Code coverage report for src/operator/groupBy.ts

Statements: 100% (144 / 144)      Branches: 97.37% (37 / 38)      Functions: 100% (27 / 27)      Lines: 100% (127 / 127)      Ignored: none     

All files » src/operator/ » groupBy.ts
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 2111 1 1 1 1 1 1 1                           1     37     1 37 37 37 37 37     1 37 37     37 37   1   1 37   1 37 37 37 37 37 37 37     1 273 273 2   271 271 271   271 34     271   271 112 112   112 59 59 1   58       112     271 144 144 2   142     127         11 11 11 10 29 29     11     19 19 19 18 42 42     19     1 150   1   1 58 58 58 58     1 26 26     1 14 14     1 39 39   1   1   37 37   1 37     1 37     1 39 36 36 33 33       1   1 171 171 171 171     1 150 150 84   150 150   1   1 84 84 84     1 84 84 84 84 3 3       1  
import {Subscriber} from '../Subscriber';
import {Subscription} from '../Subscription';
import {Observable} from '../Observable';
import {Subject} from '../Subject';
import {Map} from '../util/Map';
import {FastMap} from '../util/FastMap';
import {tryCatch} from '../util/tryCatch';
import {errorObject} from '../util/errorObject';
 
/**
 * Groups the items emitted by an Observable according to a specified criterion,
 * and emits these grouped items as `GroupedObservables`, one `GroupedObservable` per group.
 *
 * <img src="./img/groupBy.png" width="100%">
 *
 * @param {Function} keySelector - a function that extracts the key for each item
 * @param {Function} elementSelector - a function that extracts the return element for each item
 * @returns {Observable} an Observable that emits GroupedObservables, each of which corresponds
 * to a unique key value and each of which emits those items from the source Observable that share
 * that key value.
 */
export function groupBy<T, K, R>(keySelector: (value: T) => K,
                                 elementSelector?: (value: T) => R,
                                 durationSelector?: (grouped: GroupedObservable<K, R>) => Observable<any>): GroupByObservable<T, K, R> {
  return new GroupByObservable(this, keySelector, elementSelector, durationSelector);
}
 
export class GroupByObservable<T, K, R> extends Observable<GroupedObservable<K, R>> {
  constructor(public source: Observable<T>,
              private keySelector: (value: T) => K,
              private elementSelector?: (value: T) => R,
              private durationSelector?: (grouped: GroupedObservable<K, R>) => Observable<any>) {
    super();
  }
 
  protected _subscribe(subscriber: Subscriber<any>): Subscription {
    const refCountSubscription = new RefCountSubscription();
    const groupBySubscriber = new GroupBySubscriber(
      subscriber, refCountSubscription, this.keySelector, this.elementSelector, this.durationSelector
    );
    refCountSubscription.setPrimary(this.source.subscribe(groupBySubscriber));
    return refCountSubscription;
  }
}
 
class GroupBySubscriber<T, K, R> extends Subscriber<T> {
  private groups: Map<K, Subject<T|R>> = null;
 
  constructor(destination: Subscriber<R>,
              private refCountSubscription: RefCountSubscription,
              private keySelector: (value: T) => K,
              private elementSelector?: (value: T) => R,
              private durationSelector?: (grouped: GroupedObservable<K, R>) => Observable<any>) {
    super();
    this.destination = destination;
    this.add(destination);
  }
 
  protected _next(x: T): void {
    let key = tryCatch(this.keySelector)(x);
    if (key === errorObject) {
      this.error(errorObject.e);
    } else {
      let groups = this.groups;
      const elementSelector = this.elementSelector;
      const durationSelector = this.durationSelector;
 
      if (!groups) {
        groups = this.groups = typeof key === 'string' ? new FastMap() : new Map();
      }
 
      let group = groups.get(key);
 
      if (!group) {
        groups.set(key, group = new Subject<T|R>());
        let groupedObservable = new GroupedObservable(key, group, this.refCountSubscription);
 
        if (durationSelector) {
          let duration = tryCatch(durationSelector)(new GroupedObservable<K, R>(key, <any>group));
          if (duration === errorObject) {
            this.error(errorObject.e);
          } else {
            this.add(duration.subscribe(new GroupDurationSubscriber(key, group, this)));
          }
        }
 
        this.destination.next(groupedObservable);
      }
 
      if (elementSelector) {
        let value = tryCatch(elementSelector)(x);
        if (value === errorObject) {
          this.error(errorObject.e);
        } else {
          group.next(value);
        }
      } else {
        group.next(x);
      }
    }
  }
 
  protected _error(err: any): void {
    const groups = this.groups;
    if (groups) {
      groups.forEach((group, key) => {
        group.error(err);
        this.removeGroup(key);
      });
    }
    this.destination.error(err);
  }
 
  protected _complete(): void {
    const groups = this.groups;
    if (groups) {
      groups.forEach((group, key) => {
        group.complete();
        this.removeGroup(key);
      });
    }
    this.destination.complete();
  }
 
  removeGroup(key: K): void {
    this.groups.delete(key);
  }
}
 
class GroupDurationSubscriber<K, T> extends Subscriber<T> {
  constructor(private key: K,
              private group: Subject<T>,
              private parent: GroupBySubscriber<any, K, T>) {
    super();
  }
 
  protected _next(value: T): void {
    this.group.complete();
    this.parent.removeGroup(this.key);
  }
 
  protected _error(err: any): void {
    this.group.error(err);
    this.parent.removeGroup(this.key);
  }
 
  protected _complete(): void {
    this.group.complete();
    this.parent.removeGroup(this.key);
  }
}
 
export class RefCountSubscription extends Subscription {
  primary: Subscription;
  attemptedToUnsubscribePrimary: boolean = false;
  count: number = 0;
 
  constructor() {
    super();
  }
 
  setPrimary(subscription: Subscription) {
    this.primary = subscription;
  }
 
  unsubscribe() {
    if (!this.isUnsubscribed && !this.attemptedToUnsubscribePrimary) {
      this.attemptedToUnsubscribePrimary = true;
      if (this.count === 0) {
        super.unsubscribe();
        this.primary.unsubscribe();
      }
    }
  }
}
 
export class GroupedObservable<K, T> extends Observable<T> {
  constructor(public key: K,
              private groupSubject: Subject<T>,
              private refCountSubscription?: RefCountSubscription) {
    super();
  }
 
  protected _subscribe(subscriber: Subscriber<T>) {
    const subscription = new Subscription();
    if (this.refCountSubscription && !this.refCountSubscription.isUnsubscribed) {
      subscription.add(new InnerRefCountSubscription(this.refCountSubscription));
    }
    subscription.add(this.groupSubject.subscribe(subscriber));
    return subscription;
  }
}
 
export class InnerRefCountSubscription extends Subscription {
  constructor(private parent: RefCountSubscription) {
    super();
    parent.count++;
  }
 
  unsubscribe() {
    Eif (!this.parent.isUnsubscribed && !this.isUnsubscribed) {
      super.unsubscribe();
      this.parent.count--;
      if (this.parent.count === 0 && this.parent.attemptedToUnsubscribePrimary) {
        this.parent.unsubscribe();
        this.parent.primary.unsubscribe();
      }
    }
  }
}