link.h

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#pragma once
 
#include "roo_io.h"
#include "roo_io/core/output_stream.h"
#include "roo_transport.h"
#include "roo_transport/link/internal/thread_safe/channel.h"
#include "roo_transport/link/link_input_stream.h"
#include "roo_transport/link/link_output_stream.h"
#include "roo_transport/link/link_status.h"
 
namespace roo_transport {
 
// Represents a reliable bidirectional peer-to-peer link over a packet-based
// transport.
class Link {
 public:
  // Creates a dummy link in state kIdle.
  // Use LinkTransport::connect() to create a proper connected link.
  Link();
 
  Link(const Link&) = delete;
  Link& operator=(const Link&) = delete;
 
  // Support for move.
  Link(Link&& other);
 
  // Support for move.
  Link& operator=(Link&& other);
 
  // Obtains the input stream that can be used to read from the link.
  LinkInputStream& in() { return in_; }
 
  // Obtains the output stream that can be used to write to the link.
  LinkOutputStream& out() { return out_; }
 
  // Returns the current status of the link.
  LinkStatus status() const;
 
  // If the link is in state kConnecting, blocks until it becomes either
  // kConnected or kBroken. Otherwise, returns immediately.
  void awaitConnected();
 
  // If the link is kIdle, kConnected, or kBroken, does nothing and returns
  // true immediately. Otherwise (when the link is in state kConnecting), blocks
  // until it becomes either kConnected or kBroken, or until the specified
  // timeout elapses, and returns true if the link has changed state, and false
  // if the timeout has elapsed.
  bool awaitConnected(roo_time::Duration timeout);
 
  // Disconnects the link, immediately bringing it to the idle state. If the
  // link is already idle, does nothing.
  void disconnect();
 
  // Returns the ID that identifies this link. The link objects created by
  // LinkTransport::connect() will have unique stream IDs.
  uint32_t streamId() const { return my_stream_id_; }
 
 private:
  friend class LinkStream;
  friend class LinkTransport;
 
  Link(Channel& channel, uint32_t my_stream_id);
 
  Channel* channel_;
  uint32_t my_stream_id_;
  LinkInputStream in_;
  LinkOutputStream out_;
};
 
}  // namespace roo_transport