129 lines
4.8 KiB
JavaScript
129 lines
4.8 KiB
JavaScript
"use strict";
|
|
Object.defineProperty(exports, "__esModule", { value: true });
|
|
exports.ReadStreamTokenizer = void 0;
|
|
const AbstractTokenizer_1 = require("./AbstractTokenizer");
|
|
const peek_readable_1 = require("peek-readable");
|
|
// import * as _debug from 'debug';
|
|
// const debug = _debug('strtok3:ReadStreamTokenizer');
|
|
const maxBufferSize = 256000;
|
|
class ReadStreamTokenizer extends AbstractTokenizer_1.AbstractTokenizer {
|
|
constructor(stream, fileInfo) {
|
|
super(fileInfo);
|
|
this.streamReader = new peek_readable_1.StreamReader(stream);
|
|
}
|
|
/**
|
|
* Get file information, an HTTP-client may implement this doing a HEAD request
|
|
* @return Promise with file information
|
|
*/
|
|
async getFileInfo() {
|
|
return this.fileInfo;
|
|
}
|
|
/**
|
|
* Read buffer from tokenizer
|
|
* @param buffer - Target buffer to fill with data read from the tokenizer-stream
|
|
* @param options - Read behaviour options
|
|
* @returns Promise with number of bytes read
|
|
*/
|
|
async readBuffer(buffer, options) {
|
|
// const _offset = position ? position : this.position;
|
|
// debug(`readBuffer ${_offset}...${_offset + length - 1}`);
|
|
let offset = 0;
|
|
let length = buffer.length;
|
|
if (options) {
|
|
if (Number.isInteger(options.length)) {
|
|
length = options.length;
|
|
}
|
|
else {
|
|
length -= options.offset || 0;
|
|
}
|
|
if (options.position) {
|
|
const skipBytes = options.position - this.position;
|
|
if (skipBytes > 0) {
|
|
await this.ignore(skipBytes);
|
|
return this.readBuffer(buffer, options);
|
|
}
|
|
else if (skipBytes < 0) {
|
|
throw new Error('`options.position` must be equal or greater than `tokenizer.position`');
|
|
}
|
|
}
|
|
if (options.offset) {
|
|
offset = options.offset;
|
|
}
|
|
}
|
|
if (length === 0) {
|
|
return 0;
|
|
}
|
|
const bytesRead = await this.streamReader.read(buffer, offset, length);
|
|
this.position += bytesRead;
|
|
if ((!options || !options.mayBeLess) && bytesRead < length) {
|
|
throw new peek_readable_1.EndOfStreamError();
|
|
}
|
|
return bytesRead;
|
|
}
|
|
/**
|
|
* Peek (read ahead) buffer from tokenizer
|
|
* @param buffer - Target buffer to write the data read to
|
|
* @param options - Read behaviour options
|
|
* @returns Promise with number of bytes peeked
|
|
*/
|
|
async peekBuffer(buffer, options) {
|
|
// const _offset = position ? position : this.position;
|
|
// debug(`peek ${_offset}...${_offset + length - 1}`);
|
|
let offset = 0;
|
|
let bytesRead;
|
|
let length = buffer.length;
|
|
if (options) {
|
|
if (options.offset) {
|
|
offset = options.offset;
|
|
}
|
|
if (Number.isInteger(options.length)) {
|
|
length = options.length;
|
|
}
|
|
else {
|
|
length -= options.offset || 0;
|
|
}
|
|
if (options.position) {
|
|
const skipBytes = options.position - this.position;
|
|
if (skipBytes > 0) {
|
|
const skipBuffer = Buffer.alloc(length + skipBytes);
|
|
bytesRead = await this.peekBuffer(skipBuffer, { mayBeLess: options.mayBeLess });
|
|
skipBuffer.copy(buffer, offset, skipBytes);
|
|
return bytesRead - skipBytes;
|
|
}
|
|
else if (skipBytes < 0) {
|
|
throw new Error('Cannot peek from a negative offset in a stream');
|
|
}
|
|
}
|
|
}
|
|
try {
|
|
bytesRead = await this.streamReader.peek(buffer, offset, length);
|
|
}
|
|
catch (err) {
|
|
if (options && options.mayBeLess && err instanceof peek_readable_1.EndOfStreamError) {
|
|
return 0;
|
|
}
|
|
throw err;
|
|
}
|
|
if ((!options || !options.mayBeLess) && bytesRead < length) {
|
|
throw new peek_readable_1.EndOfStreamError();
|
|
}
|
|
return bytesRead;
|
|
}
|
|
async ignore(length) {
|
|
// debug(`ignore ${this.position}...${this.position + length - 1}`);
|
|
const bufSize = Math.min(maxBufferSize, length);
|
|
const buf = Buffer.alloc(bufSize);
|
|
let totBytesRead = 0;
|
|
while (totBytesRead < length) {
|
|
const remaining = length - totBytesRead;
|
|
const bytesRead = await this.readBuffer(buf, { length: Math.min(bufSize, remaining) });
|
|
if (bytesRead < 0) {
|
|
return bytesRead;
|
|
}
|
|
totBytesRead += bytesRead;
|
|
}
|
|
return totBytesRead;
|
|
}
|
|
}
|
|
exports.ReadStreamTokenizer = ReadStreamTokenizer;
|
|
//# sourceMappingURL=ReadStreamTokenizer.js.map
|