40 lines
961 B
JavaScript
40 lines
961 B
JavaScript
'use strict';
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const fs = require('fs');
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const pify = require('pify');
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const withOpenFile = require('with-open-file');
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const fsReadP = pify(fs.read, {multiArgs: true});
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const readChunk = (filePath, startPosition, length) => {
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const buffer = Buffer.alloc(length);
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return withOpenFile(filePath, 'r', fileDescriptor =>
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fsReadP(fileDescriptor, buffer, 0, length, startPosition)
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)
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.then(([bytesRead, buffer]) => {
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if (bytesRead < length) {
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buffer = buffer.slice(0, bytesRead);
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}
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return buffer;
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});
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};
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module.exports = readChunk;
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// TODO: Remove this for the next major release
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module.exports.default = readChunk;
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module.exports.sync = (filePath, startPosition, length) => {
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let buffer = Buffer.alloc(length);
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const bytesRead = withOpenFile.sync(filePath, 'r', fileDescriptor =>
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fs.readSync(fileDescriptor, buffer, 0, length, startPosition)
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);
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if (bytesRead < length) {
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buffer = buffer.slice(0, bytesRead);
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}
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return buffer;
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};
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