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/*
* Copyright 2021 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 PC_JSEP_TRANSPORT_COLLECTION_H_
#define PC_JSEP_TRANSPORT_COLLECTION_H_
#include <functional>
#include <map>
#include <memory>
#include <string>
#include <utility>
#include <vector>
#include "api/jsep.h"
#include "api/peer_connection_interface.h"
#include "api/sequence_checker.h"
#include "pc/jsep_transport.h"
#include "pc/session_description.h"
#include "rtc_base/checks.h"
#include "rtc_base/system/no_unique_address.h"
#include "rtc_base/thread_annotations.h"
namespace webrtc {
// This class manages information about RFC 8843 BUNDLE bundles
// in SDP descriptions.
// This is a work-in-progress. Planned steps:
// 1) Move all Bundle-related data structures from JsepTransport
// into this class.
// 2) Move all Bundle-related functions into this class.
// 3) Move remaining Bundle-related logic into this class.
// Make data members private.
// 4) Refine interface to have comprehensible semantics.
// 5) Add unit tests.
// 6) Change the logic to do what's right.
class BundleManager {
public:
explicit BundleManager(PeerConnectionInterface::BundlePolicy bundle_policy)
: bundle_policy_(bundle_policy) {}
const std::vector<std::unique_ptr<cricket::ContentGroup>>& bundle_groups()
const {
RTC_DCHECK_RUN_ON(&sequence_checker_);
return bundle_groups_;
}
// Lookup a bundle group by a member mid name.
const cricket::ContentGroup* LookupGroupByMid(const std::string& mid) const;
cricket::ContentGroup* LookupGroupByMid(const std::string& mid);
// Returns true if the MID is the first item of a group, or if
// the MID is not a member of a group.
bool IsFirstMidInGroup(const std::string& mid) const;
// Update the groups description. This completely replaces the group
// description with the one from the SessionDescription.
void Update(const cricket::SessionDescription* description, SdpType type);
// Delete a MID from the group that contains it.
void DeleteMid(const cricket::ContentGroup* bundle_group,
const std::string& mid);
// Delete a group.
void DeleteGroup(const cricket::ContentGroup* bundle_group);
// Roll back to previous stable state.
void Rollback();
// Commit current bundle groups.
void Commit();
private:
// Recalculate established_bundle_groups_by_mid_ from bundle_groups_.
void RefreshEstablishedBundleGroupsByMid() RTC_RUN_ON(sequence_checker_);
RTC_NO_UNIQUE_ADDRESS SequenceChecker sequence_checker_{
SequenceChecker::kDetached};
PeerConnectionInterface::BundlePolicy bundle_policy_;
std::vector<std::unique_ptr<cricket::ContentGroup>> bundle_groups_
RTC_GUARDED_BY(sequence_checker_);
std::vector<std::unique_ptr<cricket::ContentGroup>> stable_bundle_groups_
RTC_GUARDED_BY(sequence_checker_);
std::map<std::string, cricket::ContentGroup*>
established_bundle_groups_by_mid_;
};
// This class keeps the mapping of MIDs to transports.
// It is pulled out here because a lot of the code that deals with
// bundles end up modifying this map, and the two need to be consistent;
// the managers may merge.
class JsepTransportCollection {
public:
JsepTransportCollection(std::function<bool(const std::string& mid,
cricket::JsepTransport* transport)>
map_change_callback,
std::function<void()> state_change_callback)
: map_change_callback_(map_change_callback),
state_change_callback_(state_change_callback) {}
void RegisterTransport(const std::string& mid,
std::unique_ptr<cricket::JsepTransport> transport);
// Returns all transports, including those not currently mapped to any MID
// because they're being kept alive in case of rollback.
std::vector<cricket::JsepTransport*> Transports();
// Only returns transports currently mapped to a MID.
std::vector<cricket::JsepTransport*> ActiveTransports();
void DestroyAllTransports();
// Lookup a JsepTransport by the MID that was used to register it.
cricket::JsepTransport* GetTransportByName(const std::string& mid);
const cricket::JsepTransport* GetTransportByName(
const std::string& mid) const;
// Lookup a JsepTransport by any MID that refers to it.
cricket::JsepTransport* GetTransportForMid(const std::string& mid);
const cricket::JsepTransport* GetTransportForMid(
const std::string& mid) const;
cricket::JsepTransport* GetTransportForMid(absl::string_view mid);
const cricket::JsepTransport* GetTransportForMid(absl::string_view mid) const;
// Set transport for a MID. This may destroy a transport if it is no
// longer in use.
bool SetTransportForMid(const std::string& mid,
cricket::JsepTransport* jsep_transport);
// Remove a transport for a MID. This may destroy a transport if it is
// no longer in use.
void RemoveTransportForMid(const std::string& mid);
// Roll back to previous stable mid-to-transport mappings.
bool RollbackTransports();
// Commit pending mid-transport mappings (rollback is no longer possible),
// and destroy unused transports because we know now we'll never need them
// again.
void CommitTransports();
private:
// Returns true if any mid currently maps to this transport.
bool TransportInUse(cricket::JsepTransport* jsep_transport) const;
// Returns true if any mid in the last stable mapping maps to this transport,
// meaning it should be kept alive in case of rollback.
bool TransportNeededForRollback(cricket::JsepTransport* jsep_transport) const;
// Destroy a transport if it's no longer in use. This includes whether it
// will be needed in case of rollback.
void MaybeDestroyJsepTransport(cricket::JsepTransport* transport);
// Destroys all transports that are no longer in use.
void DestroyUnusedTransports();
bool IsConsistent(); // For testing only: Verify internal structure.
RTC_NO_UNIQUE_ADDRESS SequenceChecker sequence_checker_{
SequenceChecker::kDetached};
// This member owns the JSEP transports.
std::map<std::string, std::unique_ptr<cricket::JsepTransport>>
jsep_transports_by_name_ RTC_GUARDED_BY(sequence_checker_);
// This keeps track of the mapping between media section
// (BaseChannel/SctpTransport) and the JsepTransport underneath.
std::map<std::string, cricket::JsepTransport*> mid_to_transport_
RTC_GUARDED_BY(sequence_checker_);
// A snapshot of mid_to_transport_ at the last stable state. Used for
// rollback.
std::map<std::string, cricket::JsepTransport*> stable_mid_to_transport_
RTC_GUARDED_BY(sequence_checker_);
// Callback used to inform subscribers of altered transports.
const std::function<bool(const std::string& mid,
cricket::JsepTransport* transport)>
map_change_callback_;
// Callback used to inform subscribers of possibly altered state.
const std::function<void()> state_change_callback_;
};
} // namespace webrtc
#endif // PC_JSEP_TRANSPORT_COLLECTION_H_