libjava/java/nio/channels/FileChannelImpl.java

   1 /* FileChannelImpl.java --
   2    Copyright (C) 2002 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package java.nio.channels;
  40
  41 import java.io.EOFException;
  42 import java.io.FileDescriptor;
  43 import java.io.FileInputStream;
  44 import java.io.FileOutputStream;
  45 import java.io.IOException;
  46 import java.io.RandomAccessFile;
  47 import java.nio.ByteBuffer;
  48 import java.nio.MappedByteBuffer;
  49 import java.nio.MappedByteBufferImpl;
  50 import gnu.classpath.Configuration;
  51 import gnu.gcj.RawData;
  52
  53 /**
  54  * This file is not user visible !
  55  * But alas, Java does not have a concept of friendly packages
  56  * so this class is public.
  57  * Instances of this class are created by invoking getChannel
  58  * Upon a Input/Output/RandomAccessFile object.
  59  */
  60
  61 public class FileChannelImpl extends FileChannel
  62 {
  63   static
  64   {
  65     // load the shared library needed for native methods.
  66     if (Configuration.INIT_LOAD_LIBRARY)
  67       {
  68         System.loadLibrary ("javanio");
  69       }
  70   }
  71
  72   public RawData map_address;
  73
  74   int length;
  75   FileDescriptor fd;
  76   MappedByteBuffer buf;
  77   Object file_obj; // just to keep it live...
  78
  79   public FileChannelImpl (FileDescriptor fd, boolean write, Object obj)
  80   {
  81     if (!(obj instanceof RandomAccessFile)
  82         && !(obj instanceof FileInputStream)
  83         && !(obj instanceof FileOutputStream))
  84       throw new InternalError ();
  85
  86     this.fd = fd;
  87     this.file_obj = obj;
  88   }
  89
  90   public FileChannelImpl ()
  91   {
  92     this (new FileDescriptor (), true, null);
  93   }
  94
  95   private native long implPosition ();
  96   private native FileChannel implPosition (long newPosition);
  97   private native FileChannel implTruncate (long size);
  98
  99   private native RawData nio_mmap_file (long pos, long size, int mode);
 100   private native void nio_unmmap_file (RawData map_address, int size);
 101   private native void nio_msync (RawData map_address, int length);
 102
 103   public native long size () throws IOException;
 104
 105   protected void implCloseChannel() throws IOException
 106   {
 107     if (map_address != null)
 108       {
 109         nio_unmmap_file (map_address, (int) length);
 110         map_address = null;
 111       }
 112
 113     if (file_obj instanceof RandomAccessFile)
 114       {
 115         RandomAccessFile o = (RandomAccessFile) file_obj;
 116         o.close();
 117       }
 118     else if (file_obj instanceof FileInputStream)
 119       {
 120         FileInputStream o = (FileInputStream) file_obj;
 121         o.close();
 122       }
 123     else if (file_obj instanceof FileOutputStream)
 124       {
 125         FileOutputStream o = (FileOutputStream) file_obj;
 126         o.close();
 127       }
 128   }
 129
 130   public int read (ByteBuffer dst) throws IOException
 131   {
 132     // Check if file is mapped into memory.
 133     if (buf != null)
 134       {
 135         // FIXME: implement this
 136         throw new Error ("Accessing mapped buffers not implemented.");
 137       }
 138
 139     // File not mapped, access it directly.
 140     return implRead (dst);
 141   }
 142
 143   public int read (ByteBuffer dst, long position)
 144     throws IOException
 145   {
 146     if (position < 0)
 147       throw new IllegalArgumentException ();
 148
 149     if (!isOpen ())
 150       throw new ClosedChannelException ();
 151
 152     if (file_obj instanceof FileOutputStream)
 153       throw new NonReadableChannelException ();
 154
 155     int result;
 156     long oldPosition;
 157
 158     oldPosition = implPosition ();
 159     position (position);
 160     result = implRead (dst);
 161     implPosition (oldPosition);
 162
 163     return result;
 164   }
 165
 166   private int implRead (ByteBuffer dst) throws IOException
 167   {
 168     int result;
 169     byte[] buffer = new byte [dst.remaining ()];
 170
 171     result = implRead (buffer, 0, buffer.length);
 172
 173     if (result > 0)
 174       dst.put (buffer, 0, result);
 175
 176     return result;
 177   }
 178
 179   private native int implRead (byte[] buffer, int offset, int length)
 180     throws IOException;
 181
 182   public long read (ByteBuffer[] dsts, int offset, int length)
 183     throws IOException
 184   {
 185     long result = 0;
 186
 187     for (int i = offset; i < offset + length; i++)
 188       {
 189         result += read (dsts [i]);
 190       }
 191
 192     return result;
 193   }
 194
 195   public int write (ByteBuffer src) throws IOException
 196   {
 197     // Check if file is mapped into memory.
 198     if (buf != null)
 199       {
 200         // FIXME: implement this
 201         throw new Error ("Accessing mapped buffers not implemented.");
 202       }
 203
 204     // File not mapped, access it directly.
 205     return implWrite (src);
 206   }
 207
 208   public int write (ByteBuffer src, long position)
 209     throws IOException
 210   {
 211     if (position < 0)
 212       throw new IllegalArgumentException ();
 213
 214     if (!isOpen ())
 215       throw new ClosedChannelException ();
 216
 217     if (file_obj instanceof FileInputStream)
 218        throw new NonWritableChannelException ();
 219
 220     int result;
 221     long oldPosition;
 222
 223     oldPosition = implPosition ();
 224     position (position);
 225     result = implWrite (src);
 226     implPosition (oldPosition);
 227
 228     return result;
 229   }
 230
 231   private int implWrite (ByteBuffer src) throws IOException
 232   {
 233     byte[] buffer = new byte [src.remaining ()];
 234
 235     src.get (buffer, 0, buffer.length);
 236     return implWrite (buffer, 0, buffer.length);
 237   }
 238
 239   private native int implWrite (byte[] buffer, int offset, int length)
 240     throws IOException;
 241
 242   public long write(ByteBuffer[] srcs, int offset, int length)
 243     throws IOException
 244   {
 245     long result = 0;
 246
 247     for (int i = offset;i < offset + length;i++)
 248       {
 249         result += write (srcs[i]);
 250       }
 251
 252     return result;
 253   }
 254
 255   public MappedByteBuffer map (FileChannel.MapMode mode, long position,
 256                                long size)
 257     throws IOException
 258   {
 259     if ((mode != MapMode.READ_ONLY
 260          && mode != MapMode.READ_WRITE
 261          && mode != MapMode.PRIVATE)
 262         || position < 0
 263         || size < 0
 264         || size > Integer.MAX_VALUE)
 265       throw new IllegalArgumentException ();
 266
 267     // FIXME: Make this working.
 268     int cmode = mode.m;
 269     map_address = nio_mmap_file (position, size, cmode);
 270     length = (int) size;
 271     buf = new MappedByteBufferImpl (this);
 272     return buf;
 273   }
 274
 275   static MappedByteBuffer create_direct_mapped_buffer (RawData map_address,
 276                                                        long length)
 277     throws IOException
 278   {
 279     FileChannelImpl ch = new FileChannelImpl ();
 280     ch.map_address = map_address;
 281     ch.length = (int) length;
 282     ch.buf = new MappedByteBufferImpl (ch);
 283     return ch.buf;
 284   }
 285
 286   /**
 287    * msync with the disk
 288    */
 289   public void force (boolean metaData) throws IOException
 290   {
 291     if (!isOpen ())
 292       throw new ClosedChannelException ();
 293
 294     // FIXME: What to do with metaData ?
 295
 296     nio_msync (map_address, length);
 297   }
 298
 299   public long transferTo (long position, long count, WritableByteChannel target)
 300     throws IOException
 301   {
 302     if (position < 0
 303         || count < 0)
 304       throw new IllegalArgumentException ();
 305
 306     if (!isOpen ())
 307       throw new ClosedChannelException ();
 308
 309     if (file_obj instanceof FileOutputStream)
 310        throw new NonReadableChannelException ();
 311
 312     // XXX: count needs to be casted from long to int. Dataloss ?
 313     ByteBuffer buffer = ByteBuffer.allocate ((int) count);
 314     read (buffer, position);
 315     buffer.flip();
 316     return target.write (buffer);
 317   }
 318
 319   public long transferFrom (ReadableByteChannel src, long position, long count)
 320     throws IOException
 321   {
 322     if (position < 0
 323         || count < 0)
 324       throw new IllegalArgumentException ();
 325
 326     if (!isOpen ())
 327       throw new ClosedChannelException ();
 328
 329     if (file_obj instanceof FileInputStream)
 330        throw new NonWritableChannelException ();
 331
 332     // XXX: count needs to be casted from long to int. Dataloss ?
 333     ByteBuffer buffer = ByteBuffer.allocate ((int) count);
 334     src.read (buffer);
 335     buffer.flip();
 336     return write (buffer, position);
 337   }
 338
 339   public FileLock lock (long position, long size, boolean shared)
 340     throws IOException
 341   {
 342     if (position < 0
 343         || size < 0)
 344       throw new IllegalArgumentException ();
 345
 346     if (!isOpen ())
 347       throw new ClosedChannelException ();
 348
 349     if (shared &&
 350         file_obj instanceof FileOutputStream)
 351       throw new NonReadableChannelException ();
 352
 353     if (!shared &&
 354         file_obj instanceof FileInputStream)
 355       throw new NonWritableChannelException ();
 356
 357     throw new Error ("Not implemented");
 358   }
 359
 360   public FileLock tryLock (long position, long size, boolean shared)
 361     throws IOException
 362   {
 363     if (position < 0
 364         || size < 0)
 365       throw new IllegalArgumentException ();
 366
 367     if (!isOpen ())
 368       throw new ClosedChannelException ();
 369
 370     throw new Error ("Not implemented");
 371   }
 372
 373   public long position ()
 374     throws IOException
 375   {
 376     if (!isOpen ())
 377       throw new ClosedChannelException ();
 378
 379     return implPosition ();
 380   }
 381
 382   public FileChannel position (long newPosition)
 383     throws IOException
 384   {
 385     if (newPosition < 0)
 386       throw new IllegalArgumentException ();
 387
 388     if (!isOpen ())
 389       throw new ClosedChannelException ();
 390
 391     return implPosition (newPosition);
 392   }
 393
 394   public FileChannel truncate (long size)
 395     throws IOException
 396   {
 397     if (size < 0)
 398       throw new IllegalArgumentException ();
 399
 400     if (!isOpen ())
 401       throw new ClosedChannelException ();
 402
 403     if (file_obj instanceof FileInputStream)
 404        throw new NonWritableChannelException ();
 405
 406     return implTruncate (size);
 407   }
 408 }