Release 3.1.0

Release 2.27.1

- [API] New knob to set outgoing packet batch size.
- Aborted connection now become tickable immediately.
- Abort connection when HTTP/3 frame cannot be opened (can only happen
when malloc fails).

Release 2.24.5

- [FEATURE] Improve Delayed ACKs extension and turn it on by default.
- Limit receive history to a finite amount of memory.

Release 2.19.0

- [FEATURE] DPLPMTUD support. IETF connections now search for the
maximum packet size, improving throughput.
- [DEBUG] Record event in stream history when on_close() is called
in dtor.

Release 2.15.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 28 support.
- [BUGFIX] Ignore Retry packets after other packets are decrypted
successfully.
- [BUGFIX] Transport parameter decoding: CID no longer has 4-byte
length minimum.
- http_client: fix and optimize lsxpack_header allocator.
- Drop support for Internet Draft 25.

Release 2.11.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 27 support.
- [FEATURE] Add experimental delayed ACKs extension.
- Drop support for Internet Draft 24.
- Code cleanup.

Release 2.10.2

- [BUGFIX] Do not delay ACKs for Initial and Handshake packets.
- [BUGFIX] Send PATH_CHALLENGE if path changed before mini conn promotion.
- Logging improvements.
- http_client: discard data faster.

Release 2.10.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 25 support.
- [API] Drop support for ID-23.
- [BUGFIX] Set key phase bit on outgoing packets correctly.
- Code cleanup.

Release 2.8.7

- [BUGFIX] Initial packet size check for IETF mini conn applies to
UDP payload, not QUIC packet.
- Support old and new school loss_bits transport parameter.
- Use Q run length of 64 as suggested in the loss bits Draft.
- Undo square wave count when packet is delayed.
- Code cleanup; minor fixes.

Release 2.5.0

- [API] lsquic_engine_connect() can now be passed QUIC version to use.
- [OPTIMIZATION] Queue opportunistic ACKs if there is data to be sent.
- [BUGFIX] Don't evict streams from priority iterator if there is
only one queue.
- [OPTIMIZATION, BUGFIX] Several other optimizations and bug fixes.
- Use ls-qpack v0.10.7.

Release 2.4.7

- Add echo client and server to the distibution.
- Add MD5 client and server to the distibution.
- Fix http_client: check command-line arguments better, prevent crash.
- Fix IETF conn: can_write_ack() should only care about APP PNS.
- Client: delay stream creation until handshake succeds.
- Reset HTTP stream whose write end is closed prematurely.
- Fix tickable(): mirror behavior of tick() wrt buffered packets.
- Log reason why engine is tickable.

Release 2.4.2

- [BUGFIX] H3 framing: fix zero-byte write when space is available
- [BUGFIX] Don't send STREAM frame when incoming unidirectgional stream
is closed
- [BUGFIX] Cancel all pending writes by stream reset by a GOAWAY
- [BUGFIX] Fix use-after-free in IETF full conn
- [OPTIMIZATION] Wait for session tickets for two seconds and then drop
SSL object and crypto streams.

Release 2.2.0: server included, ID-22 supported (#76)

Release 1.17.11

Fix strict aliasing warning in when compiling with optimizations

[API Change, OPTIMIZATION] Only process conns that need to be processed

The API is simplified: do not expose the user code to several
queues. A "connection queue" is now an internal concept.
The user processes connections using the single function
lsquic_engine_process_conns(). When this function is called,
only those connections are processed that need to be processed.
A connection needs to be processed when:

1. New incoming packets have been fed to the connection.
2. User wants to read from a stream that is readable.
3. User wants to write to a stream that is writeable.
4. There are buffered packets that can be sent out. (This
means that the user wrote to a stream outside of the
lsquic library callback.)
5. A control frame (such as BLOCKED) needs to be sent out.
6. A stream needs to be serviced or delayed stream needs to
be created.
7. An alarm rings.
8. Pacer timer expires.

To achieve this, the library places the connections into two
priority queues (min heaps):

1. Tickable Queue; and
2. Advisory Tick Time queue (ATTQ).

Each time lsquic_engine_process_conns() is called, the Tickable
Queue is emptied. After the connections have been ticked, they are
queried again: if a connection is not being closed, it is placed
either in the Tickable Queue if it is ready to be ticked again or
it is placed in the Advisory Tick Time Queue. It is assumed that
a connection always has at least one timer set (the idle alarm).

The connections in the Tickable Queue are arranged in the least
recently ticked order. This lets connections that have been quiet
longer to get their packets scheduled first.

This change means that the library no longer needs to be ticked
periodically. The user code can query the library when is the
next tick event and schedule it exactly. When connections are
processed, only the tickable connections are processed, not *all*
the connections. When there are no tick events, it means that no
timer event is necessary -- only the file descriptor READ event
is active.

The following are improvements and simplifications that have
been triggered:

- Queue of connections with incoming packets is gone.
- "Pending Read/Write Events" Queue is gone (along with its
history and progress checks). This queue has become the
Tickable Queue.
- The connection hash no longer needs to track the connection
insertion order.

Update copyright year; add CONTRIBUTORS.txt

LSQUIC Client: Initial release