+++ /dev/null
-/**
- * Copyright (c) 2016 The xterm.js authors. All rights reserved.
- * @license MIT
- */
-
-import { ICircularList } from 'common/Types';
-import { EventEmitter, IEvent } from 'common/EventEmitter';
-
-export interface IInsertEvent {
- index: number;
- amount: number;
-}
-
-export interface IDeleteEvent {
- index: number;
- amount: number;
-}
-
-/**
- * Represents a circular list; a list with a maximum size that wraps around when push is called,
- * overriding values at the start of the list.
- */
-export class CircularList<T> implements ICircularList<T> {
- protected _array: (T | undefined)[];
- private _startIndex: number;
- private _length: number;
-
- public onDeleteEmitter = new EventEmitter<IDeleteEvent>();
- public get onDelete(): IEvent<IDeleteEvent> { return this.onDeleteEmitter.event; }
- public onInsertEmitter = new EventEmitter<IInsertEvent>();
- public get onInsert(): IEvent<IInsertEvent> { return this.onInsertEmitter.event; }
- public onTrimEmitter = new EventEmitter<number>();
- public get onTrim(): IEvent<number> { return this.onTrimEmitter.event; }
-
- constructor(
- private _maxLength: number
- ) {
- this._array = new Array<T>(this._maxLength);
- this._startIndex = 0;
- this._length = 0;
- }
-
- public get maxLength(): number {
- return this._maxLength;
- }
-
- public set maxLength(newMaxLength: number) {
- // There was no change in maxLength, return early.
- if (this._maxLength === newMaxLength) {
- return;
- }
-
- // Reconstruct array, starting at index 0. Only transfer values from the
- // indexes 0 to length.
- const newArray = new Array<T | undefined>(newMaxLength);
- for (let i = 0; i < Math.min(newMaxLength, this.length); i++) {
- newArray[i] = this._array[this._getCyclicIndex(i)];
- }
- this._array = newArray;
- this._maxLength = newMaxLength;
- this._startIndex = 0;
- }
-
- public get length(): number {
- return this._length;
- }
-
- public set length(newLength: number) {
- if (newLength > this._length) {
- for (let i = this._length; i < newLength; i++) {
- this._array[i] = undefined;
- }
- }
- this._length = newLength;
- }
-
- /**
- * Gets the value at an index.
- *
- * Note that for performance reasons there is no bounds checking here, the index reference is
- * circular so this should always return a value and never throw.
- * @param index The index of the value to get.
- * @return The value corresponding to the index.
- */
- public get(index: number): T | undefined {
- return this._array[this._getCyclicIndex(index)];
- }
-
- /**
- * Sets the value at an index.
- *
- * Note that for performance reasons there is no bounds checking here, the index reference is
- * circular so this should always return a value and never throw.
- * @param index The index to set.
- * @param value The value to set.
- */
- public set(index: number, value: T | undefined): void {
- this._array[this._getCyclicIndex(index)] = value;
- }
-
- /**
- * Pushes a new value onto the list, wrapping around to the start of the array, overriding index 0
- * if the maximum length is reached.
- * @param value The value to push onto the list.
- */
- public push(value: T): void {
- this._array[this._getCyclicIndex(this._length)] = value;
- if (this._length === this._maxLength) {
- this._startIndex = ++this._startIndex % this._maxLength;
- this.onTrimEmitter.fire(1);
- } else {
- this._length++;
- }
- }
-
- /**
- * Advance ringbuffer index and return current element for recycling.
- * Note: The buffer must be full for this method to work.
- * @throws When the buffer is not full.
- */
- public recycle(): T {
- if (this._length !== this._maxLength) {
- throw new Error('Can only recycle when the buffer is full');
- }
- this._startIndex = ++this._startIndex % this._maxLength;
- this.onTrimEmitter.fire(1);
- return this._array[this._getCyclicIndex(this._length - 1)]!;
- }
-
- /**
- * Ringbuffer is at max length.
- */
- public get isFull(): boolean {
- return this._length === this._maxLength;
- }
-
- /**
- * Removes and returns the last value on the list.
- * @return The popped value.
- */
- public pop(): T | undefined {
- return this._array[this._getCyclicIndex(this._length-- - 1)];
- }
-
- /**
- * Deletes and/or inserts items at a particular index (in that order). Unlike
- * Array.prototype.splice, this operation does not return the deleted items as a new array in
- * order to save creating a new array. Note that this operation may shift all values in the list
- * in the worst case.
- * @param start The index to delete and/or insert.
- * @param deleteCount The number of elements to delete.
- * @param items The items to insert.
- */
- public splice(start: number, deleteCount: number, ...items: T[]): void {
- // Delete items
- if (deleteCount) {
- for (let i = start; i < this._length - deleteCount; i++) {
- this._array[this._getCyclicIndex(i)] = this._array[this._getCyclicIndex(i + deleteCount)];
- }
- this._length -= deleteCount;
- }
-
- // Add items
- for (let i = this._length - 1; i >= start; i--) {
- this._array[this._getCyclicIndex(i + items.length)] = this._array[this._getCyclicIndex(i)];
- }
- for (let i = 0; i < items.length; i++) {
- this._array[this._getCyclicIndex(start + i)] = items[i];
- }
-
- // Adjust length as needed
- if (this._length + items.length > this._maxLength) {
- const countToTrim = (this._length + items.length) - this._maxLength;
- this._startIndex += countToTrim;
- this._length = this._maxLength;
- this.onTrimEmitter.fire(countToTrim);
- } else {
- this._length += items.length;
- }
- }
-
- /**
- * Trims a number of items from the start of the list.
- * @param count The number of items to remove.
- */
- public trimStart(count: number): void {
- if (count > this._length) {
- count = this._length;
- }
- this._startIndex += count;
- this._length -= count;
- this.onTrimEmitter.fire(count);
- }
-
- public shiftElements(start: number, count: number, offset: number): void {
- if (count <= 0) {
- return;
- }
- if (start < 0 || start >= this._length) {
- throw new Error('start argument out of range');
- }
- if (start + offset < 0) {
- throw new Error('Cannot shift elements in list beyond index 0');
- }
-
- if (offset > 0) {
- for (let i = count - 1; i >= 0; i--) {
- this.set(start + i + offset, this.get(start + i));
- }
- const expandListBy = (start + count + offset) - this._length;
- if (expandListBy > 0) {
- this._length += expandListBy;
- while (this._length > this._maxLength) {
- this._length--;
- this._startIndex++;
- this.onTrimEmitter.fire(1);
- }
- }
- } else {
- for (let i = 0; i < count; i++) {
- this.set(start + i + offset, this.get(start + i));
- }
- }
- }
-
- /**
- * Gets the cyclic index for the specified regular index. The cyclic index can then be used on the
- * backing array to get the element associated with the regular index.
- * @param index The regular index.
- * @returns The cyclic index.
- */
- private _getCyclicIndex(index: number): number {
- return (this._startIndex + index) % this._maxLength;
- }
-}
projects / VSoRC / .git / blobdiff