Release 2.22.0

- [FEATURE] Extensible HTTP Priorities (HTTP/3 only).
- [FEATURE] Add conn context to packet-out memory interface (PR #175).
- [BUGFIX] gQUIC proof generation: allocate buffer big enough for
  signature (issue #173).
- [BUGFIX] Make library thread-safe: drop use of global variables
  (issue #133, issue #167).
- [BUGFIX] Deactivate only *recent* HQ frame, not any HQ frame.
- [BUGFIX] gQUIC server: associate compressed cert with SSL_CTX,
  instead of keeping them in a separate hash, potentially leading
  to mismatches.
- [BUGFIX] Stream data discard infinite loop: break on FIN.
- cmake: add install target via -DCMAKE_INSTALL_PREFIX (PR #171).
- Support randomized packet number to begin a connection.
- Mini and full IETF connection size optimization.
- http_client: specify HTTP priorities based on stream conditions.

docs/apiref.rst

@@ -842,6 +842,13 @@ settings structure:
 
        Default value is :macro:`LSQUIC_DF_OPTIMISTIC_NAT`
 
+    .. member:: int             es_ext_http_prio
+
+       If set to true, Extensible HTTP Priorities are enabled.  This
+       is HTTP/3-only setting.
+
+       Default value is :macro:`LSQUIC_DF_EXT_HTTP_PRIO`
+
 To initialize the settings structure to library defaults, use the following
 convenience function:
 
@@ -1066,6 +1073,10 @@ out of date.  Please check your :file:`lsquic.h` for actual values.*
 
     Assume optimistic NAT by default.
 
+.. macro:: LSQUIC_DF_EXT_HTTP_PRIO
+
+    Turn on Extensible HTTP Priorities by default.
+
 Receiving Packets
 -----------------
 
@@ -2162,7 +2173,7 @@ The following log modules are defined:
 - *hcsi-reader*: Reader of the HTTP/3 control stream.
 - *hcso-writer*: Writer of the HTTP/3 control stream.
 - *headers*: HEADERS stream (Google QUIC).
-- *hsk-adapter*: 
+- *hsk-adapter*:
 - *http1x*: Header conversion to HTTP/1.x.
 - *logger*: Logger.
 - *mini-conn*: Mini connection.
@@ -2184,6 +2195,72 @@ The following log modules are defined:
 - *tokgen*: Token generation and validation.
 - *trapa*: Transport parameter processing.
 
+.. _extensible-http-priorities:
+
+Extensible HTTP Priorities
+--------------------------
+
+lsquic supports the
+`Extensible HTTP Priorities Extension <https://tools.ietf.org/html/draft-ietf-httpbis-priority>`_.
+It is enabled by default when HTTP/3 is used.  The "urgency" and "incremental"
+parameters are included into a dedicated type:
+
+.. type:: struct lsquic_ext_http_prio
+
+    .. member::     unsigned char       urgency
+
+        This value's range is [0, 7], where 0 is the highest and 7 is
+        the lowest urgency.
+
+    .. member::     signed char         incremental
+
+        This is a boolean value.  The valid range is [0, 1].
+
+Some useful macros are also available:
+
+.. macro:: LSQUIC_MAX_HTTP_URGENCY
+
+The maximum value of the "urgency" parameter is 7.
+
+.. macro:: LSQUIC_DEF_HTTP_URGENCY
+
+The default value of the "urgency" parameter is 3.
+
+.. macro:: LSQUIC_DEF_HTTP_INCREMENTAL
+
+The default value of the "incremental" parameter is 0.
+
+There are two functions to
+manage a stream's priority:
+
+.. function:: int lsquic_stream_get_http_prio (lsquic_stream_t \*stream, struct lsquic_ext_http_prio \*ehp)
+
+    Get a stream's priority information.
+
+    :param stream:  The stream whose priority informaion we want.
+
+    :param ehp:     Structure that is to be populated with the stream's
+                    priority information.
+
+    :return:    Returns zero on success of a negative value on failure.
+                A failure occurs if this is not an HTTP/3 stream or if
+                Extensible HTTP Priorities have not been enabled.
+                See :member:`lsquic_engine_settings.es_ext_http_prio`.
+
+.. function:: int lsquic_stream_set_http_prio (lsquic_stream_t \*stream, const struct lsquic_ext_http_prio \*ehp)
+
+    Set a stream's priority information.
+
+    :param stream:  The stream whose priority we want to set.
+
+    :param ehp:     Structure containing the stream's new priority information.
+
+    :return:        Returns zero on success of a negative value on failure.
+                    A failure occurs if some internal error occured or if this
+                    is not an HTTP/3 stream or if Extensible HTTP Priorities
+                    haven't been enabled.
+                    See :member:`lsquic_engine_settings.es_ext_http_prio`.
+
 .. _apiref-datagrams:
 
 Datagrams

docs/conf.py

@@ -24,9 +24,9 @@ copyright = u'2020, LiteSpeed Technologies'
 author = u'LiteSpeed Technologies'
 
 # The short X.Y version
-version = u'2.21'
+version = u'2.22'
 # The full version, including alpha/beta/rc tags
-release = u'2.21.0'
+release = u'2.22.0'
 
 
 # -- General configuration ---------------------------------------------------

docs/index.rst

@@ -37,6 +37,7 @@ LSQUIC supports nearly all QUIC and HTTP/3 features, including
 - TLS Key updates
 - Extensions:
 
+ - :ref:`extensible-http-priorities`
  - :ref:`apiref-datagrams`
  - Loss bits extension (allowing network observer to locate source of packet loss)
  - Timestamps extension (allowing for one-way delay calculation, improving performance of some congestion controllers)