PlzNavigate data pipe

content/browser/loader/navigation_resource_handler.cc

Index: content/browser/loader/navigation_resource_handler.cc
diff --git a/content/browser/loader/navigation_resource_handler.cc b/content/browser/loader/navigation_resource_handler.cc
index 5e6dd692da0c6a3b875e82c340a71b8d5f3e941a..49a9682a6c14350608c4184ba5a1d27c61636b46 100644
--- a/content/browser/loader/navigation_resource_handler.cc
+++ b/content/browser/loader/navigation_resource_handler.cc
@@ -21,11 +21,72 @@
 #include "content/public/browser/ssl_status.h"
 #include "content/public/browser/stream_handle.h"
 #include "content/public/common/resource_response.h"
+#include "net/base/io_buffer.h"
+#include "net/base/mime_sniffer.h"
 #include "net/base/net_errors.h"
 #include "net/url_request/url_request.h"
 
 namespace content {
 
+namespace {
+
+// TODO(kinuko): Most of the code below is dup'ed from MojoAsyncResourceHandler,
+// we should unify the implementation.
+
+// For MimeSniffingResourceHandler.
+constexpr size_t kMinAllocationSize = 2 * net::kMaxBytesToSniff;
+
+constexpr size_t kMaxChunkSize = 32 * 1024;
+
+constexpr size_t kDefaultAllocationSize = 512 * 1024;
+
+}  // namespace
+
+// This class is for sharing the ownership of a ScopedDataPipeProducerHandle
+// between WriterIOBuffer and other class.
+class NavigationResourceHandler::SharedWriter final
+    : public base::RefCountedThreadSafe<SharedWriter> {
+ public:
+  explicit SharedWriter(mojo::ScopedDataPipeProducerHandle writer)
+      : writer_(std::move(writer)) {}
+  mojo::DataPipeProducerHandle writer() { return writer_.get(); }
+
+ private:
+  friend class base::RefCountedThreadSafe<SharedWriter>;
+  ~SharedWriter() {}
+
+  const mojo::ScopedDataPipeProducerHandle writer_;
+
+  DISALLOW_COPY_AND_ASSIGN(SharedWriter);
+};
+
+// This class is a IOBuffer subclass for data gotten from a
+// ScopedDataPipeProducerHandle.
+class NavigationResourceHandler::WriterIOBuffer final
+    : public net::IOBufferWithSize {
+ public:
+  // |data| and |size| should be gotten from |writer| via BeginWriteDataRaw.
+  // They will be accesible via IOBuffer methods. As |writer| is stored in this
+  // instance, |data| will be kept valid as long as the following conditions
+  // hold:
+  //  1. |data| is not invalidated via EndWriteDataRaw.
+  //  2. |this| instance is alive.
+  WriterIOBuffer(scoped_refptr<SharedWriter> writer, void* data, size_t size)
+      : net::IOBufferWithSize(static_cast<char*>(data), size),
+        writer_(std::move(writer)) {}
+
+ private:
+  ~WriterIOBuffer() override {
+    // Avoid deleting |data_| in the IOBuffer destructor.
+    data_ = nullptr;
+  }
+
+  // This member is for keeping the writer alive.
+  scoped_refptr<SharedWriter> writer_;
+
+  DISALLOW_COPY_AND_ASSIGN(WriterIOBuffer);
+};
+
 void NavigationResourceHandler::GetSSLStatusForRequest(
     const GURL& url,
     const net::SSLInfo& ssl_info,
@@ -41,9 +102,9 @@ NavigationResourceHandler::NavigationResourceHandler(
     ResourceDispatcherHostDelegate* resource_dispatcher_host_delegate)
     : ResourceHandler(request),
       core_(core),
-      resource_dispatcher_host_delegate_(resource_dispatcher_host_delegate) {
+      resource_dispatcher_host_delegate_(resource_dispatcher_host_delegate),
+      handle_watcher_(FROM_HERE, mojo::SimpleWatcher::ArmingPolicy::MANUAL) {
   core_->set_resource_handler(this);
-  writer_.set_immediate_mode(true);
 }
 
 NavigationResourceHandler::~NavigationResourceHandler() {
@@ -95,13 +156,8 @@ void NavigationResourceHandler::OnResponseStarted(
 
   ResourceRequestInfoImpl* info = GetRequestInfo();
 
-  StreamContext* stream_context =
-      GetStreamContextForResourceContext(info->GetContext());
-  writer_.InitializeStream(
-      stream_context->registry(), request()->url().GetOrigin(),
-      base::Bind(&NavigationResourceHandler::OutOfBandCancel,
-                 base::Unretained(this), net::ERR_ABORTED,
-                 true /* tell_renderer */));
+  mojo::ScopedDataPipeConsumerHandle data_consumer_handle;
+  InitializeDataPipe(&data_consumer_handle);
 
   NetLogObserver::PopulateResponseInfo(request(), response);
   response->head.encoded_data_length = request()->raw_header_size();
@@ -123,7 +179,7 @@ void NavigationResourceHandler::OnResponseStarted(
                            info->GetChildID(), &ssl_status);
   }
 
-  core_->NotifyResponseStarted(response, writer_.stream()->CreateHandle(),
+  core_->NotifyResponseStarted(response, std::move(data_consumer_handle),
                                ssl_status, std::move(cloned_data),
                                info->GetGlobalRequestID(), info->IsDownload(),
                                info->is_stream());
@@ -159,7 +215,52 @@ void NavigationResourceHandler::OnWillRead(
     int* buf_size,
     std::unique_ptr<ResourceController> controller) {
   DCHECK(!has_controller());
-  writer_.OnWillRead(buf, buf_size, -1);
+
+  DCHECK(shared_writer_);
+  DCHECK(!buffer_);
+  DCHECK_EQ(0u, buffer_offset_);
+
+  bool first_call = first_read_;
+
+  if (first_read_) {
+    first_read_ = false;
+    handle_watcher_.Watch(shared_writer_->writer(), MOJO_HANDLE_SIGNAL_WRITABLE,
+                          base::Bind(&NavigationResourceHandler::OnWritable,
+                                     base::Unretained(this)));
+    handle_watcher_.ArmOrNotify();
+  }
+
+  bool defer = false;
+  if (!AllocateWriterIOBuffer(&buffer_, &defer)) {
+    controller->CancelWithError(net::ERR_INSUFFICIENT_RESOURCES);
+    return;
+  }
+
+  if (defer) {
+    parent_buffer_ = buf;
+    parent_buffer_size_ = buf_size;
+    HoldController(std::move(controller));
+    request()->LogBlockedBy("MojoStreamWriter");
+    did_defer_on_will_read_ = true;
+    return;
+  }
+
+  // The first call to OnWillRead must return a buffer of at least
+  // kMinAllocationSize. If the Mojo buffer is too small, need to allocate an
+  // intermediary buffer.
+  if (first_call && static_cast<size_t>(buffer_->size()) < kMinAllocationSize) {
+    // The allocated buffer is too small, so need to create an intermediary one.
+    if (EndWrite(0) != MOJO_RESULT_OK) {
+      controller->CancelWithError(net::ERR_INSUFFICIENT_RESOURCES);
+      return;
+    }
+    DCHECK(!is_using_io_buffer_not_from_writer_);
+    is_using_io_buffer_not_from_writer_ = true;
+    buffer_ = new net::IOBufferWithSize(kMinAllocationSize);
+  }
+
+  *buf = buffer_;
+  *buf_size = buffer_->size();
   controller->Resume();
 }
 
@@ -167,17 +268,51 @@ void NavigationResourceHandler::OnReadCompleted(
     int bytes_read,
     std::unique_ptr<ResourceController> controller) {
   DCHECK(!has_controller());
-  writer_.OnReadCompleted(bytes_read,
-                          base::Bind(&ResourceController::Resume,
-                                     base::Passed(std::move(controller))));
+  DCHECK_GE(bytes_read, 0);
+  DCHECK(buffer_);
+
+  if (bytes_read == 0) {
+    // Note that |buffer_| is not cleared here, which will cause a DCHECK on
+    // subsequent OnWillRead calls.
+    controller->Resume();
+    return;
+  }
+
+  if (is_using_io_buffer_not_from_writer_) {
+    // Couldn't allocate a large enough buffer on the data pipe in OnWillRead.
+    DCHECK_EQ(0u, buffer_bytes_read_);
+    buffer_bytes_read_ = bytes_read;
+    bool defer = false;
+    if (!CopyReadDataToDataPipe(&defer)) {
+      controller->CancelWithError(net::ERR_INSUFFICIENT_RESOURCES);
+      return;
+    }
+    if (defer) {
+      request()->LogBlockedBy("NavigationResourceHandler");
+      did_defer_on_writing_ = true;
+      HoldController(std::move(controller));
+      return;
+    }
+    controller->Resume();
+    return;
+  }
+
+  if (EndWrite(bytes_read) != MOJO_RESULT_OK) {
+    controller->Cancel();
+    return;
+  }
+
+  buffer_ = nullptr;
+  controller->Resume();
 }
 
 void NavigationResourceHandler::OnResponseCompleted(
     const net::URLRequestStatus& status,
     std::unique_ptr<ResourceController> controller) {
-  // If the request has already committed, close the stream and leave it as-is.
-  if (writer_.stream()) {
-    writer_.Finalize(status.error());
+  if (shared_writer_) {
+    shared_writer_ = nullptr;
+    buffer_ = nullptr;
+    handle_watcher_.Cancel();
     controller->Resume();
     return;
   }
@@ -201,4 +336,122 @@ void NavigationResourceHandler::DetachFromCore() {
   core_ = nullptr;
 }
 
+void NavigationResourceHandler::InitializeDataPipe(
+    mojo::ScopedDataPipeConsumerHandle* consumer_handle) {
+  DCHECK(!shared_writer_);
+
+  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 = kDefaultAllocationSize;
+  mojo::DataPipe data_pipe(options);
+
+  DCHECK(data_pipe.producer_handle.is_valid());
+  DCHECK(data_pipe.consumer_handle.is_valid());
+
+  *consumer_handle = std::move(data_pipe.consumer_handle);
+  shared_writer_ = new SharedWriter(std::move(data_pipe.producer_handle));
+}
+
+MojoResult NavigationResourceHandler::BeginWrite(void** data,
+                                                 uint32_t* available) {
+  MojoResult result = mojo::BeginWriteDataRaw(
+      shared_writer_->writer(), data, available, MOJO_WRITE_DATA_FLAG_NONE);
+  if (result == MOJO_RESULT_OK)
+    *available = std::min(*available, static_cast<uint32_t>(kMaxChunkSize));
+  else if (result == MOJO_RESULT_SHOULD_WAIT)
+    handle_watcher_.ArmOrNotify();
+  return result;
+}
+
+MojoResult NavigationResourceHandler::EndWrite(uint32_t written) {
+  MojoResult result = mojo::EndWriteDataRaw(shared_writer_->writer(), written);
+  if (result == MOJO_RESULT_OK)
+    handle_watcher_.ArmOrNotify();
+  return result;
+}
+
+bool NavigationResourceHandler::CopyReadDataToDataPipe(bool* defer) {
+  while (buffer_bytes_read_ > 0) {
+    scoped_refptr<net::IOBufferWithSize> dest;
+    if (!AllocateWriterIOBuffer(&dest, defer))
+      return false;
+    if (*defer)
+      return true;
+
+    size_t copied_size =
+        std::min(buffer_bytes_read_, static_cast<size_t>(dest->size()));
+    memcpy(dest->data(), buffer_->data() + buffer_offset_, copied_size);
+    buffer_offset_ += copied_size;
+    buffer_bytes_read_ -= copied_size;
+    if (EndWrite(copied_size) != MOJO_RESULT_OK)
+      return false;
+  }
+
+  // All bytes are copied.
+  buffer_ = nullptr;
+  buffer_offset_ = 0;
+  is_using_io_buffer_not_from_writer_ = false;
+  return true;
+}
+
+bool NavigationResourceHandler::AllocateWriterIOBuffer(
+    scoped_refptr<net::IOBufferWithSize>* buf,
+    bool* defer) {
+  void* data = nullptr;
+  uint32_t available = 0;
+  MojoResult result = BeginWrite(&data, &available);
+  if (result == MOJO_RESULT_SHOULD_WAIT) {
+    *defer = true;
+    return true;
+  }
+  if (result != MOJO_RESULT_OK)
+    return false;
+  DCHECK_GT(available, 0u);
+  *buf = new WriterIOBuffer(shared_writer_, data, available);
+  return true;
+}
+
+void NavigationResourceHandler::OnWritable(MojoResult result) {
+  if (did_defer_on_will_read_) {
+    DCHECK(has_controller());
+    DCHECK(!did_defer_on_writing_);
+    DCHECK(!did_defer_on_redirect_);
+
+    did_defer_on_will_read_ = false;
+
+    scoped_refptr<net::IOBuffer>* parent_buffer = parent_buffer_;
+    parent_buffer_ = nullptr;
+    int* parent_buffer_size = parent_buffer_size_;
+    parent_buffer_size_ = nullptr;
+
+    request()->LogUnblocked();
+    OnWillRead(parent_buffer, parent_buffer_size, ReleaseController());
+    return;
+  }
+
+  if (!did_defer_on_writing_)
+    return;
+  DCHECK(has_controller());
+  DCHECK(!did_defer_on_redirect_);
+  did_defer_on_writing_ = false;
+
+  DCHECK(is_using_io_buffer_not_from_writer_);
+  // |buffer_| is set to a net::IOBufferWithSize. Write the buffer contents
+  // to the data pipe.
+  DCHECK_GT(buffer_bytes_read_, 0u);
+  if (!CopyReadDataToDataPipe(&did_defer_on_writing_)) {
+    CancelWithError(net::ERR_INSUFFICIENT_RESOURCES);
+    return;
+  }
+
+  if (did_defer_on_writing_) {
+    // Continue waiting.
+    return;
+  }
+  request()->LogUnblocked();
+  Resume();
+}
+
 }  // namespace content