circular_buffer_js
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Fast TS/JS implementation of a circular buffer (aka ring queue, cyclic list, etc.) Extremely well tested.
2 lines (1 loc) • 4.25 kB
JavaScript
"use strict";Object.defineProperty(exports,"__esModule",{value:true});const version="1.10.0";class circular_buffer{constructor(uCapacity){if(!Number.isInteger(uCapacity)){throw new RangeError(`Capacity must be an integer, received ${uCapacity}`)}if(uCapacity<0){throw new RangeError(`Capacity must be a non-negative integer, received ${uCapacity}`)}this._values=new Array(uCapacity);this._capacity=uCapacity;this._cursor=0;this._offset=0;this._length=0}get capacity(){return this._capacity}set capacity(newSize){this.resize(newSize)}get length(){return this._length}set length(newLength){if(newLength>this._capacity){throw new RangeError(`Requested new length [${newLength}] exceeds container capacity [${this._capacity}]`)}if(newLength<0){throw new RangeError(`Requested new length [${newLength}] cannot be negative`)}if(!Number.isInteger(newLength)){throw new RangeError(`Requested new length [${newLength}] must be an integer`)}if(this._length<=newLength){return}this._length=newLength}get available(){return this._capacity-this._length}get isEmpty(){return this._length===0}get isFull(){return this._length===this._capacity}get first(){if(this.isEmpty){throw new RangeError("Cannot return first element of an empty container")}return this.at(0)}get last(){if(this.isEmpty){throw new RangeError("Cannot return last element of an empty container")}return this.at(this.length-1)}static from(i,map_fn,t){const new_array=map_fn?Array.from(i,map_fn,t):Array.from(i);const target_length=new_array.length;const ncb=new circular_buffer(target_length);ncb._values=new_array;ncb._length=target_length;return ncb}push(v){if(this.isFull){throw new RangeError(`Cannot push, structure is full to capacity`)}this._values[(this._cursor+this._length++)%this._capacity]=v;return v}shove(v){let shoved;if(this._capacity===0){throw new RangeError(`Cannot shove, structure is zero-capacity`)}if(this.isFull){shoved=this.pop()}this.push(v);return shoved}fill(x){for(let i=0;i<this._capacity;i++){this._values[i]=x}this._length=this._capacity;return this._values}indexOf(searchElement,fromIndex){const normalized=this.toArray();return normalized.indexOf(searchElement,fromIndex)}find(predicate,thisArg){return this.toArray().find(predicate,thisArg)}every(functor,thisArg){const normalized=this.toArray(),res=normalized.every(functor,thisArg);this._values=normalized;this._values.length=this._capacity;this._cursor=0;return res}some(functor,thisArg){const normalized=this.toArray(),res=normalized.some(functor,thisArg);this._values=normalized;this._values.length=this._capacity;this._cursor=0;return res}reverse(){const normalized=this.toArray();this._values=normalized.reverse();this._values.length=this._capacity;this._cursor=0;return this}clear(){const old=this.toArray();this._length=0;return old}pop(){if(this._length<=0){throw new RangeError(`Cannot pop, structure is empty`)}const cache=this.at(0);--this._length;++this._offset;++this._cursor;if(this._cursor>=this._capacity){this._cursor-=this._capacity}return cache}at(i){if(i<0){throw new RangeError(`circular_buffer does not support negative traversals; called at(${i})`)}if(!Number.isInteger(i)){throw new RangeError(`Accessors must be non-negative integers; called at(${i})`)}if(i>=this._capacity){throw new RangeError(`Requested cell ${i} exceeds container permanent capacity`)}if(i>=this._length){throw new RangeError(`Requested cell ${i} exceeds container current length`)}return this._values[(this._cursor+i)%this._capacity]}pos(i){return this.at(i-this.offset())}offset(){return this._offset}resize(newSize,preferEnd=false){this._values=this.toArray();this._cursor=0;const oldSize=this._length;this._length=Math.min(this._length,newSize);this._capacity=newSize;if(newSize>=oldSize){this._values.length=newSize}else{if(preferEnd){const tmp=this._values.slice(oldSize-newSize);this._values=tmp}else{this._values.length=newSize}}}toArray(){const startPoint=this._cursor%this._capacity;if(this._capacity>startPoint+this._length){return this._values.slice(startPoint,startPoint+this._length)}else{const base=this._values.slice(startPoint,this._capacity);base.push(...this._values.slice(0,this.length-(this._capacity-startPoint)));return base}}}exports.circular_buffer=circular_buffer;exports.version=version;