Hooking MHTML generation to the browser.

chrome/renderer/mhtml_generator.cc

+// Copyright (c) 2011 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/renderer/mhtml_generator.h"
+
+#include "base/platform_file.h"
+#include "content/common/view_messages.h"
+#include "content/renderer/render_view.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebCString.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebPageSerializer.h"
+
+MHTMLGenerator::MHTMLGenerator(RenderView* render_view)
+    : RenderViewObserver(render_view),
+      file_(base::kInvalidPlatformFileValue) {
+}
+
+MHTMLGenerator::~MHTMLGenerator() {
+}
+
+// RenderViewObserver implementation:
+bool MHTMLGenerator::OnMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(MHTMLGenerator, message)
+      IPC_MESSAGE_HANDLER(ViewMsg_SavePageAsMHTML, OnSavePageAsMHTML)
+      IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void MHTMLGenerator::OnSavePageAsMHTML(
+    int job_id, IPC::PlatformFileForTransit file_for_transit) {
+  base::PlatformFile file =
+      IPC::PlatformFileForTransitToPlatformFile(file_for_transit);
+  file_ = file;
+  bool success = GenerateMHTML();
+  NotifyBrowser(job_id, success);
+}
+
+void MHTMLGenerator::NotifyBrowser(int job_id, bool success) {
+  render_view()->Send(new ViewHostMsg_SavedPageAsMHTML(
+      render_view()->routing_id(), job_id, success));
+  file_ = base::kInvalidPlatformFileValue;
+}
+
+// TODO(jcivelli): write the chunks in deferred tasks to give a chance to the
+//                 message loop to process other events.

[Randy Smith (Not in Mondays), 2011/06/10 18:45:38]

Another area where I'm feeling my lack of competence to well-review the
code--I'm not sure how big a deal it is that this CL doesn't write the chunk in
deferred tasks.  My guess is that you're fine leaving this in a todo (if this
blocks for a while, it's just blocking the renderer process, and it'll be pretty
clear to the user why if they just did a save), but you might want to run this
particular issue by someone who's more familiar with the responsiveness
requirements of the renderer message loop--I've never worked in that space.

[Jay Civelli, 2011/06/10 22:38:22]

I think it is OK too, but I'll try to find someone to agree on it.

+bool MHTMLGenerator::GenerateMHTML() {
+  WebKit::WebCString mhtml =
+      WebKit::WebPageSerializer::serializeToMHTML(render_view()->webview());
+  const size_t chunk_size = 1024;
+  const char* data = mhtml.data();
+  for (size_t i = 0; i < mhtml.length(); i += chunk_size) {
+    size_t copy_size = std::min(mhtml.length() - i, chunk_size);
+    if (base::WritePlatformFile(file_, i, data + i, copy_size) == -1)

[Randy Smith (Not in Mondays), 2011/06/10 18:45:38]

Shouldn't you handle the case where WritePlatformFile returns a number of writes
other than copy_size?  I'm not sure that can ever happen given our context, but
it's part of the interface.

[Jay Civelli, 2011/06/10 22:38:22]

Good point, now taking the returned number of bytes into account.

+      return false;
+  }
+  return true;
+}