DNR Prototype: With flatbuffers

extensions/browser/api/declarative_net_request/rules_monitor.cc

+// Copyright 2017 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 "extensions/browser/api/declarative_net_request/rules_monitor.h"
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/files/file.h"
+#include "base/files/file_util.h"
+#include "base/files/memory_mapped_file.h"
+#include "base/location.h"
+#include "base/memory/ptr_util.h"
+#include "base/metrics/histogram_macros.h"
+#include "base/sequenced_task_runner.h"
+#include "base/strings/stringprintf.h"
+#include "base/threading/thread_restrictions.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/browser_thread.h"
+#include "extensions/browser/api/declarative_net_request/matcher_util.h"
+#include "extensions/browser/extension_registry.h"
+#include "extensions/browser/extension_system.h"
+#include "extensions/browser/extension_util.h"
+#include "extensions/browser/info_map.h"
+#include "extensions/common/api/declarative_net_request/indexed_rule.h"
+#include "extensions/common/extension_id.h"
+#include "extensions/common/file_util.h"
+
+namespace extensions {
+namespace declarative_net_request {
+
+namespace {
+
+// Can't seem to use a raw pointer for InfoMap here as recommended in
+// https://chromium.googlesource.com/chromium/src/+/master/docs/design/threading.md.
+void LoadRulesetOnIOThread(
+    std::string extension_id,
+    std::unique_ptr<ExtensionIndexedRulesetMatcher> ruleset_matcher,
+    scoped_refptr<InfoMap> info_map) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  info_map->ruleset_manager()->AddRuleset(std::move(extension_id),
+                                          std::move(ruleset_matcher));
+}
+
+void UnloadRulesetOnIOThread(std::string extension_id,
+                             scoped_refptr<InfoMap> info_map) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  info_map->ruleset_manager()->RemoveRuleset(std::move(extension_id));
+}
+
+// The |extension_id| here doesn't tell us about the associated BrowserContext.
+// But |info_map| does.
+void LoadRulesetOnFileThread(std::string extension_id,
+                             base::FilePath indexed_file_path,
+                             scoped_refptr<InfoMap> info_map) {
+  // TODO not sure if this is exactly the file thread, but CrxInstaller uses the
+  // same terminology. TODO is passing extension pointer safe Or would it
+  // require to add ref.
+  base::ThreadRestrictions::AssertIOAllowed();
+
+  // This can also me made a movable type, hence preventing dynamic allocation.
+  std::unique_ptr<ExtensionIndexedRulesetMatcher> ruleset_matcher =
+      CreateVerifiedExtensionIndexedRulesetMatcher(indexed_file_path);
+
+  if (!ruleset_matcher)
+    return;
+
+  base::OnceClosure task =
+      base::BindOnce(&LoadRulesetOnIOThread, std::move(extension_id),
+                     std::move(ruleset_matcher), info_map);
+
+  content::BrowserThread::PostTask(content::BrowserThread::IO, FROM_HERE,
+                                   std::move(task));
+}
+
+}  // namespace
+
+RulesMonitor::RulesMonitor(content::BrowserContext* browser_context,
+                           base::SequencedTaskRunner* task_runner,
+                           InfoMap* info_map)
+    : browser_context_(browser_context),
+      registry_observer_(this),
+      file_task_runner_(task_runner),
+      info_map_(info_map) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  DCHECK(file_task_runner_);
+  DCHECK(info_map_);
+
+  registry_observer_.Add(ExtensionRegistry::Get(browser_context_));
+}
+
+RulesMonitor::~RulesMonitor() = default;
+
+void RulesMonitor::OnExtensionLoaded(content::BrowserContext* browser_context,
+                                     const Extension* extension) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  DCHECK_EQ(browser_context_, browser_context);
+  DCHECK(file_task_runner_);
+  DCHECK(info_map_);
+  // TODO why aren't we getting notification for the associated incognito
+  // browser context?
+
+  if (!util::HasIndexedRuleset(extension))
+    return;
+
+  base::OnceClosure task =
+      base::BindOnce(&LoadRulesetOnFileThread, extension->id(),
+                     file_util::GetIndexedRulesetPath(extension->path()),
+                     make_scoped_refptr(info_map_));
+  file_task_runner_->PostTask(FROM_HERE, std::move(task));
+}
+
+void RulesMonitor::OnExtensionUnloaded(content::BrowserContext* browser_context,
+                                       const Extension* extension,
+                                       UnloadedExtensionReason reason) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  DCHECK_EQ(browser_context_, browser_context);
+  DCHECK(file_task_runner_);
+  DCHECK(info_map_);
+
+  if (!util::HasIndexedRuleset(extension))
+    return;
+
+  base::OnceClosure task = base::BindOnce(
+      &UnloadRulesetOnIOThread, extension->id(), make_scoped_refptr(info_map_));
+  content::BrowserThread::PostTask(content::BrowserThread::IO, FROM_HERE,
+                                   std::move(task));
+}
+
+}  // namespace declarative_net_request
+}  // namespace extensions