hackpro-sdk
Version:
94 lines • 4.24 kB
JavaScript
;
/*
* 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.
*/
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
Object.defineProperty(exports, "__esModule", { value: true });
const bluebird_1 = require("bluebird");
const readable_stream_1 = require("readable-stream");
const constants_1 = require("./constants");
const errors_1 = require("./errors");
const progress_1 = require("./source-destination/progress");
class BlockReadStream extends readable_stream_1.Readable {
constructor(source, bytesRead = 0, end = Infinity, chunkSize = constants_1.CHUNK_SIZE, maxRetries = 5) {
super({ objectMode: true, highWaterMark: 2 });
this.source = source;
this.bytesRead = bytesRead;
this.end = end;
this.maxRetries = maxRetries;
this.chunkSize = Math.max(Math.floor(chunkSize / this.source.blockSize) * this.source.blockSize, this.source.blockSize);
}
tryRead(buffer) {
return __awaiter(this, void 0, void 0, function* () {
// Tries to read `this.maxRetries` times if the error is transient.
// Throws EUNPLUGGED if all retries failed.
let retries = 0;
while (true) {
try {
return yield this.source.read(buffer, 0, buffer.length, this.bytesRead);
}
catch (error) {
if (errors_1.isTransientError(error)) {
if (retries < this.maxRetries) {
retries += 1;
yield bluebird_1.delay(constants_1.RETRY_BASE_TIMEOUT * retries);
continue;
}
error.code = 'EUNPLUGGED';
}
throw error;
}
}
});
}
__read() {
return __awaiter(this, void 0, void 0, function* () {
const toRead = this.end - this.bytesRead + 1; // end is inclusive
if (toRead <= 0) {
this.push(null);
return;
}
// Read chunkSize bytes if available, else all remaining bytes.
const length = Math.min(this.chunkSize, toRead);
const buffer = Buffer.allocUnsafe(length);
try {
const { bytesRead } = yield this.tryRead(buffer);
if (bytesRead === 0) {
this.push(null);
return;
}
this.bytesRead += bytesRead;
this.push(buffer.slice(0, bytesRead));
}
catch (error) {
this.emit('error', error);
}
});
}
_read() {
this.__read();
}
}
exports.BlockReadStream = BlockReadStream;
exports.ProgressBlockReadStream = progress_1.makeClassEmitProgressEvents(BlockReadStream, 'bytesRead', 'bytesRead', constants_1.PROGRESS_EMISSION_INTERVAL);
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