Initial implementation of the ByteStream refactor.

content/browser/download/download_file_impl.cc

Index: content/browser/download/download_file_impl.cc
diff --git a/content/browser/download/download_file_impl.cc b/content/browser/download/download_file_impl.cc
index ae8d4ec4395ddb88e5b5c1875f0c9b247055c5c5..40cec3f08e5c9ba37aeabe3582e4098fcd182cef 100644
--- a/content/browser/download/download_file_impl.cc
+++ b/content/browser/download/download_file_impl.cc
@@ -6,11 +6,17 @@
 
 #include <string>
 
+#include "base/bind.h"
 #include "base/file_util.h"
+#include "base/message_loop_proxy.h"
 #include "content/browser/download/download_create_info.h"
+#include "content/browser/download/download_interrupt_reasons_impl.h"
+#include "content/browser/download/download_net_log_parameters.h"
 #include "content/browser/power_save_blocker.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/download_manager.h"
+#include "content/browser/download/download_stats.h"
+#include "net/base/io_buffer.h"
 
 using content::BrowserThread;
 using content::DownloadId;
@@ -33,21 +39,42 @@ DownloadFileImpl::DownloadFileImpl(
                 info->save_info.hash_state,
                 info->save_info.file_stream,
                 bound_net_log),
+          input_pipe_(info->pipe),
           id_(info->download_id),
           request_handle_(request_handle),
           download_manager_(download_manager),
+          bound_net_log_(bound_net_log),
+          weak_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)),
           power_save_blocker_(power_save_blocker.Pass()) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 }
 
 DownloadFileImpl::~DownloadFileImpl() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  // Prevent any future callbacks from reaching us.
+  if (input_pipe_.get())
+    input_pipe_->RegisterSinkCallback(scoped_refptr<base::TaskRunner>(),
+                                      base::Closure(), 0);
 }
 
 // BaseFile delegated functions.
 net::Error DownloadFileImpl::Initialize() {
   update_timer_.reset(new base::RepeatingTimer<DownloadFileImpl>());
-  return file_.Initialize();
+  net::Error result = file_.Initialize();
+  if (result != net::OK)
+    return result;
+
+  input_pipe_->RegisterSinkCallback(
+      base::MessageLoopProxy::current(),
+      // Unretained is safe because the callback is nulled in the
+      // destructor.
+      base::Bind(&DownloadFileImpl::PipeActive, base::Unretained(this)),
+      33);
+
+  // Initial pull from the straw.
+  PipeActive();
+
+  return result;
 }
 
 net::Error DownloadFileImpl::AppendDataToFile(const char* data,
@@ -72,11 +99,6 @@ void DownloadFileImpl::Cancel() {
   file_.Cancel();
 }
 
-void DownloadFileImpl::Finish() {
-  file_.Finish();
-  update_timer_.reset();
-}
-
 void DownloadFileImpl::AnnotateWithSourceInformation() {
   file_.AnnotateWithSourceInformation();
 }
@@ -135,6 +157,99 @@ std::string DownloadFileImpl::DebugString() const {
                             file_.DebugString().c_str());
 }
 
+void DownloadFileImpl::PipeActive() {
+  base::Time start(base::Time::Now());
+  base::Time now;
+  scoped_refptr<net::IOBuffer> incoming_data;
+  size_t length = 0;
+  size_t total_length = 0;
+  size_t num_buffers = 0;
+  content::ByteStream::StreamState state(content::ByteStream::STREAM_EMPTY);
+  content::DownloadInterruptReason reason =
+      content::DOWNLOAD_INTERRUPT_REASON_NONE;
+  base::TimeDelta delta(base::TimeDelta::FromMilliseconds(1000));
+
+  // Take care of any file local activity required.
+  do {
+    state = input_pipe_->GetData(&incoming_data, &length);
+
+    net::Error result = net::OK;
+    switch (state) {
+      case content::ByteStream::STREAM_EMPTY:
+        break;
+      case content::ByteStream::STREAM_HAS_DATA:
+        ++num_buffers;
+        result = AppendDataToFile(incoming_data.get()->data(), length);
+        total_length += length;
+        reason = content::ConvertNetErrorToInterruptReason(
+            result, content::DOWNLOAD_INTERRUPT_FROM_DISK);
+        break;
+      case content::ByteStream::STREAM_COMPLETE:
+        reason = input_pipe_->GetSourceResult();
+        SendUpdate();
+        file_.Finish();
+        update_timer_.reset();
+        break;
+      default:
+        NOTREACHED();
+        break;
+    }
+    now = base::Time::Now();
+  } while (state == content::ByteStream::STREAM_HAS_DATA &&
+           reason == content::DOWNLOAD_INTERRUPT_REASON_NONE &&
+           now - start <= delta);
+
+  // If we're stopping to yield the thread, post a task so we come back.
+  if (state == content::ByteStream::STREAM_HAS_DATA && now - start > delta) {
+    BrowserThread::PostTask(
+        BrowserThread::FILE, FROM_HERE,
+        base::Bind(&DownloadFileImpl::PipeActive, weak_factory_.GetWeakPtr()));
+  }
+
+  if (total_length)
+    download_stats::RecordFileThreadReceiveBuffers(total_length);
+
+  download_stats::RecordContiguousWriteTime(now - start);
+
+  // Take care of communication with our controller.
+  if (reason != content::DOWNLOAD_INTERRUPT_REASON_NONE) {
+    // Error case for both upstream source and file write.
+    // Shut down processing and signal an error to our controller.
+    // Our controller will clean us up.
+    input_pipe_->RegisterSinkCallback(scoped_refptr<base::TaskRunner>(),
+                                      base::Closure(), 0);
+    weak_factory_.InvalidateWeakPtrs();
+    if (download_manager_.get()) {
+      BrowserThread::PostTask(
+          BrowserThread::UI, FROM_HERE,
+          base::Bind(&DownloadManager::OnDownloadInterrupted,
+                     download_manager_, id_.local(),
+                     BytesSoFar(), GetHashState(), reason));
+    }
+  } else if (state == content::ByteStream::STREAM_COMPLETE) {
+    // Signal successful completion and shut down processing.
+    input_pipe_->RegisterSinkCallback(scoped_refptr<base::TaskRunner>(),
+                                      base::Closure(), 0);
+    weak_factory_.InvalidateWeakPtrs();
+    if (download_manager_.get()) {
+      std::string hash;
+      if (!GetHash(&hash) || file_.IsEmptyHash(hash))
+        hash.clear();
+      BrowserThread::PostTask(
+          BrowserThread::UI, FROM_HERE,
+          base::Bind(&DownloadManager::OnResponseCompleted,
+                     download_manager_, id_.local(),
+                     BytesSoFar(), hash));
+    }
+  }
+  if (bound_net_log_.IsLoggingAllEvents()) {
+    bound_net_log_.AddEvent(
+        net::NetLog::TYPE_DOWNLOAD_PIPE_DRAINED,
+        make_scoped_refptr(new download_net_logs::FilePipeDrainedParameters(
+            total_length, num_buffers)));
+  }
+}
+
 void DownloadFileImpl::SendUpdate() {
   if (download_manager_.get()) {
     BrowserThread::PostTask(