ffjavascript/src/utils_native.js

/* global BigInt */
import * as Scalar from "./scalar.js";

export function stringifyBigInts(o) {
    if ((typeof(o) == "bigint") || o.eq !== undefined)  {
        return o.toString(10);
    } else if (o instanceof Uint8Array) {
        return Scalar.fromRprLE(o, 0);
    } else if (Array.isArray(o)) {
        return o.map(stringifyBigInts);
    } else if (typeof o == "object") {
        const res = {};
        const keys = Object.keys(o);
        keys.forEach( (k) => {
            res[k] = stringifyBigInts(o[k]);
        });
        return res;
    } else {
        return o;
    }
}

export function unstringifyBigInts(o) {
    if ((typeof(o) == "string") && (/^[0-9]+$/.test(o) ))  {
        return BigInt(o);
    } else if ((typeof(o) == "string") && (/^0x[0-9a-fA-F]+$/.test(o) ))  {
        return BigInt(o);
    } else if (Array.isArray(o)) {
        return o.map(unstringifyBigInts);
    } else if (typeof o == "object") {
        if (o===null) return null;
        const res = {};
        const keys = Object.keys(o);
        keys.forEach( (k) => {
            res[k] = unstringifyBigInts(o[k]);
        });
        return res;
    } else {
        return o;
    }
}

export function beBuff2int(buff) {
    let res = BigInt(0);
    let i = buff.length;
    let offset = 0;
    const buffV = new DataView(buff.buffer, buff.byteOffset, buff.byteLength);
    while (i>0) {
        if (i >= 4) {
            i -= 4;
            res += BigInt(buffV.getUint32(i)) << BigInt(offset*8);
            offset += 4;
        } else if (i >= 2) {
            i -= 2;
            res += BigInt(buffV.getUint16(i)) << BigInt(offset*8);
            offset += 2;
        } else {
            i -= 1;
            res += BigInt(buffV.getUint8(i)) << BigInt(offset*8);
            offset += 1;
        }
    }
    return res;
}

export function beInt2Buff(n, len) {
    let r = n;
    const buff = new Uint8Array(len);
    const buffV = new DataView(buff.buffer);
    let o = len;
    while (o > 0) {
        if (o-4 >= 0) {
            o -= 4;
            buffV.setUint32(o, Number(r & BigInt(0xFFFFFFFF)));
            r = r >> BigInt(32);
        } else if (o-2 >= 0) {
            o -= 2;
            buffV.setUint16(o, Number(r & BigInt(0xFFFF)));
            r = r >> BigInt(16);
        } else {
            o -= 1;
            buffV.setUint8(o, Number(r & BigInt(0xFF)));
            r = r >> BigInt(8);
        }
    }
    if (r) {
        throw new Error("Number does not fit in this length");
    }
    return buff;
}


export function leBuff2int(buff) {
    let res = BigInt(0);
    let i = 0;
    const buffV = new DataView(buff.buffer, buff.byteOffset, buff.byteLength);
    while (i<buff.length) {
        if (i + 4 <= buff.length) {
            res += BigInt(buffV.getUint32(i, true)) << BigInt( i*8);
            i += 4;
        } else if (i + 4 <= buff.length) {
            res += BigInt(buffV.getUint16(i, true)) << BigInt( i*8);
            i += 2;
        } else {
            res += BigInt(buffV.getUint8(i, true)) << BigInt( i*8);
            i += 1;
        }
    }
    return res;
}

export function leInt2Buff(n, len) {
    let r = n;
    if (typeof len === "undefined") {
        len = Math.floor((Scalar.bitLength(n) - 1) / 8) +1;
        if (len==0) len = 1;
    }
    const buff = new Uint8Array(len);
    const buffV = new DataView(buff.buffer);
    let o = 0;
    while (o < len) {
        if (o+4 <= len) {
            buffV.setUint32(o, Number(r & BigInt(0xFFFFFFFF)), true );
            o += 4;
            r = r >> BigInt(32);
        } else if (o+2 <= len) {
            buffV.setUint16(Number(o, r & BigInt(0xFFFF)), true );
            o += 2;
            r = r >> BigInt(16);
        } else {
            buffV.setUint8(Number(o, r & BigInt(0xFF)), true );
            o += 1;
            r = r >> BigInt(8);
        }
    }
    if (r) {
        throw new Error("Number does not fit in this length");
    }
    return buff;
}


export function stringifyFElements(F, o) {
    if ((typeof(o) == "bigint") || o.eq !== undefined)  {
        return o.toString(10);
    } else if (o instanceof Uint8Array) {
        return F.toString(F.e(o));
    } else if (Array.isArray(o)) {
        return o.map(stringifyFElements.bind(this,F));
    } else if (typeof o == "object") {
        const res = {};
        const keys = Object.keys(o);
        keys.forEach( (k) => {
            res[k] = stringifyFElements(F, o[k]);
        });
        return res;
    } else {
        return o;
    }
}


export function unstringifyFElements(F, o) {
    if ((typeof(o) == "string") && (/^[0-9]+$/.test(o) ))  {
        return F.e(o);
    } else if ((typeof(o) == "string") && (/^0x[0-9a-fA-F]+$/.test(o) ))  {
        return F.e(o);
    } else if (Array.isArray(o)) {
        return o.map(unstringifyFElements.bind(this,F));
    } else if (typeof o == "object") {
        if (o===null) return null;
        const res = {};
        const keys = Object.keys(o);
        keys.forEach( (k) => {
            res[k] = unstringifyFElements(F, o[k]);
        });
        return res;
    } else {
        return o;
    }
}