Implementation of URLLoader using PluginResource/ResourceHost.

ppapi/proxy/url_loader_resource.cc

Index: ppapi/proxy/url_loader_resource.cc
diff --git a/ppapi/proxy/url_loader_resource.cc b/ppapi/proxy/url_loader_resource.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5ee8d950d5646bdc044fb560e19ed25c0151c12f
--- /dev/null
+++ b/ppapi/proxy/url_loader_resource.cc
@@ -0,0 +1,392 @@
+// Copyright (c) 2013 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 "ppapi/proxy/url_loader_resource.h"
+
+#include "base/logging.h"
+#include "ppapi/c/pp_completion_callback.h"
+#include "ppapi/c/pp_errors.h"
+#include "ppapi/c/ppb_url_loader.h"
+#include "ppapi/proxy/dispatch_reply_message.h"
+#include "ppapi/proxy/ppapi_messages.h"
+#include "ppapi/proxy/ppb_file_ref_proxy.h"
+#include "ppapi/proxy/url_request_info_resource.h"
+#include "ppapi/proxy/url_response_info_resource.h"
+#include "ppapi/shared_impl/ppapi_globals.h"
+#include "ppapi/shared_impl/url_response_info_data.h"
+#include "ppapi/thunk/enter.h"
+#include "ppapi/thunk/resource_creation_api.h"
+
+using ppapi::thunk::EnterResourceNoLock;
+using ppapi::thunk::PPB_URLLoader_API;
+using ppapi::thunk::PPB_URLRequestInfo_API;
+
+#ifdef _MSC_VER
+// Do not warn about use of std::copy with raw pointers.
+#pragma warning(disable : 4996)
+#endif
+
+namespace ppapi {
+namespace proxy {
+
+URLLoaderResource::URLLoaderResource(Connection connection,
+                                     PP_Instance instance)
+    : PluginResource(connection, instance),
+      mode_(MODE_WAITING_TO_OPEN),
+      status_callback_(NULL),
+      bytes_sent_(0),
+      total_bytes_to_be_sent_(-1),
+      bytes_received_(0),
+      total_bytes_to_be_received_(-1),
+      user_buffer_(NULL),
+      user_buffer_size_(0),
+      done_status_(PP_OK_COMPLETIONPENDING),
+      is_streaming_to_file_(false),
+      is_asynchronous_load_suspended_(false) {
+  SendCreate(RENDERER, PpapiHostMsg_URLLoader_Create());
+}
+
+URLLoaderResource::URLLoaderResource(Connection connection,
+                                     PP_Instance instance,
+                                     int pending_main_document_loader_id,
+                                     const ppapi::URLResponseInfoData& data)
+    : PluginResource(connection, instance),
+      mode_(MODE_OPENING),
+      status_callback_(NULL),
+      bytes_sent_(0),
+      total_bytes_to_be_sent_(-1),
+      bytes_received_(0),
+      total_bytes_to_be_received_(-1),
+      user_buffer_(NULL),
+      user_buffer_size_(0),
+      done_status_(PP_OK_COMPLETIONPENDING),
+      is_streaming_to_file_(false),
+      is_asynchronous_load_suspended_(false) {
+  AttachToPendingHost(RENDERER, pending_main_document_loader_id);
+  SaveResponseInfo(data);
+}
+
+URLLoaderResource::~URLLoaderResource() {
+}
+
+PPB_URLLoader_API* URLLoaderResource::AsPPB_URLLoader_API() {
+  return this;
+}
+
+int32_t URLLoaderResource::Open(PP_Resource request_id,
+                                scoped_refptr<TrackedCallback> callback) {
+  EnterResourceNoLock<PPB_URLRequestInfo_API> enter_request(request_id, true);
+  if (enter_request.failed()) {
+    Log(PP_LOGLEVEL_ERROR,
+        "PPB_URLLoader.Open: invalid request resource ID. (Hint to C++ wrapper"
+        " users: use the ResourceRequest constructor that takes an instance or"
+        " else the request will be null.)");
+    return PP_ERROR_BADARGUMENT;
+  }
+  return Open(enter_request.object()->GetData(), 0, callback);
+}
+
+int32_t URLLoaderResource::Open(
+    const ::ppapi::URLRequestInfoData& request_data,
+    int requestor_pid,
+    scoped_refptr<TrackedCallback> callback) {
+  int32_t rv = ValidateCallback(callback);
+  if (rv != PP_OK)
+    return rv;
+  if (mode_ != MODE_WAITING_TO_OPEN)
+    return PP_ERROR_INPROGRESS;
+
+  request_data_ = request_data;
+
+  mode_ = MODE_OPENING;
+  is_asynchronous_load_suspended_ = false;
+
+  RegisterCallback(callback);
+  Post(RENDERER, PpapiHostMsg_URLLoader_Open(request_data));
+  return PP_OK_COMPLETIONPENDING;
+}
+
+int32_t URLLoaderResource::FollowRedirect(
+    scoped_refptr<TrackedCallback> callback) {
+  int32_t rv = ValidateCallback(callback);
+  if (rv != PP_OK)
+    return rv;
+  if (mode_ != MODE_OPENING)
+    return PP_ERROR_INPROGRESS;
+
+  SetDefersLoading(false);  // Allow the redirect to continue.
+  RegisterCallback(callback);
+  return PP_OK_COMPLETIONPENDING;
+}
+
+PP_Bool URLLoaderResource::GetUploadProgress(int64_t* bytes_sent,
+                                              int64_t* total_bytes_to_be_sent) {
+  if (!request_data_.record_upload_progress) {
+    *bytes_sent = 0;
+    *total_bytes_to_be_sent = 0;
+    return PP_FALSE;
+  }
+  *bytes_sent = bytes_sent_;
+  *total_bytes_to_be_sent = total_bytes_to_be_sent_;
+  return PP_TRUE;
+}
+
+PP_Bool URLLoaderResource::GetDownloadProgress(
+    int64_t* bytes_received,
+    int64_t* total_bytes_to_be_received) {
+  if (!request_data_.record_download_progress) {
+    *bytes_received = 0;
+    *total_bytes_to_be_received = 0;
+    return PP_FALSE;
+  }
+  *bytes_received = bytes_received_;
+  *total_bytes_to_be_received = total_bytes_to_be_received_;
+  return PP_TRUE;
+}
+
+PP_Resource URLLoaderResource::GetResponseInfo() {
+  if (response_info_.get())
+    return response_info_->GetReference();
+  return 0;
+}
+
+int32_t URLLoaderResource::ReadResponseBody(
+    void* buffer,
+    int32_t bytes_to_read,
+    scoped_refptr<TrackedCallback> callback) {
+  int32_t rv = ValidateCallback(callback);
+  if (rv != PP_OK)
+    return rv;
+  if (!response_info_.get() ||
+      !response_info_->data().body_as_file_ref.resource.is_null())
+    return PP_ERROR_FAILED;
+  if (bytes_to_read <= 0 || !buffer)
+    return PP_ERROR_BADARGUMENT;
+
+  user_buffer_ = static_cast<char*>(buffer);
+  user_buffer_size_ = bytes_to_read;
+
+  if (!buffer_.empty())
+    return FillUserBuffer();
+
+  // We may have already reached EOF.
+  if (done_status_ != PP_OK_COMPLETIONPENDING) {
+    user_buffer_ = NULL;
+    user_buffer_size_ = 0;
+    return done_status_;
+  }
+
+  RegisterCallback(callback);
+  return PP_OK_COMPLETIONPENDING;
+}
+
+int32_t URLLoaderResource::FinishStreamingToFile(
+    scoped_refptr<TrackedCallback> callback) {
+  int32_t rv = ValidateCallback(callback);
+  if (rv != PP_OK)
+    return rv;
+  if (!response_info_.get() ||
+      response_info_->data().body_as_file_ref.resource.is_null())
+    return PP_ERROR_FAILED;
+
+  // We may have already reached EOF.
+  if (done_status_ != PP_OK_COMPLETIONPENDING)
+    return done_status_;
+
+  is_streaming_to_file_ = true;
+  if (is_asynchronous_load_suspended_)
+    SetDefersLoading(false);
+
+  // Wait for didFinishLoading / didFail.
+  RegisterCallback(callback);
+  return PP_OK_COMPLETIONPENDING;
+}
+
+void URLLoaderResource::Close() {
+  mode_ = MODE_LOAD_COMPLETE;
+  done_status_ = PP_ERROR_ABORTED;
+
+  Post(RENDERER, PpapiHostMsg_URLLoader_Close());
+
+  // Abort the callbacks, the plugin doesn't want to be called back after this.
+  // TODO(brettw) this should fix bug 69457, mark it fixed. ============
+  if (TrackedCallback::IsPending(pending_callback_))
+    pending_callback_->PostAbort();
+}
+
+void URLLoaderResource::GrantUniversalAccess() {
+  Post(RENDERER, PpapiHostMsg_URLLoader_GrantUniversalAccess());
+}
+
+void URLLoaderResource::RegisterStatusCallback(
+    PP_URLLoaderTrusted_StatusCallback callback) {
+  status_callback_ = callback;
+}
+
+void URLLoaderResource::OnReplyReceived(
+    const ResourceMessageReplyParams& params,
+    const IPC::Message& msg) {
+  IPC_BEGIN_MESSAGE_MAP(URLLoaderResource, msg)
+    case PpapiPluginMsg_URLLoader_SendData::ID:
+      // Special message, manually dispatch since we don't want the automatic
+      // unpickling.
+      OnPluginMsgSendData(params, msg);
+      break;
+
+    PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL(
+        PpapiPluginMsg_URLLoader_ReceivedResponse,
+        OnPluginMsgReceivedResponse)
+    PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL(
+        PpapiPluginMsg_URLLoader_FinishedLoading,
+        OnPluginMsgFinishedLoading)
+    PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL(
+        PpapiPluginMsg_URLLoader_UpdateProgress,
+        OnPluginMsgUpdateProgress)
+  IPC_END_MESSAGE_MAP()
+}
+
+void URLLoaderResource::OnPluginMsgReceivedResponse(
+    const ResourceMessageReplyParams& params,
+    const URLResponseInfoData& data) {
+  SaveResponseInfo(data);
+  RunCallback(PP_OK);
+}
+
+void URLLoaderResource::OnPluginMsgSendData(
+    const ResourceMessageReplyParams& params,
+    const IPC::Message& message) {
+  PickleIterator iter(message);
+  const char* data;
+  int data_length;
+  if (!iter.ReadData(&data, &data_length)) {
+    NOTREACHED() << "Expecting data";
+    return;
+  }
+
+  mode_ = MODE_STREAMING_DATA;
+  buffer_.insert(buffer_.end(), data, data + data_length);
+
+  // To avoid letting the network stack download an entire stream all at once,
+  // defer loading when we have enough buffer.
+  // Check for this before we run the callback, even though that could move
+  // data out of the buffer. Doing anything after the callback is unsafe.
+  DCHECK(request_data_.prefetch_buffer_lower_threshold <
+         request_data_.prefetch_buffer_upper_threshold);
+  if (!is_streaming_to_file_ &&
+      !is_asynchronous_load_suspended_ &&
+      (buffer_.size() >= static_cast<size_t>(
+          request_data_.prefetch_buffer_upper_threshold))) {
+    DVLOG(1) << "Suspending async load - buffer size: " << buffer_.size();
+    SetDefersLoading(true);
+  }
+
+  if (user_buffer_)
+    RunCallback(FillUserBuffer());
+  else
+    DCHECK(!TrackedCallback::IsPending(pending_callback_));
+}
+
+void URLLoaderResource::OnPluginMsgFinishedLoading(
+    const ResourceMessageReplyParams& params,
+    int32_t result) {
+  mode_ = MODE_LOAD_COMPLETE;
+  done_status_ = result;
+  user_buffer_ = NULL;
+  user_buffer_size_ = 0;
+
+  // If the client hasn't called any function that takes a callback since
+  // the initial call to Open, or called ReadResponseBody and got a
+  // synchronous return, then the callback will be NULL.
+  if (TrackedCallback::IsPending(pending_callback_))
+    RunCallback(done_status_);
+}
+
+void URLLoaderResource::OnPluginMsgUpdateProgress(
+    const ResourceMessageReplyParams& params,
+    int64_t bytes_sent,
+    int64_t total_bytes_to_be_sent,
+    int64_t bytes_received,
+    int64_t total_bytes_to_be_received) {
+  bytes_sent_ = bytes_sent;
+  total_bytes_to_be_sent_ = total_bytes_to_be_sent;
+  bytes_received_ = bytes_received;
+  total_bytes_to_be_received_ = total_bytes_to_be_received;
+
+  if (status_callback_)
+    status_callback_(pp_instance(), pp_resource(),
+                     bytes_sent_, total_bytes_to_be_sent_,
+                     bytes_received_, total_bytes_to_be_received_);
+}
+
+void URLLoaderResource::SetDefersLoading(bool defers_loading) {
+  Post(RENDERER, PpapiHostMsg_URLLoader_SetDeferLoading(defers_loading));
+}
+
+int32_t URLLoaderResource::ValidateCallback(
+    scoped_refptr<TrackedCallback> callback) {
+  DCHECK(callback);
+  if (TrackedCallback::IsPending(pending_callback_))
+    return PP_ERROR_INPROGRESS;
+  return PP_OK;
+}
+
+void URLLoaderResource::RegisterCallback(
+    scoped_refptr<TrackedCallback> callback) {
+  DCHECK(!TrackedCallback::IsPending(pending_callback_));
+  pending_callback_ = callback;
+}
+
+void URLLoaderResource::RunCallback(int32_t result) {
+  // This may be null when this is a main document loader.
+  if (!pending_callback_.get())
+    return;
+
+  // If |user_buffer_| was set as part of registering a callback, the paths
+  // which trigger that callack must have cleared it since the callback is now
+  // free to delete it.
+  DCHECK(!user_buffer_);
+
+  // As a second line of defense, clear the |user_buffer_| in case the
+  // callbacks get called in an unexpected order.
+  user_buffer_ = NULL;
+  user_buffer_size_ = 0;
+  pending_callback_->Run(result);
+}
+
+void URLLoaderResource::SaveResponseInfo(const URLResponseInfoData& data) {
+  // Create a proxy resource for the the file ref host resource if needed.
+  PP_Resource body_as_file_ref = 0;
+  if (!data.body_as_file_ref.resource.is_null()) {
+    thunk::EnterResourceCreationNoLock enter(pp_instance());
+    body_as_file_ref =
+        enter.functions()->CreateFileRef(data.body_as_file_ref);
+  }
+  response_info_ = new URLResponseInfoResource(
+      connection(), pp_instance(), data, body_as_file_ref);
+}
+
+size_t URLLoaderResource::FillUserBuffer() {
+  DCHECK(user_buffer_);
+  DCHECK(user_buffer_size_);
+
+  size_t bytes_to_copy = std::min(buffer_.size(), user_buffer_size_);
+  std::copy(buffer_.begin(), buffer_.begin() + bytes_to_copy, user_buffer_);
+  buffer_.erase(buffer_.begin(), buffer_.begin() + bytes_to_copy);
+
+  // If the buffer is getting too empty, resume asynchronous loading.
+  if (is_asynchronous_load_suspended_ &&
+      buffer_.size() <= static_cast<size_t>(
+          request_data_.prefetch_buffer_lower_threshold)) {
+    DVLOG(1) << "Resuming async load - buffer size: " << buffer_.size();
+    SetDefersLoading(false);
+  }
+
+  // Reset for next time.
+  user_buffer_ = NULL;
+  user_buffer_size_ = 0;
+  return bytes_to_copy;
+}
+
+}  // namespace proxy
+}  // namespace ppapi