Samuel Kent
38 lines
1.3 KiB
JavaScript
38 lines
1.3 KiB
JavaScript
"use strict";
|
|
Object.defineProperty(exports, "__esModule", { value: true });
|
|
exports.RandomFileReader = void 0;
|
|
const fs = require("fs");
|
|
/**
|
|
* Provides abstract file access via the IRandomRead interface
|
|
*/
|
|
class RandomFileReader {
|
|
constructor(filePath, fileSize) {
|
|
this.fileSize = fileSize;
|
|
this.fd = fs.openSync(filePath, 'r');
|
|
}
|
|
/**
|
|
* Read from a given position of an abstracted file or buffer.
|
|
* @param buffer {Buffer} is the buffer that the data will be written to.
|
|
* @param offset {number} is the offset in the buffer to start writing at.
|
|
* @param length {number}is an integer specifying the number of bytes to read.
|
|
* @param position {number} is an argument specifying where to begin reading from in the file.
|
|
* @return {Promise<number>} bytes read
|
|
*/
|
|
randomRead(buffer, offset, length, position) {
|
|
return new Promise((resolve, reject) => {
|
|
fs.read(this.fd, buffer, offset, length, position, (err, bytesRead) => {
|
|
if (err) {
|
|
reject(err);
|
|
}
|
|
else {
|
|
resolve(bytesRead);
|
|
}
|
|
});
|
|
});
|
|
}
|
|
close() {
|
|
fs.closeSync(this.fd);
|
|
}
|
|
}
|
|
exports.RandomFileReader = RandomFileReader;
|