nxkit/_bigint.js

This is a collection of tools, independent of any other libraries

"use strict";
/* ***** BEGIN LICENSE BLOCK *****
 * Distributed under the BSD license:
 *
 * Copyright (c) 2015, xuewen.chu
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of xuewen.chu nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL xuewen.chu BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * ***** END LICENSE BLOCK ***** */
var checkInt = null;
function _readBigUIntBE(self, offset, end) {
    var num = 0n;
    while (offset < end) {
        num <<= 8n;
        num |= BigInt(self[offset]);
        offset++;
    }
    return num;
}
function _readBigInt64BE(self, offset) {
    const hi = (self[offset++] << 24) + // Overflow
        self[offset++] * 2 ** 16 +
        self[offset++] * 2 ** 8 +
        self[offset++];
    const lo = self[offset++] * 2 ** 24 +
        self[offset++] * 2 ** 16 +
        self[offset++] * 2 ** 8 +
        self[offset++];
    return (BigInt(hi) << 32n) + BigInt(lo);
}
function _readBigUInt64BE(self, offset) {
    const hi = self[offset++] * 2 ** 24 +
        self[offset++] * 2 ** 16 +
        self[offset++] * 2 ** 8 +
        self[offset++];
    const lo = self[offset++] * 2 ** 24 +
        self[offset++] * 2 ** 16 +
        self[offset++] * 2 ** 8 +
        self[offset++];
    return (BigInt(hi) << 32n) + BigInt(lo);
}
function _writeBigIntLE(bytes, bigint) {
    var i = 0;
    do {
        bytes.push(Number(bigint & 0xffn));
        bigint >>= 8n;
        i++;
    } while (bigint || i < 8);
    return i;
}
function writeBigU_Int64BE(buf, value, offset, min, max) {
    checkInt(value, min, max, buf, offset, 7);
    let lo = Number(value & 0xffffffffn);
    buf[offset + 7] = lo;
    lo = lo >> 8;
    buf[offset + 6] = lo;
    lo = lo >> 8;
    buf[offset + 5] = lo;
    lo = lo >> 8;
    buf[offset + 4] = lo;
    let hi = Number(value >> 32n & 0xffffffffn);
    buf[offset + 3] = hi;
    hi = hi >> 8;
    buf[offset + 2] = hi;
    hi = hi >> 8;
    buf[offset + 1] = hi;
    hi = hi >> 8;
    buf[offset] = hi;
    return Number(offset) + 8;
}
function _writeBigInt64BE(self, value, offset = 0) {
    return writeBigU_Int64BE(self, value, offset, -0x8000000000000000n, 0x7fffffffffffffffn);
}
function _writeBigUInt64BE(self, value, offset = 0) {
    return writeBigU_Int64BE(self, value, offset, 0n, 0xffffffffffffffffn);
}
module.exports = {
    _set(_checkInt) {
        checkInt = _checkInt;
    },
    _readBigUIntBE,
    _readBigInt64BE,
    _readBigUInt64BE,
    _writeBigIntLE,
    _writeBigInt64BE,
    _writeBigUInt64BE,
};