Added event-driven server.

[jagi.git] / src / jagi / scgi / Bootstrap.java

package jagi.scgi;

import jagi.*;
import java.lang.reflect.*;
import java.util.*;
import java.util.function.*;
import java.io.*;
import java.net.*;
import java.nio.channels.*;

public class Bootstrap {
    private static InetSocketAddress resolveinaddr(String spec) {
	int p = spec.indexOf(':');
	SocketAddress bind;
	if(p >= 0) {
	    InetAddress host;
	    try {
		if(spec.charAt(0) == '[') {
		    p = spec.indexOf(']');
		    if((p < 0) || (spec.charAt(p + 1) != ':'))
			throw(new IllegalArgumentException("invalid address syntax: " + spec));
		    host = InetAddress.getByName(spec.substring(1, p));
		    p++;
		} else {
		    host = InetAddress.getByName(spec.substring(0, p));
		}
	    } catch(UnknownHostException e) {
		throw(new IllegalArgumentException("could not resolve inet host: " + spec, e));
	    }
	    try {
		return(new InetSocketAddress(host, Integer.parseInt(spec.substring(p + 1))));
	    } catch(NumberFormatException e) {
		throw(new IllegalArgumentException("not a valid port number: " + spec.substring(p + 1), e));
	    }
	} else {
	    try {
		return(new InetSocketAddress(Integer.parseInt(spec)));
	    } catch(NumberFormatException e) {
		throw(new IllegalArgumentException("not a valid port number: " + spec, e));
	    }
	}
    }

    private static ServerSocketChannel tcplisten(String spec) {
	SocketAddress bind;
	try {
	    bind = resolveinaddr(spec);
	} catch(IllegalArgumentException e) {
	    System.err.println("scgi-jagi: " + e.getMessage());
	    System.exit(1);
	    return(null);
	}
	try {
	    ServerSocketChannel sk = ServerSocketChannel.open();
	    sk.bind(bind);
	    return(sk);
	} catch(IOException e) {
	    System.err.println("scgi-jagi: could not create TCP socket: " + e.getMessage());
	    System.exit(1);
	    return(null);
	}
    }

    private static ServerSocketChannel getstdin() {
	Channel stdin;
	try {
	    stdin = System.inheritedChannel();
	} catch(IOException e) {
	    System.err.println("scgi-jagi: could not get stdin channel: " + e.getMessage());
	    System.exit(1);
	    return(null);
	}
	if(!(stdin instanceof ServerSocketChannel)) {
	    System.err.println("scgi-jagi: stdin is not a listening socket");
	    System.exit(1);
	    return(null);
	}
	return((ServerSocketChannel)stdin);
    }

    private static Function gethandler(ClassLoader loader, String nm, String... args) {
	Class<?> cl;
	try {
	    cl = loader.loadClass(nm);
	} catch(ClassNotFoundException e) {
	    try {
		cl = loader.loadClass(nm + ".Bootstrap");
	    } catch(ClassNotFoundException e2) {
		System.err.println("scgi-jagi: could not find handler class or package: " + nm);
		System.exit(1);
		return(null);
	    }
	}
	Method wmain;
	try {
	    wmain = cl.getDeclaredMethod("wmain", String[].class);
	    int mod = wmain.getModifiers();
	    if(((mod & Modifier.STATIC) == 0) || ((mod & Modifier.PUBLIC) == 0))
		throw(new NoSuchMethodException());
	} catch(NoSuchMethodException e) {
	    System.err.println("scgi-jagi: could not find wmain method in " + cl.getName());
	    System.exit(1);
	    return(null);
	}
	Object handler;
	try {
	    handler = wmain.invoke(null, new Object[] {args});
	} catch(IllegalAccessException e) {
	    System.err.println("scgi-jagi: could not call wmain in " + cl.getName());
	    System.exit(1);
	    return(null);
	} catch(InvocationTargetException e) {
	    System.err.println("scgi-jagi: wmain in " + cl.getName() + " failed");
	    e.printStackTrace(System.err);
	    System.exit(1);
	    return(null);
	}
	if(!(handler instanceof Function)) {
	    System.err.println("scgi-jagi: wmain in " + cl.getName() + " returned " + ((handler == null) ? "null" : ("a " + handler.getClass())));
	    System.exit(1);
	    return(null);
	}
	return((Function)handler);
    }

    private static void usage(PrintStream out) {
	out.println("usage: jagi.jar [-h] [-T [HOST:]PORT] HANDLER-CLASS [ARGS...]");
    }

    public static void main(String[] args) {
	PosixArgs opt = PosixArgs.getopt(args, "hT:");
	if(opt == null) {
	    usage(System.err);
	    System.exit(1);
	    return;
	}
	String tcpspec = null;
	ClassLoader loader = Bootstrap.class.getClassLoader();
	for(char c : opt.parsed()) {
	    switch(c) {
	    case 'h':
		usage(System.out);
		System.exit(0);
		break;
	    case 'T':
		tcpspec = opt.arg;
		break;
	    }
	}
	if(opt.rest.length < 1) {
	    usage(System.err);
	    System.exit(1);
	    return;
	}
	Function handler = gethandler(loader, opt.rest[0], Arrays.copyOfRange(opt.rest, 1, opt.rest.length));
	ServerSocketChannel sk;
	if(tcpspec != null) {
	    sk = tcplisten(tcpspec);
	} else {
	    sk = getstdin();
	}
	Runnable server = new EventServer(sk, handler);
	try {
	    server.run();
	} catch(Throwable e) {
	    System.err.println("scgi-jagi: server exited abnormally");
	    e.printStackTrace();
	    System.exit(1);
	}
	System.exit(0);
    }
}