Summary:
The retransmission buffer tracks stream frame data we have sent that is currently unacked. We keep this as a sorted `deque`. This isn't so bad for performance, but we can do better if we break ourselves of the requirement that it be sorted (removing a binary search on ACK).
To do this we make the buffer a map of offset -> `StreamBuffer`.
There were two places that were dependent on the sorted nature of the list.
1. For partial reliablity we call `shrinkBuffers` to remove all unacked buffers less than an offset. For this we now have to do it with a full traversal of the retransmission buffer instead of only having to do an O(offset) search. In the future we could make this better by only lazily deleting from the retransmission buffer on ACK or packet loss.
2. We used the start of the retransmission buffer to determine if a delivery callback could be fired for a given offset. We need some new state to track this. Instead of tracking unacked buffers, we now track acked ranges using the existing `IntervalSet`. This set should be small for the typical case, as we think most ACKs will come in order and just cause existing ranges to merge.
Reviewed By: yangchi
Differential Revision: D18609467
fbshipit-source-id: 13cd2164352f1183362be9f675c1bdc686426698
Summary: The state machine logic is quite abstruse, this modifies it to make it more readable.
Reviewed By: siyengar
Differential Revision: D18488301
fbshipit-source-id: c6fd52973880931e34904713e8b147f56d0c4629
Summary: Add transportStateUpdate event so it can be part of qlog.
Reviewed By: mjoras
Differential Revision: D16342467
fbshipit-source-id: 109189275d44996850b82646bab4a733a3a4c7a1
Summary: This is no longer part of the spec. It's up to the application how to handle reset
Reviewed By: lnicco
Differential Revision: D15107164
fbshipit-source-id: 2a1fe0c552bd7f054e84ef86a01a78c379b0a483
Summary: This is step 1 for removing reset on reset, since the send side may need to transition to waiting for a reset ack while the read side is an any state.
Reviewed By: lnicco
Differential Revision: D15075849
fbshipit-source-id: 1e094942a8a1ca9a01d4161cd6309b4136a9cfbf
