etcher-sdk
Version:
100 lines • 4.18 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.ProgressSparseWriteStream = exports.SparseWriteStream = void 0;
const direct_io_1 = require("@ronomon/direct-io");
const stream_1 = require("stream");
const aligned_lockable_buffer_1 = require("../aligned-lockable-buffer");
const constants_1 = require("../constants");
const errors_1 = require("../errors");
const progress_1 = require("../source-destination/progress");
const utils_1 = require("../utils");
class SparseWriteStream extends stream_1.Writable {
constructor({ destination, highWaterMark, firstBytesToKeep = 0, maxRetries = 5, }) {
super({ objectMode: true, highWaterMark });
this.bytesWritten = 0;
this._firstChunks = [];
this.destination = destination;
this.firstBytesToKeep = firstBytesToKeep;
this.maxRetries = maxRetries;
}
async writeChunk(chunk, flushing = false) {
await (0, errors_1.retryOnTransientError)(async () => {
this.position = chunk.position;
await this.destination.write(chunk.buffer, 0, chunk.buffer.length, chunk.position);
if (!flushing) {
this.position += chunk.buffer.length;
this.bytesWritten += chunk.buffer.length;
}
}, this.maxRetries, constants_1.RETRY_BASE_TIMEOUT);
}
copyChunk(chunk) {
if ((0, aligned_lockable_buffer_1.isAlignedLockableBuffer)(chunk.buffer)) {
const buffer = (0, direct_io_1.getAlignedBuffer)(chunk.buffer.length, chunk.buffer.alignment);
chunk.buffer.copy(buffer);
return { position: chunk.position, buffer };
}
else {
return chunk;
}
}
async __write(chunk) {
const unlock = (0, aligned_lockable_buffer_1.isAlignedLockableBuffer)(chunk.buffer)
? await chunk.buffer.rlock()
: undefined;
try {
// Keep the first blocks in memory and write them once the rest has been written.
// This is to prevent Windows from mounting the device while we flash it.
if (chunk.position < this.firstBytesToKeep) {
const end = chunk.position + chunk.buffer.length;
if (end <= this.firstBytesToKeep) {
this._firstChunks.push(this.copyChunk(chunk));
this.position = chunk.position + chunk.buffer.length;
this.bytesWritten += chunk.buffer.length;
}
else {
const difference = this.firstBytesToKeep - chunk.position;
this._firstChunks.push(this.copyChunk({
position: chunk.position,
buffer: chunk.buffer.slice(0, difference),
}));
this.position = this.firstBytesToKeep;
this.bytesWritten += difference;
const remainingBuffer = chunk.buffer.slice(difference);
await this.writeChunk({
position: this.firstBytesToKeep,
buffer: remainingBuffer,
});
}
}
else {
await this.writeChunk(chunk);
}
}
finally {
unlock === null || unlock === void 0 ? void 0 : unlock();
}
}
_write(chunk, _enc, callback) {
(0, utils_1.asCallback)(this.__write(chunk), callback);
}
async __final() {
try {
for (const chunk of this._firstChunks) {
await this.writeChunk(chunk, true);
}
}
catch (error) {
this.destroy();
throw error;
}
}
/**
* @summary Write buffered data before a stream ends, called by stream internals
*/
_final(callback) {
(0, utils_1.asCallback)(this.__final(), callback);
}
}
exports.SparseWriteStream = SparseWriteStream;
exports.ProgressSparseWriteStream = (0, progress_1.makeClassEmitProgressEvents)(SparseWriteStream, 'bytesWritten', 'position');
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