src/jagi/scgi/EventServer.java

   1 package jagi.scgi;
   2
   3 import jagi.*;
   4 import jagi.event.*;
   5 import java.util.*;
   6 import java.util.function.*;
   7 import java.util.concurrent.*;
   8 import java.util.logging.*;
   9 import java.io.*;
  10 import java.nio.*;
  11 import java.nio.channels.*;
  12
  13 public class EventServer implements Runnable {
  14     private static final double timeout = 5;
  15     private static final Logger log = Logger.getLogger("jagi.server");
  16     private final ServerSocketChannel sk;
  17     private final Function handler;
  18     private final Driver ev = Driver.get();
  19     private final ExecutorService handlers = new ThreadPoolExecutor(0, Runtime.getRuntime().availableProcessors() * 2,
  20                                                                     5, TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>(64),
  21                                                                     tgt -> new Thread(tgt, "Request handler thread"));
  22
  23     public EventServer(ServerSocketChannel sk, Function handler) {
  24         try {
  25             sk.configureBlocking(false);
  26         } catch(IOException e) {
  27             throw(new RuntimeException(e));
  28         }
  29         this.sk = sk;
  30         this.handler = handler;
  31     }
  32
  33     public static class Request {
  34         public final Map<Object, Object> env;
  35         public final SocketChannel sk;
  36
  37         public Request(Map<Object, Object> env, SocketChannel sk) {
  38             this.env = env;
  39             this.sk = sk;
  40         }
  41
  42         public void close() {
  43             ArrayList<Object> cleanup = new ArrayList<>((Collection<?>)env.get("jagi.cleanup"));
  44             cleanup.add(sk);
  45             RuntimeException ce = null;
  46             for(Object obj : cleanup) {
  47                 if(obj instanceof AutoCloseable) {
  48                     try {
  49                         ((AutoCloseable)obj).close();
  50                     } catch(Exception e) {
  51                         if(ce == null)
  52                             ce = new RuntimeException("error(s) occurred during cleanup");
  53                         ce.addSuppressed(e);
  54                     }
  55                 }
  56             }
  57             if(ce != null)
  58                 throw(ce);
  59         }
  60     }
  61
  62     protected void error(Request req, Throwable error) {
  63         log.log(Level.WARNING, "uncaught exception while handling request", error);
  64     }
  65
  66     public static abstract class ChainWatcher implements Watcher {
  67         private Runnable then;
  68         public ChainWatcher then(Runnable then) {this.then = then; return(this);}
  69
  70         public void close() {
  71             if(then != null)
  72                 then.run();
  73         }
  74     }
  75
  76     public static class BufferedOutput extends ChainWatcher {
  77         public final SocketChannel sk;
  78         public final ByteBuffer buf;
  79         private double lastwrite;
  80
  81         public BufferedOutput(SocketChannel sk, ByteBuffer buf) {
  82             this.sk = sk;
  83             this.buf = buf;
  84         }
  85
  86         public void added(Driver d) {lastwrite = d.time();}
  87         public SelectableChannel channel() {return(sk);}
  88         public int events() {return((buf.remaining() > 0) ? SelectionKey.OP_WRITE : -1);}
  89         public double timeout() {return(lastwrite + timeout);}
  90
  91         public void handle(int events) throws IOException {
  92             double now = Driver.current().time();
  93             if((events & SelectionKey.OP_WRITE) != 0) {
  94                 if(sk.write(buf) > 0)
  95                     lastwrite = now;
  96             }
  97             if(now > lastwrite + timeout)
  98                 buf.position(buf.limit());
  99         }
 100     }
 101
 102     public static class TransferOutput extends ChainWatcher {
 103         public final SocketChannel sk;
 104         public final ReadableByteChannel in;
 105         private final ByteBuffer buf;
 106         private boolean eof = false;
 107         private double lastwrite;
 108
 109         public TransferOutput(SocketChannel sk, ReadableByteChannel in) {
 110             this.sk = sk;
 111             this.in = in;
 112             buf = ByteBuffer.allocate(65536);
 113             buf.flip();
 114         }
 115
 116         public void added(Driver d) {lastwrite = d.time();}
 117         public SelectableChannel channel() {return(sk);}
 118         public int events() {return((eof && (buf.remaining() == 0)) ? -1 : SelectionKey.OP_WRITE);}
 119         public double timeout() {return(lastwrite + timeout);}
 120
 121         public void handle(int events) throws IOException {
 122             if(!eof && (buf.remaining() == 0)) {
 123                 buf.rewind();
 124                 while(buf.remaining() > 0) {
 125                     if(in.read(buf) < 0)
 126                         break;
 127                 }
 128             }
 129             double now = Driver.current().time();
 130             if((events & SelectionKey.OP_WRITE) != 0) {
 131                 if(sk.write(buf) > 0)
 132                     lastwrite = now;
 133             }
 134             if(now > lastwrite + timeout) {
 135                 eof = true;
 136                 buf.position(buf.limit());
 137             }
 138         }
 139
 140         public void close() {
 141             try {
 142                 in.close();
 143             } catch(IOException e) {
 144                 log.log(Level.WARNING, "failed to close transfer channel: " + in, e);
 145             } finally {
 146                 super.close();
 147             }
 148         }
 149     }
 150
 151     public static class TransferInput extends ChainWatcher {
 152         public final SocketChannel sk;
 153         public final WritableByteChannel out;
 154         private final ByteBuffer buf;
 155         private final long max;
 156         private boolean eof = false;
 157         private double lastread;
 158         private long cur = 0;
 159
 160         public TransferInput(SocketChannel sk, WritableByteChannel out, long max) {
 161             this.sk = sk;
 162             this.out = out;
 163             this.max = max;
 164             buf = ByteBuffer.allocate(65536);
 165             buf.flip();
 166         }
 167
 168         public void added(Driver d) {lastread = d.time();}
 169         public SelectableChannel channel() {return(sk);}
 170         public int events() {return(eof ? -1 : SelectionKey.OP_READ);}
 171         public double timeout() {return(lastread + timeout);}
 172
 173         public void handle(int events) throws IOException {
 174             double now = Driver.current().time();
 175             if((events & SelectionKey.OP_READ) != 0) {
 176                 buf.rewind();
 177                 if(buf.remaining() > max - cur)
 178                     buf.limit(buf.position() + (int)Math.min(max - cur, Integer.MAX_VALUE));
 179                 int rv = sk.read(buf);
 180                 if(rv < 0) {
 181                     eof = true;
 182                 } else if(rv > 0) {
 183                     lastread = now;
 184                     cur += rv;
 185                 }
 186                 buf.flip();
 187                 while(buf.remaining() > 0)
 188                     out.write(buf);
 189             }
 190             if(now > lastread + timeout) {
 191                 eof = true;
 192                 buf.position(buf.limit());
 193             }
 194         }
 195
 196         public void close() {
 197             try {
 198                 out.close();
 199             } catch(IOException e) {
 200                 log.log(Level.WARNING, "failed to close transfer channel: " + out, e);
 201             } finally {
 202                 super.close();
 203             }
 204         }
 205     }
 206
 207     protected void respond(Request req, String status, Map resp) {
 208         Object output = resp.get("jagi.output");
 209         ByteArrayOutputStream buf = new ByteArrayOutputStream();
 210         try {
 211             Writer head = new OutputStreamWriter(buf, Utils.UTF8);
 212             head.write("Status: ");
 213             head.write(status);
 214             head.write("\n");
 215             for(Iterator it = resp.entrySet().iterator(); it.hasNext();) {
 216                 Map.Entry ent = (Map.Entry)it.next();
 217                 Object val = ent.getValue();
 218                 if((ent.getKey() instanceof String) && (val != null)) {
 219                     String key = (String)ent.getKey();
 220                     if(key.startsWith("http.")) {
 221                         String nm = key.substring(5);
 222                         if(nm.equalsIgnoreCase("status"))
 223                             continue;
 224                         if(val instanceof Collection) {
 225                             for(Object part : (Collection)val) {
 226                                 head.write(nm);
 227                                 head.write(": ");
 228                                 head.write(part.toString());
 229                                 head.write("\n");
 230                             }
 231                         } else {
 232                             head.write(nm);
 233                             head.write(": ");
 234                             head.write(val.toString());
 235                             head.write("\n");
 236                         }
 237                     }
 238                 }
 239             }
 240             head.write("\n");
 241             head.flush();
 242         } catch(IOException e) {
 243             throw(new RuntimeException("cannot happen"));
 244         }
 245         ChainWatcher out;
 246         if(output == null) {
 247             out = new BufferedOutput(req.sk, ByteBuffer.allocate(0));
 248         } else if(output instanceof byte[]) {
 249             out = new BufferedOutput(req.sk, ByteBuffer.wrap((byte[])output));
 250         } else if(output instanceof ByteBuffer) {
 251             out = new BufferedOutput(req.sk, (ByteBuffer)output);
 252         } else if(output instanceof String) {
 253             out = new BufferedOutput(req.sk, ByteBuffer.wrap(((String)output).getBytes(Utils.UTF8)));
 254         } else if(output instanceof CharSequence) {
 255             out = new BufferedOutput(req.sk, Utils.UTF8.encode(CharBuffer.wrap((CharSequence)output)));
 256         } else if(output instanceof InputStream) {
 257             out = new TransferOutput(req.sk, Channels.newChannel((InputStream)output));
 258         } else if(output instanceof ReadableByteChannel) {
 259             out = new TransferOutput(req.sk, (ReadableByteChannel)output);
 260         } else {
 261             throw(new IllegalArgumentException("response-body: " + output));
 262         }
 263         out.then(() -> submit(req::close));
 264         ev.add(new BufferedOutput(req.sk, ByteBuffer.wrap(buf.toByteArray())).then(() -> ev.add(out)));
 265     }
 266
 267     @SuppressWarnings("unchecked")
 268     protected void handle(Request req, Function handler) {
 269         boolean handoff = false;
 270         try {
 271             Throwable error = null;
 272             try {
 273                 Map resp = (Map)handler.apply(req.env);
 274                 String st;
 275                 if((st = (String)resp.get("jagi.status")) != null) {
 276                     Function next = (Function)resp.get("jagi.next");
 277                     switch(st) {
 278                     case "feed-input":
 279                         Object sink = resp.get("jagi.input-sink");
 280                         Object clen = req.env.get("HTTP_CONTENT_LENGTH");
 281                         long max = 0;
 282                         if(clen instanceof String) {
 283                             try {
 284                                 max = Long.parseLong((String)clen);
 285                             } catch(NumberFormatException e) {
 286                             }
 287                         }
 288                         if(sink instanceof WritableByteChannel) {
 289                             ev.add(new TransferInput(req.sk, (WritableByteChannel)sink, max).then(() -> submit(() -> handle(req, next))));
 290                         } else if(sink instanceof OutputStream) {
 291                             ev.add(new TransferInput(req.sk, Channels.newChannel((OutputStream)sink), max).then(() -> submit(() -> handle(req, next))));
 292                         } else {
 293                             throw(new IllegalArgumentException("input-sink: " + sink));
 294                         }
 295                         handoff = true;
 296                         break;
 297                     case "chain":
 298                         submit(() -> handle(req, next));
 299                         handoff = true;
 300                         break;
 301                     default:
 302                         throw(new IllegalArgumentException("jagi.status: " + st));
 303                     }
 304                 } else if((st = (String)resp.get("http.status")) != null) {
 305                     respond(req, st, resp);
 306                     handoff = true;
 307                 } else {
 308                     throw(new IllegalArgumentException("neither http.status nor jagi.status set"));
 309                 }
 310             } catch(Throwable t) {
 311                 error = t;
 312                 throw(t);
 313             } finally {
 314                 if(!handoff) {
 315                     try {
 316                         req.close();
 317                     } catch(Throwable ce) {
 318                         if(error == null) {
 319                             throw(ce);
 320                         } else {
 321                             error.addSuppressed(ce);
 322                         }
 323                     }
 324                 }
 325             }
 326         } catch(Throwable t) {
 327             error(req, t);
 328         }
 329     }
 330
 331     protected void submit(Runnable task) {
 332         handlers.submit(task);
 333     }
 334
 335     class Client implements Watcher {
 336         final SocketChannel sk;
 337         double lastread;
 338         boolean eof = false, handoff = false;
 339         int headlen = 0;
 340         ByteBuffer head = null;
 341         Map<Object, Object> env = null;
 342
 343         Client(SocketChannel sk) {
 344             this.sk = sk;
 345         }
 346
 347         public void added(Driver d) {lastread = d.time();}
 348         public SelectableChannel channel() {return(sk);}
 349         public double timeout() {return(lastread + timeout);}
 350         public int events() {
 351             if(eof)
 352                 return(-1);
 353             if(env == null)
 354                 return(SelectionKey.OP_READ);
 355             return(-1);
 356         }
 357
 358         boolean readhead() throws IOException {
 359             if(head == null) {
 360                 ByteBuffer buf = ByteBuffer.allocate(1);
 361                 while(true) {
 362                     buf.rewind();
 363                     int rv = sk.read(buf);
 364                     if(rv < 0) {
 365                         eof = true;
 366                         return(false);
 367                     } else if(rv == 0) {
 368                         return(false);
 369                     } else {
 370                         lastread = Driver.current().time();
 371                         int c = buf.get(0);
 372                         if((c >= '0') && (c <= '9')) {
 373                             headlen = (headlen * 10) + (c - '0');
 374                         } else if(c == ':') {
 375                             head = ByteBuffer.allocate(headlen + 1);
 376                             break;
 377                         } else {
 378                             eof = true;
 379                             return(false);
 380                         }
 381                     }
 382                 }
 383             }
 384             while(true) {
 385                 if(head.remaining() == 0) {
 386                     if(head.get(head.limit() - 1) != ',') {
 387                         /* Unterminated netstring */
 388                         eof = true;
 389                         return(false);
 390                     }
 391                     head.limit(head.limit() - 1);
 392                     env = Jagi.mkenv(Scgi.splithead(head), sk);
 393                     return(true);
 394                 }
 395                 int rv = sk.read(head);
 396                 if(rv < 0) {
 397                     eof = true;
 398                     return(false);
 399                 } else if(rv == 0) {
 400                     return(false);
 401                 }
 402             }
 403         }
 404
 405         public void handle(int events) throws IOException {
 406             if((events & SelectionKey.OP_READ) != 0) {
 407                 if((env == null) && !readhead())
 408                     return;
 409                 Request req = new Request(env, sk);
 410                 submit(() -> EventServer.this.handle(req, handler));
 411                 handoff = true;
 412             }
 413             if(Driver.current().time() > (lastread + timeout))
 414                 eof = true;
 415         }
 416
 417         public void close() {
 418             if(!handoff) {
 419                 try {
 420                     sk.close();
 421                 } catch(IOException e) {
 422                 }
 423             }
 424         }
 425     }
 426
 427     class Accepter implements Watcher {
 428         boolean closed = false;
 429
 430         public SelectableChannel channel() {return(sk);}
 431         public int events() {return(SelectionKey.OP_ACCEPT);}
 432
 433         public void handle(int events) throws IOException {
 434             if((events & SelectionKey.OP_ACCEPT) != 0) {
 435                 SocketChannel cl = sk.accept();
 436                 cl.configureBlocking(false);
 437                 Driver.current().add(new Client(cl));
 438             }
 439         }
 440
 441         public void close() {
 442             synchronized(this) {
 443                 closed = true;
 444                 notifyAll();
 445             }
 446         }
 447     }
 448
 449     public void run() {
 450         Accepter main = new Accepter();
 451         ev.add(main);
 452         try {
 453             synchronized(main) {
 454                 while(!main.closed) {
 455                     main.wait();
 456                 }
 457             }
 458         } catch(InterruptedException e) {
 459             ev.remove(main);
 460         } finally {
 461             try {
 462                 sk.close();
 463             } catch(IOException e) {
 464                 throw(new RuntimeException(e));
 465             }
 466         }
 467     }
 468 }