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TMessagesProj/jni/voip/webrtc/api/data_channel_interface.h

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+/*
+ *  Copyright 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+// This file contains interfaces for DataChannels
+// http://dev.w3.org/2011/webrtc/editor/webrtc.html#rtcdatachannel
+
+#ifndef API_DATA_CHANNEL_INTERFACE_H_
+#define API_DATA_CHANNEL_INTERFACE_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <string>
+
+#include "absl/functional/any_invocable.h"
+#include "absl/types/optional.h"
+#include "api/priority.h"
+#include "api/ref_count.h"
+#include "api/rtc_error.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/copy_on_write_buffer.h"
+#include "rtc_base/system/rtc_export.h"
+
+namespace webrtc {
+
+// C++ version of: https://www.w3.org/TR/webrtc/#idl-def-rtcdatachannelinit
+// TODO(deadbeef): Use absl::optional for the "-1 if unset" things.
+struct DataChannelInit {
+  // Deprecated. Reliability is assumed, and channel will be unreliable if
+  // maxRetransmitTime or MaxRetransmits is set.
+  bool reliable = false;
+
+  // True if ordered delivery is required.
+  bool ordered = true;
+
+  // The max period of time in milliseconds in which retransmissions will be
+  // sent. After this time, no more retransmissions will be sent.
+  //
+  // Cannot be set along with `maxRetransmits`.
+  // This is called `maxPacketLifeTime` in the WebRTC JS API.
+  // Negative values are ignored, and positive values are clamped to [0-65535]
+  absl::optional<int> maxRetransmitTime;
+
+  // The max number of retransmissions.
+  //
+  // Cannot be set along with `maxRetransmitTime`.
+  // Negative values are ignored, and positive values are clamped to [0-65535]
+  absl::optional<int> maxRetransmits;
+
+  // This is set by the application and opaque to the WebRTC implementation.
+  std::string protocol;
+
+  // True if the channel has been externally negotiated and we do not send an
+  // in-band signalling in the form of an "open" message. If this is true, `id`
+  // below must be set; otherwise it should be unset and will be negotiated
+  // in-band.
+  bool negotiated = false;
+
+  // The stream id, or SID, for SCTP data channels. -1 if unset (see above).
+  int id = -1;
+
+  // https://w3c.github.io/webrtc-priority/#new-rtcdatachannelinit-member
+  absl::optional<Priority> priority;
+};
+
+// At the JavaScript level, data can be passed in as a string or a blob, so
+// this structure's `binary` flag tells whether the data should be interpreted
+// as binary or text.
+struct DataBuffer {
+  DataBuffer(const rtc::CopyOnWriteBuffer& data, bool binary)
+      : data(data), binary(binary) {}
+  // For convenience for unit tests.
+  explicit DataBuffer(const std::string& text)
+      : data(text.data(), text.length()), binary(false) {}
+  size_t size() const { return data.size(); }
+
+  rtc::CopyOnWriteBuffer data;
+  // Indicates if the received data contains UTF-8 or binary data.
+  // Note that the upper layers are left to verify the UTF-8 encoding.
+  // TODO(jiayl): prefer to use an enum instead of a bool.
+  bool binary;
+};
+
+// Used to implement RTCDataChannel events.
+//
+// The code responding to these callbacks should unwind the stack before
+// using any other webrtc APIs; re-entrancy is not supported.
+class DataChannelObserver {
+ public:
+  // The data channel state have changed.
+  virtual void OnStateChange() = 0;
+  //  A data buffer was successfully received.
+  virtual void OnMessage(const DataBuffer& buffer) = 0;
+  // The data channel's buffered_amount has changed.
+  virtual void OnBufferedAmountChange(uint64_t sent_data_size) {}
+
+  // Override this to get callbacks directly on the network thread.
+  // An implementation that does that must not block the network thread
+  // but rather only use the callback to trigger asynchronous processing
+  // elsewhere as a result of the notification.
+  // The default return value, `false`, means that notifications will be
+  // delivered on the signaling thread associated with the peerconnection
+  // instance.
+  // TODO(webrtc:11547): Eventually all DataChannelObserver implementations
+  // should be called on the network thread and this method removed.
+  virtual bool IsOkToCallOnTheNetworkThread() { return false; }
+
+ protected:
+  virtual ~DataChannelObserver() = default;
+};
+
+class RTC_EXPORT DataChannelInterface : public RefCountInterface {
+ public:
+  // C++ version of: https://www.w3.org/TR/webrtc/#idl-def-rtcdatachannelstate
+  // Unlikely to change, but keep in sync with DataChannel.java:State and
+  // RTCDataChannel.h:RTCDataChannelState.
+  enum DataState {
+    kConnecting,
+    kOpen,  // The DataChannel is ready to send data.
+    kClosing,
+    kClosed
+  };
+
+  static const char* DataStateString(DataState state) {
+    switch (state) {
+      case kConnecting:
+        return "connecting";
+      case kOpen:
+        return "open";
+      case kClosing:
+        return "closing";
+      case kClosed:
+        return "closed";
+    }
+    RTC_CHECK(false) << "Unknown DataChannel state: " << state;
+    return "";
+  }
+
+  // Used to receive events from the data channel. Only one observer can be
+  // registered at a time. UnregisterObserver should be called before the
+  // observer object is destroyed.
+  virtual void RegisterObserver(DataChannelObserver* observer) = 0;
+  virtual void UnregisterObserver() = 0;
+
+  // The label attribute represents a label that can be used to distinguish this
+  // DataChannel object from other DataChannel objects.
+  virtual std::string label() const = 0;
+
+  // The accessors below simply return the properties from the DataChannelInit
+  // the data channel was constructed with.
+  virtual bool reliable() const = 0;
+  // TODO(deadbeef): Remove these dummy implementations when all classes have
+  // implemented these APIs. They should all just return the values the
+  // DataChannel was created with.
+  virtual bool ordered() const;
+  // TODO(hta): Deprecate and remove the following two functions.
+  virtual uint16_t maxRetransmitTime() const;
+  virtual uint16_t maxRetransmits() const;
+  virtual absl::optional<int> maxRetransmitsOpt() const;
+  virtual absl::optional<int> maxPacketLifeTime() const;
+  virtual std::string protocol() const;
+  virtual bool negotiated() const;
+
+  // Returns the ID from the DataChannelInit, if it was negotiated out-of-band.
+  // If negotiated in-band, this ID will be populated once the DTLS role is
+  // determined, and until then this will return -1.
+  virtual int id() const = 0;
+  virtual Priority priority() const { return Priority::kLow; }
+  virtual DataState state() const = 0;
+  // When state is kClosed, and the DataChannel was not closed using
+  // the closing procedure, returns the error information about the closing.
+  // The default implementation returns "no error".
+  virtual RTCError error() const { return RTCError(); }
+  virtual uint32_t messages_sent() const = 0;
+  virtual uint64_t bytes_sent() const = 0;
+  virtual uint32_t messages_received() const = 0;
+  virtual uint64_t bytes_received() const = 0;
+
+  // Returns the number of bytes of application data (UTF-8 text and binary
+  // data) that have been queued using Send but have not yet been processed at
+  // the SCTP level. See comment above Send below.
+  // Values are less or equal to MaxSendQueueSize().
+  virtual uint64_t buffered_amount() const = 0;
+
+  // Begins the graceful data channel closing procedure. See:
+  // https://tools.ietf.org/html/draft-ietf-rtcweb-data-channel-13#section-6.7
+  virtual void Close() = 0;
+
+  // Sends `data` to the remote peer. If the data can't be sent at the SCTP
+  // level (due to congestion control), it's buffered at the data channel level,
+  // up to a maximum of MaxSendQueueSize().
+  // Returns false if the data channel is not in open state or if the send
+  // buffer is full.
+  // TODO(webrtc:13289): Return an RTCError with information about the failure.
+  // TODO(tommi): Remove this method once downstream implementations don't refer
+  // to it.
+  virtual bool Send(const DataBuffer& buffer);
+
+  // Queues up an asynchronus send operation to run on a network thread.
+  // Once the operation has completed the `on_complete` callback is invoked,
+  // on the thread the send operation was done on. It's important that
+  // `on_complete` implementations do not block the current thread but rather
+  // post any expensive operations to other worker threads.
+  // TODO(tommi): Make pure virtual after updating mock class in Chromium.
+  // Deprecate `Send` in favor of this variant since the return value of `Send`
+  // is limiting for a fully async implementation (yet in practice is ignored).
+  virtual void SendAsync(DataBuffer buffer,
+                         absl::AnyInvocable<void(RTCError) &&> on_complete);
+
+  // Amount of bytes that can be queued for sending on the data channel.
+  // Those are bytes that have not yet been processed at the SCTP level.
+  static uint64_t MaxSendQueueSize();
+
+ protected:
+  ~DataChannelInterface() override = default;
+};
+
+}  // namespace webrtc
+
+#endif  // API_DATA_CHANNEL_INTERFACE_H_