snarkjs/src/bigarray.js
2020-08-18 20:09:46 +02:00

81 lines
2.1 KiB
JavaScript

const SUBARRAY_SIZE = 0x40000;
const BigArrayHandler = {
get: function(obj, prop) {
if (!isNaN(prop)) {
return obj.getElement(prop);
} else return obj[prop];
},
set: function(obj, prop, value) {
if (!isNaN(prop)) {
return obj.setElement(prop, value);
} else {
obj[prop] = value;
return true;
}
}
};
class _BigArray {
constructor (initSize) {
this.length = initSize || 0;
this.arr = new Array(SUBARRAY_SIZE);
for (let i=0; i<initSize; i+=SUBARRAY_SIZE) {
this.arr[i/SUBARRAY_SIZE] = new Array(Math.min(SUBARRAY_SIZE, initSize - i));
}
return this;
}
push () {
for (let i=0; i<arguments.length; i++) {
this.setElement (this.length, arguments[i]);
}
}
slice (f, t) {
const arr = new Array(t-f);
for (let i=f; i< t; i++) arr[i-f] = this.getElement(i);
return arr;
}
getElement(idx) {
idx = parseInt(idx);
const idx1 = Math.floor(idx / SUBARRAY_SIZE);
const idx2 = idx % SUBARRAY_SIZE;
return this.arr[idx1] ? this.arr[idx1][idx2] : undefined;
}
setElement(idx, value) {
idx = parseInt(idx);
const idx1 = Math.floor(idx / SUBARRAY_SIZE);
if (!this.arr[idx1]) {
this.arr[idx1] = new Array(SUBARRAY_SIZE);
}
const idx2 = idx % SUBARRAY_SIZE;
this.arr[idx1][idx2] = value;
if (idx >= this.length) this.length = idx+1;
return true;
}
getKeys() {
const newA = new BigArray();
for (let i=0; i<this.arr.length; i++) {
if (this.arr[i]) {
for (let j=0; j<this.arr[i].length; j++) {
if (typeof this.arr[i][j] !== "undefined") {
newA.push(i*SUBARRAY_SIZE+j);
}
}
}
}
return newA;
}
}
class BigArray {
constructor( initSize ) {
const obj = new _BigArray(initSize);
const extObj = new Proxy(obj, BigArrayHandler);
return extObj;
}
}
export default BigArray;