52 lines
1.9 KiB
JavaScript
52 lines
1.9 KiB
JavaScript
import { EndOfStreamError } from 'peek-readable';
|
|
import { AbstractTokenizer } from './AbstractTokenizer.js';
|
|
export class BufferTokenizer extends AbstractTokenizer {
|
|
/**
|
|
* Construct BufferTokenizer
|
|
* @param uint8Array - Uint8Array to tokenize
|
|
* @param fileInfo - Pass additional file information to the tokenizer
|
|
*/
|
|
constructor(uint8Array, fileInfo) {
|
|
super(fileInfo);
|
|
this.uint8Array = uint8Array;
|
|
this.fileInfo.size = this.fileInfo.size ? this.fileInfo.size : uint8Array.length;
|
|
}
|
|
/**
|
|
* Read buffer from tokenizer
|
|
* @param uint8Array - Uint8Array to tokenize
|
|
* @param options - Read behaviour options
|
|
* @returns {Promise<number>}
|
|
*/
|
|
async readBuffer(uint8Array, options) {
|
|
if (options && options.position) {
|
|
if (options.position < this.position) {
|
|
throw new Error('`options.position` must be equal or greater than `tokenizer.position`');
|
|
}
|
|
this.position = options.position;
|
|
}
|
|
const bytesRead = await this.peekBuffer(uint8Array, options);
|
|
this.position += bytesRead;
|
|
return bytesRead;
|
|
}
|
|
/**
|
|
* Peek (read ahead) buffer from tokenizer
|
|
* @param uint8Array
|
|
* @param options - Read behaviour options
|
|
* @returns {Promise<number>}
|
|
*/
|
|
async peekBuffer(uint8Array, options) {
|
|
const normOptions = this.normalizeOptions(uint8Array, options);
|
|
const bytes2read = Math.min(this.uint8Array.length - normOptions.position, normOptions.length);
|
|
if ((!normOptions.mayBeLess) && bytes2read < normOptions.length) {
|
|
throw new EndOfStreamError();
|
|
}
|
|
else {
|
|
uint8Array.set(this.uint8Array.subarray(normOptions.position, normOptions.position + bytes2read), normOptions.offset);
|
|
return bytes2read;
|
|
}
|
|
}
|
|
async close() {
|
|
// empty
|
|
}
|
|
}
|