Port WebSockets to Mojo IPC

content/browser/renderer_host/websocket_blob_sender.h

-// Copyright 2016 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.
-
-#ifndef CONTENT_BROWSER_RENDERER_HOST_WEBSOCKET_BLOB_SENDER_H_
-#define CONTENT_BROWSER_RENDERER_HOST_WEBSOCKET_BLOB_SENDER_H_
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include <iosfwd>
-#include <memory>
-#include <string>
-#include <vector>
-
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "content/common/content_export.h"
-#include "net/base/completion_callback.h"
-#include "net/websockets/websocket_event_interface.h"
-
-namespace base {
-class SingleThreadTaskRunner;
-}
-
-namespace net {
-class IOBuffer;
-}
-
-namespace storage {
-class BlobReader;
-class BlobStorageContext;
-class FileSystemContext;
-}
-
-namespace content {
-
-class WebSocketHost;
-
-// Read the contents of a Blob and write it to a WebSocket. Single-use: a new
-// object must be created each time a Blob is sent. Destroying the object
-// cancels all pending operations.
-class CONTENT_EXPORT WebSocketBlobSender final {
- public:
-  // An abstraction of the WebSocketChannel this object will send frames to.
-  class Channel {
-   public:
-    using ChannelState = net::WebSocketEventInterface::ChannelState;
-
-    Channel() {}
-    virtual ~Channel() {}
-
-    // The currently available quota for sending. It must not decrease without
-    // SendFrame() being called.
-    virtual size_t GetSendQuota() const = 0;
-
-    // Send a binary frame. |fin| is true for the final frame of the message.
-    // |data| is the contents of the frame. data.size() must be less than
-    // GetSendQuota(). If this call returns CHANNEL_DELETED, WebSocketBlobSender
-    // will assume that it has been deleted and return without calling any
-    // callbacks or accessing any other member data.
-    virtual ChannelState SendFrame(bool fin, const std::vector<char>& data) = 0;
-
-   private:
-    DISALLOW_COPY_AND_ASSIGN(Channel);
-  };
-
-  // |channel| will be destroyed when this object is.
-  explicit WebSocketBlobSender(std::unique_ptr<Channel> channel);
-  ~WebSocketBlobSender();
-
-  // Checks that the blob identified by |uuid| exists, has the size
-  // |expected_size| and then starts sending it via |channel_|. Returns
-  // ERR_IO_PENDING to indicate that |callback| will be called later with the
-  // result. net::OK indicates synchronous success. Any other net error code
-  // indicates synchronous failure. This method may result in the destruction of
-  // the channel, in which case |*channel_state| will be set to CHANNEL_DELETED.
-  int Start(const std::string& uuid,
-            uint64_t expected_size,
-            storage::BlobStorageContext* context,
-            storage::FileSystemContext* file_system_context,
-            base::SingleThreadTaskRunner* file_task_runner,
-            net::WebSocketEventInterface::ChannelState* channel_state,
-            const net::CompletionCallback& callback);
-
-  // Sends more data if the object was waiting for quota and the new value of
-  // GetSendQuota() is large enough.
-  void OnNewSendQuota();
-
-  uint64_t expected_size() const { return expected_size_; }
-
-  // ActualSize() should only be called after completion: ie. Start() returned a
-  // value other than ERR_IO_PENDING or |callback_| has been called.
-  uint64_t ActualSize() const;
-
- private:
-  // State proceeds through READ_SIZE and READ_SIZE_COMPLETE, then
-  // loops WAIT_FOR_QUOTA -> WAIT_FOR_QUOTA_COMPLETE -> READ
-  // -> READ_COMPLETE -> WAIT_FOR_QUOTA until the Blob is completely
-  // sent.
-  enum class State {
-    NONE = 0,
-    READ_SIZE,
-    READ_SIZE_COMPLETE,
-    WAIT_FOR_QUOTA,
-    WAIT_FOR_QUOTA_COMPLETE,
-    READ,
-    READ_COMPLETE,
-  };
-
-  // This is needed to make DCHECK_EQ(), etc. compile.
-  friend std::ostream& operator<<(std::ostream& os, State state);
-
-  void OnReadComplete(int rv);
-  void OnSizeCalculated(int rv);
-  // |channel_state| should point to CHANNEL_ALIVE when called. If it is
-  // CHANNEL_DELETED on return, the object has been deleted.
-  int DoLoop(int result, Channel::ChannelState* channel_state);
-  void DoLoopAsync(int result);
-  int DoReadSize();
-  int DoReadSizeComplete(int result);
-  int DoWaitForQuota();
-  int DoWaitForQuotaComplete();
-  int DoRead();
-  int DoReadComplete(int result, Channel::ChannelState* channel_state);
-
-  State next_state_ = State::NONE;
-  uint64_t expected_size_ = 0;
-  uint64_t bytes_left_ = 0;
-  net::CompletionCallback callback_;
-  scoped_refptr<net::IOBuffer> buffer_;
-  std::unique_ptr<storage::BlobReader> reader_;
-  const std::unique_ptr<Channel> channel_;
-
-  DISALLOW_COPY_AND_ASSIGN(WebSocketBlobSender);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_RENDERER_HOST_WEBSOCKET_BLOB_SENDER_H_