snarkjs/src/wtns_utils.js
2020-07-11 10:31:52 +02:00

74 lines
2.0 KiB
JavaScript

import { Scalar } from "ffjavascript";
import * as binFileUtils from "./binfileutils.js";
export async function write(fd, witness, prime) {
await binFileUtils.startWriteSection(fd, 1);
const n8 = (Math.floor( (Scalar.bitLength(prime) - 1) / 64) +1)*8;
await fd.writeULE32(n8);
await binFileUtils.writeBigInt(fd, prime, n8);
await fd.writeULE32(witness.length);
await binFileUtils.endWriteSection(fd);
await binFileUtils.startWriteSection(fd, 2);
for (let i=0; i<witness.length; i++) {
await binFileUtils.writeBigInt(fd, witness[i], n8);
}
await binFileUtils.endWriteSection(fd, 2);
}
export async function writeBin(fd, witnessBin, prime) {
await binFileUtils.startWriteSection(fd, 1);
const n8 = (Math.floor( (Scalar.bitLength(prime) - 1) / 64) +1)*8;
await fd.writeULE32(n8);
await binFileUtils.writeBigInt(fd, prime, n8);
if (witnessBin.byteLength % n8 != 0) {
throw new Error("Invalid witness length");
}
await fd.writeULE32(witnessBin.byteLength / n8);
await binFileUtils.endWriteSection(fd);
await binFileUtils.startWriteSection(fd, 2);
await fd.write(witnessBin);
await binFileUtils.endWriteSection(fd);
}
export async function readHeader(fd, sections) {
await binFileUtils.startReadUniqueSection(fd, sections, 1);
const n8 = await fd.readULE32();
const q = await binFileUtils.readBigInt(fd, n8);
const nWitness = await fd.readULE32();
await binFileUtils.endReadSection(fd);
return {n8, q, nWitness};
}
export async function read(fileName) {
const {fd, sections} = await binFileUtils.readBinFile(fileName, "wtns", 2);
const {n8, nWitness} = await readHeader(fd, sections);
await binFileUtils.startReadUniqueSection(fd, sections, 2);
const res = [];
for (let i=0; i<nWitness; i++) {
const v = await binFileUtils.readBigInt(fd, n8);
res.push(v);
}
await binFileUtils.endReadSection(fd);
await fd.close();
return res;
}