115 lines
3.7 KiB
JavaScript
115 lines
3.7 KiB
JavaScript
"use strict";
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.BufferTokenizer = void 0;
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const peek_readable_1 = require("peek-readable");
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class BufferTokenizer {
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/**
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* Construct BufferTokenizer
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* @param buffer - Buffer to tokenize
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* @param fileInfo - Pass additional file information to the tokenizer
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*/
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constructor(buffer, fileInfo) {
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this.buffer = buffer;
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this.position = 0;
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this.fileInfo = fileInfo ? fileInfo : {};
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this.fileInfo.size = this.fileInfo.size ? this.fileInfo.size : buffer.length;
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}
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/**
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* Read buffer from tokenizer
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* @param buffer
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* @param options - Read behaviour options
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* @returns {Promise<number>}
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*/
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async readBuffer(buffer, options) {
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if (options && options.position) {
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if (options.position < this.position) {
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throw new Error('`options.position` must be equal or greater than `tokenizer.position`');
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}
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this.position = options.position;
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}
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return this.peekBuffer(buffer, options).then(bytesRead => {
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this.position += bytesRead;
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return bytesRead;
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});
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}
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/**
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* Peek (read ahead) buffer from tokenizer
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* @param buffer
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* @param options - Read behaviour options
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* @returns {Promise<number>}
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*/
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async peekBuffer(buffer, options) {
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let offset = 0;
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let length = buffer.length;
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let position = this.position;
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if (options) {
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if (options.position) {
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if (options.position < this.position) {
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throw new Error('`options.position` can be less than `tokenizer.position`');
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}
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position = options.position;
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}
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if (Number.isInteger(options.length)) {
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length = options.length;
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}
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else {
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length -= options.offset || 0;
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}
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if (options.offset) {
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offset = options.offset;
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}
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}
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if (length === 0) {
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return Promise.resolve(0);
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}
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position = position || this.position;
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if (!length) {
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length = buffer.length;
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}
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const bytes2read = Math.min(this.buffer.length - position, length);
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if ((!options || !options.mayBeLess) && bytes2read < length) {
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throw new peek_readable_1.EndOfStreamError();
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}
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else {
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this.buffer.copy(buffer, offset, position, position + bytes2read);
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return bytes2read;
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}
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}
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async readToken(token, position) {
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this.position = position || this.position;
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try {
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const tv = this.peekToken(token, this.position);
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this.position += token.len;
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return tv;
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}
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catch (err) {
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this.position += this.buffer.length - position;
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throw err;
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}
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}
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async peekToken(token, position = this.position) {
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if (this.buffer.length - position < token.len) {
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throw new peek_readable_1.EndOfStreamError();
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}
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return token.get(this.buffer, position);
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}
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async readNumber(token) {
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return this.readToken(token);
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}
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async peekNumber(token) {
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return this.peekToken(token);
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}
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/**
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* @return actual number of bytes ignored
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*/
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async ignore(length) {
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const bytesIgnored = Math.min(this.buffer.length - this.position, length);
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this.position += bytesIgnored;
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return bytesIgnored;
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}
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async close() {
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// empty
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}
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}
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exports.BufferTokenizer = BufferTokenizer;
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//# sourceMappingURL=BufferTokenizer.js.map
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