sourcemap-codec.es.js 4.1 KB
var charToInteger = {};
var chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
for (var i = 0; i < chars.length; i++) {
    charToInteger[chars.charCodeAt(i)] = i;
}
function decode(mappings) {
    var decoded = [];
    var line = [];
    var segment = [
        0,
        0,
        0,
        0,
        0,
    ];
    var j = 0;
    for (var i = 0, shift = 0, value = 0; i < mappings.length; i++) {
        var c = mappings.charCodeAt(i);
        if (c === 44) { // ","
            segmentify(line, segment, j);
            j = 0;
        }
        else if (c === 59) { // ";"
            segmentify(line, segment, j);
            j = 0;
            decoded.push(line);
            line = [];
            segment[0] = 0;
        }
        else {
            var integer = charToInteger[c];
            if (integer === undefined) {
                throw new Error('Invalid character (' + String.fromCharCode(c) + ')');
            }
            var hasContinuationBit = integer & 32;
            integer &= 31;
            value += integer << shift;
            if (hasContinuationBit) {
                shift += 5;
            }
            else {
                var shouldNegate = value & 1;
                value >>>= 1;
                if (shouldNegate) {
                    value = value === 0 ? -0x80000000 : -value;
                }
                segment[j] += value;
                j++;
                value = shift = 0; // reset
            }
        }
    }
    segmentify(line, segment, j);
    decoded.push(line);
    return decoded;
}
function segmentify(line, segment, j) {
    // This looks ugly, but we're creating specialized arrays with a specific
    // length. This is much faster than creating a new array (which v8 expands to
    // a capacity of 17 after pushing the first item), or slicing out a subarray
    // (which is slow). Length 4 is assumed to be the most frequent, followed by
    // length 5 (since not everything will have an associated name), followed by
    // length 1 (it's probably rare for a source substring to not have an
    // associated segment data).
    if (j === 4)
        line.push([segment[0], segment[1], segment[2], segment[3]]);
    else if (j === 5)
        line.push([segment[0], segment[1], segment[2], segment[3], segment[4]]);
    else if (j === 1)
        line.push([segment[0]]);
}
function encode(decoded) {
    var sourceFileIndex = 0; // second field
    var sourceCodeLine = 0; // third field
    var sourceCodeColumn = 0; // fourth field
    var nameIndex = 0; // fifth field
    var mappings = '';
    for (var i = 0; i < decoded.length; i++) {
        var line = decoded[i];
        if (i > 0)
            mappings += ';';
        if (line.length === 0)
            continue;
        var generatedCodeColumn = 0; // first field
        var lineMappings = [];
        for (var _i = 0, line_1 = line; _i < line_1.length; _i++) {
            var segment = line_1[_i];
            var segmentMappings = encodeInteger(segment[0] - generatedCodeColumn);
            generatedCodeColumn = segment[0];
            if (segment.length > 1) {
                segmentMappings +=
                    encodeInteger(segment[1] - sourceFileIndex) +
                        encodeInteger(segment[2] - sourceCodeLine) +
                        encodeInteger(segment[3] - sourceCodeColumn);
                sourceFileIndex = segment[1];
                sourceCodeLine = segment[2];
                sourceCodeColumn = segment[3];
            }
            if (segment.length === 5) {
                segmentMappings += encodeInteger(segment[4] - nameIndex);
                nameIndex = segment[4];
            }
            lineMappings.push(segmentMappings);
        }
        mappings += lineMappings.join(',');
    }
    return mappings;
}
function encodeInteger(num) {
    var result = '';
    num = num < 0 ? (-num << 1) | 1 : num << 1;
    do {
        var clamped = num & 31;
        num >>>= 5;
        if (num > 0) {
            clamped |= 32;
        }
        result += chars[clamped];
    } while (num > 0);
    return result;
}

export { decode, encode };
//# sourceMappingURL=sourcemap-codec.es.js.map