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
type encoder = { payload : Bytes.t; mutable pos : int }
type error = [ `No_enough_space ]
let pp_error ppf `No_enough_space = Fmt.string ppf "No enough space"
type 'err state =
| Write of {
buffer : string;
off : int;
len : int;
continue : int -> 'err state;
}
| Error of 'err
| Done
let io_buffer_size = 65536
let create () = { payload = Bytes.create io_buffer_size; pos = 0 }
exception Leave of error
let leave_with (_ : encoder) error = raise (Leave error)
let safe : (encoder -> ([> error ] as 'err) state) -> encoder -> 'err state =
fun k encoder ->
try k encoder with Leave (#error as err) -> Error (err :> 'err)
let flush k0 encoder =
if encoder.pos > 0 then
let rec k1 n =
if n < encoder.pos then
Write
{
buffer = Bytes.unsafe_to_string encoder.payload;
off = n;
len = encoder.pos - n;
continue = (fun m -> k1 (n + m));
}
else (
encoder.pos <- 0;
k0 encoder)
in
k1 0
else k0 encoder
let write ({ pos; payload } as encoder) s =
let max = Bytes.length payload in
let s_len = String.length s in
let rem = max - pos in
let wr_n_bytes = min rem s_len in
Bytes.blit_string s 0 payload pos wr_n_bytes;
encoder.pos <- pos + wr_n_bytes;
if wr_n_bytes < s_len then leave_with encoder `No_enough_space
let blit encoder ~buf ~off ~len =
let max = Bytes.length encoder.payload in
let go j l encoder =
let rem = max - encoder.pos in
let len = if l > rem then rem else l in
Bytes.blit_string buf (off + j) encoder.payload encoder.pos len;
encoder.pos <- encoder.pos + len;
if len < l then leave_with encoder `No_enough_space
in
go 0 len encoder