56 lines
1.4 KiB
JavaScript
56 lines
1.4 KiB
JavaScript
import * as Chunk from "../Chunk.js";
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import { constUndefined } from "../Function.js";
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import * as Option from "../Option.js";
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/** @internal */
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export class RingBuffer {
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capacity;
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array;
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size = 0;
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current = 0;
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constructor(capacity) {
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this.capacity = capacity;
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this.array = Array.from({
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length: capacity
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}, constUndefined);
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}
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head() {
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return Option.fromNullable(this.array[this.current]);
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}
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lastOrNull() {
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if (this.size === 0) {
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return undefined;
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}
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const index = this.current === 0 ? this.array.length - 1 : this.current - 1;
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return this.array[index] ?? undefined;
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}
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put(value) {
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this.array[this.current] = value;
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this.increment();
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}
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dropLast() {
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if (this.size > 0) {
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this.decrement();
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this.array[this.current] = undefined;
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}
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}
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toChunk() {
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const begin = this.current - this.size;
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const newArray = begin < 0 ? [...this.array.slice(this.capacity + begin, this.capacity), ...this.array.slice(0, this.current)] : this.array.slice(begin, this.current);
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return Chunk.fromIterable(newArray);
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}
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increment() {
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if (this.size < this.capacity) {
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this.size += 1;
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}
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this.current = (this.current + 1) % this.capacity;
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}
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decrement() {
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this.size -= 1;
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if (this.current > 0) {
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this.current -= 1;
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} else {
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this.current = this.capacity - 1;
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}
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}
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}
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//# sourceMappingURL=ringBuffer.js.map
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