Source file payload.ml

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
(*----------------------------------------------------------------------------
 *  Copyright (c) 2018 Inhabited Type LLC.
 *  Copyright (c) 2021 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 author nor the names of his contributors
 *     may be used to endorse or promote products derived from this software
 *     without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE 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 AUTHORS 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.
 *----------------------------------------------------------------------------*)

module Httpaf = Dream_httpaf_.Httpaf

module IOVec = Httpaf.IOVec

  type t =
  { faraday : Faraday.t
  ; mutable read_scheduled : bool
  ; mutable on_eof : unit -> unit
  ; mutable on_read : Bigstringaf.t -> off:int -> len:int -> unit
  }

  let default_on_eof         = Sys.opaque_identity (fun () -> ())
  let default_on_read        = Sys.opaque_identity (fun _ ~off:_ ~len:_ -> ())

  let of_faraday faraday =
    { faraday
    ; read_scheduled         = false
    ; on_eof                 = default_on_eof
    ; on_read                = default_on_read
    }

  let create buffer =
    of_faraday (Faraday.of_bigstring buffer)

  let create_empty () =
    let t = create Bigstringaf.empty in
    Faraday.close t.faraday;
    t

  let empty = create_empty ()

  let is_closed t =
    Faraday.is_closed t.faraday

  let unsafe_faraday t =
    t.faraday

  let rec do_execute_read t on_eof on_read =
    match Faraday.operation t.faraday with
    | `Yield           -> ()
    | `Close           ->
      t.read_scheduled <- false;
      t.on_eof         <- default_on_eof;
      t.on_read        <- default_on_read;
      on_eof ()
    | `Writev []       -> assert false
    | `Writev (iovec::_) ->
      t.read_scheduled <- false;
      t.on_eof         <- default_on_eof;
      t.on_read        <- default_on_read;
      let { IOVec.buffer; off; len } = iovec in
      Faraday.shift t.faraday len;
      on_read buffer ~off ~len;
      execute_read t
  and execute_read t =
    if t.read_scheduled then do_execute_read t t.on_eof t.on_read

  let schedule_read t ~on_eof ~on_read =
    if t.read_scheduled
    then failwith "Payload.schedule_read: reader already scheduled";
    if not (is_closed t)
    then begin
      t.read_scheduled <- true;
      t.on_eof         <- on_eof;
      t.on_read        <- on_read;
    end;
    do_execute_read t on_eof on_read

  let is_read_scheduled t = t.read_scheduled

  let close t =
    Faraday.close t.faraday;
    execute_read t