Create immutable storage

src/app/app.component.ts

@@ -1,5 +1,6 @@
 import { Component } from '@angular/core';
-import { ModalService } from './services/modal.service';
+import { Cloneable } from './storage/cloneable';
+import { Root } from './storage/root';
 
 @Component({
   selector: 'app-root',
@@ -8,4 +9,19 @@ import { ModalService } from './services/modal.service';
 })
 export class AppComponent {
   title = 'frontend';
+
+  constructor() {
+    const root = new Root<Cloneable>();
+
+    const l1 = new Cloneable(root, 'l1');
+    const r1 = new Cloneable(root, 'r1');
+    const r1r1 = new Cloneable(r1, 'r1r1');
+    const r1l1 = new Cloneable(r1, 'r1l1');
+
+    r1r1.changeName('r1r1 new');
+
+    r1l1.changeName('r1l1 new');
+
+    r1l1.map((c: Cloneable) => c.changeNameMap('bdeiwf'));
+  }
 }

src/app/model/base.ts

@@ -1,7 +1,11 @@
+import { Subject } from 'rxjs/internal/Subject';
+
 export class Base {
   private static propertyList: any = {};
   protected subscribers: (() => void)[] = [];
 
+  subject: Subject<this> = new Subject();
+
   constructor(properties: any) {
     const type = this.constructor.name;
     if (!Base.propertyList.hasOwnProperty(type)) {
@@ -37,7 +41,8 @@ export class Base {
         [property]: this[property],
         ...object
       }),
-      {}
+      // TODO
+      { type: this.constructor.name }
     );
   }
 
@@ -46,6 +51,7 @@ export class Base {
   }
 
   protected update() {
+    this.subject.next(this);
     this.subscribers.map(f => f());
   }
 }

src/app/services/data.service.ts

@@ -1,4 +1,4 @@
-import { ApplicationRef, Injectable } from '@angular/core';
+import { Injectable } from '@angular/core';
 import { StoreService } from './store.service';
 import { Page } from '../model/page';
 
@@ -22,7 +22,7 @@ export class DataService {
   private hasLoaded = new Promise(resolve => (this.afterLoadFinished = resolve));
   private afterLoadFinished: () => void;
 
-  constructor(private storeService: StoreService, private applicationRef: ApplicationRef) {
+  constructor(private storeService: StoreService) {
     this.init();
   }
 
@@ -72,7 +72,6 @@ export class DataService {
 
   private update() {
     this.subscribers.map(f => f());
-    this.applicationRef.tick();
   }
 
   private loadActiveIndex() {

src/app/storage/cloneable.ts

@@ -0,0 +1,71 @@
+import { InnerNode } from './inner-node';
+import { Node } from './node';
+
+export class Cloneable extends InnerNode {
+  name;
+  constructor(parent: Node, name: any) {
+    super(parent);
+    this.name = name;
+  }
+
+  changeNameMap = (newValue: string) => {
+    this.name = newValue;
+  };
+
+  changeName = (newValue: any) => {
+    this.changeValue({
+      oldValue: this.name,
+      newValue
+    });
+  };
+
+  protected cloneWithMap(map: (node: this) => void): this {
+    const insides = Object.getOwnPropertyDescriptors(this);
+
+    const insidesProxy = new Proxy(insides, {
+      get: (target, prop, proxy) => {
+        if (prop == '__target__') {
+          return target;
+        }
+        const value = target[prop as string].value;
+        if (typeof value === 'function') {
+          return value.bind(proxy);
+        }
+        return value;
+      },
+      set: (target, prop, value) => {
+        return (target[prop as string].value = value);
+      }
+    });
+    map(<any>insidesProxy);
+
+    return Object.create(Object.getPrototypeOf(this), <any>insidesProxy.__target__);
+  }
+
+  protected cloneWithAdd({ value, propertyName }: { value: any; propertyName: string }): this {
+    const insides = Object.getOwnPropertyDescriptors(this);
+    insides[propertyName].value = value;
+    insides.id.value = Node.id++;
+
+    return Object.create(Object.getPrototypeOf(this), insides);
+  }
+
+  protected cloneWithModify({ oldValue, newValue }: { oldValue: any; newValue: any }): this {
+    const insides = Object.getOwnPropertyDescriptors(this);
+    insides.id.value = Node.id++;
+
+    let wasMatch = false;
+    for (let name in insides) {
+      if (insides.hasOwnProperty(name) && insides[name].value === oldValue) {
+        insides[name].value = newValue;
+        wasMatch = true;
+      }
+    }
+
+    if (!wasMatch) {
+      throw new TypeError(`Object has no property with value: ${oldValue.toString()}`);
+    }
+
+    return Object.create(Object.getPrototypeOf(this), insides);
+  }
+}

src/app/storage/inner-node.ts

@@ -0,0 +1,67 @@
+import { Node } from './node';
+
+export abstract class InnerNode extends Node {
+  parent: Node;
+  nextVersion: this = null;
+
+  protected readonly children: Array<InnerNode> = [];
+
+  get latestVersion(): this {
+    let version;
+    for (version = this; version.nextVersion !== null; version = version.nextVersion) {
+      // pass
+    }
+    return version;
+  }
+
+  protected constructor(parent: Node) {
+    super();
+
+    parent.addChild({
+      value: this
+    });
+  }
+
+  map(map: (a: this) => void) {
+    return this.update((self: this) => this.cloneWithMap.call(self, map));
+  }
+
+  changeKey(update: { value: any; propertyName: string }): this {
+    return this.update((self: this) => this.cloneWithAdd.call(self, update));
+  }
+
+  changeValue(update: { oldValue: any; newValue: any }): this {
+    return this.update((self: this) => this.cloneWithModify.call(self, update));
+  }
+
+  addChild(update: { value: InnerNode }) {
+    super.addChild.call(this.latestVersion, update);
+  }
+
+  changeChild(update: { oldValue: InnerNode; newValue: InnerNode }) {
+    super.changeChild.call(this.latestVersion, update);
+  }
+
+  protected abstract cloneWithMap(map: (a: this) => void): this;
+  protected abstract cloneWithAdd(update: { value: any; propertyName: string }): this;
+  protected abstract cloneWithModify(update: { oldValue: any; newValue: any }): this;
+
+  private update(cloneMethod: (self: this) => this): this {
+    if (this.nextVersion !== null) {
+      this.latestVersion.update(cloneMethod);
+    }
+
+    const clone = cloneMethod(this);
+    for (let child of clone.children) {
+      child.parent = clone;
+    }
+
+    this.parent.changeChild({
+      oldValue: this,
+      newValue: clone
+    });
+
+    this.nextVersion = clone;
+    return clone;
+  }
+}

src/app/storage/node.ts

@@ -0,0 +1,29 @@
+import { InnerNode } from './inner-node';
+
+export abstract class Node {
+  public static id = 0;
+  protected abstract readonly children: Array<InnerNode>;
+  private id = Node.id++;
+
+  changeKey(update: { value: any; propertyName: string }) {
+    throw new TypeError('Not implemented!');
+  }
+
+  changeValue(update: { oldValue: any; newValue: any }) {
+    throw new TypeError('Not implemented!');
+  }
+
+  addChild(update: { value: InnerNode }) {
+    this.changeValue({
+      oldValue: this.children,
+      newValue: [...this.children, update.value]
+    });
+  }
+
+  changeChild({ oldValue, newValue }: { oldValue: InnerNode; newValue: InnerNode }) {
+    this.changeValue({
+      oldValue: this.children,
+      newValue: this.children.map(c => (c === oldValue ? newValue : c))
+    });
+  }
+}

src/app/storage/root.ts

@@ -0,0 +1,28 @@
+import { BehaviorSubject } from 'rxjs/internal/BehaviorSubject';
+import { Observable } from 'rxjs/internal/Observable';
+import { Node } from './node';
+import { InnerNode } from './inner-node';
+
+export class Root<T extends InnerNode> extends Node {
+  private readonly _children: BehaviorSubject<Array<T>> = new BehaviorSubject([]);
+  readonly children$: Observable<Array<T>> = this._children.asObservable();
+
+  get children(): Array<T> {
+    return this._children.getValue();
+  }
+
+  set children(value: Array<T>) {
+    this._children.next(value);
+  }
+
+  changeValue({ oldValue, newValue }: { oldValue: any; newValue: any }) {
+    if (this.children === oldValue) {
+      this.children = newValue;
+      for (let child of this.children) {
+        child.parent = this;
+      }
+    } else {
+      throw new TypeError('Only children can be changed.');
+    }
+  }
+}

src/app/utils/hash.ts

@@ -1,8 +1,13 @@
 export const hash = (text: string): number => {
-  // Return number between 0 and 1.
+  // Return number from [0, 1)
   if (!text) {
     return 0;
   }
-  const hash = Array.prototype.reduce.call(text, (hash, char) => (hash << 5) - hash + char.charCodeAt(0), 7);
-  return hash / (Math.pow(2, 32) - 1);
+  const hashValue = Array.prototype.reduce.call(
+    // tslint:disable-next-line:no-bitwise
+    text,
+    (value, char) => ((value << 5) - value + (char.charCodeAt(0) as number)) | 0,
+    7
+  );
+  return hashValue / (Math.pow(2, 32) - 2) + 0.5;
 };