| // Copyright 2023 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 QUICHE_QUIC_MOQT_MOQT_SUBSCRIPTION_H_ |
| #define QUICHE_QUIC_MOQT_MOQT_SUBSCRIPTION_H_ |
| |
| #include <cstdint> |
| #include <optional> |
| |
| #include "absl/strings/string_view.h" |
| #include "quiche/quic/moqt/moqt_messages.h" |
| #include "quiche/quic/moqt/moqt_subscribe_windows.h" |
| |
| namespace moqt { |
| |
| // A track to which the peer might subscribe. |
| class LocalTrack { |
| public: |
| class Visitor { |
| public: |
| virtual ~Visitor() = default; |
| |
| // Requests that application re-publish objects from {start_group, |
| // start_object} to the latest object. If the return value is nullopt, the |
| // subscribe is valid and the application will deliver the object and |
| // the session will send SUBSCRIBE_OK. If the return has a value, the value |
| // is the error message (the session will send SUBSCRIBE_ERROR). Via this |
| // API, the application decides if a partially fulfillable |
| // SUBSCRIBE_REQUEST results in an error or not. |
| virtual std::optional<absl::string_view> OnSubscribeRequestForPast( |
| const SubscribeWindow& window) = 0; |
| }; |
| // |visitor| must not be nullptr. |
| LocalTrack(const FullTrackName& full_track_name, uint64_t track_alias, |
| Visitor* visitor) |
| : full_track_name_(full_track_name), |
| track_alias_(track_alias), |
| visitor_(visitor) {} |
| // Creates a LocalTrack that does not start at sequence (0,0) |
| LocalTrack(const FullTrackName& full_track_name, uint64_t track_alias, |
| Visitor* visitor, FullSequence next_sequence) |
| : full_track_name_(full_track_name), |
| track_alias_(track_alias), |
| next_sequence_(next_sequence), |
| visitor_(visitor) {} |
| |
| const FullTrackName& full_track_name() const { return full_track_name_; } |
| |
| uint64_t track_alias() const { return track_alias_; } |
| |
| Visitor* visitor() { return visitor_; } |
| |
| bool ShouldSend(uint64_t group, uint64_t object) const { |
| return windows_.SequenceIsSubscribed(group, object); |
| } |
| |
| void AddWindow(SubscribeWindow window) { windows_.AddWindow(window); } |
| |
| // Returns the largest observed sequence, but increments the object sequence |
| // by one. |
| const FullSequence& next_sequence() const { return next_sequence_; } |
| |
| FullSequence& next_sequence_mutable() { return next_sequence_; } |
| |
| bool HasSubscriber() const { return !windows_.IsEmpty(); } |
| |
| private: |
| // This only needs to track subscriptions to current and future objects; |
| // requests for objects in the past are forwarded to the application. |
| const FullTrackName full_track_name_; |
| const uint64_t track_alias_; |
| // The sequence numbers from this track to which the peer is subscribed. |
| MoqtSubscribeWindows windows_; |
| FullSequence next_sequence_ = {0, 0}; |
| Visitor* visitor_; |
| }; |
| |
| // A track on the peer to which the session has subscribed. |
| class RemoteTrack { |
| public: |
| class Visitor { |
| public: |
| virtual ~Visitor() = default; |
| // Called when the session receives a response to the SUBSCRIBE_REQUEST. |
| virtual void OnReply( |
| const FullTrackName& full_track_name, |
| std::optional<absl::string_view> error_reason_phrase) = 0; |
| virtual void OnObjectFragment(const FullTrackName& full_track_name, |
| uint32_t stream_id, uint64_t group_sequence, |
| uint64_t object_sequence, |
| uint64_t object_send_order, |
| absl::string_view object, |
| bool end_of_message) = 0; |
| // TODO(martinduke): Add final sequence numbers |
| }; |
| RemoteTrack(const FullTrackName& full_track_name, Visitor* visitor) |
| : full_track_name_(full_track_name), visitor_(visitor) {} |
| |
| const FullTrackName& full_track_name() { return full_track_name_; } |
| |
| std::optional<uint64_t> track_alias() const { return track_alias_; } |
| |
| Visitor* visitor() { return visitor_; } |
| |
| void set_track_alias(uint64_t track_alias) { track_alias_ = track_alias; } |
| |
| private: |
| // TODO: There is no accounting for the number of outstanding subscribes, |
| // because we can't match track names to individual subscribes. |
| FullTrackName full_track_name_; |
| std::optional<uint64_t> track_alias_; |
| Visitor* visitor_; |
| }; |
| |
| } // namespace moqt |
| |
| #endif // QUICHE_QUIC_MOQT_MOQT_SUBSCRIPTION_H_ |