zig-picohttpparser

This is a small Zig wrapper to use picohttpparser.

picohttpparser could be used directly but this wrapper makes it feel more idiomatic Zig.

This package leverages the Zig build system and is based on zig-picohttpparser-sys.

Supported Zig version

Only Zig master is currently supported. Once 0.14.0 is released we should be able to support it.

Installation

Use zig fetch:

zig fetch --save git+https://github.com/vrischmann/zig-picohttpparser#master

You can then import picohttpparser in your build.zig:

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

your_exe.addImport("picohttpparser", picohttpparser.module("picohttpparser"));

Features implemented

picohttpparser doesn't have many features. The following is a list of what is implemented in this wrapper.

• Parsing a request
• Parsing a response
• Parsing chunk-encoded data
• Parsing headers only

Usage

There is only one function exposed, parseRequest:

pub fn parseRequest(buffer: []const u8, previous_buffer_len: usize) ParseRequestError!?ParseRequestResult {

This function takes in a buffer and a previous buffer length and returns either a parsing error or a result.

The buffer is easy to understand, it's the string you want to parse as an HTTP request. The previous buffer length is the length in the current buffer that you already tried to parse. This is needed to resume parsing incomplete buffers.

The returned result contains the raw request (of type RawRequest) and the number of bytes consumed from the buffer.

Here is an example usage:

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

pub fn main() !void {
    const data = "GET /lol/foo HTTP/1.0\r\nfoo: ab\r\nContent-Length: 200\r\n\r\n";

    if (try picohttpparser.parseRequest(data, 0)) |result| {
        std.log.info("request: {s}, consumed: {d}", .{ result.raw_request.getPath(), result.consumed });
    }
}

This assumes the data is complete, in the real world you probably can't assume this. You probably want to do something like this:

var buf = std.ArrayList(u8).init(allocator);
const result = while (true) {
    // Feed more data to buf somehow: read from a socket, copy from another buffer, etc

    if (try picohttpparser.parseRequest(buf.items, 0)) |result| {
        break result;
    }
};

// Use the result

Look into example/main.zig for a more complete example.

You can also take a look at my project zig-io_uring-http-server where I use picohttpparser.