Skip to content
Permalink
9bfb9ba527
Switch branches/tags

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?
Go to file
 
 
Cannot retrieve contributors at this time
477 lines (430 sloc) 12.6 KB
/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Tobias Koppers @sokra
*/
"use strict";
const nextTick = require("process").nextTick;
/** @typedef {import("./Resolver").FileSystem} FileSystem */
/** @typedef {import("./Resolver").SyncFileSystem} SyncFileSystem */
const dirname = path => {
let idx = path.length - 1;
while (idx >= 0) {
const c = path.charCodeAt(idx);
// slash or backslash
if (c === 47 || c === 92) break;
idx--;
}
if (idx < 0) return "";
return path.slice(0, idx);
};
const runCallbacks = (callbacks, err, result) => {
if (callbacks.length === 1) {
callbacks[0](err, result);
callbacks.length = 0;
return;
}
let error;
for (const callback of callbacks) {
try {
callback(err, result);
} catch (e) {
if (!error) error = e;
}
}
callbacks.length = 0;
if (error) throw error;
};
class OperationMergerBackend {
/**
* @param {any} provider async method
* @param {any} syncProvider sync method
* @param {any} providerContext call context for the provider methods
*/
constructor(provider, syncProvider, providerContext) {
this._provider = provider;
this._syncProvider = syncProvider;
this._providerContext = providerContext;
this._activeAsyncOperations = new Map();
this.provide = this._provider
? (path, options, callback) => {
if (typeof options === "function") {
callback = options;
options = undefined;
}
if (options) {
return this._provider.call(
this._providerContext,
path,
options,
callback
);
}
if (typeof path !== "string") {
callback(new TypeError("path must be a string"));
return;
}
let callbacks = this._activeAsyncOperations.get(path);
if (callbacks) {
callbacks.push(callback);
return;
}
this._activeAsyncOperations.set(path, (callbacks = [callback]));
provider(path, (err, result) => {
this._activeAsyncOperations.delete(path);
runCallbacks(callbacks, err, result);
});
}
: null;
this.provideSync = this._syncProvider
? (path, options) => {
return this._syncProvider.call(this._providerContext, path, options);
}
: null;
}
purge() {}
purgeParent() {}
}
/*
IDLE:
insert data: goto SYNC
SYNC:
before provide: run ticks
event loop tick: goto ASYNC_ACTIVE
ASYNC:
timeout: run tick, goto ASYNC_PASSIVE
ASYNC_PASSIVE:
before provide: run ticks
IDLE --[insert data]--> SYNC --[event loop tick]--> ASYNC_ACTIVE --[interval tick]-> ASYNC_PASSIVE
^ |
+---------[insert data]-------+
*/
const STORAGE_MODE_IDLE = 0;
const STORAGE_MODE_SYNC = 1;
const STORAGE_MODE_ASYNC = 2;
class CacheBackend {
/**
* @param {number} duration max cache duration of items
* @param {any} provider async method
* @param {any} syncProvider sync method
* @param {any} providerContext call context for the provider methods
*/
constructor(duration, provider, syncProvider, providerContext) {
this._duration = duration;
this._provider = provider;
this._syncProvider = syncProvider;
this._providerContext = providerContext;
/** @type {Map<string, (function(Error, any): void)[]>} */
this._activeAsyncOperations = new Map();
/** @type {Map<string, { err: Error, result: any, level: Set<string> }>} */
this._data = new Map();
/** @type {Set<string>[]} */
this._levels = [];
for (let i = 0; i < 10; i++) this._levels.push(new Set());
for (let i = 5000; i < duration; i += 500) this._levels.push(new Set());
this._currentLevel = 0;
this._tickInterval = Math.floor(duration / this._levels.length);
/** @type {STORAGE_MODE_IDLE | STORAGE_MODE_SYNC | STORAGE_MODE_ASYNC} */
this._mode = STORAGE_MODE_IDLE;
/** @type {NodeJS.Timeout | undefined} */
this._timeout = undefined;
/** @type {number | undefined} */
this._nextDecay = undefined;
this.provide = provider ? this.provide.bind(this) : null;
this.provideSync = syncProvider ? this.provideSync.bind(this) : null;
}
provide(path, options, callback) {
if (typeof options === "function") {
callback = options;
options = undefined;
}
if (typeof path !== "string") {
callback(new TypeError("path must be a string"));
return;
}
if (options) {
return this._provider.call(
this._providerContext,
path,
options,
callback
);
}
// When in sync mode we can move to async mode
if (this._mode === STORAGE_MODE_SYNC) {
this._enterAsyncMode();
}
// Check in cache
let cacheEntry = this._data.get(path);
if (cacheEntry !== undefined) {
if (cacheEntry.err) return nextTick(callback, cacheEntry.err);
return nextTick(callback, null, cacheEntry.result);
}
// Check if there is already the same operation running
let callbacks = this._activeAsyncOperations.get(path);
if (callbacks !== undefined) {
callbacks.push(callback);
return;
}
this._activeAsyncOperations.set(path, (callbacks = [callback]));
// Run the operation
this._provider.call(this._providerContext, path, (err, result) => {
this._activeAsyncOperations.delete(path);
this._storeResult(path, err, result);
// Enter async mode if not yet done
this._enterAsyncMode();
runCallbacks(callbacks, err, result);
});
}
provideSync(path, options) {
if (typeof path !== "string") {
throw new TypeError("path must be a string");
}
if (options) {
return this._syncProvider.call(this._providerContext, path, options);
}
// In sync mode we may have to decay some cache items
if (this._mode === STORAGE_MODE_SYNC) {
this._runDecays();
}
// Check in cache
let cacheEntry = this._data.get(path);
if (cacheEntry !== undefined) {
if (cacheEntry.err) throw cacheEntry.err;
return cacheEntry.result;
}
// Get all active async operations
// This sync operation will also complete them
const callbacks = this._activeAsyncOperations.get(path);
this._activeAsyncOperations.delete(path);
// Run the operation
// When in idle mode, we will enter sync mode
let result;
try {
result = this._syncProvider.call(this._providerContext, path);
} catch (err) {
this._storeResult(path, err, undefined);
this._enterSyncModeWhenIdle();
if (callbacks) runCallbacks(callbacks, err, undefined);
throw err;
}
this._storeResult(path, undefined, result);
this._enterSyncModeWhenIdle();
if (callbacks) runCallbacks(callbacks, undefined, result);
return result;
}
purge(what) {
if (!what) {
if (this._mode !== STORAGE_MODE_IDLE) {
this._data.clear();
for (const level of this._levels) {
level.clear();
}
this._enterIdleMode();
}
} else if (typeof what === "string") {
for (let [key, data] of this._data) {
if (key.startsWith(what)) {
this._data.delete(key);
data.level.delete(key);
}
}
if (this._data.size === 0) {
this._enterIdleMode();
}
} else {
for (let [key, data] of this._data) {
for (const item of what) {
if (key.startsWith(item)) {
this._data.delete(key);
data.level.delete(key);
break;
}
}
}
if (this._data.size === 0) {
this._enterIdleMode();
}
}
}
purgeParent(what) {
if (!what) {
this.purge();
} else if (typeof what === "string") {
this.purge(dirname(what));
} else {
const set = new Set();
for (const item of what) {
set.add(dirname(item));
}
this.purge(set);
}
}
_storeResult(path, err, result) {
if (this._data.has(path)) return;
const level = this._levels[this._currentLevel];
this._data.set(path, { err, result, level });
level.add(path);
}
_decayLevel() {
const nextLevel = (this._currentLevel + 1) % this._levels.length;
const decay = this._levels[nextLevel];
this._currentLevel = nextLevel;
for (let item of decay) {
this._data.delete(item);
}
decay.clear();
if (this._data.size === 0) {
this._enterIdleMode();
} else {
// @ts-ignore _nextDecay is always a number in sync mode
this._nextDecay += this._tickInterval;
}
}
_runDecays() {
while (
/** @type {number} */ (this._nextDecay) <= Date.now() &&
this._mode !== STORAGE_MODE_IDLE
) {
this._decayLevel();
}
}
_enterAsyncMode() {
let timeout = 0;
switch (this._mode) {
case STORAGE_MODE_ASYNC:
return;
case STORAGE_MODE_IDLE:
this._nextDecay = Date.now() + this._tickInterval;
timeout = this._tickInterval;
break;
case STORAGE_MODE_SYNC:
this._runDecays();
// @ts-ignore _runDecays may change the mode
if (this._mode === STORAGE_MODE_IDLE) return;
timeout = Math.max(
0,
/** @type {number} */ (this._nextDecay) - Date.now()
);
break;
}
this._mode = STORAGE_MODE_ASYNC;
const ref = setTimeout(() => {
this._mode = STORAGE_MODE_SYNC;
this._runDecays();
}, timeout);
if (ref.unref) ref.unref();
this._timeout = ref;
}
_enterSyncModeWhenIdle() {
if (this._mode === STORAGE_MODE_IDLE) {
this._mode = STORAGE_MODE_SYNC;
this._nextDecay = Date.now() + this._tickInterval;
}
}
_enterIdleMode() {
this._mode = STORAGE_MODE_IDLE;
this._nextDecay = undefined;
if (this._timeout) clearTimeout(this._timeout);
}
}
const createBackend = (duration, provider, syncProvider, providerContext) => {
if (duration > 0) {
return new CacheBackend(duration, provider, syncProvider, providerContext);
}
return new OperationMergerBackend(provider, syncProvider, providerContext);
};
module.exports = class CachedInputFileSystem {
constructor(fileSystem, duration) {
this.fileSystem = fileSystem;
this._lstatBackend = createBackend(
duration,
this.fileSystem.lstat,
this.fileSystem.lstatSync,
this.fileSystem
);
const lstat = this._lstatBackend.provide;
this.lstat = /** @type {FileSystem["lstat"]} */ (lstat);
const lstatSync = this._lstatBackend.provideSync;
this.lstatSync = /** @type {SyncFileSystem["lstatSync"]} */ (lstatSync);
this._statBackend = createBackend(
duration,
this.fileSystem.stat,
this.fileSystem.statSync,
this.fileSystem
);
const stat = this._statBackend.provide;
this.stat = /** @type {FileSystem["stat"]} */ (stat);
const statSync = this._statBackend.provideSync;
this.statSync = /** @type {SyncFileSystem["statSync"]} */ (statSync);
this._readdirBackend = createBackend(
duration,
this.fileSystem.readdir,
this.fileSystem.readdirSync,
this.fileSystem
);
const readdir = this._readdirBackend.provide;
this.readdir = /** @type {FileSystem["readdir"]} */ (readdir);
const readdirSync = this._readdirBackend.provideSync;
this.readdirSync = /** @type {SyncFileSystem["readdirSync"]} */ (readdirSync);
this._readFileBackend = createBackend(
duration,
this.fileSystem.readFile,
this.fileSystem.readFileSync,
this.fileSystem
);
const readFile = this._readFileBackend.provide;
this.readFile = /** @type {FileSystem["readFile"]} */ (readFile);
const readFileSync = this._readFileBackend.provideSync;
this.readFileSync = /** @type {SyncFileSystem["readFileSync"]} */ (readFileSync);
this._readJsonBackend = createBackend(
duration,
this.fileSystem.readJson ||
(this.readFile &&
((path, callback) => {
// @ts-ignore
this.readFile(path, (err, buffer) => {
if (err) return callback(err);
if (!buffer || buffer.length === 0)
return callback(new Error("No file content"));
let data;
try {
data = JSON.parse(buffer.toString("utf-8"));
} catch (e) {
return callback(e);
}
callback(null, data);
});
})),
this.fileSystem.readJsonSync ||
(this.readFileSync &&
(path => {
const buffer = this.readFileSync(path);
const data = JSON.parse(buffer.toString("utf-8"));
return data;
})),
this.fileSystem
);
const readJson = this._readJsonBackend.provide;
this.readJson = /** @type {FileSystem["readJson"]} */ (readJson);
const readJsonSync = this._readJsonBackend.provideSync;
this.readJsonSync = /** @type {SyncFileSystem["readJsonSync"]} */ (readJsonSync);
this._readlinkBackend = createBackend(
duration,
this.fileSystem.readlink,
this.fileSystem.readlinkSync,
this.fileSystem
);
const readlink = this._readlinkBackend.provide;
this.readlink = /** @type {FileSystem["readlink"]} */ (readlink);
const readlinkSync = this._readlinkBackend.provideSync;
this.readlinkSync = /** @type {SyncFileSystem["readlinkSync"]} */ (readlinkSync);
}
purge(what) {
this._statBackend.purge(what);
this._lstatBackend.purge(what);
this._readdirBackend.purgeParent(what);
this._readFileBackend.purge(what);
this._readlinkBackend.purge(what);
this._readJsonBackend.purge(what);
}
};