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.rewind();
 119                 while(buf.remaining() > 0) {
 120                     if(in.read(buf) < 0)
 121                         break;
 122                 }
 123             }
 124             double now = Driver.current().time();
 125             if((events & SelectionKey.OP_WRITE) != 0) {
 126                 if(sk.write(buf) > 0)
 127                     lastwrite = now;
 128             }
 129             if(now > lastwrite + timeout) {
 130                 eof = true;
 131                 buf.position(buf.limit());
 132             }
 133         }
 134
 135         public void close() {
 136             try {
 137                 in.close();
 138             } catch(IOException e) {
 139                 log.log(Level.WARNING, "failed to close transfer channel: " + in, e);
 140             } finally {
 141                 super.close();
 142             }
 143         }
 144     }
 145
 146     public static class TransferInput extends ChainWatcher {
 147         public final SocketChannel sk;
 148         public final WritableByteChannel out;
 149         private final ByteBuffer buf;
 150         private final long max;
 151         private boolean eof = false;
 152         private double lastread;
 153         private long cur = 0;
 154
 155         public TransferInput(SocketChannel sk, WritableByteChannel out, long max) {
 156             this.sk = sk;
 157             this.out = out;
 158             this.max = max;
 159             buf = ByteBuffer.allocate(65536);
 160             buf.flip();
 161         }
 162
 163         public void added(Driver d) {lastread = d.time();}
 164         public SelectableChannel channel() {return(sk);}
 165         public int events() {return(eof ? -1 : SelectionKey.OP_READ);}
 166         public double timeout() {return(lastread + timeout);}
 167
 168         public void handle(int events) throws IOException {
 169             double now = Driver.current().time();
 170             if((events & SelectionKey.OP_READ) != 0) {
 171                 buf.rewind();
 172                 if(buf.remaining() > max - cur)
 173                     buf.limit(buf.position() + (int)Math.min(max - cur, Integer.MAX_VALUE));
 174                 int rv = sk.read(buf);
 175                 if(rv < 0) {
 176                     eof = true;
 177                 } else if(rv > 0) {
 178                     lastread = now;
 179                     cur += rv;
 180                 }
 181                 buf.flip();
 182                 while(buf.remaining() > 0)
 183                     out.write(buf);
 184             }
 185             if(now > lastread + timeout) {
 186                 eof = true;
 187                 buf.position(buf.limit());
 188             }
 189         }
 190
 191         public void close() {
 192             try {
 193                 out.close();
 194             } catch(IOException e) {
 195                 log.log(Level.WARNING, "failed to close transfer channel: " + out, e);
 196             } finally {
 197                 super.close();
 198             }
 199         }
 200     }
 201
 202     protected void respond(Request req, String status, Map resp) {
 203         Object output = resp.get("jagi.output");
 204         ByteArrayOutputStream buf = new ByteArrayOutputStream();
 205         try {
 206             Writer head = new OutputStreamWriter(buf, Utils.UTF8);
 207             head.write("Status: ");
 208             head.write(status);
 209             head.write("\n");
 210             for(Iterator it = resp.entrySet().iterator(); it.hasNext();) {
 211                 Map.Entry ent = (Map.Entry)it.next();
 212                 Object val = ent.getValue();
 213                 if((ent.getKey() instanceof String) && (val != null)) {
 214                     String key = (String)ent.getKey();
 215                     if(key.startsWith("http.")) {
 216                         String nm = key.substring(5);
 217                         if(nm.equalsIgnoreCase("status"))
 218                             continue;
 219                         if(val instanceof Collection) {
 220                             for(Object part : (Collection)val) {
 221                                 head.write(nm);
 222                                 head.write(": ");
 223                                 head.write(part.toString());
 224                                 head.write("\n");
 225                             }
 226                         } else {
 227                             head.write(nm);
 228                             head.write(": ");
 229                             head.write(val.toString());
 230                             head.write("\n");
 231                         }
 232                     }
 233                 }
 234             }
 235             head.write("\n");
 236             head.flush();
 237         } catch(IOException e) {
 238             throw(new RuntimeException("cannot happen"));
 239         }
 240         ChainWatcher out;
 241         if(output == null) {
 242             out = new BufferedOutput(req.sk, ByteBuffer.allocate(0));
 243         } else if(output instanceof byte[]) {
 244             out = new BufferedOutput(req.sk, ByteBuffer.wrap((byte[])output));
 245         } else if(output instanceof ByteBuffer) {
 246             out = new BufferedOutput(req.sk, (ByteBuffer)output);
 247         } else if(output instanceof String) {
 248             out = new BufferedOutput(req.sk, ByteBuffer.wrap(((String)output).getBytes(Utils.UTF8)));
 249         } else if(output instanceof CharSequence) {
 250             out = new BufferedOutput(req.sk, Utils.UTF8.encode(CharBuffer.wrap((CharSequence)output)));
 251         } else if(output instanceof InputStream) {
 252             out = new TransferOutput(req.sk, Channels.newChannel((InputStream)output));
 253         } else if(output instanceof ReadableByteChannel) {
 254             out = new TransferOutput(req.sk, (ReadableByteChannel)output);
 255         } else {
 256             throw(new IllegalArgumentException("response-body: " + output));
 257         }
 258         out.then(() -> submit(req::close));
 259         ev.add(new BufferedOutput(req.sk, ByteBuffer.wrap(buf.toByteArray())).then(() -> ev.add(out)));
 260     }
 261
 262     @SuppressWarnings("unchecked")
 263     protected void handle(Request req, Function handler) {
 264         boolean handoff = false;
 265         try {
 266             Throwable error = null;
 267             try {
 268                 Map resp = (Map)handler.apply(req.env);
 269                 String st;
 270                 if((st = (String)resp.get("jagi.status")) != null) {
 271                     Function next = (Function)resp.get("jagi.next");
 272                     switch(st) {
 273                     case "feed-input":
 274                         Object sink = resp.get("jagi.input-sink");
 275                         Object clen = req.env.get("HTTP_CONTENT_LENGTH");
 276                         long max = 0;
 277                         if(clen instanceof String) {
 278                             try {
 279                                 max = Long.parseLong((String)clen);
 280                             } catch(NumberFormatException e) {
 281                             }
 282                         }
 283                         if(sink instanceof WritableByteChannel) {
 284                             ev.add(new TransferInput(req.sk, (WritableByteChannel)sink, max).then(() -> submit(() -> handle(req, next))));
 285                         } else if(sink instanceof OutputStream) {
 286                             ev.add(new TransferInput(req.sk, Channels.newChannel((OutputStream)sink), max).then(() -> submit(() -> handle(req, next))));
 287                         } else {
 288                             throw(new IllegalArgumentException("input-sink: " + sink));
 289                         }
 290                         handoff = true;
 291                         break;
 292                     case "chain":
 293                         submit(() -> handle(req, next));
 294                         handoff = true;
 295                         break;
 296                     default:
 297                         throw(new IllegalArgumentException("jagi.status: " + st));
 298                     }
 299                 } else if((st = (String)resp.get("http.status")) != null) {
 300                     respond(req, st, resp);
 301                     handoff = true;
 302                 } else {
 303                     throw(new IllegalArgumentException("neither http.status nor jagi.status set"));
 304                 }
 305             } catch(Throwable t) {
 306                 error = t;
 307                 throw(t);
 308             } finally {
 309                 if(!handoff) {
 310                     try {
 311                         req.close();
 312                     } catch(Throwable ce) {
 313                         if(error == null) {
 314                             throw(ce);
 315                         } else {
 316                             error.addSuppressed(ce);
 317                         }
 318                     }
 319                 }
 320             }
 321         } catch(Throwable t) {
 322             error(req, t);
 323         }
 324     }
 325
 326     protected void submit(Runnable task) {
 327         handlers.submit(task);
 328     }
 329
 330     class Client implements Watcher {
 331         final SocketChannel sk;
 332         double lastread;
 333         boolean eof = false, handoff = false;
 334         int headlen = 0;
 335         ByteBuffer head = null;
 336         Map<Object, Object> env = null;
 337         Request req = null;
 338
 339         Client(SocketChannel sk) {
 340             this.sk = sk;
 341         }
 342
 343         public void added(Driver d) {lastread = d.time();}
 344         public SelectableChannel channel() {return(sk);}
 345         public double timeout() {return(lastread + timeout);}
 346         public int events() {
 347             if(eof)
 348                 return(-1);
 349             if(env == null)
 350                 return(SelectionKey.OP_READ);
 351             return(-1);
 352         }
 353
 354         boolean readhead() throws IOException {
 355             if(head == null) {
 356                 ByteBuffer buf = ByteBuffer.allocate(1);
 357                 while(true) {
 358                     buf.rewind();
 359                     int rv = sk.read(buf);
 360                     if(rv < 0) {
 361                         eof = true;
 362                         return(false);
 363                     } else if(rv == 0) {
 364                         return(false);
 365                     } else {
 366                         lastread = Driver.current().time();
 367                         int c = buf.get(0);
 368                         if((c >= '0') && (c <= '9')) {
 369                             headlen = (headlen * 10) + (c - '0');
 370                         } else if(c == ':') {
 371                             head = ByteBuffer.allocate(headlen + 1);
 372                             break;
 373                         } else {
 374                             eof = true;
 375                             return(false);
 376                         }
 377                     }
 378                 }
 379             }
 380             while(true) {
 381                 if(head.remaining() == 0) {
 382                     if(head.get(head.limit() - 1) != ',') {
 383                         /* Unterminated netstring */
 384                         eof = true;
 385                         return(false);
 386                     }
 387                     head.limit(head.limit() - 1);
 388                     env = Jagi.mkenv(Scgi.splithead(head), sk);
 389                     return(true);
 390                 }
 391                 int rv = sk.read(head);
 392                 if(rv < 0) {
 393                     eof = true;
 394                     return(false);
 395                 } else if(rv == 0) {
 396                     return(false);
 397                 }
 398             }
 399         }
 400
 401         public void handle(int events) throws IOException {
 402             if((events & SelectionKey.OP_READ) != 0) {
 403                 if((env == null) && !readhead())
 404                     return;
 405                 req = new Request(env, sk);
 406                 handoff = true;
 407             }
 408             if(Driver.current().time() > (lastread + timeout))
 409                 eof = true;
 410         }
 411
 412         public void close() {
 413             if(req != null)
 414                 submit(() -> EventServer.this.handle(req, handler));
 415             if(!handoff) {
 416                 try {
 417                     sk.close();
 418                 } catch(IOException e) {
 419                 }
 420             }
 421         }
 422     }
 423
 424     class Accepter implements Watcher {
 425         boolean closed = false;
 426
 427         public SelectableChannel channel() {return(sk);}
 428         public int events() {return(SelectionKey.OP_ACCEPT);}
 429
 430         public void handle(int events) throws IOException {
 431             if((events & SelectionKey.OP_ACCEPT) != 0)
 432                 Driver.current().add(new Client(sk.accept()));
 433         }
 434
 435         public void close() {
 436             synchronized(this) {
 437                 closed = true;
 438                 notifyAll();
 439             }
 440         }
 441     }
 442
 443     public void run() {
 444         Accepter main = new Accepter();
 445         ev.add(main);
 446         try {
 447             synchronized(main) {
 448                 while(!main.closed) {
 449                     main.wait();
 450                 }
 451             }
 452         } catch(InterruptedException e) {
 453             ev.remove(main);
 454         } finally {
 455             try {
 456                 sk.close();
 457             } catch(IOException e) {
 458                 throw(new RuntimeException(e));
 459             }
 460         }
 461     }
 462 }