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