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         synchronized(l) {
 216             while(!donep[0]) {
 217                 l.wait();
 218             }
 219         }
 220         if(errp[0] != null)
 221             throw(new ClosedException(errp[0]));
 222         return(resp[0]);
 223     }
 224
 225     public Response ecmd(String... tokens) throws ClosedException, InterruptedException {
 226         return(ecmd(new Command(tokens)));
 227     }
 228
 229     static private class StopCondition extends Error {
 230         final boolean normal;
 231
 232         public StopCondition(Exception cause, boolean normal) {
 233             super(cause);
 234             this.normal = normal;
 235         }
 236     }
 237
 238     private class Writer extends Thread {
 239         public Writer() {
 240             setDaemon(true);
 241         }
 242
 243         private String quote(String t) {
 244             if(t.length() == 0)
 245                 return("\"\"");
 246             StringBuilder sb = new StringBuilder();
 247             boolean quote = false;
 248             for(int i = 0; i < t.length(); i++) {
 249                 char c = t.charAt(i);
 250                 if(c == '\"') {
 251                     sb.append("\\\"");
 252                 } else if(Character.isWhitespace(c)) {
 253                     quote = true;
 254                     sb.append(c);
 255                 } else {
 256                     sb.append(c);
 257                 }
 258             }
 259             if(quote)
 260                 return("\"" + sb.toString() + "\"");
 261             else
 262                 return(sb.toString());
 263         }
 264
 265         private void guarded() {
 266             try {
 267                 java.io.Writer w = new OutputStreamWriter(s.getOutputStream(), "UTF-8");
 268                 while(true) {
 269                     Command cmd;
 270                     try {
 271                         synchronized(queue) {
 272                             while(pending.size() > 0)
 273                                 queue.wait();
 274                             while((cmd = queue.poll()) == null)
 275                                 queue.wait();
 276                             pending.offer(cmd);
 277                         }
 278                     } catch(InterruptedException e) {
 279                         throw(new StopCondition(e, true));
 280                     }
 281                     StringBuilder out = new StringBuilder();
 282                     for(String s : cmd.tokens) {
 283                         if(out.length() > 0)
 284                             out.append(' ');
 285                         out.append(quote(s));
 286                     }
 287                     w.write(out.toString());
 288                 }
 289             } catch(IOException e) {
 290                 throw(new StopCondition(e, false));
 291             }
 292         }
 293
 294         public void run() {
 295             try {
 296                 guarded();
 297             } catch(Throwable t) {
 298                 error(t);
 299             }
 300         }
 301     }
 302
 303     private class Reader extends Thread {
 304         private void dispatch(Response resp) throws Exception {
 305             if(resp.code < 600) {
 306                 synchronized(queue) {
 307                     try {
 308                         resp.cmd = pending.remove();
 309                     } catch(NoSuchElementException e) {
 310                         throw(new RuntimeException("DC server sent reply without a pending command"));
 311                     }
 312                     queue.notifyAll();
 313                 }
 314                 resp.cmd.done(resp);
 315             } else {
 316                 synchronized(notls) {
 317                     for(NotifyListener l : notls) {
 318                         l.notified(resp);
 319                     }
 320                 }
 321             }
 322         }
 323
 324         private void guarded() {
 325             try {
 326                 java.io.Reader r = new BufferedReader(new InputStreamReader(s.getInputStream(), "UTF-8"));
 327                 String state = "start";
 328                 StringBuilder ct = new StringBuilder();
 329                 int code = -1;
 330                 boolean last = true;
 331                 List<List<String>> lines = new LinkedList<List<String>>();
 332                 List<String> tokens = new LinkedList<String>();
 333                 while(true) {
 334                     char c;
 335                     {
 336                         int i;
 337                         try {
 338                             if((i = r.read()) < 0) {
 339                                 throw(new IOException("The server closed the connection"));
 340                             }
 341                         } catch(java.nio.channels.ClosedByInterruptException e) {
 342                             throw(new StopCondition(e, true));
 343                         }
 344                         c = (char)i;
 345                     }
 346                     eat: do {
 347                         if(state == "start") {
 348                             if(c == '\r') {
 349                                 state = "nl";
 350                             } else if(Character.isWhitespace(c)) {
 351                             } else {
 352                                 if(code == -1)
 353                                     state = "code";
 354                                 else
 355                                     state = "token";
 356                                 continue eat;
 357                             }
 358                         } else if(state == "nl") {
 359                             if(c == '\n') {
 360                                 if((code < 100) || (code >= 1000)) {
 361                                     throw(new IOException("Illegal response code " + code + " from the server"));
 362                                 }
 363                                 lines.add(tokens);
 364                                 tokens = new LinkedList<String>();
 365                                 if(last) {
 366                                     dispatch(new Response(code, lines));
 367                                     lines = new LinkedList<List<String>>();
 368                                 }
 369                                 code = -1;
 370                                 state = "start";
 371                             } else {
 372                                 state = "start";
 373                                 continue eat;
 374                             }
 375                         } else if(state == "code") {
 376                             if((c == '-') || Character.isWhitespace(c)) {
 377                                 last = c != '-';
 378                                 code = Integer.parseInt(ct.toString());
 379                                 ct.setLength(0);
 380                                 state = "start";
 381                                 continue eat;
 382                             } else {
 383                                 ct.append(c);
 384                             }
 385                         } else if(state == "token") {
 386                             if(Character.isWhitespace(c)) {
 387                                 tokens.add(ct.toString());
 388                                 ct.setLength(0);
 389                                 state = "start";
 390                                 continue eat;
 391                             } else if(c == '\\') {
 392                                 state = "bs";
 393                             } else if(c == '"') {
 394                                 state = "cited";
 395                             } else {
 396                                 ct.append(c);
 397                             }
 398                         } else if(state == "bs") {
 399                             ct.append(c);
 400                             state = "token";
 401                         } else if(state == "cited") {
 402                             if(c == '\\')
 403                                 state = "cbs";
 404                             else if(c == '"')
 405                                 state = "token";
 406                             else
 407                                 ct.append(c);
 408                         } else if(state == "cbs") {
 409                             ct.append(c);
 410                             state = "cited";
 411                         } else {
 412                             throw(new Error("invalid state " + state));
 413                         }
 414                         break;
 415                     } while(true);
 416                 }
 417             } catch(Exception e) {
 418                 throw(new StopCondition(e, false));
 419             }
 420         }
 421
 422         public void run() {
 423             try {
 424                 guarded();
 425             } catch(Throwable t) {
 426                 error(t);
 427             }
 428         }
 429     }
 430
 431     public void close() {
 432         try {
 433             s.close();
 434         } catch(IOException e) {}
 435         reader.interrupt();
 436         writer.interrupt();
 437     }
 438 }