hackpro-sdk
Version:
66 lines • 2.37 kB
JavaScript
"use strict";
/*
* Copyright 2018 balena.io
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
Object.defineProperty(exports, "__esModule", { value: true });
const readable_stream_1 = require("readable-stream");
class BlockTransformStream extends readable_stream_1.Transform {
constructor(chunkSize) {
super();
this.chunkSize = chunkSize;
this.bytesRead = 0;
this.bytesWritten = 0;
this._buffers = [];
this._bytes = 0;
}
writeBuffers(flush = false) {
if (flush || this._bytes >= this.chunkSize) {
let block = Buffer.concat(this._buffers);
const length = flush
? block.length
: Math.floor(block.length / this.chunkSize) * this.chunkSize;
this._buffers.length = 0;
this._bytes = 0;
if (block.length !== length) {
this._buffers.push(block.slice(length));
this._bytes += block.length - length;
block = block.slice(0, length);
}
this.bytesWritten += block.length;
this.push(block);
}
}
_transform(chunk, _encoding, callback) {
this.bytesRead += chunk.length;
if (this._bytes === 0 &&
chunk.length >= this.chunkSize &&
chunk.length % this.chunkSize === 0) {
this.bytesWritten += chunk.length;
this.push(chunk);
}
else {
this._buffers.push(chunk);
this._bytes += chunk.length;
this.writeBuffers();
}
callback();
}
_flush(callback) {
this.writeBuffers(true);
callback();
}
}
exports.BlockTransformStream = BlockTransformStream;
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