securityos/node_modules/multiformats/vendor/varint.js

92 lines
1.6 KiB
JavaScript

var encode_1 = encode;
var MSB = 0x80
, REST = 0x7F
, MSBALL = ~REST
, INT = Math.pow(2, 31);
function encode(num, out, offset) {
out = out || [];
offset = offset || 0;
var oldOffset = offset;
while(num >= INT) {
out[offset++] = (num & 0xFF) | MSB;
num /= 128;
}
while(num & MSBALL) {
out[offset++] = (num & 0xFF) | MSB;
num >>>= 7;
}
out[offset] = num | 0;
encode.bytes = offset - oldOffset + 1;
return out
}
var decode = read;
var MSB$1 = 0x80
, REST$1 = 0x7F;
function read(buf, offset) {
var res = 0
, offset = offset || 0
, shift = 0
, counter = offset
, b
, l = buf.length;
do {
if (counter >= l) {
read.bytes = 0;
throw new RangeError('Could not decode varint')
}
b = buf[counter++];
res += shift < 28
? (b & REST$1) << shift
: (b & REST$1) * Math.pow(2, shift);
shift += 7;
} while (b >= MSB$1)
read.bytes = counter - offset;
return res
}
var N1 = Math.pow(2, 7);
var N2 = Math.pow(2, 14);
var N3 = Math.pow(2, 21);
var N4 = Math.pow(2, 28);
var N5 = Math.pow(2, 35);
var N6 = Math.pow(2, 42);
var N7 = Math.pow(2, 49);
var N8 = Math.pow(2, 56);
var N9 = Math.pow(2, 63);
var length = function (value) {
return (
value < N1 ? 1
: value < N2 ? 2
: value < N3 ? 3
: value < N4 ? 4
: value < N5 ? 5
: value < N6 ? 6
: value < N7 ? 7
: value < N8 ? 8
: value < N9 ? 9
: 10
)
};
var varint = {
encode: encode_1
, decode: decode
, encodingLength: length
};
var _brrp_varint = varint;
export default _brrp_varint;