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