0.6.1 • Published 6 years ago

nzyme v0.6.1

Weekly downloads
12
License
MIT
Repository
github
Last release
6 years ago

Nzyme • Transactional, Reactive, and Asynchronous State Management for JavaScript

Inspired by: MobX, Nezaboodka, React, Excel.

Introduction

Nzyme is a transactional, reactive, and asynchronous state management library for JavaScript that is designed to be extermely lightweight, easy, and fast.

Transactivity means that multiple objects can be changed at once with full respect to the all-or-nothing principle (atomicity, consistency, and isolation). Nzyme maintains separate data snapshot for each transaction. The snapshot is logical and doesn't create full copy of all the data. Intermediate state is visible only inside transaction itself, but is not visible outside of transaction until it is committed. Compensating actions are not needed in case of transaction failure, because all the changes made by transaction in its logical snapshot are simply discarded.

Reactivity means that recomputation of computable objects (observers) is triggered automatically upon changes in their dependencies (observables). All the dependencies between observers and their observables are detected and maintained automatically. It is achieved by injecting property getters/setters into all objects and tracking get/set calls during execution of observer computation. Affected observers are recomputed in a proper order at the end of a transaction, when all the changes are committed.

Asynchrony means that asynchronous operations are supported as first class citizens during transaction processing. Transaction may consist of a set of asynchronous operations and being committed upon completion of all them. Moreover, any asynchronous operation may spawn other asynchronous operations, which prolong transaction execution until whole the chain of asynchronous operations is fully completed.

Differentiators

  • Consistency and clarity are the first priorities
  • Transactional -- full-fledged atomicity, consistency, and isolation
  • Reactive -- automatic dependency tracking and fine-grained recomputation
  • Asynchronous -- transaction may consist of parallel and chained asynchronous operations
  • Historical -- built-in undo/redo functionality provided out of the box
  • Minimalistic -- it's a tool and approach, not a framework
  • Trivial -- implementation consists of less than 1000 lines of code

Demo

import { Nzyme, Transaction, tran, cache } from "nzyme";
import { Person } from "./person";

@tran
export class DemoApp {
  @tran title: string = "Demo";
  @tran users: Person[] = [];

  @tran
  loadUsers(): void {
    this.users.push(new Person({
      name: "John", age: 38,
      emails: ["john@mail.com"],
      children: [
        new Person({ name: "Billy" }), // William
        new Person({ name: "Barry" }), // Barry
        new Person({ name: "Steve" }), // Steven
      ],
    }));
    this.users.push(new Person({
      name: "Kevin", age: 27,
      emails: ["kevin@mail.com"],
      children: [
        new Person({ name: "Britney" }),
      ],
    }));
  }
}

@tran
export class DemoAppView {
  readonly model: DemoApp;
  @tran userFilter: string = "Jo";

  constructor(model: DemoApp) {
    this.model = model;
  }

  @cache
  filteredUsers(): Person[] {
    const m = this.model;
    let result: Person[] = m.users;
    if (this.userFilter.length > 0) {
      result = [];
      for (let x of m.users)
        if (x.name && x.name.indexOf(this.userFilter) === 0)
          result.push(x);
    }
    return result;
  }

  @cache
  render(): string[] {
    // Print only those users whos name starts with filter string
    let r: string[] = [];
    r.push("---");
    r.push(`Filter: ${this.userFilter}`);
    const a = this.filteredUsers();
    for (let x of a) {
      let childNames = x.children.map(child => child.name);
      r.push(`${x.name}'s children: ${childNames.join(", ")}`);
    }
    r.push("---");
    return r;
  }

  @cache
  autoprint(): void {
    this.render().forEach(x => console.log(x));
  }
}

export function sample(): void {
  // Simple actions (transactions)
  let app = new DemoApp();
  let view = new DemoAppView(app);
  try {
    app.loadUsers();
    Nzyme.autorenew(0, view.autoprint);
    // Multi-part transaction
    let t1 = new Transaction("t1");
    t1.run(() => {
      let daddy = app.users[0];
      daddy.age += 2; // causes no execution of DemoApp.render
      daddy.name = "John Smith"; // causes execution of DemoApp.render upon transaction end
      daddy.children[0].name = "Barry Smith";   // Barry
      daddy.children[1].name = "William Smith"; // Billy
      daddy.children[2].name = "Steven Smith";  // Steve
    });
    t1.run(() => {
      // daddy.age is 38 outside of t2 transaction, but is 40 inside t2
      let daddy = app.users[0];
      daddy.age += 5; // 40 + 5 = 45
      view.userFilter = "";
      if (daddy.emails)
        daddy.emails[0] = "daddy@mail.com";
      let x = daddy.children[1];
      x.parent = null;
      x.parent = daddy;
    });
    t1.commit(); // changes are applied, caches are invalidated/renewed
    // Protection from modification outside of a transaction
    try {
      let daddy = app.users[0];
      if (daddy.emails)
        daddy.emails.push("dad@mail.com");
      else
        daddy.children[1].name = "Billy Smithy";
    }
    catch (e) {
      console.log(`Expected: ${e}`);
    }
    // Turn off auto renew
    Nzyme.autorenew(-1, view.autoprint);
  }
  finally { // cleanup
    Nzyme.dispose(view);
    Nzyme.dispose(app);
  }
}

/* Console output:

#nz t11 ╔═══ v10 DemoApp.ctor
#nz t11 ║ M DemoApp#11t11: title, users
#nz t11 ╚═══ v11 DemoApp.ctor - COMMIT(1)
#nz t11  gc t11 (DemoApp.ctor)
#nz t11  gc DemoApp#11t10 is ready for GC (overwritten by DemoApp#11t11}
#nz t12 ╔═══ v11 DemoAppView.ctor
#nz t12 ║ M DemoAppView#12t12: userFilter
#nz t12 ╚═══ v12 DemoAppView.ctor - COMMIT(1)
#nz t12  gc t12 (DemoAppView.ctor)
#nz t12  gc DemoAppView#12t10 is ready for GC (overwritten by DemoAppView#12t12}
#nz t13 ╔═══ v12 DemoApp#11t10.loadUsers
#nz t13 ║ M DemoApp#11t13: users
#nz t13 ║ M Person#13t13: id, name, age, emails, log, _parent, _children
#nz t13 ║ M Person#14t13: id, name, age, emails, log, _parent, _children
#nz t13 ║ M Person#15t13: id, name, age, emails, log, _parent, _children
#nz t13 ║ M Person#16t13: id, name, age, emails, log, _parent, _children
#nz t13 ║ M Person#17t13: id, name, age, emails, log, _parent, _children
#nz t13 ║ M Person#18t13: id, name, age, emails, log, _parent, _children
#nz t13 ╚═══ v13 DemoApp#11t10.loadUsers - COMMIT(7)
#nz t13  gc t13 (DemoApp#11t10.loadUsers)
#nz t13  gc DemoApp#11t11 is ready for GC (overwritten by DemoApp#11t13}
#nz t13  gc Person#13t10 is ready for GC (overwritten by Person#13t13}
#nz t13  gc Person#14t10 is ready for GC (overwritten by Person#14t13}
#nz t13  gc Person#15t10 is ready for GC (overwritten by Person#15t13}
#nz t13  gc Person#16t10 is ready for GC (overwritten by Person#16t13}
#nz t13  gc Person#17t10 is ready for GC (overwritten by Person#17t13}
#nz t13  gc Person#18t10 is ready for GC (overwritten by Person#18t13}
#nz t14 ╔═══ v13 DemoAppView#12t10.autoprint
---
Filter: Jo
John's children: Billy, Barry, Steve
---
#nz t14 ║ M DemoAppView#12t14: filteredUsers, render, autoprint
#nz t14 ╚═══ v14 DemoAppView#12t10.autoprint - COMMIT(1)
#nz t14   ∞ DemoAppView#12t14.filteredUsers: #11t13.users, #12t14.userFilter, #16t13.name, #18t13.name
#nz t14   ∞ DemoAppView#12t14.render: #12t14.userFilter, #12t14.filteredUsers, #16t13._children, #13t13.name, #14t13.name, #15t13.name, #16t13.name
#nz t14   ∞ DemoAppView#12t14.autoprint: #12t14.render
#nz t14  gc t14 (DemoAppView#12t10.autoprint)
#nz t14  gc DemoAppView#12t12 is ready for GC (overwritten by DemoAppView#12t14}
#nz t15 ╔═══ v14 t1
#nz t15 ║ M Person#16t15: age, name, emails, _children
#nz t15 ║ M Person#13t15: name
#nz t15 ║ M Person#14t15: name
#nz t15 ║ M Person#15t15: name
#nz t15 ║ M DemoAppView#12t15: userFilter
#nz t15 ╚═══ v15 t1 - COMMIT(5)
#nz t15   x DemoAppView#12t14.filteredUsers is obsolete (by Person#16t15.name)
#nz t15   x DemoAppView#12t14.render is obsolete (by DemoAppView#12t14.filteredUsers)
#nz t15   x DemoAppView#12t14.autoprint is obsolete (by DemoAppView#12t14.render)
#nz t15   ■ DemoAppView#12t14.autoprint will be renewed automatically
#nz t15  gc t15 (t1)
#nz t15  gc Person#16t13 is ready for GC (overwritten by Person#16t15}
#nz t15  gc Person#13t13 is ready for GC (overwritten by Person#13t15}
#nz t15  gc Person#14t13 is ready for GC (overwritten by Person#14t15}
#nz t15  gc Person#15t13 is ready for GC (overwritten by Person#15t15}
#nz t15  gc DemoAppView#12t14 is ready for GC (overwritten by DemoAppView#12t15}
#nz t16 ╔═══ v15 DemoAppView#12t14.autoprint
---
Filter:
John Smith's children: Barry Smith, Steven Smith, William Smith
Kevin's children: Britney
---
#nz t16 ║ M DemoAppView#12t16: filteredUsers, render, autoprint
#nz t16 ╚═══ v16 DemoAppView#12t14.autoprint - COMMIT(1)
#nz t16   ∞ DemoAppView#12t16.filteredUsers: #11t13.users, #12t16.userFilter
#nz t16   ∞ DemoAppView#12t16.render: #12t16.userFilter, #12t16.filteredUsers, #16t15._children, #18t13._children, #13t15.name, #15t15.name, #14t15.name, #16t15.name, #17t13.name, #18t13.name
#nz t16   ∞ DemoAppView#12t16.autoprint: #12t16.render
#nz t16  gc t16 (DemoAppView#12t14.autoprint)
#nz t16  gc DemoAppView#12t15 is ready for GC (overwritten by DemoAppView#12t16}
Expected: Error: E609: object cannot be changed outside of transaction
#nz t17 ╔═══ v16 DemoAppView#12.dtor
#nz t17 ║ M DemoAppView#12t17: Symbol(dtor)
#nz t17 ╚═══ v17 DemoAppView#12.dtor - COMMIT(1)
#nz t17   x DemoAppView#12t16.filteredUsers is obsolete (by DemoAppView#12t17.userFilter)
#nz t17   x DemoAppView#12t16.render is obsolete (by DemoAppView#12t16.filteredUsers)
#nz t17   x DemoAppView#12t16.autoprint is obsolete (by DemoAppView#12t16.render)
#nz t17  gc t17 (DemoAppView#12.dtor)
#nz t17  gc DemoAppView#12t16 is ready for GC (overwritten by DemoAppView#12t17}
#nz t18 ╔═══ v17 DemoApp#11.dtor
#nz t18 ║ M DemoApp#11t18: Symbol(dtor)
#nz t18 ╚═══ v18 DemoApp#11.dtor - COMMIT(1)
#nz t18  gc t18 (DemoApp#11.dtor)
#nz t18  gc DemoApp#11t13 is ready for GC (overwritten by DemoApp#11t18}

*/

Async Demo

import { Nzyme, tran, cache } from "nzyme";
import { setTimeout } from "timers";
import fetch from "node-fetch";

@tran
export class DemoApp {
  @tran title: string = "Demo";
  @tran items: string[] = [];

  @tran
  async download(url: string, delay: number): Promise<void> {
    this.title = "Demo (" + new Date().toISOString() + ")";
    let start = Date.now();
    await all([fetch(url), sleep(delay)]);
    let ms = Date.now() - start;
    this.items.push(`${url} in ${ms} ms`);
  }
}

export class DemoAppView {
  readonly model: DemoApp;

  constructor(model: DemoApp) {
    this.model = model;
  }

  @cache
  async render(): Promise<string[]> {
    let r: string[] = [];
    r.push("---");
    r.push("Title: " + this.model.title);
    await sleep(1000);
    r.push("Items: ");
    for (let x of this.model.items)
      r.push(" - " + x);
    r.push("---");
    return r;
  }

  @cache
  async autoprint(): Promise<void> {
    let lines: string[] = await this.render();
    lines.forEach(x => console.log(x));
  }
}

export async function sample(): Promise<void> {
  let app = new DemoApp();
  let view = new DemoAppView(app);
  try {
    Nzyme.autorenew(0, view.autoprint);
    let list: Array<{ url: string, delay: number }> = [
      { url: "https://nezaboodka.com", delay: 700 },
      { url: "https://google.com", delay: 2000 },
      { url: "https://microsoft.com", delay: 700 },
    ];
    await all(list.map(x => app.download(x.url, x.delay)));
    Nzyme.autorenew(-1, view.autoprint);
  }
  catch (error) {
    console.log(`${error}`);
  }
  finally {
    Nzyme.dispose(view);
    Nzyme.dispose(app);
  }
}

async function sleep(timeout: number): Promise<void> {
  return new Promise<void>(function(resolve) {
    setTimeout(resolve.bind(null, () => resolve), timeout);
  });
}

async function all(promises: Array<Promise<any>>): Promise<any[]> {
  let error: any;
  let result = await Promise.all(promises.map(x => x.catch(e => { error = error || e; return e; })));
  if (error)
    throw error;
  return result;
}

/* Console output:

#nz t19 ╔═══ v18 DemoApp.ctor
#nz t19 ║ M DemoApp#19t19: title, items
#nz t19 ╚═══ v19 DemoApp.ctor - COMMIT(1)
#nz t19  gc t19 (DemoApp.ctor)
#nz t19  gc DemoApp#19t10 is ready for GC (overwritten by DemoApp#19t19}
#nz t20 ╔═══ v19 DemoAppView#20t10.autoprint
#nz t21 ╔═══ v19 DemoApp#19t10.download
#nz t22 ╔═══ v19 DemoApp#19t10.download
#nz t23 ╔═══ v19 DemoApp#19t10.download
#nz t21 ║ M DemoApp#19t21: title, items
#nz t21 ╚═══ v20 DemoApp#19t10.download - COMMIT(1)
#nz t23 ║ M DemoApp#19t23: title, items
#nz t23 ╚═══ v19 DemoApp#19t10.download - DISCARD(1) - Error: DemoApp#19t10.download conflicts with other transactions on: DemoApp#19t21.title, DemoApp#19t21.items
---
Title: Demo
Items:
---
#nz t20 ║ M DemoAppView#20t20: render, autoprint
#nz t20 ╚═══ v21 DemoAppView#20t10.autoprint - COMMIT(1)
#nz t20   ∞ DemoAppView#20t20.render: #19t19.title, #19t19.items
#nz t20   x DemoAppView#20t20.render is obsolete (by DemoApp#19t19.title)
#nz t20   ∞ DemoAppView#20t20.autoprint: #20t20.render
#nz t20   x DemoAppView#20t20.autoprint is obsolete (by DemoAppView#20t20.render)
#nz t20   ■ DemoAppView#20t20.autoprint will be renewed automatically
#nz t20  gc t20 (DemoAppView#20t10.autoprint)
#nz t20  gc DemoAppView#20t10 is ready for GC (overwritten by DemoAppView#20t20}
#nz t20  gc t21 (DemoApp#19t10.download)
#nz t20  gc DemoApp#19t19 is ready for GC (overwritten by DemoApp#19t21}
#nz t24 ╔═══ v21 DemoAppView#20t20.autoprint
#nz t22 ║ M DemoApp#19t22: title, items
#nz t22 ╚═══ v19 DemoApp#19t10.download - DISCARD(1) - Error: DemoApp#19t10.download conflicts with other transactions on: DemoApp#19t21.title, DemoApp#19t21.items
Error: DemoApp#19t10.download conflicts with other transactions on: DemoApp#19t21.title, DemoApp#19t21.items
#nz t25 ╔═══ v21 DemoAppView#20.dtor
#nz t25 ║ M DemoAppView#20t25: Symbol(dtor)
#nz t25 ╚═══ v22 DemoAppView#20.dtor - COMMIT(1)
#nz t26 ╔═══ v22 DemoApp#19.dtor
#nz t26 ║ M DemoApp#19t26: Symbol(dtor)
#nz t26 ╚═══ v23 DemoApp#19.dtor - COMMIT(1)
---
Title: Demo (2018-10-10T19:48:33.195Z)
Items:
 - https://nezaboodka.com in 722 ms
---
#nz t24 ║ M DemoAppView#20t24: render, autoprint
#nz t24 ╚═══ v21 DemoAppView#20t20.autoprint - DISCARD(1) - Error: DemoAppView#20t20.autoprint conflicts with other transactions on: DemoAppView#20t25.render, DemoAppView#20t25.autoprint
#nz t24  gc t25 (DemoAppView#20.dtor)
#nz t24  gc DemoAppView#20t20 is ready for GC (overwritten by DemoAppView#20t25}
#nz t24  gc t26 (DemoApp#19.dtor)
#nz t24  gc DemoApp#19t21 is ready for GC (overwritten by DemoApp#19t26}

*/

API (TypeScript)

// Decorators

export type F<T> = (...args: any[]) => T;
export function tran(target: object, prop?: string, descriptor?: TypedPropertyDescriptor<F<any>>): any;
export function cache(target: Object, prop: string, descriptor: TypedPropertyDescriptor<F<any>>): any;

// Control functions

export interface Status { value: any; obsolete: boolean; error: any; latency: number; }
export class Nzyme {
  statusof(method: F<any>): Status;
  autorenew(latency: number, method: F<any>, ...args: any[]): void;
  dispose(obj: object | undefined): void;
}
  
// Transaction

export class Transaction {
  constructor(hint?: string);
  run<T>(func: F<T>, ...args: any[]): T;
  wrap<T>(func: F<T>): F<T>;
  commit(): void;
  sealToCommit(): Transaction; // t1.sealToCommit().waitForFinish().then(fulfill, reject)
  discard(error?: any): Transaction; // t1.sealToCommit().waitForFinish().then(...)
  waitForFinish(): Promise<void>;
  finished(): boolean;
  static run<T>(hint: string, func: F<T>, ...args: any[]): T;
  static async runAsync<T>(hint: string, func: F<Promise<T>>, ...args: any[]): Promise<T>;
  static get current(): Transaction;
}
nzyme
node-fetch
@infinitebrahmanuniverse/nolb-nz@everything-registry/sub-chunk-2362@zalastax/nolb-nz
0.6.1

6 years ago

0.6.0

6 years ago