dns-packet-typescript/dist/typebitmap.js

An abstract-encoding compliant module for encoding / decoding DNS packets

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.encodingLength = exports.decode = exports.encode = void 0;
var types = require("./types");
function encode(typelist, buf, offset) {
    if (offset === void 0) { offset = 0; }
    if (!buf) {
        buf = Buffer.allocUnsafe(encodingLength(typelist));
    }
    if (!offset) {
        offset = 0;
    }
    var oldOffset = offset;
    var typesByWindow = [];
    for (var i = 0; i < typelist.length; i++) {
        var typeid = types.toType(typelist[i]);
        if (typesByWindow[typeid >> 8] === undefined) {
            typesByWindow[typeid >> 8] = [];
        }
        typesByWindow[typeid >> 8][(typeid >> 3) & 0x1F] |= 1 << (7 - (typeid & 0x7));
    }
    for (i = 0; i < typesByWindow.length; i++) {
        if (typesByWindow[i] !== undefined) {
            var windowBuf = Buffer.from(typesByWindow[i]);
            buf.writeUInt8(i, offset);
            offset += 1;
            buf.writeUInt8(windowBuf.length, offset);
            offset += 1;
            windowBuf.copy(buf, offset);
            offset += windowBuf.length;
        }
    }
    encode.bytes = offset - oldOffset;
    return buf;
}
exports.encode = encode;
encode.bytes = 0;
function decode(buf, offset, length) {
    if (!offset) {
        offset = 0;
    }
    var oldOffset = offset;
    var typelist = [];
    while (offset - oldOffset < length) {
        var window = buf.readUInt8(offset);
        offset += 1;
        var windowLength = buf.readUInt8(offset);
        offset += 1;
        for (var i = 0; i < windowLength; i++) {
            var b = buf.readUInt8(offset + i);
            for (var j = 0; j < 8; j++) {
                if (b & (1 << (7 - j))) {
                    var typeid = types.toString((window << 8) | (i << 3) | j);
                    typelist.push(typeid);
                }
            }
        }
        offset += windowLength;
    }
    decode.bytes = offset - oldOffset;
    return typelist;
}
exports.decode = decode;
decode.bytes = 0;
function encodingLength(typelist) {
    var extents = [];
    for (var i = 0; i < typelist.length; i++) {
        var typeid = types.toType(typelist[i]);
        extents[typeid >> 8] = Math.max(extents[typeid >> 8] || 0, typeid & 0xFF);
    }
    var len = 0;
    for (i = 0; i < extents.length; i++) {
        if (extents[i] !== undefined) {
            len += 2 + Math.ceil((extents[i] + 1) / 8);
        }
    }
    return len;
}
exports.encodingLength = encodingLength;
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