rvx/dist/rvx.store.js

A signal based rendering library

/*!
MIT License

Copyright (c) 2025 Max J. Polster

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
import { Signal, isTracking, batch, $, watchUpdates } from './rvx.js';

class ProbeSignal extends Signal {
	#onDisposable;
	constructor(onDisposable, value) {
		super(value);
		this.#onDisposable = onDisposable;
	}
	notify() {
		super.notify();
		if (!this.active) {
			this.#onDisposable();
		}
	}
}
class ProbeMap {
	#probes = new Map();
	#get;
	constructor(get) {
		this.#get = get;
	}
	access(key) {
		if (isTracking()) {
			let probe = this.#probes.get(key);
			if (probe === undefined) {
				probe = new ProbeSignal(() => this.#probes.delete(key), this.#get(key));
				this.#probes.set(key, probe);
			}
			probe.access();
		}
	}
	update(key, value) {
		const probe = this.#probes.get(key);
		if (probe !== undefined) {
			probe.value = value;
		}
	}
	fill(value) {
		for (const probe of this.#probes.values()) {
			probe.value = value;
		}
	}
}

function createReactiveArrayProxy(target, barrier) {
	const length = $(target.length);
	const indexProbes = new ProbeMap(i => target[i]);
	return new Proxy(target, {
		get(target, prop, recv) {
			if (prop === "length") {
				length.access();
				return target.length;
			}
			const index = asCanonicalIndex(prop);
			if (index !== undefined) {
				indexProbes.access(index);
				return barrier.wrap(target[index]);
			}
			if (Object.hasOwn(replacements, prop)) {
				return replacements[prop];
			}
			return Reflect.get(target, prop, recv);
		},
		set(target, prop, value, recv) {
			if (prop === "length") {
				batch(() => {
					const previous = target.length;
					target.length = value;
					for (let i = previous; i >= target.length; i--) {
						indexProbes.update(i, undefined);
					}
					length.value = Number(value);
				});
				return true;
			}
			const index = asCanonicalIndex(prop);
			if (index !== undefined) {
				batch(() => {
					value = barrier.unwrap(value);
					target[index] = value;
					indexProbes.update(index, value);
				});
				return true;
			}
			return Reflect.set(target, prop, value, recv);
		},
		has(target, prop) {
			const cIndex = asCanonicalIndex(prop);
			if (cIndex !== undefined) {
				indexProbes.access(cIndex);
				return cIndex in target;
			}
			return Reflect.has(target, prop);
		},
		deleteProperty(target, prop) {
			const index = asCanonicalIndex(prop);
			if (index !== undefined) {
				batch(() => {
					delete target[index];
					indexProbes.update(index, undefined);
				});
				return true;
			}
			return Reflect.deleteProperty(target, prop);
		},
		ownKeys(target) {
			if (isTracking()) {
				length.access();
				for (let i = 0; i < target.length; i++) {
					indexProbes.access(i);
				}
			}
			return Reflect.ownKeys(target);
		},
	});
}
const replacements = Object.create(null);
for (const key of [
	"copyWithin",
	"fill",
	"pop",
	"push",
	"reverse",
	"shift",
	"sort",
	"splice",
	"unshift",
]) {
	replacements[key] = function (...args) {
		return batch(() => {
			return Array.prototype[key].call(this, ...args);
		});
	};
}
function asCanonicalIndex(value) {
	if (typeof value === "symbol") {
		return undefined;
	}
	const index = Number(value);
	if (Number.isSafeInteger(index) && index >= 0 && index <= 0xFFFFFFFF) {
		return index;
	}
	return undefined;
}

class ReactiveMap extends Map {
	#target;
	#barrier;
	#size;
	#iterators;
	#getProbes;
	#hasProbes;
	constructor(target, barrier) {
		super();
		this.#target = target;
		this.#barrier = barrier;
		this.#size = $(target.size);
		this.#iterators = $();
		this.#getProbes = new ProbeMap(key => target.get(key));
		this.#hasProbes = new ProbeMap(key => target.has(key));
	}
	get size() {
		this.#size.access();
		return this.#target.size;
	}
	get(key) {
		this.#getProbes.access(key);
		return this.#barrier.wrap(this.#target.get(key));
	}
	has(key) {
		this.#hasProbes.access(key);
		return this.#target.has(key);
	}
	set(key, value) {
		batch(() => {
			value = this.#barrier.unwrap(value);
			this.#target.set(key, value);
			this.#size.value = this.#target.size;
			this.#iterators.notify();
			this.#getProbes.update(key, value);
			this.#hasProbes.update(key, true);
		});
		return this;
	}
	delete(key) {
		return batch(() => {
			const deleted = this.#target.delete(key);
			if (deleted) {
				this.#size.value = this.#target.size;
				this.#iterators.notify();
				this.#getProbes.update(key, undefined);
				this.#hasProbes.update(key, false);
			}
			return deleted;
		});
	}
	clear() {
		batch(() => {
			this.#target.clear();
			this.#size.value = 0;
			this.#iterators.notify();
			this.#getProbes.fill(undefined);
			this.#hasProbes.fill(false);
		});
	}
	*entries() {
		this.#iterators.access();
		for (const entry of this.#target.entries()) {
			yield [entry[0], this.#barrier.wrap(entry[1])];
		}
	}
	keys() {
		this.#iterators.access();
		return this.#target.keys();
	}
	*values() {
		this.#iterators.access();
		for (const entry of this.#target.values()) {
			yield this.#barrier.wrap(entry);
		}
	}
	forEach(callback, thisArg) {
		this.#iterators.access();
		return this.#target.forEach((value, key) => callback.call(thisArg, this.#barrier.wrap(value), key, this));
	}
	*[Symbol.iterator]() {
		this.#iterators.access();
		for (const entry of this.#target.entries()) {
			yield [entry[0], this.#barrier.wrap(entry[1])];
		}
	}
	get [Symbol.toStringTag]() {
		return this.#target[Symbol.toStringTag];
	}
}

function createReactiveProxy(target, barrier) {
	const iterators = $();
	const getProbes = new ProbeMap(key => target[key]);
	const hasProbes = new ProbeMap(key => key in target);
	const proto = Object.getPrototypeOf(target);
	function isReactive(prop) {
		if (proto !== null && prop in proto) {
			return false;
		}
		return true;
	}
	return new Proxy(target, {
		get(target, prop, recv) {
			if (isReactive(prop)) {
				getProbes.access(prop);
			}
			return barrier.wrap(Reflect.get(target, prop, recv));
		},
		has(target, prop) {
			if (isReactive(prop)) {
				hasProbes.access(prop);
			}
			return Reflect.has(target, prop);
		},
		set(target, prop, value, recv) {
			value = barrier.unwrap(value);
			if (isReactive(prop)) {
				return batch(() => {
					const ok = Reflect.set(target, prop, value, recv);
					if (ok) {
						iterators.notify();
						getProbes.update(prop, value);
						hasProbes.update(prop, true);
					}
					return ok;
				});
			}
			return Reflect.set(target, prop, value, recv);
		},
		deleteProperty(target, prop) {
			return batch(() => {
				const ok = Reflect.deleteProperty(target, prop);
				if (ok && isReactive(prop)) {
					iterators.notify();
					getProbes.update(prop, undefined);
					hasProbes.update(prop, false);
				}
				return ok;
			});
		},
		ownKeys(target) {
			iterators.access();
			return Reflect.ownKeys(target);
		},
	});
}

class ReactiveSet extends Set {
	#target;
	#barrier;
	#size;
	#iterators;
	#probes;
	constructor(target, barrier) {
		super();
		this.#target = target;
		this.#barrier = barrier;
		this.#size = $(target.size);
		this.#iterators = $();
		this.#probes = new ProbeMap(key => target.has(key));
	}
	get size() {
		this.#size.access();
		return this.#target.size;
	}
	has(value) {
		value = this.#barrier.unwrap(value);
		this.#probes.access(value);
		return this.#target.has(value);
	}
	add(value) {
		batch(() => {
			value = this.#barrier.unwrap(value);
			this.#target.add(value);
			this.#size.value = this.#target.size;
			this.#iterators.notify();
			this.#probes.update(value, true);
		});
		return this;
	}
	delete(value) {
		return batch(() => {
			value = this.#barrier.unwrap(value);
			const deleted = this.#target.delete(value);
			if (deleted) {
				this.#size.value = this.#target.size;
				this.#iterators.notify();
				this.#probes.update(value, false);
			}
			return deleted;
		});
	}
	clear() {
		batch(() => {
			this.#target.clear();
			this.#size.value = 0;
			this.#iterators.notify();
			this.#probes.fill(false);
		});
	}
	*entries() {
		this.#iterators.access();
		for (const entry of this.#target.entries()) {
			const value = this.#barrier.wrap(entry[0]);
			yield [value, value];
		}
	}
	*keys() {
		this.#iterators.access();
		for (const key of this.#target.keys()) {
			yield this.#barrier.wrap(key);
		}
	}
	*values() {
		this.#iterators.access();
		for (const value of this.#target.values()) {
			yield this.#barrier.wrap(value);
		}
	}
	forEach(callback, thisArg) {
		this.#iterators.access();
		return this.#target.forEach(value => {
			value = this.#barrier.wrap(value);
			callback.call(thisArg, value, value, this);
		}, thisArg);
	}
	*[Symbol.iterator]() {
		this.#iterators.access();
		for (const value of this.#target) {
			yield this.#barrier.wrap(value);
		}
	}
	get [Symbol.toStringTag]() {
		return this.#target[Symbol.toStringTag];
	}
}

const WRAP_INSTANCE = Symbol.for("rvx:store:wrap_instance");
const WRAPPERS = new WeakMap();
const TARGETS = new WeakMap();
const BARRIER = { wrap, unwrap };
function wrap(value) {
	if (value !== null && typeof value === "object") {
		if (TARGETS.has(value)) {
			return value;
		}
		let wrapper = WRAPPERS.get(value);
		if (wrapper !== undefined) {
			return wrapper;
		}
		const ctor = value.constructor;
		const wrapInstance = ctor[WRAP_INSTANCE];
		if (wrapInstance) {
			wrapper = wrapInstance(value);
		}
		else {
			const proto = Object.getPrototypeOf(value);
			switch (proto) {
				case Object.prototype:
					wrapper = createReactiveProxy(value, BARRIER);
					break;
				case Array.prototype:
					wrapper = createReactiveArrayProxy(value, BARRIER);
					break;
				case Map.prototype:
					wrapper = new ReactiveMap(value, BARRIER);
					break;
				case Set.prototype:
					wrapper = new ReactiveSet(value, BARRIER);
					break;
				default:
					return value;
			}
		}
		WRAPPERS.set(value, wrapper);
		TARGETS.set(wrapper, value);
		return wrapper;
	}
	return value;
}
function unwrap(value) {
	if (value !== null && typeof value === "object") {
		const target = TARGETS.get(value);
		if (target !== undefined) {
			return target;
		}
	}
	return value;
}
function defaultWrapInstance(value) {
	return createReactiveProxy(value, BARRIER);
}
function wrapInstancesOf(targetClass, wrap) {
	Object.defineProperty(targetClass, WRAP_INSTANCE, {
		configurable: true,
		enumerable: false,
		writable: false,
		value: wrap ?? defaultWrapInstance,
	});
}

function reflect(target, key) {
	const prop = $(watchUpdates(() => target[key], value => prop.value = value));
	watchUpdates(prop, value => target[key] = value);
	return prop;
}

export { BARRIER, ProbeMap, ProbeSignal, ReactiveMap, ReactiveSet, createReactiveArrayProxy, createReactiveProxy, reflect, unwrap, wrap, wrapInstancesOf };