OOPIFs: Deduplicating MHTML parts across frames.

content/browser/download/mhtml_generation_manager.cc

Index: content/browser/download/mhtml_generation_manager.cc
diff --git a/content/browser/download/mhtml_generation_manager.cc b/content/browser/download/mhtml_generation_manager.cc
index c63405e93d55507e4e871dfa85c1ded7c295ae9f..f0c6606dbd1f54db5e6f85182a8248a6d1994e78 100644
--- a/content/browser/download/mhtml_generation_manager.cc
+++ b/content/browser/download/mhtml_generation_manager.cc
@@ -22,6 +22,7 @@
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_process_host_observer.h"
 #include "content/public/browser/web_contents.h"
+#include "url/gurl.h"
 
 namespace content {
 
@@ -36,6 +37,12 @@ class MHTMLGenerationManager::Job : public RenderProcessHostObserver {
 
   GenerateMHTMLCallback callback() const { return callback_; }
 
+  // Handler for FrameHostMsg_SerializeAsMHTMLResponse (a notification from the
+  // renderer that the MHTML generation for previous frame has finished).
+  // Returns |true| upon success; |false| otherwise.
+  bool OnSerializeAsMHTMLResponse(
+      const std::set<std::string>& digests_of_uris_of_serialized_resources);
+
   // Sends IPC to the renderer, asking for MHTML generation of the next frame.
   //
   // Returns true if the message was sent successfully; false otherwise.
@@ -84,6 +91,10 @@ class MHTMLGenerationManager::Job : public RenderProcessHostObserver {
   // MIME multipart boundary to use in the MHTML doc.
   std::string mhtml_boundary_marker_;
 
+  // Digests of URIs of already generated MHTML parts.
+  std::set<std::string> digests_of_already_serialized_uris_;
+  std::string salt_;
+
   // The callback to call once generation is complete.
   GenerateMHTMLCallback callback_;
 
@@ -99,6 +110,7 @@ MHTMLGenerationManager::Job::Job(int job_id,
                                  GenerateMHTMLCallback callback)
     : job_id_(job_id),
       mhtml_boundary_marker_(GenerateMHTMLBoundaryMarker()),
+      salt_(base::GenerateGUID()),
       callback_(callback),
       observed_renderer_process_host_(this) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
@@ -142,9 +154,13 @@ bool MHTMLGenerationManager::Job::SendToNextRenderFrame() {
   DCHECK(browser_file_.IsValid());
   DCHECK_LT(0u, pending_frame_tree_node_ids_.size());
 
+  FrameMsg_SerializeAsMHTML_Params ipc_params;
+  ipc_params.job_id = job_id_;
+  ipc_params.mhtml_boundary_marker = mhtml_boundary_marker_;
+
   int frame_tree_node_id = pending_frame_tree_node_ids_.front();
   pending_frame_tree_node_ids_.pop();
-  bool is_last_frame = pending_frame_tree_node_ids_.empty();
+  ipc_params.is_last_frame = pending_frame_tree_node_ids_.empty();
 
   FrameTreeNode* ftn = FrameTreeNode::GloballyFindByID(frame_tree_node_id);
   if (!ftn)  // The contents went away.
@@ -155,12 +171,16 @@ bool MHTMLGenerationManager::Job::SendToNextRenderFrame() {
   observed_renderer_process_host_.RemoveAll();
   observed_renderer_process_host_.Add(rfh->GetProcess());
 
-  IPC::PlatformFileForTransit renderer_file = IPC::GetFileHandleForProcess(
+  // Tell the renderer to skip (= deduplicate) already covered MHTML parts.
+  ipc_params.salt = salt_;
+  ipc_params.digests_of_uris_to_skip = digests_of_already_serialized_uris_;
+
+  ipc_params.destination_file = IPC::GetFileHandleForProcess(
       browser_file_.GetPlatformFile(), rfh->GetProcess()->GetHandle(),
       false);  // |close_source_handle|.
-  rfh->Send(new FrameMsg_SerializeAsMHTML(
-      rfh->GetRoutingID(), job_id_, renderer_file, mhtml_boundary_marker_,
-      CreateFrameRoutingIdToContentId(rfh->GetSiteInstance()), is_last_frame));
+  ipc_params.frame_routing_id_to_content_id =
+      CreateFrameRoutingIdToContentId(rfh->GetSiteInstance());
+  rfh->Send(new FrameMsg_SerializeAsMHTML(rfh->GetRoutingID(), ipc_params));
   return true;
 }
 
@@ -205,6 +225,18 @@ void MHTMLGenerationManager::Job::CloseFile(
       callback);
 }
 
+bool MHTMLGenerationManager::Job::OnSerializeAsMHTMLResponse(
+    const std::set<std::string>& digests_of_uris_of_serialized_resources) {
+  digests_of_already_serialized_uris_.insert(
+      digests_of_uris_of_serialized_resources.begin(),
+      digests_of_uris_of_serialized_resources.end());
+
+  if (!HasMoreFramesToProcess())
+    return true;  // Success.
+
+  return SendToNextRenderFrame();
+}
+
 // static
 int64 MHTMLGenerationManager::Job::CloseFileOnFileThread(base::File file) {
   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
@@ -258,9 +290,10 @@ void MHTMLGenerationManager::SaveMHTML(WebContents* web_contents,
                  job_id));
 }
 
-void MHTMLGenerationManager::OnSavedFrameAsMHTML(
+void MHTMLGenerationManager::OnSerializeAsMHTMLResponse(
     int job_id,
-    bool mhtml_generation_in_renderer_succeeded) {
+    bool mhtml_generation_in_renderer_succeeded,
+    const std::set<std::string>& digests_of_uris_of_serialized_resources) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   if (!mhtml_generation_in_renderer_succeeded) {
@@ -272,14 +305,15 @@ void MHTMLGenerationManager::OnSavedFrameAsMHTML(
   if (!job)
     return;
 
-  if (job->HasMoreFramesToProcess()) {
-    if (!job->SendToNextRenderFrame()) {
-      JobFinished(job_id, JobStatus::FAILURE);
-    }
+  if (!job->HasMoreFramesToProcess()) {
+    JobFinished(job_id, JobStatus::SUCCESS);
     return;
   }
 
-  JobFinished(job_id, JobStatus::SUCCESS);
+  if (!job->OnSerializeAsMHTMLResponse(
+          digests_of_uris_of_serialized_resources)) {
+    JobFinished(job_id, JobStatus::FAILURE);
+  }
 }
 
 // static