fast-cidr-tools
v0.3.1
Published
cidr-tools but up to 20x faster
Downloads
316
Readme
fast-cidr-tools
Tools to work with IPv4 and IPv6 CIDR, but 20x faster than cidr-tools, and is not Pure ESM (publish both CommonJS and ESM).
Requires BigInt supports.
Usage
import {
ip2bigint, // support both IPv4 and IPv6
bigint2ip, // support both IPv4 and IPv6
contains,
exclude,
expand,
merge,
overlap
} from 'fast-cidr-tools';
contains(['1.0.0.0/24', '2.0.0.0/24'], ['1.0.0.1']) //=> true
exclude(['::1/127'], ['::1/128']) //=> ['::/128']
expand(['2001:db8::/126']) //=> ['2001:db8::', '2001:db8::1', '2001:db8::2', '2001:db8::3']
merge(['1.0.0.0/24'], ['1.0.1.0/24']); //=> ['1.0.0.0/23']
overlap(['1.0.0.0/24'], ['1.0.0.128/25']) //=> true
Performance
fast-cidr-tools
is very fast, and is specfically optimized for IPv4. In some cases, it can be 20x faster than cidr-tools
. fast-cidr-tools
acheive this performance by:
- Doing less things, E.g.:
cidr-tools
will cast input to an array if it is string (cidrTools.merge('1.0.0.0/24', '1.0.1.0/24')
).fast-cidr-tools
only supports array input.cidr-tools
sort the return value ofmerge
andexclude
by default.fast-cidr-tools
's sort is opt-in.- And many more.
- Use efficient calculation and avoid unnecessary string operations.
- how
cidr-tools
andfast-cidr-tools
calculate the "biggest power of two":// cidr-tools function biggestPowerOfTwo(num) { if (num === 0n) return 0n; return 2n ** BigInt(String(num.toString(2).length - 1)); } // fast-cidr-tools // Not the actual implementation: fast-cidr-tools actually inlines the calculation // for better performance const uint64 = new BigUint64Array(1); const uint32 = new Uint32Array(uint64.buffer); function clz64(bigint: bigint) { uint64[0] = bigint; let r = Math.clz32(uint32[1]); if (r === 32) { r += Math.clz32(uint32[0]); } return r; } function biggestPowerOfTwo(num: bigint) { if (num === 0n) return 0n; const power = BigInt(64 - clz64(size) - 1); return 2n ** (power === -1n ? 128n : power); }
- how
cidr-tools
andfast-cidr-tools
calculate the prefix of a CIDR:// cidr-tools const zeroes = (part.end + 1n - part.start).toString(2); const prefix = bits[v] - (zeroes.match(/0/g) || []).length; // fast-cidr-tools function fast_popcnt(value: bigint | number) { let v = Number(value); v -= v >>> 1 & 0x55_55_55_55; v = (v & 0x33_33_33_33) + (v >>> 2 & 0x33_33_33_33); return BigInt((((v + (v >>> 4)) & 0x0F_0F_0F_0F) * 0x01_01_01_01) >>> 24); } const uint64_0 = new BigInt64Array(1); const uint32_0 = new Int32Array(uint64_0.buffer); function fast_popcnt64(value: bigint) { uint64_0[0] = value; return fast_popcnt(uint32_0[0]) + fast_popcnt(uint32_0[1]); } const prefix = bits[v] - (v === 4 ? fast_popcnt(end - start) : fast_popcnt64(end - start));
- how
- Use a more compact internal data structure. Compare how
cidr-tools
andfast-cidr-tools
represent a CIDR internally:// cidr-tools parse('::/64'); //=> { cidr: '::/64', version: 6, prefix: '64', start: 0n, end: 18446744073709551615n } // fast-cidr-tools parse('::/64'); //=> [0n, 18446744073709551615n, 6]
- Avoid repeated calculations. Notice how
fast-cidr-tools
pre-parse inputs instead of parsing them repeatedly:
fast-cidr-tools © Sukka, Authored and maintained by Sukka with help from contributors (list).
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