Repo created

TMessagesProj/jni/voip/webrtc/p2p/base/ice_controller_interface.h

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+/*
+ *  Copyright 2019 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.
+ */
+
+#ifndef P2P_BASE_ICE_CONTROLLER_INTERFACE_H_
+#define P2P_BASE_ICE_CONTROLLER_INTERFACE_H_
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "absl/types/optional.h"
+#include "p2p/base/connection.h"
+#include "p2p/base/ice_switch_reason.h"
+#include "p2p/base/ice_transport_internal.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/system/rtc_export.h"
+
+namespace cricket {
+
+struct IceFieldTrials;  // Forward declaration to avoid circular dependency.
+
+struct RTC_EXPORT IceRecheckEvent {
+  IceRecheckEvent(IceSwitchReason _reason, int _recheck_delay_ms)
+      : reason(_reason), recheck_delay_ms(_recheck_delay_ms) {}
+
+  std::string ToString() const;
+
+  IceSwitchReason reason;
+  int recheck_delay_ms;
+};
+
+// Defines the interface for a module that control
+// - which connection to ping
+// - which connection to use
+// - which connection to prune
+// - which connection to forget learned state on
+//
+// The P2PTransportChannel owns (creates and destroys) Connections,
+// but P2PTransportChannel gives const pointers to the the IceController using
+// `AddConnection`, i.e the IceController should not call any non-const methods
+// on a Connection but signal back in the interface if any mutable function
+// shall be called.
+//
+// Current these are limited to:
+// Connection::Ping               - returned in PingResult
+// Connection::Prune              - retuned in PruneConnections
+// Connection::ForgetLearnedState - return in SwitchResult
+//
+// The IceController shall keep track of all connections added
+// (and not destroyed) and give them back using the GetConnections() function.
+//
+// When a Connection gets destroyed
+// - signals on Connection::SignalDestroyed
+// - P2PTransportChannel calls IceController::OnConnectionDestroyed
+class IceControllerInterface {
+ public:
+  // This represents the result of a switch call.
+  struct SwitchResult {
+    // Connection that we should (optionally) switch to.
+    absl::optional<const Connection*> connection;
+
+    // An optional recheck event for when a Switch() should be attempted again.
+    absl::optional<IceRecheckEvent> recheck_event;
+
+    // A vector with connection to run ForgetLearnedState on.
+    std::vector<const Connection*> connections_to_forget_state_on;
+  };
+
+  // This represents the result of a call to SelectConnectionToPing.
+  struct PingResult {
+    PingResult(const Connection* conn, int _recheck_delay_ms)
+        : connection(conn ? absl::optional<const Connection*>(conn)
+                          : absl::nullopt),
+          recheck_delay_ms(_recheck_delay_ms) {}
+
+    // Connection that we should (optionally) ping.
+    const absl::optional<const Connection*> connection;
+
+    // The delay before P2PTransportChannel shall call SelectConnectionToPing()
+    // again.
+    //
+    // Since the IceController determines which connection to ping and
+    // only returns one connection at a time, the recheck_delay_ms does not have
+    // any obvious implication on bitrate for pings. E.g the recheck_delay_ms
+    // will be shorter if there are more connections available.
+    const int recheck_delay_ms = 0;
+  };
+
+  virtual ~IceControllerInterface() = default;
+
+  // These setters are called when the state of P2PTransportChannel is mutated.
+  virtual void SetIceConfig(const IceConfig& config) = 0;
+  virtual void SetSelectedConnection(const Connection* selected_connection) = 0;
+  virtual void AddConnection(const Connection* connection) = 0;
+  virtual void OnConnectionDestroyed(const Connection* connection) = 0;
+
+  // These are all connections that has been added and not destroyed.
+  virtual rtc::ArrayView<const Connection* const> GetConnections() const {
+    // Stub implementation to simplify downstream roll.
+    RTC_CHECK_NOTREACHED();
+    return {};
+  }
+  // TODO(bugs.webrtc.org/15702): Remove this after downstream is cleaned up.
+  virtual rtc::ArrayView<const Connection*> connections() const {
+    // Stub implementation to simplify downstream removal.
+    RTC_CHECK_NOTREACHED();
+    return {};
+  }
+
+  // Is there a pingable connection ?
+  // This function is used to boot-strap pinging, after this returns true
+  // SelectConnectionToPing() will be called periodically.
+  virtual bool HasPingableConnection() const = 0;
+
+  // Select a connection to Ping, or nullptr if none.
+  virtual PingResult SelectConnectionToPing(int64_t last_ping_sent_ms) = 0;
+
+  // Compute the "STUN_ATTR_USE_CANDIDATE" for `conn`.
+  virtual bool GetUseCandidateAttr(const Connection* conn,
+                                   NominationMode mode,
+                                   IceMode remote_ice_mode) const = 0;
+
+  // These methods is only added to not have to change all unit tests
+  // that simulate pinging by marking a connection pinged.
+  virtual const Connection* FindNextPingableConnection() = 0;
+  virtual void MarkConnectionPinged(const Connection* con) = 0;
+
+  // Check if we should switch to `connection`.
+  // This method is called for IceSwitchReasons that can switch directly
+  // i.e without resorting.
+  virtual SwitchResult ShouldSwitchConnection(IceSwitchReason reason,
+                                              const Connection* connection) = 0;
+
+  // Sort connections and check if we should switch.
+  virtual SwitchResult SortAndSwitchConnection(IceSwitchReason reason) = 0;
+
+  // Prune connections.
+  virtual std::vector<const Connection*> PruneConnections() = 0;
+};
+
+}  // namespace cricket
+
+#endif  // P2P_BASE_ICE_CONTROLLER_INTERFACE_H_