Express_Crud_Example/node_modules/bson/lib/float_parser.js

"use strict";
// Copyright (c) 2008, Fair Oaks Labs, Inc.
// 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 Fair Oaks Labs, Inc. 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 THE COPYRIGHT OWNER OR CONTRIBUTORS 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.
//
//
// Modifications to writeIEEE754 to support negative zeroes made by Brian White
Object.defineProperty(exports, "__esModule", { value: true });
exports.writeIEEE754 = exports.readIEEE754 = void 0;
function readIEEE754(buffer, offset, endian, mLen, nBytes) {
    var e;
    var m;
    var bBE = endian === 'big';
    var eLen = nBytes * 8 - mLen - 1;
    var eMax = (1 << eLen) - 1;
    var eBias = eMax >> 1;
    var nBits = -7;
    var i = bBE ? 0 : nBytes - 1;
    var d = bBE ? 1 : -1;
    var s = buffer[offset + i];
    i += d;
    e = s & ((1 << -nBits) - 1);
    s >>= -nBits;
    nBits += eLen;
    for (; nBits > 0; e = e * 256 + buffer[offset + i], i += d, nBits -= 8)
        ;
    m = e & ((1 << -nBits) - 1);
    e >>= -nBits;
    nBits += mLen;
    for (; nBits > 0; m = m * 256 + buffer[offset + i], i += d, nBits -= 8)
        ;
    if (e === 0) {
        e = 1 - eBias;
    }
    else if (e === eMax) {
        return m ? NaN : (s ? -1 : 1) * Infinity;
    }
    else {
        m = m + Math.pow(2, mLen);
        e = e - eBias;
    }
    return (s ? -1 : 1) * m * Math.pow(2, e - mLen);
}
exports.readIEEE754 = readIEEE754;
function writeIEEE754(buffer, value, offset, endian, mLen, nBytes) {
    var e;
    var m;
    var c;
    var bBE = endian === 'big';
    var eLen = nBytes * 8 - mLen - 1;
    var eMax = (1 << eLen) - 1;
    var eBias = eMax >> 1;
    var rt = mLen === 23 ? Math.pow(2, -24) - Math.pow(2, -77) : 0;
    var i = bBE ? nBytes - 1 : 0;
    var d = bBE ? -1 : 1;
    var s = value < 0 || (value === 0 && 1 / value < 0) ? 1 : 0;
    value = Math.abs(value);
    if (isNaN(value) || value === Infinity) {
        m = isNaN(value) ? 1 : 0;
        e = eMax;
    }
    else {
        e = Math.floor(Math.log(value) / Math.LN2);
        if (value * (c = Math.pow(2, -e)) < 1) {
            e--;
            c *= 2;
        }
        if (e + eBias >= 1) {
            value += rt / c;
        }
        else {
            value += rt * Math.pow(2, 1 - eBias);
        }
        if (value * c >= 2) {
            e++;
            c /= 2;
        }
        if (e + eBias >= eMax) {
            m = 0;
            e = eMax;
        }
        else if (e + eBias >= 1) {
            m = (value * c - 1) * Math.pow(2, mLen);
            e = e + eBias;
        }
        else {
            m = value * Math.pow(2, eBias - 1) * Math.pow(2, mLen);
            e = 0;
        }
    }
    if (isNaN(value))
        m = 0;
    while (mLen >= 8) {
        buffer[offset + i] = m & 0xff;
        i += d;
        m /= 256;
        mLen -= 8;
    }
    e = (e << mLen) | m;
    if (isNaN(value))
        e += 8;
    eLen += mLen;
    while (eLen > 0) {
        buffer[offset + i] = e & 0xff;
        i += d;
        e /= 256;
        eLen -= 8;
    }
    buffer[offset + i - d] |= s * 128;
}
exports.writeIEEE754 = writeIEEE754;
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