Matt Jones' Blog » Code Fragment

Porting Tornado to D

mattjones — Sat, 13 Mar 2010 03:03:53 +0000

The other day I started porting the Tornado web server to D. I just got the IO Loop part ported. I’m planning on using this in my web framework Rootin Tootin.

You can check out the code on Launchpad: http://launchpad.net/dornado. Next I will add proper Epoll and the HTTP part. But in the meantime, you can try it out with this demo code snippet:

private import tango.net.device.Socket;
private import tango.io.model.IConduit;
private import tango.net.InternetAddress;
private import tango.io.Stdout;
public import ioloop;
 
class HelloServer {
    private ServerSocket sock;
    private char[1024] buffer;
 
    public void handle_connection(Socket connection, char[] address) {
        connection.read(buffer);
 
        connection.write("hello world!");
        connection.shutdown();
        connection.detach();
    }
 
    public void connection_ready(ServerSocket sock, ISelectable.Handle fd, uint events) {
        while(true) {
            Socket connection = sock.accept();
            connection.socket.blocking(false);
            handle_connection(connection, "");
        }
    }
 
    public void call_connection_ready(ISelectable.Handle fd, uint events) {
        connection_ready(sock, fd, events);
    }
 
    public void start() {
        int port = 3000;
        int max_waiting_clients = 128;
        bool reuse_address = true;
 
        this.sock = new ServerSocket(new InternetAddress("0.0.0.0", port), max_waiting_clients, reuse_address);
        this.sock.socket.blocking(false);
 
        auto io_loop = IOLoop.instance();
        auto callback = &this.call_connection_ready;
        io_loop.add_handler(this.sock.fileHandle, callback, io_loop.READ);
        Stdout("http://localhost:3000").newline.flush;
        io_loop.start(sock);
    }
}
 
public void main() {
    IOLoop.use_epoll = false;
    auto server = new HelloServer();
    server.start();
}

You can compile this with:
ldc helloworld.d ../ioloop.d ../language_helper.d

Python: Find objects of a certain type in memory

mattjones — Mon, 24 Aug 2009 04:33:43 +0000

This code snippet will allow you to look for objects of a certain type in memory. This is very useful for plugins:

"""
    This looks through all the objects in memory, to find ones
    of the designated type.
"""
 
import gc
 
class Animal(object):
    def make_noise(self):
        print "snort"
 
animal = Animal()
 
for obj in gc.get_objects():
    if type(obj) == Animal:
        obj.make_noise()

Code Fragment: How to programatically get MySQL table relationships

mattjones — Fri, 27 Feb 2009 19:43:47 +0000

This magical chunk of goodness will allow you to query a mysql database to determine what table fields are foreign keys, and what they reference. Just replace ‘database_name’ and ‘table_name’ with the respective names you want:

SELECT column_name, referenced_table_name,
referenced_column_name
FROM information_schema.key_column_usage
WHERE table_schema='database_name'
AND table_name='table_name'
AND referenced_table_name IS NOT NULL
AND referenced_column_name IS NOT NULL;