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
// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.// Ported to Deno from// Copyright 2009 The Go Authors. All rights reserved.// Use of this source code is governed by a BSD-style// license that can be found in the LICENSE file.import type { Reader } from "./types.d.ts";
/** OneByteReader returns a Reader that implements * each non-empty Read by reading one byte from r. */export class OneByteReader implements Reader {  constructor(readonly r: Reader) {}
  read(p: Uint8Array): Promise<number | null> {    if (p.byteLength === 0) {      return Promise.resolve(0);    }    if (!(p instanceof Uint8Array)) {      throw Error("expected Uint8Array");    }    return Promise.resolve(this.r.read(p.subarray(0, 1)));  }}
/** HalfReader returns a Reader that implements Read * by reading half as many requested bytes from r. */export class HalfReader implements Reader {  constructor(readonly r: Reader) {}
  read(p: Uint8Array): Promise<number | null> {    if (!(p instanceof Uint8Array)) {      throw Error("expected Uint8Array");    }    const half = Math.floor((p.byteLength + 1) / 2);    return Promise.resolve(this.r.read(p.subarray(0, half)));  }}
/** TimeoutReader returns `Deno.errors.TimedOut` on the second read * with no data. Subsequent calls to read succeed. */export class TimeoutReader implements Reader {  count = 0;  constructor(readonly r: Reader) {}
  read(p: Uint8Array): Promise<number | null> {    this.count++;    if (this.count === 2) {      throw new Deno.errors.TimedOut();    }    return Promise.resolve(this.r.read(p));  }}