_dir, true);  // Recursive.
+      }
+    }
+  }
+}
+
+void ExtensionGarbageCollector::RemoveExtensionsMissingLocalContent(
+    const std::vector<std::string>& bad_extensions) {
+  for (std::vector<std::string>::const_iterator iter = bad_extensions.begin();

[Aaron Boodman, 2012/03/31 23:33:33]

Add a CHECK for UI thread?

[Devlin, 2012/04/05 01:58:01]

Done.

+       iter != bad_extensions.end(); ++iter) {
+    DVLOG(1) << "Could not access local content for extension with id " <<
+        *iter << "; uninstalling extension.";
+
+    // If the extension failed to load fully (e.g. the user deleted an unpacked
+    // extension's manifest or the manifest points to the wrong path), we cannot
+    // use UninstallExtension, which relies on a valid Extension object.
+    if (!extension_service_->GetInstalledExtension(*iter)) {
+      scoped_ptr<ExtensionInfo> info(extension_service_->extension_prefs()
+          ->GetInstalledExtensionInfo(*iter));
+      extension_service_->UnloadExtension(

[Aaron Boodman, 2012/03/31 23:39:50]

In that case, it seems like we wouldn't need to send this notification?

[Devlin, 2012/04/05 01:58:01]

Done.

+          *iter, extension_misc::UNLOAD_REASON_UNINSTALL);
+      extension_service_->extension_prefs()->OnExtensionUninstalled(
+          *iter, info->extension_location, false);
+    } else {
+      extension_service_->UninstallExtension(*iter, false, NULL);
+    }
+  }
+}