handy-httpd 1.1.0

handy-httpd

An extremely lightweight HTTP server for the D programming language. Handy-httpd uses a simple worker pool to process incoming requests, in conjunction with a user-defined HttpRequestHandler. Consider the following example:

import handy_httpd;

void main() {
	auto s = new HttpServer(new FileResolvingHandler("static"));
	s.start();
}

We create a new HttpServer that is using a FileResolvingHandler (tries to serve static files according to URL path), and start it. It's that simple.

It's also quite simple to define your own custom request handler. Here's an example of a custom request handler that only responds to the /hello endpoint:

import handy_httpd;

void main() {
	auto s = new HttpServer(simpleHandler((request) {
		if (request.url == "/hello") {
			return okResponse()
				.setBody("Hello world!");
		} else {
			return notFound();
		}
	}));
	s.start();
}

Note: the HttpRequestHandler simpleHandler(HttpResponse function(HttpRequest) fn) function allows you to pass a function as a request handler. Internally, it's using an anonymous class.

Besides these barebones showcases, handy-httpd also gives you the ability to configure almost everything about how the server works, including the following properties:

• Hostname and port
• Connection queue size.
• Receive buffer size.
• Whether to show verbose logging output.
• Number of worker threads to use for request processing.

Requests

Each HTTP request is parsed into the following struct for use with any HttpRequestHandler:

struct HttpRequest {
    public const string method;
    public const string url;
    public const int ver;
    public const string[string] headers;
    public const string[string] params;
}

Responses

The following struct is used to send responses from any HttpRequestHandler:

struct HttpResponse {
    ushort status;
    string statusText;
    string[string] headers;
    ubyte[] messageBody;

Path-Delegating Handler

In many cases, you'll want a dedicated handler for specific URL paths on your server. You can achieve this with the PathDelegatingHandler.

import handy_httpd.server;
import handy_httpd.responses;
import handy_httpd.handlers.path_delegating_handler;
import handy_httpd.handlers.file_resolving_handler;

auto handler = new PathDelegatingHandler()
	.addPath("/home", simpleHandler(request => okResponse()))
	.addPath("/users", simpleHandler(request => okResponse()))
	.addPath("/users/{id}", simpleHandler(request => okResponse()))
	.addPath("/files/**", new FileResolvingHandler("static-files"));

HttpServer server = new HttpServer(handler);

The PathDelegatingHandler allows you to register an HttpRequestHandler for specific path patterns. These patterns allow for some basic Ant-style path matching:

** will match any substring in a path, including multiple segments.

/users/**
  WILL match: /users
  WILL match: /users/123
  WILL match: /users/abc/123
  WILL NOT match: /user

* will match a single segment in a path.

/users/*
  WILL match: /users/123
  WILL match: /users/a
  WILL NOT match: /users/a/b

? will match a single character in a path.

/users/?
  WILL match: /users/a
  WILL match: /users/1
  WILL NOT match: /users/123
  WILL NOT match: /users