45 lines
914 B
JavaScript
45 lines
914 B
JavaScript
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'use strict';
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const fs = require('fs');
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const pify = require('pify');
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const Buffer = require('safe-buffer').Buffer;
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const fsP = pify(fs);
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const fsReadP = pify(fs.read, {multiArgs: true});
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module.exports = (filepath, pos, len) => {
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const buf = Buffer.alloc(len);
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return fsP.open(filepath, 'r')
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.then(fd =>
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fsReadP(fd, buf, 0, len, pos)
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.then(readArgs => fsP.close(fd)
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.then(() => readArgs))
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)
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.then(readArgs => {
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// TODO: Use destructuring when Node.js 6 is target
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const bytesRead = readArgs[0];
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let buf = readArgs[1];
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if (bytesRead < len) {
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buf = buf.slice(0, bytesRead);
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}
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return buf;
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});
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};
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module.exports.sync = (filepath, pos, len) => {
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let buf = Buffer.alloc(len);
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const fd = fs.openSync(filepath, 'r');
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const bytesRead = fs.readSync(fd, buf, 0, len, pos);
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fs.closeSync(fd);
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if (bytesRead < len) {
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buf = buf.slice(0, bytesRead);
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}
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return buf;
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};
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