Handle webuis when using the network service.

content/browser/webui/web_ui_url_loader_factory.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 "content/browser/webui/web_ui_url_loader_factory.h"
+
+#include <map>
+
+#include "base/bind.h"
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "base/memory/ref_counted_memory.h"
+#include "base/strings/string_piece.h"
+#include "base/sys_byteorder.h"
+#include "content/browser/frame_host/frame_tree_node.h"
+#include "content/browser/frame_host/render_frame_host_impl.h"
+#include "content/browser/resource_context_impl.h"
+#include "content/browser/webui/url_data_manager_backend.h"
+#include "content/browser/webui/url_data_source_impl.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/web_contents.h"
+#include "mojo/public/cpp/bindings/binding_set.h"
+#include "third_party/zlib/google/compression_utils.h"
+#include "ui/base/template_expressions.h"
+
+namespace content {
+
+namespace {

[scottmg, 2017/05/05 22:38:10]

super nit; \n after opening { to match the blank line before the closing }

[jam, 2017/05/05 23:25:07]

Done.

+class WebUIURLLoaderFactory;
+base::LazyInstance<std::map<int, std::unique_ptr<WebUIURLLoaderFactory>>>::Leaky
+    g_factories = LAZY_INSTANCE_INITIALIZER;
+
+class URLLoaderImpl : public mojom::URLLoader {
+ public:
+  static void Create(mojom::URLLoaderAssociatedRequest loader,
+                     const ResourceRequest& request,
+                     int frame_tree_node_id,
+                     mojo::InterfacePtrInfo<mojom::URLLoaderClient> client_info,
+                     ResourceContext* resource_context) {
+    mojom::URLLoaderClientPtr client;
+    client.Bind(std::move(client_info));
+    new URLLoaderImpl(std::move(loader), request, frame_tree_node_id,
+                      std::move(client), resource_context);
+  }
+
+ private:
+  URLLoaderImpl(mojom::URLLoaderAssociatedRequest loader,
+                const ResourceRequest& request,
+                int frame_tree_node_id,
+                mojom::URLLoaderClientPtr client,
+                ResourceContext* resource_context)
+      : binding_(this, std::move(loader)),
+        client_(std::move(client)),
+        replacements_(nullptr),
+        weak_factory_(this) {
+    // NOTE: this duplicates code in URLDataManagerBackend::StartRequest.
+    if (!URLDataManagerBackend::CheckURLIsValid(request.url)) {
+      OnError(net::ERR_INVALID_URL);
+      return;
+    }
+
+    URLDataSourceImpl* source =
+        GetURLDataManagerForResourceContext(resource_context)
+            ->GetDataSourceFromURL(request.url);
+    if (!source) {
+      OnError(net::ERR_INVALID_URL);
+      return;
+    }
+
+    if (!source->source()->ShouldServiceRequest(request.url, resource_context,
+                                                -1)) {
+      OnError(net::ERR_INVALID_URL);
+      return;
+    }
+
+    std::string path;
+    URLDataManagerBackend::URLToRequestPath(request.url, &path);
+    gzipped_ = source->source()->IsGzipped(path);
+    if (source->source()->GetMimeType(path) == "text/html")
+      replacements_ = source->GetReplacements();
+
+    net::HttpRequestHeaders request_headers;
+    request_headers.AddHeadersFromString(request.headers);
+    std::string origin_header;
+    request_headers.GetHeader(net::HttpRequestHeaders::kOrigin, &origin_header);
+
+    scoped_refptr<net::HttpResponseHeaders> headers =
+        URLDataManagerBackend::GetHeaders(source, path, origin_header);
+
+    ResourceResponseHead head;
+    head.headers = headers;
+    head.mime_type = source->source()->GetMimeType(path);
+    // TODO: fill all the time related field i.e. request_time response_time
+    // request_start response_start
+    client_->OnReceiveResponse(head, base::nullopt, nullptr);
+
+    ResourceRequestInfo::WebContentsGetter wc_getter =
+        base::Bind(WebContents::FromFrameTreeNodeId, frame_tree_node_id);
+
+    // Forward along the request to the data source.
+    // TODO(jam): once we only have this code path for WebUI, and not the
+    // URLLRequestJob one, then we should switch data sources to run on the UI
+    // thread by default.
+    scoped_refptr<base::SingleThreadTaskRunner> target_runner =
+        source->source()->TaskRunnerForRequestPath(path);
+    if (!target_runner) {
+      source->source()->StartDataRequest(
+          path, wc_getter,
+          base::Bind(&URLLoaderImpl::DataAvailable,
+                     weak_factory_.GetWeakPtr()));
+    } else {
+      // The DataSource wants StartDataRequest to be called on a specific
+      // thread, usually the UI thread, for this path.
+      target_runner->PostTask(
+          FROM_HERE, base::Bind(&URLLoaderImpl::CallStartDataRequest,
+                                base::RetainedRef(source), path, wc_getter,
+                                weak_factory_.GetWeakPtr()));
+    }
+  }
+
+  void FollowRedirect() override { NOTREACHED(); }
+  void SetPriority(net::RequestPriority priority,
+                   int32_t intra_priority_value) override {
+    NOTREACHED();
+  }
+
+  static void CallStartDataRequest(
+      scoped_refptr<URLDataSourceImpl> source,
+      const std::string& path,
+      const ResourceRequestInfo::WebContentsGetter& wc_getter,
+      const base::WeakPtr<URLLoaderImpl>& weak_ptr) {
+    source->source()->StartDataRequest(
+        path, wc_getter,
+        base::Bind(URLLoaderImpl::DataAvailableOnTargetThread, weak_ptr));
+  }
+
+  static void DataAvailableOnTargetThread(
+      const base::WeakPtr<URLLoaderImpl>& weak_ptr,
+      scoped_refptr<base::RefCountedMemory> bytes) {
+    BrowserThread::PostTask(
+        BrowserThread::IO, FROM_HERE,
+        base::Bind(&URLLoaderImpl::DataAvailable, weak_ptr, bytes));
+  }
+
+  void DataAvailable(scoped_refptr<base::RefCountedMemory> bytes) {
+    if (!bytes) {
+      OnError(net::ERR_FAILED);
+      return;
+    }
+
+    base::StringPiece input(reinterpret_cast<const char*>(bytes->front()),
+                            bytes->size());
+    if (replacements_) {
+      std::string temp_string;
+      // We won't know the the final output size ahead of time, so we have to
+      // use an intermediate string.
+      base::StringPiece source;
+      std::string temp_str;
+      if (gzipped_) {
+        temp_str.resize(compression::GetUncompressedSize(input));
+        source.set(temp_str.c_str(), temp_str.size());
+        CHECK(compression::GzipUncompress(input, source));
+        gzipped_ = false;
+      } else {
+        source = input;
+      }
+      temp_str = ui::ReplaceTemplateExpressions(source, *replacements_);
+      bytes = base::RefCountedString::TakeString(&temp_str);
+      input.set(reinterpret_cast<const char*>(bytes->front()), bytes->size());
+    }
+
+    uint32_t output_size =
+        gzipped_ ? compression::GetUncompressedSize(input) : bytes->size();
+
+    MojoCreateDataPipeOptions options;
+    options.struct_size = sizeof(MojoCreateDataPipeOptions);
+    options.flags = MOJO_CREATE_DATA_PIPE_OPTIONS_FLAG_NONE;
+    options.element_num_bytes = 1;
+    options.capacity_num_bytes = output_size;
+    mojo::DataPipe data_pipe(options);
+
+    DCHECK(data_pipe.producer_handle.is_valid());
+    DCHECK(data_pipe.consumer_handle.is_valid());
+
+    void* buffer = nullptr;
+    uint32_t num_bytes = output_size;
+    MojoResult result =
+        BeginWriteDataRaw(data_pipe.producer_handle.get(), &buffer, &num_bytes,
+                          MOJO_WRITE_DATA_FLAG_NONE);
+    CHECK_EQ(result, MOJO_RESULT_OK);
+    CHECK_EQ(num_bytes, output_size);
+
+    if (gzipped_) {
+      base::StringPiece output(static_cast<char*>(buffer), num_bytes);
+      CHECK(compression::GzipUncompress(input, output));
+    } else {
+      memcpy(buffer, bytes->front(), output_size);
+    }
+    result = EndWriteDataRaw(data_pipe.producer_handle.get(), num_bytes);
+    CHECK_EQ(result, MOJO_RESULT_OK);
+
+    client_->OnStartLoadingResponseBody(std::move(data_pipe.consumer_handle));
+
+    ResourceRequestCompletionStatus request_complete_data;
+    request_complete_data.error_code = net::OK;
+    request_complete_data.exists_in_cache = false;
+    request_complete_data.completion_time = base::TimeTicks::Now();
+    request_complete_data.encoded_data_length = output_size;
+    request_complete_data.encoded_body_length = output_size;
+    client_->OnComplete(request_complete_data);
+    delete this;
+  }
+
+  void OnError(int error_code) {
+    ResourceRequestCompletionStatus status;
+    status.error_code = error_code;
+    client_->OnComplete(status);
+    delete this;
+  }
+
+  mojo::AssociatedBinding<mojom::URLLoader> binding_;
+  mojom::URLLoaderClientPtr client_;
+  bool gzipped_;
+  // Replacement dictionary for i18n.
+  const ui::TemplateReplacements* replacements_;
+  base::WeakPtrFactory<URLLoaderImpl> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(URLLoaderImpl);
+};
+
+class WebUIURLLoaderFactory : public mojom::URLLoaderFactory,
+                              public FrameTreeNode::Observer {
+ public:
+  WebUIURLLoaderFactory(FrameTreeNode* ftn)
+      : frame_tree_node_id_(ftn->frame_tree_node_id()),
+        resource_context_(ftn->current_frame_host()
+                              ->GetProcess()
+                              ->GetBrowserContext()
+                              ->GetResourceContext()) {
+    ftn->AddObserver(this);
+  }
+
+  ~WebUIURLLoaderFactory() override {}
+
+  mojom::URLLoaderFactoryPtr CreateBinding() {
+    return loader_factory_bindings_.CreateInterfacePtrAndBind(this);
+  }
+
+  // mojom::URLLoaderFactory implementation:
+  void CreateLoaderAndStart(mojom::URLLoaderAssociatedRequest loader,
+                            int32_t routing_id,
+                            int32_t request_id,
+                            uint32_t options,
+                            const ResourceRequest& request,
+                            mojom::URLLoaderClientPtr client) override {
+    DCHECK_CURRENTLY_ON(BrowserThread::UI);
+    BrowserThread::PostTask(
+        BrowserThread::IO, FROM_HERE,
+        base::BindOnce(&URLLoaderImpl::Create, std::move(loader), request,
+                       frame_tree_node_id_, client.PassInterface(),
+                       resource_context_));
+  }
+
+  void SyncLoad(int32_t routing_id,
+                int32_t request_id,
+                const ResourceRequest& request,
+                SyncLoadCallback callback) override {
+    NOTREACHED();
+  }
+
+  // FrameTreeNode::Observer implementation:
+  void OnFrameTreeNodeDestroyed(FrameTreeNode* node) override {
+    g_factories.Get().erase(frame_tree_node_id_);
+  }
+
+ private:
+  int frame_tree_node_id_;
+  ResourceContext* resource_context_;
+  mojo::BindingSet<mojom::URLLoaderFactory> loader_factory_bindings_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebUIURLLoaderFactory);
+};
+
+}  // namespace
+
+mojom::URLLoaderFactoryPtr GetWebUIURLLoader(FrameTreeNode* node) {
+  int ftn_id = node->frame_tree_node_id();
+  if (g_factories.Get()[ftn_id].get() == nullptr)
+    g_factories.Get()[ftn_id] = base::MakeUnique<WebUIURLLoaderFactory>(node);
+  return g_factories.Get()[ftn_id]->CreateBinding();
+}
+
+}  // namespace content