Web restrictions component only.

components/web_restrictions/content_resolver_web_restrictions_provider.cc

Index: components/web_restrictions/content_resolver_web_restrictions_provider.cc
diff --git a/components/web_restrictions/content_resolver_web_restrictions_provider.cc b/components/web_restrictions/content_resolver_web_restrictions_provider.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8ebb2928fa605b75fd31a78d704cc41b1624d72f
--- /dev/null
+++ b/components/web_restrictions/content_resolver_web_restrictions_provider.cc
@@ -0,0 +1,304 @@
+// Copyright 2015 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 "components/web_restrictions/content_resolver_web_restrictions_provider.h"
+
+#include "base/android/jni_string.h"
+#include "base/android/scoped_java_ref.h"
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/thread_task_runner_handle.h"
+#include "content/public/browser/browser_thread.h"
+#include "jni/ContentResolverWebRestrictionsProvider_jni.h"
+
+namespace web_restrictions {
+
+namespace {
+
+const size_t kMaxCacheSize = 100;
+
+void AsyncShouldProceed(const GURL& url,
+                        jlong callback,
+                        const base::android::JavaRef<jobject>& java_provider) {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  Java_ContentResolverWebRestrictionsProvider_shouldProceed(
+      env, java_provider.obj(), callback,
+      base::android::ConvertUTF8ToJavaString(env, url.spec()).obj());
+}
+
+void AsyncRequestPermission(
+    const GURL& url,
+    jlong callback,
+    const base::android::JavaRef<jobject>& java_provider) {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  Java_ContentResolverWebRestrictionsProvider_requestPermission(
+      env, java_provider.obj(), callback,
+      base::android::ConvertUTF8ToJavaString(env, url.spec()).obj());
+}
+
+bool AsyncCheckSupportsRequest(
+    const base::android::JavaRef<jobject>& java_provider) {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  return Java_ContentResolverWebRestrictionsProvider_supportsRequest(
+      env, java_provider.obj());
+}
+
+}  // namespace
+
+// A wrapper to the callback class to facilitate getting a callback from java
+// into C++. Objects of this class delete itself only when they are called back
+// so we must ensure that happens even for error cases.
+class SelfDeletingCallback {
+ public:
+  SelfDeletingCallback(
+      const GURL& url,
+      const base::Callback<void(bool)>& callback,
+      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
+      const std::string& provider_authority,
+      ContentResolverWebRestrictionsProvider* provider);
+  void RequestSuccess(bool request_success);
+  void ShouldProceed(bool should_proceed, std::string error_page);
+
+ private:
+  // Only the callback can delete itself. We must ensure it is indeed
+  // called back.
+  ~SelfDeletingCallback() {}
+
+  GURL url_;
+  base::Callback<void(bool)> callback_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  std::string provider_authority_;
+  ContentResolverWebRestrictionsProvider* provider_;
+
+  DISALLOW_COPY_AND_ASSIGN(SelfDeletingCallback);
+};
+
+SelfDeletingCallback::SelfDeletingCallback(
+    const GURL& url,
+    const base::Callback<void(bool)>& callback,
+    const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
+    const std::string& provider_authority,
+    ContentResolverWebRestrictionsProvider* provider)
+    : url_(url),
+      callback_(callback),
+      task_runner_(task_runner),
+      provider_authority_(provider_authority),
+      provider_(provider) {}
+
+void SelfDeletingCallback::ShouldProceed(bool should_proceed,
+                                         std::string error_page) {
+  task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&ContentResolverWebRestrictionsProvider::UpdateCache,
+                 base::Unretained(provider_), provider_authority_, url_,
+                 should_proceed, error_page));
+  task_runner_->PostTask(FROM_HERE, base::Bind(callback_, should_proceed));
+  delete this;
+}
+
+void SelfDeletingCallback::RequestSuccess(bool request_success) {
+  task_runner_->PostTask(FROM_HERE, base::Bind(callback_, request_success));
+  delete this;
+}
+
+// static
+bool ContentResolverWebRestrictionsProvider::Register(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+ContentResolverWebRestrictionsProvider::ContentResolverWebRestrictionsProvider()
+    : initialized_(false), supports_request_(false) {
+  single_thread_task_runner_ = base::ThreadTaskRunnerHandle::Get();
+  base::SequencedWorkerPool* worker_pool =
+      content::BrowserThread::GetBlockingPool();
+  background_task_runner_ =
+      worker_pool->GetSequencedTaskRunnerWithShutdownBehavior(
+          worker_pool->GetSequenceToken(),
+          base::SequencedWorkerPool::SKIP_ON_SHUTDOWN);
+}
+
+ContentResolverWebRestrictionsProvider::
+    ~ContentResolverWebRestrictionsProvider() {
+  if (java_provider_.is_null())
+    return;
+  JNIEnv* env = base::android::AttachCurrentThread();
+  Java_ContentResolverWebRestrictionsProvider_onDestroy(env,
+                                                        java_provider_.obj());
+  java_provider_.Reset();
+}
+
+void ContentResolverWebRestrictionsProvider::SetAuthority(
+    const std::string& content_provider_authority) {
+  DCHECK(single_thread_task_runner_->BelongsToCurrentThread());
+  // Destroy any existing content resolver.
+  JNIEnv* env = base::android::AttachCurrentThread();
+  if (!java_provider_.is_null()) {
+    Java_ContentResolverWebRestrictionsProvider_onDestroy(env,
+                                                          java_provider_.obj());
+    java_provider_.Reset();
+  }
+  ClearCache();
+  provider_authority_ = content_provider_authority;
+
+  // Initialize the content resolver.
+  initialized_ = !content_provider_authority.empty();
+  if (!initialized_)
+    return;
+  java_provider_.Reset(Java_ContentResolverWebRestrictionsProvider_create(
+      env,
+      base::android::ConvertUTF8ToJavaString(env, content_provider_authority)
+          .obj(),
+      reinterpret_cast<jlong>(this)));
+  supports_request_ = false;
+  base::PostTaskAndReplyWithResult(
+      content::BrowserThread::GetBlockingPool(), FROM_HERE,
+      base::Bind(&AsyncCheckSupportsRequest, java_provider_),
+      base::Bind(&ContentResolverWebRestrictionsProvider::RequestSupportKnown,
+                 base::Unretained(this), provider_authority_));
+}
+
+UrlAccess ContentResolverWebRestrictionsProvider::ShouldProceed(
+    bool is_main_frame,
+    const GURL& url,
+    const base::Callback<void(bool)>& callback) {
+  DCHECK(single_thread_task_runner_->BelongsToCurrentThread());
+  if (!initialized_)
+    return ALLOW;
+  auto iter = url_access_cache_.find(url);
+  if (iter != url_access_cache_.end()) {
+    RecordURLAccess(url);
+    return iter->second ? ALLOW : DISALLOW;
+  }
+  SelfDeletingCallback* wrapped_callback = new SelfDeletingCallback(
+      url, callback, single_thread_task_runner_, provider_authority_, this);
+  background_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&AsyncShouldProceed, url,
+                 reinterpret_cast<jlong>(wrapped_callback), java_provider_));
+  return PENDING;
+}
+
+bool ContentResolverWebRestrictionsProvider::SupportsRequest() const {
+  return initialized_ && supports_request_;
+}
+
+bool ContentResolverWebRestrictionsProvider::GetErrorHtml(
+    const GURL& url,
+    std::string* error_page) const {
+  DCHECK(single_thread_task_runner_->BelongsToCurrentThread());
+  if (!initialized_)
+    return false;
+  auto iter = error_page_cache_.find(url);
+  if (iter == error_page_cache_.end())
+    return false;
+  *error_page = iter->second;
+  return true;
+}
+
+void ContentResolverWebRestrictionsProvider::RequestPermission(
+    const GURL& url,
+    const base::Callback<void(bool)>& request_success) {
+  if (!initialized_) {
+    request_success.Run(false);
+    return;
+  }
+  SelfDeletingCallback* wrapped_callback =
+      new SelfDeletingCallback(url, request_success, single_thread_task_runner_,
+                               provider_authority_, this);
+  background_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&AsyncRequestPermission, url,
+                 reinterpret_cast<jlong>(wrapped_callback), java_provider_));
+}
+
+void ContentResolverWebRestrictionsProvider::OnWebRestrictionsChanged() {
+  single_thread_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&ContentResolverWebRestrictionsProvider::ClearCache,
+                            base::Unretained(this)));
+}
+
+void ContentResolverWebRestrictionsProvider::RecordURLAccess(const GURL& url) {
+  DCHECK(single_thread_task_runner_->BelongsToCurrentThread());
+  // Move the URL to the front of the cache.
+  recent_urls_.remove(url);
+  recent_urls_.push_front(url);
+}
+
+void ContentResolverWebRestrictionsProvider::UpdateCache(
+    std::string provider_authority,
+    GURL url,
+    bool should_proceed,
+    std::string error_page) {
+  DCHECK(single_thread_task_runner_->BelongsToCurrentThread());
+  // If the webrestrictions provider changed when the old one was being queried,
+  // do not update the cache for the new provider.
+  if (provider_authority != provider_authority_)
+    return;
+  RecordURLAccess(url);
+  if (recent_urls_.size() >= kMaxCacheSize) {
+    url_access_cache_.erase(recent_urls_.back());
+    error_page_cache_.erase(recent_urls_.back());
+    recent_urls_.pop_back();
+  }
+  url_access_cache_[url] = should_proceed;
+  if (!error_page.empty()) {
+    error_page_cache_[url] = error_page;
+  } else {
+    error_page_cache_.erase(url);
+  }
+}
+
+void ContentResolverWebRestrictionsProvider::RequestSupportKnown(
+    std::string provider_authority,
+    bool supports_request) {
+  // |supports_request_| is initialized to false.
+  DCHECK(!supports_request_);
+  DCHECK(single_thread_task_runner_->BelongsToCurrentThread());
+  // If the webrestrictions provider changed when the old one was being queried,
+  // ignore the result.
+  if (provider_authority != provider_authority_)
+    return;
+  supports_request_ = supports_request;
+}
+
+void ContentResolverWebRestrictionsProvider::ClearCache() {
+  DCHECK(single_thread_task_runner_->BelongsToCurrentThread());
+  error_page_cache_.clear();
+  url_access_cache_.clear();
+  recent_urls_.clear();
+}
+
+void ShouldProceed(JNIEnv* env,
+                   const base::android::JavaParamRef<jclass>& clazz,
+                   jlong callback_ptr,
+                   jboolean should_proceed,
+                   const base::android::JavaParamRef<jstring>& j_error_page) {
+  SelfDeletingCallback* callback =
+      reinterpret_cast<SelfDeletingCallback*>(callback_ptr);
+  std::string error_page;
+  if (!j_error_page.is_null())
+    error_page = base::android::ConvertJavaStringToUTF8(j_error_page);
+  callback->ShouldProceed(should_proceed, error_page);
+}
+
+void RequestSuccess(JNIEnv* env,
+                    const base::android::JavaParamRef<jclass>& clazz,
+                    jlong callback_ptr,
+                    jboolean request_success) {
+  SelfDeletingCallback* callback =
+      reinterpret_cast<SelfDeletingCallback*>(callback_ptr);
+  callback->RequestSuccess(request_success);
+}
+
+void NotifyWebRestrictionsChanged(
+    JNIEnv* env,
+    const base::android::JavaParamRef<jclass>& clazz,
+    jlong provider_ptr) {
+  ContentResolverWebRestrictionsProvider* provider =
+      reinterpret_cast<ContentResolverWebRestrictionsProvider*>(provider_ptr);
+  // TODO(knn): Also reload existing interstitials/error pages.
+  provider->OnWebRestrictionsChanged();
+}
+
+}  // namespace web_restrictions