Zig MaxMind DB Reader

This Zig package reads the MaxMind DB format. It's based on maxminddb-rust implementation.

⚠️ Note, that strings such as geolite2.City.postal.code are backed by the memory of an open database file. You must create a copy if you wish to continue using the string when the database is closed.

You'll need MaxMind-DB/test-data to run tests/examples and GeoLite2-City.mmdb to run the benchmark.

$ git submodule update --init
$ zig build test
$ zig build example_lookup
zh-CN = 瑞典
de = Schweden
pt-BR = Suécia
es = Suecia
en = Sweden
ru = Швеция
fr = Suède
ja = スウェーデン王国

Quick start

Add maxminddb.zig as a dependency in your build.zig.zon.

$ zig fetch --save git+https://github.com/marselester/maxminddb.zig#master

Add the maxminddb module as a dependency in your build.zig:

const mmdb = b.dependency("maxminddb", .{
    .target = target,
    .optimize = optimize,
});
exe.root_module.addImport("maxminddb", mmdb.module("maxminddb"));

See examples.

Suggestions

Try ArenaAllocator to get ~3% improvement in lookups per second (639,848 vs 659,630) as tested on Intel i5-10600, see examples/benchmark.zig.

If you don't need all the struct fields, define your own one. For example, commenting out all the geolite2.City's fields but geolite2.City.names increases throughput by 60% (639,848 vs 1,025,477 lookups per second).

$ zig build example_benchmark -Doptimize=ReleaseFast

Smp allocator

Benchmarking with:
  Database: GeoLite2-City.mmdb
  Lookups:  1000000
Opening database...
Database opened successfully in 0.086381 ms. Type: GeoLite2-City
Starting benchmark...

--- Benchmark Finished ---
Total Lookups Attempted: 1000000
Successful Lookups:      858992
IPs Not Found:           141008
Lookup Errors:           0
Elapsed Time:            1.562869106 s
Lookups Per Second (avg):639848.8498882644

Smp and Arena allocators

Benchmarking with:
  Database: GeoLite2-City.mmdb
  Lookups:  1000000
Opening database...
Database opened successfully in 0.051751 ms. Type: GeoLite2-City
Starting benchmark...

--- Benchmark Finished ---
Total Lookups Attempted: 1000000
Successful Lookups:      858715
IPs Not Found:           141285
Lookup Errors:           0
Elapsed Time:            1.516001233 s
Lookups Per Second (avg):659630.0703668359

Decoding names only

Benchmarking with:
  Database: GeoLite2-City.mmdb
  Lookups:  1000000
Opening database...
Database opened successfully in 0.061682 ms. Type: GeoLite2-City
Starting benchmark...

--- Benchmark Finished ---
Total Lookups Attempted: 1000000
Successful Lookups:      858516
IPs Not Found:           141484
Lookup Errors:           0
Elapsed Time:            0.975155208 s
Lookups Per Second (avg):1025477.7821993645