unikernel/duniverse/ocaml-h2/lib/stream_identifier.ml

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+(*----------------------------------------------------------------------------
+ *  Copyright (c) 2019 António Nuno Monteiro
+ *
+ *  All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright notice,
+ *  this list of conditions and the following disclaimer.
+ *
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *  notice, this list of conditions and the following disclaimer in the
+ *  documentation and/or other materials provided with the distribution.
+ *
+ *  3. Neither the name of the copyright holder nor the names of its
+ *  contributors may be used to endorse or promote products derived from this
+ *  software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ *  POSSIBILITY OF SUCH DAMAGE.
+ *---------------------------------------------------------------------------*)
+
+(* From RFC7540§5.1.1:
+ *   Streams are identified with an unsigned 31-bit integer. *)
+type t = int32
+
+let ( === ) = Int32.equal
+let[@inline] ( <= ) s1 s2 = Int32.compare s1 s2 <= 0
+let[@inline] ( > ) s1 s2 = Int32.compare s1 s2 > 0
+let[@inline] ( >= ) s1 s2 = Int32.compare s1 s2 >= 0
+
+(* From RFC7540§5.1.1:
+ *   A stream identifier of zero (0x0) is used for connection control messages;
+ *   the stream identifier of zero cannot be used to establish a new stream. *)
+let connection = Int32.zero
+
+(* From RFC7540§5.1.1:
+ *   A stream identifier of zero (0x0) is used for connection control messages;
+ *   the stream identifier of zero cannot be used to establish a new stream. *)
+let[@inline] is_connection id = Int32.equal id connection
+
+(* From RFC7540§5.1.1:
+ *   Streams initiated by a client MUST use odd-numbered stream
+ *   identifiers [...]. *)
+let[@inline] is_request id = Int32.rem id 2l === 1l
+
+(* From RFC7540§5.1.1:
+ *   Streams initiated by [...] the server MUST use even-numbered stream
+ *   identifiers. A stream identifier of zero (0x0) is used for connection
+ *   control messages [...]. *)
+let[@inline] is_pushed = function 0l -> false | n -> Int32.rem n 2l === 0l
+
+(* From RFC7540§5.1.1:
+ *   Streams are identified with an unsigned 31-bit integer. *)
+let max_stream_id = Int32.max_int