683 lines
18 KiB
JavaScript
683 lines
18 KiB
JavaScript
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/*
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MIT License http://www.opensource.org/licenses/mit-license.php
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*/
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"use strict";
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const { constants } = require("buffer");
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const { pipeline } = require("stream");
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const {
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createBrotliCompress,
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createBrotliDecompress,
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createGzip,
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createGunzip,
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constants: zConstants
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} = require("zlib");
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const createHash = require("../util/createHash");
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const { dirname, join, mkdirp } = require("../util/fs");
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const memoize = require("../util/memoize");
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const SerializerMiddleware = require("./SerializerMiddleware");
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/** @typedef {typeof import("../util/Hash")} Hash */
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/** @typedef {import("../util/fs").IntermediateFileSystem} IntermediateFileSystem */
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/** @typedef {import("./types").BufferSerializableType} BufferSerializableType */
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/*
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Format:
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File -> Header Section*
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Version -> u32
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AmountOfSections -> u32
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SectionSize -> i32 (if less than zero represents lazy value)
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Header -> Version AmountOfSections SectionSize*
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Buffer -> n bytes
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Section -> Buffer
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*/
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// "wpc" + 1 in little-endian
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const VERSION = 0x01637077;
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const WRITE_LIMIT_TOTAL = 0x7fff0000;
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const WRITE_LIMIT_CHUNK = 511 * 1024 * 1024;
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/**
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* @param {Buffer[]} buffers buffers
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* @param {string | Hash} hashFunction hash function to use
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* @returns {string} hash
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*/
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const hashForName = (buffers, hashFunction) => {
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const hash = createHash(hashFunction);
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for (const buf of buffers) hash.update(buf);
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return /** @type {string} */ (hash.digest("hex"));
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};
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const COMPRESSION_CHUNK_SIZE = 100 * 1024 * 1024;
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const DECOMPRESSION_CHUNK_SIZE = 100 * 1024 * 1024;
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const writeUInt64LE = Buffer.prototype.writeBigUInt64LE
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? (buf, value, offset) => {
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buf.writeBigUInt64LE(BigInt(value), offset);
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}
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: (buf, value, offset) => {
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const low = value % 0x100000000;
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const high = (value - low) / 0x100000000;
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buf.writeUInt32LE(low, offset);
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buf.writeUInt32LE(high, offset + 4);
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};
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const readUInt64LE = Buffer.prototype.readBigUInt64LE
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? (buf, offset) => {
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return Number(buf.readBigUInt64LE(offset));
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}
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: (buf, offset) => {
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const low = buf.readUInt32LE(offset);
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const high = buf.readUInt32LE(offset + 4);
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return high * 0x100000000 + low;
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};
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/**
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* @typedef {Object} SerializeResult
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* @property {string | false} name
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* @property {number} size
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* @property {Promise=} backgroundJob
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*/
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/**
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* @param {FileMiddleware} middleware this
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* @param {BufferSerializableType[] | Promise<BufferSerializableType[]>} data data to be serialized
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* @param {string | boolean} name file base name
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* @param {function(string | false, Buffer[], number): Promise<void>} writeFile writes a file
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* @param {string | Hash} hashFunction hash function to use
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* @returns {Promise<SerializeResult>} resulting file pointer and promise
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*/
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const serialize = async (
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middleware,
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data,
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name,
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writeFile,
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hashFunction = "md4"
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) => {
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/** @type {(Buffer[] | Buffer | SerializeResult | Promise<SerializeResult>)[]} */
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const processedData = [];
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/** @type {WeakMap<SerializeResult, function(): any | Promise<any>>} */
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const resultToLazy = new WeakMap();
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/** @type {Buffer[]} */
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let lastBuffers = undefined;
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for (const item of await data) {
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if (typeof item === "function") {
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if (!SerializerMiddleware.isLazy(item))
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throw new Error("Unexpected function");
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if (!SerializerMiddleware.isLazy(item, middleware)) {
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throw new Error(
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"Unexpected lazy value with non-this target (can't pass through lazy values)"
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);
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}
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lastBuffers = undefined;
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const serializedInfo = SerializerMiddleware.getLazySerializedValue(item);
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if (serializedInfo) {
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if (typeof serializedInfo === "function") {
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throw new Error(
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"Unexpected lazy value with non-this target (can't pass through lazy values)"
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);
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} else {
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processedData.push(serializedInfo);
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}
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} else {
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const content = item();
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if (content) {
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const options = SerializerMiddleware.getLazyOptions(item);
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processedData.push(
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serialize(
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middleware,
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content,
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(options && options.name) || true,
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writeFile,
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hashFunction
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).then(result => {
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/** @type {any} */ (item).options.size = result.size;
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resultToLazy.set(result, item);
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return result;
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})
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);
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} else {
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throw new Error(
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"Unexpected falsy value returned by lazy value function"
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);
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}
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}
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} else if (item) {
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if (lastBuffers) {
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lastBuffers.push(item);
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} else {
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lastBuffers = [item];
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processedData.push(lastBuffers);
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}
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} else {
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throw new Error("Unexpected falsy value in items array");
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}
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}
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/** @type {Promise<any>[]} */
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const backgroundJobs = [];
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const resolvedData = (
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await Promise.all(
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/** @type {Promise<Buffer[] | Buffer | SerializeResult>[]} */ (
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processedData
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)
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)
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).map(item => {
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if (Array.isArray(item) || Buffer.isBuffer(item)) return item;
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backgroundJobs.push(item.backgroundJob);
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// create pointer buffer from size and name
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const name = /** @type {string} */ (item.name);
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const nameBuffer = Buffer.from(name);
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const buf = Buffer.allocUnsafe(8 + nameBuffer.length);
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writeUInt64LE(buf, item.size, 0);
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nameBuffer.copy(buf, 8, 0);
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const lazy = resultToLazy.get(item);
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SerializerMiddleware.setLazySerializedValue(lazy, buf);
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return buf;
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});
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/** @type {number[]} */
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const lengths = [];
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for (const item of resolvedData) {
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if (Array.isArray(item)) {
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let l = 0;
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for (const b of item) l += b.length;
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while (l > 0x7fffffff) {
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lengths.push(0x7fffffff);
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l -= 0x7fffffff;
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}
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lengths.push(l);
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} else if (item) {
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lengths.push(-item.length);
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} else {
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throw new Error("Unexpected falsy value in resolved data " + item);
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}
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}
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const header = Buffer.allocUnsafe(8 + lengths.length * 4);
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header.writeUInt32LE(VERSION, 0);
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header.writeUInt32LE(lengths.length, 4);
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for (let i = 0; i < lengths.length; i++) {
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header.writeInt32LE(lengths[i], 8 + i * 4);
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}
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/** @type {Buffer[]} */
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const buf = [header];
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for (const item of resolvedData) {
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if (Array.isArray(item)) {
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for (const b of item) buf.push(b);
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} else if (item) {
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buf.push(item);
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}
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}
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if (name === true) {
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name = hashForName(buf, hashFunction);
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}
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let size = 0;
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for (const b of buf) size += b.length;
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backgroundJobs.push(writeFile(name, buf, size));
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return {
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size,
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name,
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backgroundJob:
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backgroundJobs.length === 1
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? backgroundJobs[0]
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: Promise.all(backgroundJobs)
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};
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};
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/**
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* @param {FileMiddleware} middleware this
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* @param {string | false} name filename
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* @param {function(string | false): Promise<Buffer[]>} readFile read content of a file
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* @returns {Promise<BufferSerializableType[]>} deserialized data
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*/
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const deserialize = async (middleware, name, readFile) => {
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const contents = await readFile(name);
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if (contents.length === 0) throw new Error("Empty file " + name);
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let contentsIndex = 0;
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let contentItem = contents[0];
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let contentItemLength = contentItem.length;
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let contentPosition = 0;
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if (contentItemLength === 0) throw new Error("Empty file " + name);
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const nextContent = () => {
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contentsIndex++;
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contentItem = contents[contentsIndex];
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contentItemLength = contentItem.length;
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contentPosition = 0;
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};
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/**
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* @param {number} n number of bytes to ensure
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*/
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const ensureData = n => {
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if (contentPosition === contentItemLength) {
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nextContent();
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}
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while (contentItemLength - contentPosition < n) {
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const remaining = contentItem.slice(contentPosition);
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let lengthFromNext = n - remaining.length;
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const buffers = [remaining];
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for (let i = contentsIndex + 1; i < contents.length; i++) {
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const l = contents[i].length;
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if (l > lengthFromNext) {
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buffers.push(contents[i].slice(0, lengthFromNext));
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contents[i] = contents[i].slice(lengthFromNext);
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lengthFromNext = 0;
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break;
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} else {
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buffers.push(contents[i]);
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contentsIndex = i;
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lengthFromNext -= l;
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}
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}
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if (lengthFromNext > 0) throw new Error("Unexpected end of data");
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contentItem = Buffer.concat(buffers, n);
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contentItemLength = n;
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contentPosition = 0;
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}
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};
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/**
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* @returns {number} value value
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*/
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const readUInt32LE = () => {
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ensureData(4);
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const value = contentItem.readUInt32LE(contentPosition);
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contentPosition += 4;
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return value;
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};
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/**
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* @returns {number} value value
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*/
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const readInt32LE = () => {
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ensureData(4);
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const value = contentItem.readInt32LE(contentPosition);
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contentPosition += 4;
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return value;
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};
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/**
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* @param {number} l length
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* @returns {Buffer} buffer
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*/
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const readSlice = l => {
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ensureData(l);
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if (contentPosition === 0 && contentItemLength === l) {
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const result = contentItem;
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if (contentsIndex + 1 < contents.length) {
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nextContent();
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} else {
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contentPosition = l;
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}
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return result;
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}
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const result = contentItem.slice(contentPosition, contentPosition + l);
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contentPosition += l;
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// we clone the buffer here to allow the original content to be garbage collected
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return l * 2 < contentItem.buffer.byteLength ? Buffer.from(result) : result;
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};
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const version = readUInt32LE();
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if (version !== VERSION) {
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throw new Error("Invalid file version");
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}
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const sectionCount = readUInt32LE();
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const lengths = [];
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let lastLengthPositive = false;
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for (let i = 0; i < sectionCount; i++) {
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const value = readInt32LE();
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const valuePositive = value >= 0;
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if (lastLengthPositive && valuePositive) {
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lengths[lengths.length - 1] += value;
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} else {
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lengths.push(value);
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lastLengthPositive = valuePositive;
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}
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}
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const result = [];
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for (let length of lengths) {
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if (length < 0) {
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const slice = readSlice(-length);
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const size = Number(readUInt64LE(slice, 0));
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const nameBuffer = slice.slice(8);
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const name = nameBuffer.toString();
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result.push(
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SerializerMiddleware.createLazy(
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memoize(() => deserialize(middleware, name, readFile)),
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middleware,
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{
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name,
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size
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},
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slice
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)
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);
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} else {
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if (contentPosition === contentItemLength) {
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nextContent();
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} else if (contentPosition !== 0) {
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if (length <= contentItemLength - contentPosition) {
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result.push(
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Buffer.from(
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contentItem.buffer,
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contentItem.byteOffset + contentPosition,
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length
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)
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);
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contentPosition += length;
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length = 0;
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} else {
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const l = contentItemLength - contentPosition;
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result.push(
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Buffer.from(
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contentItem.buffer,
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contentItem.byteOffset + contentPosition,
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l
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)
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);
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length -= l;
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contentPosition = contentItemLength;
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}
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} else {
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if (length >= contentItemLength) {
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result.push(contentItem);
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length -= contentItemLength;
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contentPosition = contentItemLength;
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} else {
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result.push(
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Buffer.from(contentItem.buffer, contentItem.byteOffset, length)
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);
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contentPosition += length;
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length = 0;
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}
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}
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while (length > 0) {
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nextContent();
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if (length >= contentItemLength) {
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result.push(contentItem);
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length -= contentItemLength;
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contentPosition = contentItemLength;
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} else {
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result.push(
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Buffer.from(contentItem.buffer, contentItem.byteOffset, length)
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);
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contentPosition += length;
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length = 0;
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}
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}
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}
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}
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return result;
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};
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/**
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* @typedef {BufferSerializableType[]} DeserializedType
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* @typedef {true} SerializedType
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* @extends {SerializerMiddleware<DeserializedType, SerializedType>}
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*/
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class FileMiddleware extends SerializerMiddleware {
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/**
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* @param {IntermediateFileSystem} fs filesystem
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* @param {string | Hash} hashFunction hash function to use
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*/
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||
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constructor(fs, hashFunction = "md4") {
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super();
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this.fs = fs;
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this._hashFunction = hashFunction;
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}
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/**
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* @param {DeserializedType} data data
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* @param {Object} context context object
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* @returns {SerializedType|Promise<SerializedType>} serialized data
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*/
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serialize(data, context) {
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const { filename, extension = "" } = context;
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return new Promise((resolve, reject) => {
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mkdirp(this.fs, dirname(this.fs, filename), err => {
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if (err) return reject(err);
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// It's important that we don't touch existing files during serialization
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// because serialize may read existing files (when deserializing)
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const allWrittenFiles = new Set();
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const writeFile = async (name, content, size) => {
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const file = name
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? join(this.fs, filename, `../${name}${extension}`)
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: filename;
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await new Promise((resolve, reject) => {
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let stream = this.fs.createWriteStream(file + "_");
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let compression;
|
||
|
if (file.endsWith(".gz")) {
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compression = createGzip({
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|
chunkSize: COMPRESSION_CHUNK_SIZE,
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level: zConstants.Z_BEST_SPEED
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});
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} else if (file.endsWith(".br")) {
|
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|
compression = createBrotliCompress({
|
||
|
chunkSize: COMPRESSION_CHUNK_SIZE,
|
||
|
params: {
|
||
|
[zConstants.BROTLI_PARAM_MODE]: zConstants.BROTLI_MODE_TEXT,
|
||
|
[zConstants.BROTLI_PARAM_QUALITY]: 2,
|
||
|
[zConstants.BROTLI_PARAM_DISABLE_LITERAL_CONTEXT_MODELING]: true,
|
||
|
[zConstants.BROTLI_PARAM_SIZE_HINT]: size
|
||
|
}
|
||
|
});
|
||
|
}
|
||
|
if (compression) {
|
||
|
pipeline(compression, stream, reject);
|
||
|
stream = compression;
|
||
|
stream.on("finish", () => resolve());
|
||
|
} else {
|
||
|
stream.on("error", err => reject(err));
|
||
|
stream.on("finish", () => resolve());
|
||
|
}
|
||
|
// split into chunks for WRITE_LIMIT_CHUNK size
|
||
|
const chunks = [];
|
||
|
for (const b of content) {
|
||
|
if (b.length < WRITE_LIMIT_CHUNK) {
|
||
|
chunks.push(b);
|
||
|
} else {
|
||
|
for (let i = 0; i < b.length; i += WRITE_LIMIT_CHUNK) {
|
||
|
chunks.push(b.slice(i, i + WRITE_LIMIT_CHUNK));
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
const len = chunks.length;
|
||
|
let i = 0;
|
||
|
const batchWrite = err => {
|
||
|
// will be handled in "on" error handler
|
||
|
if (err) return;
|
||
|
|
||
|
if (i === len) {
|
||
|
stream.end();
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
// queue up a batch of chunks up to the write limit
|
||
|
// end is exclusive
|
||
|
let end = i;
|
||
|
let sum = chunks[end++].length;
|
||
|
while (end < len) {
|
||
|
sum += chunks[end].length;
|
||
|
if (sum > WRITE_LIMIT_TOTAL) break;
|
||
|
end++;
|
||
|
}
|
||
|
while (i < end - 1) {
|
||
|
stream.write(chunks[i++]);
|
||
|
}
|
||
|
stream.write(chunks[i++], batchWrite);
|
||
|
};
|
||
|
batchWrite();
|
||
|
});
|
||
|
if (name) allWrittenFiles.add(file);
|
||
|
};
|
||
|
|
||
|
resolve(
|
||
|
serialize(this, data, false, writeFile, this._hashFunction).then(
|
||
|
async ({ backgroundJob }) => {
|
||
|
await backgroundJob;
|
||
|
|
||
|
// Rename the index file to disallow access during inconsistent file state
|
||
|
await new Promise(resolve =>
|
||
|
this.fs.rename(filename, filename + ".old", err => {
|
||
|
resolve();
|
||
|
})
|
||
|
);
|
||
|
|
||
|
// update all written files
|
||
|
await Promise.all(
|
||
|
Array.from(
|
||
|
allWrittenFiles,
|
||
|
file =>
|
||
|
new Promise((resolve, reject) => {
|
||
|
this.fs.rename(file + "_", file, err => {
|
||
|
if (err) return reject(err);
|
||
|
resolve();
|
||
|
});
|
||
|
})
|
||
|
)
|
||
|
);
|
||
|
|
||
|
// As final step automatically update the index file to have a consistent pack again
|
||
|
await new Promise(resolve => {
|
||
|
this.fs.rename(filename + "_", filename, err => {
|
||
|
if (err) return reject(err);
|
||
|
resolve();
|
||
|
});
|
||
|
});
|
||
|
return /** @type {true} */ (true);
|
||
|
}
|
||
|
)
|
||
|
);
|
||
|
});
|
||
|
});
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* @param {SerializedType} data data
|
||
|
* @param {Object} context context object
|
||
|
* @returns {DeserializedType|Promise<DeserializedType>} deserialized data
|
||
|
*/
|
||
|
deserialize(data, context) {
|
||
|
const { filename, extension = "" } = context;
|
||
|
const readFile = name =>
|
||
|
new Promise((resolve, reject) => {
|
||
|
const file = name
|
||
|
? join(this.fs, filename, `../${name}${extension}`)
|
||
|
: filename;
|
||
|
this.fs.stat(file, (err, stats) => {
|
||
|
if (err) {
|
||
|
reject(err);
|
||
|
return;
|
||
|
}
|
||
|
let remaining = /** @type {number} */ (stats.size);
|
||
|
/** @type {Buffer | undefined} */
|
||
|
let currentBuffer;
|
||
|
/** @type {number | undefined} */
|
||
|
let currentBufferUsed;
|
||
|
const buf = [];
|
||
|
let decompression;
|
||
|
if (file.endsWith(".gz")) {
|
||
|
decompression = createGunzip({
|
||
|
chunkSize: DECOMPRESSION_CHUNK_SIZE
|
||
|
});
|
||
|
} else if (file.endsWith(".br")) {
|
||
|
decompression = createBrotliDecompress({
|
||
|
chunkSize: DECOMPRESSION_CHUNK_SIZE
|
||
|
});
|
||
|
}
|
||
|
if (decompression) {
|
||
|
let newResolve, newReject;
|
||
|
resolve(
|
||
|
Promise.all([
|
||
|
new Promise((rs, rj) => {
|
||
|
newResolve = rs;
|
||
|
newReject = rj;
|
||
|
}),
|
||
|
new Promise((resolve, reject) => {
|
||
|
decompression.on("data", chunk => buf.push(chunk));
|
||
|
decompression.on("end", () => resolve());
|
||
|
decompression.on("error", err => reject(err));
|
||
|
})
|
||
|
]).then(() => buf)
|
||
|
);
|
||
|
resolve = newResolve;
|
||
|
reject = newReject;
|
||
|
}
|
||
|
this.fs.open(file, "r", (err, fd) => {
|
||
|
if (err) {
|
||
|
reject(err);
|
||
|
return;
|
||
|
}
|
||
|
const read = () => {
|
||
|
if (currentBuffer === undefined) {
|
||
|
currentBuffer = Buffer.allocUnsafeSlow(
|
||
|
Math.min(
|
||
|
constants.MAX_LENGTH,
|
||
|
remaining,
|
||
|
decompression ? DECOMPRESSION_CHUNK_SIZE : Infinity
|
||
|
)
|
||
|
);
|
||
|
currentBufferUsed = 0;
|
||
|
}
|
||
|
let readBuffer = currentBuffer;
|
||
|
let readOffset = currentBufferUsed;
|
||
|
let readLength = currentBuffer.length - currentBufferUsed;
|
||
|
// values passed to fs.read must be valid int32 values
|
||
|
if (readOffset > 0x7fffffff) {
|
||
|
readBuffer = currentBuffer.slice(readOffset);
|
||
|
readOffset = 0;
|
||
|
}
|
||
|
if (readLength > 0x7fffffff) {
|
||
|
readLength = 0x7fffffff;
|
||
|
}
|
||
|
this.fs.read(
|
||
|
fd,
|
||
|
readBuffer,
|
||
|
readOffset,
|
||
|
readLength,
|
||
|
null,
|
||
|
(err, bytesRead) => {
|
||
|
if (err) {
|
||
|
this.fs.close(fd, () => {
|
||
|
reject(err);
|
||
|
});
|
||
|
return;
|
||
|
}
|
||
|
currentBufferUsed += bytesRead;
|
||
|
remaining -= bytesRead;
|
||
|
if (currentBufferUsed === currentBuffer.length) {
|
||
|
if (decompression) {
|
||
|
decompression.write(currentBuffer);
|
||
|
} else {
|
||
|
buf.push(currentBuffer);
|
||
|
}
|
||
|
currentBuffer = undefined;
|
||
|
if (remaining === 0) {
|
||
|
if (decompression) {
|
||
|
decompression.end();
|
||
|
}
|
||
|
this.fs.close(fd, err => {
|
||
|
if (err) {
|
||
|
reject(err);
|
||
|
return;
|
||
|
}
|
||
|
resolve(buf);
|
||
|
});
|
||
|
return;
|
||
|
}
|
||
|
}
|
||
|
read();
|
||
|
}
|
||
|
);
|
||
|
};
|
||
|
read();
|
||
|
});
|
||
|
});
|
||
|
});
|
||
|
return deserialize(this, false, readFile);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
module.exports = FileMiddleware;
|