All files / lib/internal/fs read_file_context.js

98.44% Statements 127/129
94.11% Branches 32/34
100% Functions 6/6
98.44% Lines 127/129

Press n or j to go to the next uncovered block, b, p or k for the previous block.

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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 13021x 21x 21x 21x 21x 21x 21x 21x 21x 21x 21x 21x 21x 21x 21x 21x 21x 21x 21x 21x 21x 21x 21x 21x 224x 224x 224x 224x 224x 224x 224x 224x 224x 203x 223x 21x 17x 17x 17x 17x 17x 21x 21x 224x 21x 205x 205x 205x 205x 205x 205x 205x 203x 203x 203x 205x 173x 173x 172x 172x 203x 203x 205x 205x     205x 205x 205x 21x 21x 21x 234x 234x 234x 234x 234x 234x 234x 234x 234x 234x 234x 21x 21x 225x 225x 225x 225x 225x 1x 1x 1x 225x 47x 47x 47x 47x 217x 177x 177x 177x 177x 224x 224x 224x 224x 224x 224x 225x 21x 21x 205x 3x 3x 3x 3x 3x 205x 205x 205x 205x 205x 205x 205x 205x 21x 21x 21x  
'use strict';
 
const {
  ArrayPrototypePush,
  MathMin,
  ReflectApply,
} = primordials;
 
const {
  constants: {
    kReadFileBufferLength,
    kReadFileUnknownBufferLength,
  }
} = require('internal/fs/utils');
 
const { Buffer } = require('buffer');
 
const { FSReqCallback, close, read } = internalBinding('fs');
 
const {
  AbortError,
  aggregateTwoErrors,
} = require('internal/errors');
 
function readFileAfterRead(err, bytesRead) {
  const context = this.context;
 
  if (err)
    return context.close(err);
 
  context.pos += bytesRead;
 
  if (context.pos === context.size || bytesRead === 0) {
    context.close();
  } else {
    if (context.size === 0) {
      // Unknown size, just read until we don't get bytes.
      const buffer = bytesRead === kReadFileUnknownBufferLength ?
        context.buffer : context.buffer.slice(0, bytesRead);
      ArrayPrototypePush(context.buffers, buffer);
    }
    context.read();
  }
}
 
function readFileAfterClose(err) {
  const context = this.context;
  const callback = context.callback;
  let buffer = null;
 
  if (context.err || err)
    return callback(aggregateTwoErrors(err, context.err));
 
  try {
    if (context.size === 0)
      buffer = Buffer.concat(context.buffers, context.pos);
    else if (context.pos < context.size)
      buffer = context.buffer.slice(0, context.pos);
    else
      buffer = context.buffer;
 
    if (context.encoding)
      buffer = buffer.toString(context.encoding);
  } catch (err) {
    return callback(err);
  }
 
  callback(null, buffer);
}
 
class ReadFileContext {
  constructor(callback, encoding) {
    this.fd = undefined;
    this.isUserFd = undefined;
    this.size = 0;
    this.callback = callback;
    this.buffers = null;
    this.buffer = null;
    this.pos = 0;
    this.encoding = encoding;
    this.err = null;
    this.signal = undefined;
  }
 
  read() {
    let buffer;
    let offset;
    let length;
 
    if (this.signal?.aborted) {
      return this.close(
        new AbortError(undefined, { cause: this.signal?.reason }));
    }
    if (this.size === 0) {
      buffer = Buffer.allocUnsafeSlow(kReadFileUnknownBufferLength);
      offset = 0;
      length = kReadFileUnknownBufferLength;
      this.buffer = buffer;
    } else {
      buffer = this.buffer;
      offset = this.pos;
      length = MathMin(kReadFileBufferLength, this.size - this.pos);
    }
 
    const req = new FSReqCallback();
    req.oncomplete = readFileAfterRead;
    req.context = this;
 
    read(this.fd, buffer, offset, length, -1, req);
  }
 
  close(err) {
    if (this.isUserFd) {
      process.nextTick(function tick(context) {
        ReflectApply(readFileAfterClose, { context }, [null]);
      }, this);
      return;
    }
 
    const req = new FSReqCallback();
    req.oncomplete = readFileAfterClose;
    req.context = this;
    this.err = err;
 
    close(this.fd, req);
  }
}
 
module.exports = ReadFileContext;