Commit bacb2cb
Large diffs are not rendered by default.
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
@@ -0,0 +1,108 @@ | |||
| 1 | + 'use strict'; | ||
| 2 | + | ||
| 3 | + const { Buffer } = require('buffer'); | ||
| 4 | + const { FSReqWrap, close, read } = process.binding('fs'); | ||
| 5 | + | ||
| 6 | + const kReadFileBufferLength = 8 * 1024; | ||
| 7 | + | ||
| 8 | + function readFileAfterRead(err, bytesRead) { | ||
| 9 | + const context = this.context; | ||
| 10 | + | ||
| 11 | + if (err) | ||
| 12 | + return context.close(err); | ||
| 13 | + | ||
| 14 | + if (bytesRead === 0) | ||
| 15 | + return context.close(); | ||
| 16 | + | ||
| 17 | + context.pos += bytesRead; | ||
| 18 | + | ||
| 19 | + if (context.size !== 0) { | ||
| 20 | + if (context.pos === context.size) | ||
| 21 | + context.close(); | ||
| 22 | + else | ||
| 23 | + context.read(); | ||
| 24 | + } else { | ||
| 25 | + // unknown size, just read until we don't get bytes. | ||
| 26 | + context.buffers.push(context.buffer.slice(0, bytesRead)); | ||
| 27 | + context.read(); | ||
| 28 | + } | ||
| 29 | + } | ||
| 30 | + | ||
| 31 | + function readFileAfterClose(err) { | ||
| 32 | + const context = this.context; | ||
| 33 | + const callback = context.callback; | ||
| 34 | + let buffer = null; | ||
| 35 | + | ||
| 36 | + if (context.err || err) | ||
| 37 | + return callback(context.err || err); | ||
| 38 | + | ||
| 39 | + try { | ||
| 40 | + if (context.size === 0) | ||
| 41 | + buffer = Buffer.concat(context.buffers, context.pos); | ||
| 42 | + else if (context.pos < context.size) | ||
| 43 | + buffer = context.buffer.slice(0, context.pos); | ||
| 44 | + else | ||
| 45 | + buffer = context.buffer; | ||
| 46 | + | ||
| 47 | + if (context.encoding) | ||
| 48 | + buffer = buffer.toString(context.encoding); | ||
| 49 | + } catch (err) { | ||
| 50 | + return callback(err); | ||
| 51 | + } | ||
| 52 | + | ||
| 53 | + callback(null, buffer); | ||
| 54 | + } | ||
| 55 | + | ||
| 56 | + class ReadFileContext { | ||
| 57 | + constructor(callback, encoding) { | ||
| 58 | + this.fd = undefined; | ||
| 59 | + this.isUserFd = undefined; | ||
| 60 | + this.size = undefined; | ||
| 61 | + this.callback = callback; | ||
| 62 | + this.buffers = null; | ||
| 63 | + this.buffer = null; | ||
| 64 | + this.pos = 0; | ||
| 65 | + this.encoding = encoding; | ||
| 66 | + this.err = null; | ||
| 67 | + } | ||
| 68 | + | ||
| 69 | + read() { | ||
| 70 | + let buffer; | ||
| 71 | + let offset; | ||
| 72 | + let length; | ||
| 73 | + | ||
| 74 | + if (this.size === 0) { | ||
| 75 | + buffer = this.buffer = Buffer.allocUnsafeSlow(kReadFileBufferLength); | ||
| 76 | + offset = 0; | ||
| 77 | + length = kReadFileBufferLength; | ||
| 78 | + } else { | ||
| 79 | + buffer = this.buffer; | ||
| 80 | + offset = this.pos; | ||
| 81 | + length = Math.min(kReadFileBufferLength, this.size - this.pos); | ||
| 82 | + } | ||
| 83 | + | ||
| 84 | + const req = new FSReqWrap(); | ||
| 85 | + req.oncomplete = readFileAfterRead; | ||
| 86 | + req.context = this; | ||
| 87 | + | ||
| 88 | + read(this.fd, buffer, offset, length, -1, req); | ||
| 89 | + } | ||
| 90 | + | ||
| 91 | + close(err) { | ||
| 92 | + const req = new FSReqWrap(); | ||
| 93 | + req.oncomplete = readFileAfterClose; | ||
| 94 | + req.context = this; | ||
| 95 | + this.err = err; | ||
| 96 | + | ||
| 97 | + if (this.isUserFd) { | ||
| 98 | + process.nextTick(function tick() { | ||
| 99 | + req.oncomplete(null); | ||
| 100 | + }); | ||
| 101 | + return; | ||
| 102 | + } | ||
| 103 | + | ||
| 104 | + close(this.fd, req); | ||
| 105 | + } | ||
| 106 | + } | ||
| 107 | + | ||
| 108 | + module.exports = ReadFileContext; | ||
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