lib/java/dolda/dolcon/protocol/Connection.java

   1 package dolda.dolcon.protocol;
   2
   3 import java.io.*;
   4 import java.net.Socket;
   5 import java.util.*;
   6
   7 public class Connection {
   8     private Socket s;
   9     private Reader reader;
  10     private Writer writer;
  11     private Queue<Command> queue = new LinkedList<Command>();
  12     private Queue<Command> pending = new LinkedList<Command>();
  13     private int reqver = 2, revlo, revhi;
  14     private String aspec;
  15     private String state;
  16     private Set<ConnectListener> connls = new HashSet<ConnectListener>();
  17     private Set<NotifyListener> notls = new HashSet<NotifyListener>();
  18     private Exception error;
  19
  20     public interface ConnectListener {
  21         public void connected() throws Exception;
  22         public void error(Exception cause);
  23     }
  24
  25     public Connection(String aspec) {
  26         this.aspec = aspec;
  27         state = "idle";
  28     }
  29
  30     public void connect() throws ConnectException {
  31         synchronized(this) {
  32             if(state != "idle")
  33                 throw(new IllegalStateException("Already connected"));
  34             state = "connecting";
  35         }
  36         try {
  37             s = new Socket(aspec, 1500);
  38         } catch(java.net.UnknownHostException e) {
  39             throw(new ConnectException("Could not resolve host " + aspec, e));
  40         } catch(IOException e) {
  41             throw(new ConnectException("Could not connect to host " + aspec, e));
  42         }
  43         pending = new LinkedList<Command>();
  44         Command ccmd = new Command(".connect");
  45         ccmd.new Listener() {
  46                 public void done(Response resp) throws Exception {
  47                     try {
  48                         checkver(resp);
  49                     } catch(VersionException e) {
  50                         error(e);
  51                         throw(e);
  52                     }
  53                     synchronized(Connection.this) {
  54                         state = "connected";
  55                     }
  56                     synchronized(connls) {
  57                         try {
  58                             for(ConnectListener l : connls)
  59                                 l.connected();
  60                         } finally {
  61                             connls.clear();
  62                         }
  63                     }
  64                 }
  65
  66                 public void error(Exception cause) {
  67                     synchronized(connls) {
  68                         try {
  69                             for(ConnectListener l : connls)
  70                                 l.error(cause);
  71                         } finally {
  72                             connls.clear();
  73                         }
  74                     }
  75                 }
  76             };
  77         pending.offer(ccmd);
  78         reader = new Reader();
  79         writer = new Writer();
  80         reader.start();
  81         writer.start();
  82     }
  83
  84     private void error(Throwable c) {
  85         boolean n = false;
  86         if(c instanceof StopCondition) {
  87             StopCondition s = (StopCondition)c;
  88             n = s.normal;
  89             c = s.getCause();
  90         }
  91         Exception e;
  92         if(c instanceof Exception)
  93             e = (Exception)c;
  94         else
  95             e = new Exception(c);
  96         if(!n) {
  97             close();
  98             error = e;
  99         }
 100         synchronized(queue) {
 101             Command cmd;
 102             while((cmd = pending.poll()) != null) {
 103                 cmd.error(e);
 104             }
 105             while((cmd = queue.poll()) != null) {
 106                 cmd.error(e);
 107             }
 108         }
 109     }
 110
 111     private void checkthread() {
 112         if(Thread.currentThread() == reader)
 113             throw(new RuntimeException("Cannot call synchronous method with dispatch thread!"));
 114     }
 115
 116     public void syncConnect() throws ConnectException, InterruptedException {
 117         checkthread();
 118         final boolean[] donep = new boolean[] {false};
 119         final Exception[] errp = new Exception[] {null};
 120         ConnectListener l = new ConnectListener() {
 121                 public void connected() {
 122                     donep[0] = true;
 123                     synchronized(this) {
 124                         notifyAll();
 125                     }
 126                 }
 127
 128                 public void error(Exception cause) {
 129                     donep[0] = true;
 130                     errp[0] = cause;
 131                     synchronized(this) {
 132                         notifyAll();
 133                     }
 134                 }
 135             };
 136         addConnectListener(l);
 137         connect();
 138         while(!donep[0]) {
 139             synchronized(l) {
 140                 l.wait();
 141             }
 142         }
 143         if(errp[0] != null)
 144             throw(new ConnectException("DC connection has been closed", errp[0]));
 145     }
 146
 147     public void expectVersion(int reqver) {
 148         this.reqver = reqver;
 149     }
 150
 151     private void checkver(Response resp) throws VersionException {
 152         revlo = Integer.parseInt(resp.token(0, 0));
 153         revhi = Integer.parseInt(resp.token(0, 1));
 154         if((reqver < revlo) || (reqver > revhi))
 155             throw(new VersionException(reqver, revlo, revhi));
 156     }
 157
 158     public Exception join() throws InterruptedException {
 159         while(reader.isAlive()) {
 160             reader.join();
 161         }
 162         close();
 163         return(error);
 164     }
 165
 166     public void addNotifyListener(NotifyListener l) {
 167         synchronized(notls) {
 168             notls.add(l);
 169         }
 170     }
 171
 172     public void removeNotifyListener(NotifyListener l) {
 173         synchronized(notls) {
 174             notls.remove(l);
 175         }
 176     }
 177
 178     public synchronized void addConnectListener(ConnectListener l) {
 179         if((state != "idle") && (state != "connecting"))
 180             throw(new IllegalStateException("Already connected"));
 181         synchronized(connls) {
 182             connls.add(l);
 183         }
 184     }
 185
 186     public void qcmd(Command cmd) {
 187         synchronized(queue) {
 188             queue.offer(cmd);
 189             queue.notifyAll();
 190         }
 191     }
 192
 193     public void qcmd(String... tokens) {
 194         qcmd(new Command(tokens));
 195     }
 196
 197     public Response ecmd(Command cmd) throws ClosedException, InterruptedException {
 198         checkthread();
 199         final boolean[] donep = new boolean[] {false};
 200         final Response[] resp = new Response[] {null};
 201         final Exception[] errp = new Exception[] {null};
 202         Object l = cmd.new Listener() {
 203                 public synchronized void done(Response rsp) {
 204                     resp[0] = rsp;
 205                     donep[0] = true;
 206                     notifyAll();
 207                 }
 208
 209                 public synchronized void error(Exception e) {
 210                     errp[0] = e;
 211                     donep[0] = true;
 212                     notifyAll();
 213                 }
 214             };
 215         qcmd(cmd);
 216         synchronized(l) {
 217             while(!donep[0]) {
 218                 l.wait();
 219             }
 220         }
 221         if(errp[0] != null)
 222             throw(new ClosedException(errp[0]));
 223         return(resp[0]);
 224     }
 225
 226     public Response ecmd(String... tokens) throws ClosedException, InterruptedException {
 227         return(ecmd(new Command(tokens)));
 228     }
 229
 230     static private class StopCondition extends Error {
 231         final boolean normal;
 232
 233         public StopCondition(Exception cause, boolean normal) {
 234             super(cause);
 235             this.normal = normal;
 236         }
 237     }
 238
 239     private class Writer extends Thread {
 240         public Writer() {
 241             setDaemon(true);
 242         }
 243
 244         private String quote(String t) {
 245             if(t.length() == 0)
 246                 return("\"\"");
 247             StringBuilder sb = new StringBuilder();
 248             boolean quote = false;
 249             for(int i = 0; i < t.length(); i++) {
 250                 char c = t.charAt(i);
 251                 if(c == '\"') {
 252                     sb.append("\\\"");
 253                 } else if(Character.isWhitespace(c)) {
 254                     quote = true;
 255                     sb.append(c);
 256                 } else {
 257                     sb.append(c);
 258                 }
 259             }
 260             if(quote)
 261                 return("\"" + sb.toString() + "\"");
 262             else
 263                 return(sb.toString());
 264         }
 265
 266         private void guarded() {
 267             try {
 268                 java.io.Writer w = new OutputStreamWriter(s.getOutputStream(), "UTF-8");
 269                 while(true) {
 270                     Command cmd;
 271                     try {
 272                         synchronized(queue) {
 273                             while(pending.size() > 0)
 274                                 queue.wait();
 275                             while((cmd = queue.poll()) == null)
 276                                 queue.wait();
 277                             pending.offer(cmd);
 278                         }
 279                     } catch(InterruptedException e) {
 280                         throw(new StopCondition(e, true));
 281                     }
 282                     StringBuilder out = new StringBuilder();
 283                     for(String s : cmd.tokens) {
 284                         if(out.length() > 0)
 285                             out.append(' ');
 286                         out.append(quote(s));
 287                     }
 288                     out.append("\r\n");
 289                     w.write(out.toString());
 290                     w.flush();
 291                 }
 292             } catch(IOException e) {
 293                 throw(new StopCondition(e, false));
 294             }
 295         }
 296
 297         public void run() {
 298             try {
 299                 guarded();
 300             } catch(Throwable t) {
 301                 error(t);
 302             }
 303         }
 304     }
 305
 306     private class Reader extends Thread {
 307         private void dispatch(Response resp) throws Exception {
 308             if(resp.code < 600) {
 309                 synchronized(queue) {
 310                     try {
 311                         resp.cmd = pending.remove();
 312                     } catch(NoSuchElementException e) {
 313                         throw(new RuntimeException("DC server sent reply without a pending command"));
 314                     }
 315                     queue.notifyAll();
 316                 }
 317                 resp.cmd.done(resp);
 318             } else {
 319                 synchronized(notls) {
 320                     for(NotifyListener l : notls) {
 321                         l.notified(resp);
 322                     }
 323                 }
 324             }
 325         }
 326
 327         private void guarded() {
 328             try {
 329                 java.io.Reader r = new BufferedReader(new InputStreamReader(s.getInputStream(), "UTF-8"));
 330                 String state = "start";
 331                 StringBuilder ct = new StringBuilder();
 332                 int code = -1;
 333                 boolean last = true;
 334                 List<List<String>> lines = new LinkedList<List<String>>();
 335                 List<String> tokens = new LinkedList<String>();
 336                 while(true) {
 337                     char c;
 338                     {
 339                         int i;
 340                         try {
 341                             if((i = r.read()) < 0) {
 342                                 throw(new IOException("The server closed the connection"));
 343                             }
 344                         } catch(java.nio.channels.ClosedByInterruptException e) {
 345                             throw(new StopCondition(e, true));
 346                         }
 347                         c = (char)i;
 348                     }
 349                     eat: do {
 350                         if(state == "start") {
 351                             if(c == '\r') {
 352                                 state = "nl";
 353                             } else if(Character.isWhitespace(c)) {
 354                             } else {
 355                                 if(code == -1)
 356                                     state = "code";
 357                                 else
 358                                     state = "token";
 359                                 continue eat;
 360                             }
 361                         } else if(state == "nl") {
 362                             if(c == '\n') {
 363                                 if((code < 100) || (code >= 1000)) {
 364                                     throw(new IOException("Illegal response code " + code + " from the server"));
 365                                 }
 366                                 lines.add(tokens);
 367                                 tokens = new LinkedList<String>();
 368                                 if(last) {
 369                                     dispatch(new Response(code, lines));
 370                                     lines = new LinkedList<List<String>>();
 371                                 }
 372                                 code = -1;
 373                                 state = "start";
 374                             } else {
 375                                 state = "start";
 376                                 continue eat;
 377                             }
 378                         } else if(state == "code") {
 379                             if((c == '-') || Character.isWhitespace(c)) {
 380                                 last = c != '-';
 381                                 code = Integer.parseInt(ct.toString());
 382                                 ct.setLength(0);
 383                                 state = "start";
 384                                 continue eat;
 385                             } else {
 386                                 ct.append(c);
 387                             }
 388                         } else if(state == "token") {
 389                             if(Character.isWhitespace(c)) {
 390                                 tokens.add(ct.toString());
 391                                 ct.setLength(0);
 392                                 state = "start";
 393                                 continue eat;
 394                             } else if(c == '\\') {
 395                                 state = "bs";
 396                             } else if(c == '"') {
 397                                 state = "cited";
 398                             } else {
 399                                 ct.append(c);
 400                             }
 401                         } else if(state == "bs") {
 402                             ct.append(c);
 403                             state = "token";
 404                         } else if(state == "cited") {
 405                             if(c == '\\')
 406                                 state = "cbs";
 407                             else if(c == '"')
 408                                 state = "token";
 409                             else
 410                                 ct.append(c);
 411                         } else if(state == "cbs") {
 412                             ct.append(c);
 413                             state = "cited";
 414                         } else {
 415                             throw(new Error("invalid state " + state));
 416                         }
 417                         break;
 418                     } while(true);
 419                 }
 420             } catch(Exception e) {
 421                 throw(new StopCondition(e, false));
 422             }
 423         }
 424
 425         public void run() {
 426             try {
 427                 guarded();
 428             } catch(Throwable t) {
 429                 error(t);
 430             }
 431         }
 432     }
 433
 434     public void close() {
 435         try {
 436             s.close();
 437         } catch(IOException e) {}
 438         reader.interrupt();
 439         writer.interrupt();
 440     }
 441 }