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zimit

api atomics backend concurrency gcra generic-cell-rate-algorithm networking rate-limit rate-limiter rate-limiting scheduler server throttle throttling token-bucket zero-allocation zigistry

zimit

A zero-dependency GCRA-based rate limiter with a token-bucket-like API for Zig 0.16.0+.

Features

  • Global limiting: Use GlobalLimiter when you want a single shared limit across all requests (e.g. protect total server throughput). It’s lock-free and thread-safe.
  • Per-key rate limiting: Each key is tracked independently (e.g. per user ID or IP address). The RateLimiter is not thread-safe. If you share it across multiple threads, you should protect it with a std.Io.Mutex.
  • Blocking vs non-blocking:
    • allow() → Immediate decision
    • wait(io, key) → Blocks until allowed (uses std.Io.sleep)
  • Clocks:
    • SystemClock → Production (requires std.process.Init.io)
    • ManualClock → Deterministic tests

Usage

const std = @import("std");
const zimit = @import("zimit");

pub fn main(init: std.process.Init) !void {
    const gpa = init.gpa;
    const io = init.io;

    var sys = zimit.SystemClock.init(io);

    var limiter = try zimit.RateLimiter([]const u8).init(.{
        .allocator = gpa,
        .rate = 5,
        .per = .second,
        .burst = 2,
        .clock = sys.clock(),
    });
    defer limiter.deinit();

    const key = "127.0.0.1";

    var i: usize = 0;
    while (i < 5) : (i += 1) {
        switch (try limiter.allow(key)) {
            .allowed => std.debug.print("allowed\n", .{}),
            .denied => |d| {
                std.debug.print("denied, time until allowed: {d}ms\n", .{d.retry_after_ms_ceil()});
            },
        }
    }
}

See examples for more.

Installation

Run:

zig fetch --save git+https://github.com/minhqdao/zimit.git#0.2.1

Then in your build.zig:

const zimit_dep = b.dependency("zimit", .{
    .target = target,
    .optimize = optimize,
});

const exe = b.addExecutable(.{
    .name = "yourapp",
    .root_module = b.createModule(.{
        .root_source_file = b.path("src/main.zig"),
        .target = target,
        .optimize = optimize,
        .imports = &.{
            .{ .name = "zimit", .module = zimit_dep.module("zimit") },
        },
    }),
});

License

MIT

Install 
zig f -S zub.sh/zimit
Repository
License
MIT
Category
Author
minhqdao
minhqdao
Dependencies

No explicit dependencies.

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