mirror of git://gcc.gnu.org/git/gcc.git
				
				
				
			
		
			
				
	
	
		
			786 lines
		
	
	
		
			22 KiB
		
	
	
	
		
			Java
		
	
	
	
			
		
		
	
	
			786 lines
		
	
	
		
			22 KiB
		
	
	
	
		
			Java
		
	
	
	
| /* ZipFile.java --
 | |
|    Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
 | |
|    Free Software Foundation, Inc.
 | |
| 
 | |
| This file is part of GNU Classpath.
 | |
| 
 | |
| GNU Classpath is free software; you can redistribute it and/or modify
 | |
| it under the terms of the GNU General Public License as published by
 | |
| the Free Software Foundation; either version 2, or (at your option)
 | |
| any later version.
 | |
| 
 | |
| GNU Classpath is distributed in the hope that it will be useful, but
 | |
| WITHOUT ANY WARRANTY; without even the implied warranty of
 | |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 | |
| General Public License for more details.
 | |
| 
 | |
| You should have received a copy of the GNU General Public License
 | |
| along with GNU Classpath; see the file COPYING.  If not, write to the
 | |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 | |
| 02110-1301 USA.
 | |
| 
 | |
| Linking this library statically or dynamically with other modules is
 | |
| making a combined work based on this library.  Thus, the terms and
 | |
| conditions of the GNU General Public License cover the whole
 | |
| combination.
 | |
| 
 | |
| As a special exception, the copyright holders of this library give you
 | |
| permission to link this library with independent modules to produce an
 | |
| executable, regardless of the license terms of these independent
 | |
| modules, and to copy and distribute the resulting executable under
 | |
| terms of your choice, provided that you also meet, for each linked
 | |
| independent module, the terms and conditions of the license of that
 | |
| module.  An independent module is a module which is not derived from
 | |
| or based on this library.  If you modify this library, you may extend
 | |
| this exception to your version of the library, but you are not
 | |
| obligated to do so.  If you do not wish to do so, delete this
 | |
| exception statement from your version. */
 | |
| 
 | |
| 
 | |
| package java.util.zip;
 | |
| 
 | |
| import gnu.java.util.EmptyEnumeration;
 | |
| 
 | |
| import java.io.EOFException;
 | |
| import java.io.File;
 | |
| import java.io.FileNotFoundException;
 | |
| import java.io.IOException;
 | |
| import java.io.InputStream;
 | |
| import java.io.RandomAccessFile;
 | |
| import java.io.UnsupportedEncodingException;
 | |
| import java.nio.ByteBuffer;
 | |
| import java.nio.charset.Charset;
 | |
| import java.nio.charset.CharsetDecoder;
 | |
| import java.util.Enumeration;
 | |
| import java.util.Iterator;
 | |
| import java.util.LinkedHashMap;
 | |
| 
 | |
| /**
 | |
|  * This class represents a Zip archive.  You can ask for the contained
 | |
|  * entries, or get an input stream for a file entry.  The entry is
 | |
|  * automatically decompressed.
 | |
|  *
 | |
|  * This class is thread safe:  You can open input streams for arbitrary
 | |
|  * entries in different threads.
 | |
|  *
 | |
|  * @author Jochen Hoenicke
 | |
|  * @author Artur Biesiadowski
 | |
|  */
 | |
| public class ZipFile implements ZipConstants
 | |
| {
 | |
| 
 | |
|   /**
 | |
|    * Mode flag to open a zip file for reading.
 | |
|    */
 | |
|   public static final int OPEN_READ = 0x1;
 | |
| 
 | |
|   /**
 | |
|    * Mode flag to delete a zip file after reading.
 | |
|    */
 | |
|   public static final int OPEN_DELETE = 0x4;
 | |
| 
 | |
|   /**
 | |
|    * This field isn't defined in the JDK's ZipConstants, but should be.
 | |
|    */
 | |
|   static final int ENDNRD =  4;
 | |
| 
 | |
|   // Name of this zip file.
 | |
|   private final String name;
 | |
| 
 | |
|   // File from which zip entries are read.
 | |
|   private final RandomAccessFile raf;
 | |
| 
 | |
|   // The entries of this zip file when initialized and not yet closed.
 | |
|   private LinkedHashMap<String, ZipEntry> entries;
 | |
| 
 | |
|   private boolean closed = false;
 | |
| 
 | |
| 
 | |
|   /**
 | |
|    * Helper function to open RandomAccessFile and throw the proper
 | |
|    * ZipException in case opening the file fails.
 | |
|    *
 | |
|    * @param name the file name, or null if file is provided
 | |
|    *
 | |
|    * @param file the file, or null if name is provided
 | |
|    *
 | |
|    * @return the newly open RandomAccessFile, never null
 | |
|    */
 | |
|   private RandomAccessFile openFile(String name,
 | |
|                                     File file)
 | |
|     throws ZipException, IOException
 | |
|   {
 | |
|     try
 | |
|       {
 | |
|         return
 | |
|           (name != null)
 | |
|           ? new RandomAccessFile(name, "r")
 | |
|           : new RandomAccessFile(file, "r");
 | |
|       }
 | |
|     catch (FileNotFoundException f)
 | |
|       {
 | |
|         ZipException ze = new ZipException(f.getMessage());
 | |
|         ze.initCause(f);
 | |
|         throw ze;
 | |
|       }
 | |
|   }
 | |
| 
 | |
| 
 | |
|   /**
 | |
|    * Opens a Zip file with the given name for reading.
 | |
|    * @exception IOException if a i/o error occured.
 | |
|    * @exception ZipException if the file doesn't contain a valid zip
 | |
|    * archive.
 | |
|    */
 | |
|   public ZipFile(String name) throws ZipException, IOException
 | |
|   {
 | |
|     this.raf = openFile(name,null);
 | |
|     this.name = name;
 | |
|     checkZipFile();
 | |
|   }
 | |
| 
 | |
|   /**
 | |
|    * Opens a Zip file reading the given File.
 | |
|    * @exception IOException if a i/o error occured.
 | |
|    * @exception ZipException if the file doesn't contain a valid zip
 | |
|    * archive.
 | |
|    */
 | |
|   public ZipFile(File file) throws ZipException, IOException
 | |
|   {
 | |
|     this.raf = openFile(null,file);
 | |
|     this.name = file.getPath();
 | |
|     checkZipFile();
 | |
|   }
 | |
| 
 | |
|   /**
 | |
|    * Opens a Zip file reading the given File in the given mode.
 | |
|    *
 | |
|    * If the OPEN_DELETE mode is specified, the zip file will be deleted at
 | |
|    * some time moment after it is opened. It will be deleted before the zip
 | |
|    * file is closed or the Virtual Machine exits.
 | |
|    *
 | |
|    * The contents of the zip file will be accessible until it is closed.
 | |
|    *
 | |
|    * @since JDK1.3
 | |
|    * @param mode Must be one of OPEN_READ or OPEN_READ | OPEN_DELETE
 | |
|    *
 | |
|    * @exception IOException if a i/o error occured.
 | |
|    * @exception ZipException if the file doesn't contain a valid zip
 | |
|    * archive.
 | |
|    */
 | |
|   public ZipFile(File file, int mode) throws ZipException, IOException
 | |
|   {
 | |
|     if (mode != OPEN_READ && mode != (OPEN_READ | OPEN_DELETE))
 | |
|       throw new IllegalArgumentException("invalid mode");
 | |
|     if ((mode & OPEN_DELETE) != 0)
 | |
|       file.deleteOnExit();
 | |
|     this.raf = openFile(null,file);
 | |
|     this.name = file.getPath();
 | |
|     checkZipFile();
 | |
|   }
 | |
| 
 | |
|   private void checkZipFile() throws ZipException
 | |
|   {
 | |
|     boolean valid = false;
 | |
| 
 | |
|     try
 | |
|       {
 | |
|         byte[] buf = new byte[4];
 | |
|         raf.readFully(buf);
 | |
|         int sig = buf[0] & 0xFF
 | |
|                 | ((buf[1] & 0xFF) << 8)
 | |
|                 | ((buf[2] & 0xFF) << 16)
 | |
|                 | ((buf[3] & 0xFF) << 24);
 | |
|         valid = sig == LOCSIG;
 | |
|       }
 | |
|     catch (IOException _)
 | |
|       {
 | |
|       }
 | |
| 
 | |
|     if (!valid)
 | |
|       {
 | |
|         try
 | |
|           {
 | |
|             raf.close();
 | |
|           }
 | |
|         catch (IOException _)
 | |
|           {
 | |
|           }
 | |
|         throw new ZipException("Not a valid zip file");
 | |
|       }
 | |
|   }
 | |
| 
 | |
|   /**
 | |
|    * Checks if file is closed and throws an exception.
 | |
|    */
 | |
|   private void checkClosed()
 | |
|   {
 | |
|     if (closed)
 | |
|       throw new IllegalStateException("ZipFile has closed: " + name);
 | |
|   }
 | |
| 
 | |
|   /**
 | |
|    * Read the central directory of a zip file and fill the entries
 | |
|    * array.  This is called exactly once when first needed. It is called
 | |
|    * while holding the lock on <code>raf</code>.
 | |
|    *
 | |
|    * @exception IOException if a i/o error occured.
 | |
|    * @exception ZipException if the central directory is malformed
 | |
|    */
 | |
|   private void readEntries() throws ZipException, IOException
 | |
|   {
 | |
|     /* Search for the End Of Central Directory.  When a zip comment is
 | |
|      * present the directory may start earlier.
 | |
|      * Note that a comment has a maximum length of 64K, so that is the
 | |
|      * maximum we search backwards.
 | |
|      */
 | |
|     PartialInputStream inp = new PartialInputStream(raf, 4096);
 | |
|     long pos = raf.length() - ENDHDR;
 | |
|     long top = Math.max(0, pos - 65536);
 | |
|     do
 | |
|       {
 | |
|         if (pos < top)
 | |
|           throw new ZipException
 | |
|             ("central directory not found, probably not a zip file: " + name);
 | |
|         inp.seek(pos--);
 | |
|       }
 | |
|     while (inp.readLeInt() != ENDSIG);
 | |
| 
 | |
|     if (inp.skip(ENDTOT - ENDNRD) != ENDTOT - ENDNRD)
 | |
|       throw new EOFException(name);
 | |
|     int count = inp.readLeShort();
 | |
|     if (inp.skip(ENDOFF - ENDSIZ) != ENDOFF - ENDSIZ)
 | |
|       throw new EOFException(name);
 | |
|     int centralOffset = inp.readLeInt();
 | |
| 
 | |
|     entries = new LinkedHashMap<String, ZipEntry> (count+count/2);
 | |
|     inp.seek(centralOffset);
 | |
| 
 | |
|     for (int i = 0; i < count; i++)
 | |
|       {
 | |
|         if (inp.readLeInt() != CENSIG)
 | |
|           throw new ZipException("Wrong Central Directory signature: " + name);
 | |
| 
 | |
|         inp.skip(4);
 | |
|         int flags = inp.readLeShort();
 | |
|         if ((flags & 1) != 0)
 | |
|           throw new ZipException("invalid CEN header (encrypted entry)");
 | |
|         int method = inp.readLeShort();
 | |
|         int dostime = inp.readLeInt();
 | |
|         int crc = inp.readLeInt();
 | |
|         int csize = inp.readLeInt();
 | |
|         int size = inp.readLeInt();
 | |
|         int nameLen = inp.readLeShort();
 | |
|         int extraLen = inp.readLeShort();
 | |
|         int commentLen = inp.readLeShort();
 | |
|         inp.skip(8);
 | |
|         int offset = inp.readLeInt();
 | |
|         String name = inp.readString(nameLen);
 | |
| 
 | |
|         ZipEntry entry = new ZipEntry(name);
 | |
|         entry.setMethod(method);
 | |
|         entry.setCrc(crc & 0xffffffffL);
 | |
|         entry.setSize(size & 0xffffffffL);
 | |
|         entry.setCompressedSize(csize & 0xffffffffL);
 | |
|         entry.setDOSTime(dostime);
 | |
|         if (extraLen > 0)
 | |
|           {
 | |
|             byte[] extra = new byte[extraLen];
 | |
|             inp.readFully(extra);
 | |
|             entry.setExtra(extra);
 | |
|           }
 | |
|         if (commentLen > 0)
 | |
|           {
 | |
|             entry.setComment(inp.readString(commentLen));
 | |
|           }
 | |
|         entry.offset = offset;
 | |
|         entries.put(name, entry);
 | |
|       }
 | |
|   }
 | |
| 
 | |
|   /**
 | |
|    * Closes the ZipFile.  This also closes all input streams given by
 | |
|    * this class.  After this is called, no further method should be
 | |
|    * called.
 | |
|    *
 | |
|    * @exception IOException if a i/o error occured.
 | |
|    */
 | |
|   public void close() throws IOException
 | |
|   {
 | |
|     RandomAccessFile raf = this.raf;
 | |
|     if (raf == null)
 | |
|       return;
 | |
| 
 | |
|     synchronized (raf)
 | |
|       {
 | |
|         closed = true;
 | |
|         entries = null;
 | |
|         raf.close();
 | |
|       }
 | |
|   }
 | |
| 
 | |
|   /**
 | |
|    * Calls the <code>close()</code> method when this ZipFile has not yet
 | |
|    * been explicitly closed.
 | |
|    */
 | |
|   protected void finalize() throws IOException
 | |
|   {
 | |
|     if (!closed && raf != null) close();
 | |
|   }
 | |
| 
 | |
|   /**
 | |
|    * Returns an enumeration of all Zip entries in this Zip file.
 | |
|    *
 | |
|    * @exception IllegalStateException when the ZipFile has already been closed
 | |
|    */
 | |
|   public Enumeration<? extends ZipEntry> entries()
 | |
|   {
 | |
|     checkClosed();
 | |
| 
 | |
|     try
 | |
|       {
 | |
|         return new ZipEntryEnumeration(getEntries().values().iterator());
 | |
|       }
 | |
|     catch (IOException ioe)
 | |
|       {
 | |
|         return new EmptyEnumeration<ZipEntry>();
 | |
|       }
 | |
|   }
 | |
| 
 | |
|   /**
 | |
|    * Checks that the ZipFile is still open and reads entries when necessary.
 | |
|    *
 | |
|    * @exception IllegalStateException when the ZipFile has already been closed.
 | |
|    * @exception IOException when the entries could not be read.
 | |
|    */
 | |
|   private LinkedHashMap<String, ZipEntry> getEntries() throws IOException
 | |
|   {
 | |
|     synchronized(raf)
 | |
|       {
 | |
|         checkClosed();
 | |
| 
 | |
|         if (entries == null)
 | |
|           readEntries();
 | |
| 
 | |
|         return entries;
 | |
|       }
 | |
|   }
 | |
| 
 | |
|   /**
 | |
|    * Searches for a zip entry in this archive with the given name.
 | |
|    *
 | |
|    * @param name the name. May contain directory components separated by
 | |
|    * slashes ('/').
 | |
|    * @return the zip entry, or null if no entry with that name exists.
 | |
|    *
 | |
|    * @exception IllegalStateException when the ZipFile has already been closed
 | |
|    */
 | |
|   public ZipEntry getEntry(String name)
 | |
|   {
 | |
|     checkClosed();
 | |
| 
 | |
|     try
 | |
|       {
 | |
|         LinkedHashMap<String, ZipEntry> entries = getEntries();
 | |
|         ZipEntry entry = entries.get(name);
 | |
|         // If we didn't find it, maybe it's a directory.
 | |
|         if (entry == null && !name.endsWith("/"))
 | |
|           entry = entries.get(name + '/');
 | |
|         return entry != null ? new ZipEntry(entry, name) : null;
 | |
|       }
 | |
|     catch (IOException ioe)
 | |
|       {
 | |
|         return null;
 | |
|       }
 | |
|   }
 | |
| 
 | |
|   /**
 | |
|    * Creates an input stream reading the given zip entry as
 | |
|    * uncompressed data.  Normally zip entry should be an entry
 | |
|    * returned by getEntry() or entries().
 | |
|    *
 | |
|    * This implementation returns null if the requested entry does not
 | |
|    * exist.  This decision is not obviously correct, however, it does
 | |
|    * appear to mirror Sun's implementation, and it is consistant with
 | |
|    * their javadoc.  On the other hand, the old JCL book, 2nd Edition,
 | |
|    * claims that this should return a "non-null ZIP entry".  We have
 | |
|    * chosen for now ignore the old book, as modern versions of Ant (an
 | |
|    * important application) depend on this behaviour.  See discussion
 | |
|    * in this thread:
 | |
|    * http://gcc.gnu.org/ml/java-patches/2004-q2/msg00602.html
 | |
|    *
 | |
|    * @param entry the entry to create an InputStream for.
 | |
|    * @return the input stream, or null if the requested entry does not exist.
 | |
|    *
 | |
|    * @exception IllegalStateException when the ZipFile has already been closed
 | |
|    * @exception IOException if a i/o error occured.
 | |
|    * @exception ZipException if the Zip archive is malformed.
 | |
|    */
 | |
|   public InputStream getInputStream(ZipEntry entry) throws IOException
 | |
|   {
 | |
|     checkClosed();
 | |
| 
 | |
|     LinkedHashMap<String, ZipEntry> entries = getEntries();
 | |
|     String name = entry.getName();
 | |
|     ZipEntry zipEntry = entries.get(name);
 | |
|     if (zipEntry == null)
 | |
|       return null;
 | |
| 
 | |
|     PartialInputStream inp = new PartialInputStream(raf, 1024);
 | |
|     inp.seek(zipEntry.offset);
 | |
| 
 | |
|     if (inp.readLeInt() != LOCSIG)
 | |
|       throw new ZipException("Wrong Local header signature: " + name);
 | |
| 
 | |
|     inp.skip(4);
 | |
| 
 | |
|     if (zipEntry.getMethod() != inp.readLeShort())
 | |
|       throw new ZipException("Compression method mismatch: " + name);
 | |
| 
 | |
|     inp.skip(16);
 | |
| 
 | |
|     int nameLen = inp.readLeShort();
 | |
|     int extraLen = inp.readLeShort();
 | |
|     inp.skip(nameLen + extraLen);
 | |
| 
 | |
|     inp.setLength(zipEntry.getCompressedSize());
 | |
| 
 | |
|     int method = zipEntry.getMethod();
 | |
|     switch (method)
 | |
|       {
 | |
|       case ZipOutputStream.STORED:
 | |
|         return inp;
 | |
|       case ZipOutputStream.DEFLATED:
 | |
|         inp.addDummyByte();
 | |
|         final Inflater inf = new Inflater(true);
 | |
|         final int sz = (int) entry.getSize();
 | |
|         return new InflaterInputStream(inp, inf)
 | |
|         {
 | |
|           public int available() throws IOException
 | |
|           {
 | |
|             if (sz == -1)
 | |
|               return super.available();
 | |
|             if (super.available() != 0)
 | |
|               return sz - inf.getTotalOut();
 | |
|             return 0;
 | |
|           }
 | |
|         };
 | |
|       default:
 | |
|         throw new ZipException("Unknown compression method " + method);
 | |
|       }
 | |
|   }
 | |
| 
 | |
|   /**
 | |
|    * Returns the (path) name of this zip file.
 | |
|    */
 | |
|   public String getName()
 | |
|   {
 | |
|     return name;
 | |
|   }
 | |
| 
 | |
|   /**
 | |
|    * Returns the number of entries in this zip file.
 | |
|    *
 | |
|    * @exception IllegalStateException when the ZipFile has already been closed
 | |
|    */
 | |
|   public int size()
 | |
|   {
 | |
|     checkClosed();
 | |
| 
 | |
|     try
 | |
|       {
 | |
|         return getEntries().size();
 | |
|       }
 | |
|     catch (IOException ioe)
 | |
|       {
 | |
|         return 0;
 | |
|       }
 | |
|   }
 | |
| 
 | |
|   private static class ZipEntryEnumeration implements Enumeration<ZipEntry>
 | |
|   {
 | |
|     private final Iterator<ZipEntry> elements;
 | |
| 
 | |
|     public ZipEntryEnumeration(Iterator<ZipEntry> elements)
 | |
|     {
 | |
|       this.elements = elements;
 | |
|     }
 | |
| 
 | |
|     public boolean hasMoreElements()
 | |
|     {
 | |
|       return elements.hasNext();
 | |
|     }
 | |
| 
 | |
|     public ZipEntry nextElement()
 | |
|     {
 | |
|       /* We return a clone, just to be safe that the user doesn't
 | |
|        * change the entry.
 | |
|        */
 | |
|       return (ZipEntry) (elements.next().clone());
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   private static final class PartialInputStream extends InputStream
 | |
|   {
 | |
|     /**
 | |
|      * The UTF-8 charset use for decoding the filenames.
 | |
|      */
 | |
|     private static final Charset UTF8CHARSET = Charset.forName("UTF-8");
 | |
| 
 | |
|     /**
 | |
|      * The actual UTF-8 decoder. Created on demand.
 | |
|      */
 | |
|     private CharsetDecoder utf8Decoder;
 | |
| 
 | |
|     private final RandomAccessFile raf;
 | |
|     private final byte[] buffer;
 | |
|     private long bufferOffset;
 | |
|     private int pos;
 | |
|     private long end;
 | |
|     // We may need to supply an extra dummy byte to our reader.
 | |
|     // See Inflater.  We use a count here to simplify the logic
 | |
|     // elsewhere in this class.  Note that we ignore the dummy
 | |
|     // byte in methods where we know it is not needed.
 | |
|     private int dummyByteCount;
 | |
| 
 | |
|     public PartialInputStream(RandomAccessFile raf, int bufferSize)
 | |
|       throws IOException
 | |
|     {
 | |
|       this.raf = raf;
 | |
|       buffer = new byte[bufferSize];
 | |
|       bufferOffset = -buffer.length;
 | |
|       pos = buffer.length;
 | |
|       end = raf.length();
 | |
|     }
 | |
| 
 | |
|     void setLength(long length)
 | |
|     {
 | |
|       end = bufferOffset + pos + length;
 | |
|     }
 | |
| 
 | |
|     private void fillBuffer() throws IOException
 | |
|     {
 | |
|       synchronized (raf)
 | |
|         {
 | |
|           long len = end - bufferOffset;
 | |
|           if (len == 0 && dummyByteCount > 0)
 | |
|             {
 | |
|               buffer[0] = 0;
 | |
|               dummyByteCount = 0;
 | |
|             }
 | |
|           else
 | |
|             {
 | |
|               raf.seek(bufferOffset);
 | |
|               raf.readFully(buffer, 0, (int) Math.min(buffer.length, len));
 | |
|             }
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     public int available()
 | |
|     {
 | |
|       long amount = end - (bufferOffset + pos);
 | |
|       if (amount > Integer.MAX_VALUE)
 | |
|         return Integer.MAX_VALUE;
 | |
|       return (int) amount;
 | |
|     }
 | |
| 
 | |
|     public int read() throws IOException
 | |
|     {
 | |
|       if (bufferOffset + pos >= end + dummyByteCount)
 | |
|         return -1;
 | |
|       if (pos == buffer.length)
 | |
|         {
 | |
|           bufferOffset += buffer.length;
 | |
|           pos = 0;
 | |
|           fillBuffer();
 | |
|         }
 | |
| 
 | |
|       return buffer[pos++] & 0xFF;
 | |
|     }
 | |
| 
 | |
|     public int read(byte[] b, int off, int len) throws IOException
 | |
|     {
 | |
|       if (len > end + dummyByteCount - (bufferOffset + pos))
 | |
|         {
 | |
|           len = (int) (end + dummyByteCount - (bufferOffset + pos));
 | |
|           if (len == 0)
 | |
|             return -1;
 | |
|         }
 | |
| 
 | |
|       int totalBytesRead = Math.min(buffer.length - pos, len);
 | |
|       System.arraycopy(buffer, pos, b, off, totalBytesRead);
 | |
|       pos += totalBytesRead;
 | |
|       off += totalBytesRead;
 | |
|       len -= totalBytesRead;
 | |
| 
 | |
|       while (len > 0)
 | |
|         {
 | |
|           bufferOffset += buffer.length;
 | |
|           pos = 0;
 | |
|           fillBuffer();
 | |
|           int remain = Math.min(buffer.length, len);
 | |
|           System.arraycopy(buffer, pos, b, off, remain);
 | |
|           pos += remain;
 | |
|           off += remain;
 | |
|           len -= remain;
 | |
|           totalBytesRead += remain;
 | |
|         }
 | |
| 
 | |
|       return totalBytesRead;
 | |
|     }
 | |
| 
 | |
|     public long skip(long amount) throws IOException
 | |
|     {
 | |
|       if (amount < 0)
 | |
|         return 0;
 | |
|       if (amount > end - (bufferOffset + pos))
 | |
|         amount = end - (bufferOffset + pos);
 | |
|       seek(bufferOffset + pos + amount);
 | |
|       return amount;
 | |
|     }
 | |
| 
 | |
|     void seek(long newpos) throws IOException
 | |
|     {
 | |
|       long offset = newpos - bufferOffset;
 | |
|       if (offset >= 0 && offset <= buffer.length)
 | |
|         {
 | |
|           pos = (int) offset;
 | |
|         }
 | |
|       else
 | |
|         {
 | |
|           bufferOffset = newpos;
 | |
|           pos = 0;
 | |
|           fillBuffer();
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     void readFully(byte[] buf) throws IOException
 | |
|     {
 | |
|       if (read(buf, 0, buf.length) != buf.length)
 | |
|         throw new EOFException();
 | |
|     }
 | |
| 
 | |
|     void readFully(byte[] buf, int off, int len) throws IOException
 | |
|     {
 | |
|       if (read(buf, off, len) != len)
 | |
|         throw new EOFException();
 | |
|     }
 | |
| 
 | |
|     int readLeShort() throws IOException
 | |
|     {
 | |
|       int result;
 | |
|       if(pos + 1 < buffer.length)
 | |
|         {
 | |
|           result = ((buffer[pos + 0] & 0xff) | (buffer[pos + 1] & 0xff) << 8);
 | |
|           pos += 2;
 | |
|         }
 | |
|       else
 | |
|         {
 | |
|           int b0 = read();
 | |
|           int b1 = read();
 | |
|           if (b1 == -1)
 | |
|             throw new EOFException();
 | |
|           result = (b0 & 0xff) | (b1 & 0xff) << 8;
 | |
|         }
 | |
|       return result;
 | |
|     }
 | |
| 
 | |
|     int readLeInt() throws IOException
 | |
|     {
 | |
|       int result;
 | |
|       if(pos + 3 < buffer.length)
 | |
|         {
 | |
|           result = (((buffer[pos + 0] & 0xff) | (buffer[pos + 1] & 0xff) << 8)
 | |
|                    | ((buffer[pos + 2] & 0xff)
 | |
|                        | (buffer[pos + 3] & 0xff) << 8) << 16);
 | |
|           pos += 4;
 | |
|         }
 | |
|       else
 | |
|         {
 | |
|           int b0 = read();
 | |
|           int b1 = read();
 | |
|           int b2 = read();
 | |
|           int b3 = read();
 | |
|           if (b3 == -1)
 | |
|             throw new EOFException();
 | |
|           result =  (((b0 & 0xff) | (b1 & 0xff) << 8) | ((b2 & 0xff)
 | |
|                     | (b3 & 0xff) << 8) << 16);
 | |
|         }
 | |
|       return result;
 | |
|     }
 | |
| 
 | |
|     /**
 | |
|      * Decode chars from byte buffer using UTF8 encoding.  This
 | |
|      * operation is performance-critical since a jar file contains a
 | |
|      * large number of strings for the name of each file in the
 | |
|      * archive.  This routine therefore avoids using the expensive
 | |
|      * utf8Decoder when decoding is straightforward.
 | |
|      *
 | |
|      * @param buffer the buffer that contains the encoded character
 | |
|      *        data
 | |
|      * @param pos the index in buffer of the first byte of the encoded
 | |
|      *        data
 | |
|      * @param length the length of the encoded data in number of
 | |
|      *        bytes.
 | |
|      *
 | |
|      * @return a String that contains the decoded characters.
 | |
|      */
 | |
|     private String decodeChars(byte[] buffer, int pos, int length)
 | |
|       throws IOException
 | |
|     {
 | |
|       String result;
 | |
|       int i=length - 1;
 | |
|       while ((i >= 0) && (buffer[i] <= 0x7f))
 | |
|         {
 | |
|           i--;
 | |
|         }
 | |
|       if (i < 0)
 | |
|         {
 | |
|           result = new String(buffer, 0, pos, length);
 | |
|         }
 | |
|       else
 | |
|         {
 | |
|           ByteBuffer bufferBuffer = ByteBuffer.wrap(buffer, pos, length);
 | |
|           if (utf8Decoder == null)
 | |
|             utf8Decoder = UTF8CHARSET.newDecoder();
 | |
|           utf8Decoder.reset();
 | |
|           char [] characters = utf8Decoder.decode(bufferBuffer).array();
 | |
|           result = String.valueOf(characters);
 | |
|         }
 | |
|       return result;
 | |
|     }
 | |
| 
 | |
|     String readString(int length) throws IOException
 | |
|     {
 | |
|       if (length > end - (bufferOffset + pos))
 | |
|         throw new EOFException();
 | |
| 
 | |
|       String result = null;
 | |
|       try
 | |
|         {
 | |
|           if (buffer.length - pos >= length)
 | |
|             {
 | |
|               result = decodeChars(buffer, pos, length);
 | |
|               pos += length;
 | |
|             }
 | |
|           else
 | |
|             {
 | |
|               byte[] b = new byte[length];
 | |
|               readFully(b);
 | |
|               result = decodeChars(b, 0, length);
 | |
|             }
 | |
|         }
 | |
|       catch (UnsupportedEncodingException uee)
 | |
|         {
 | |
|           throw new AssertionError(uee);
 | |
|         }
 | |
|       return result;
 | |
|     }
 | |
| 
 | |
|     public void addDummyByte()
 | |
|     {
 | |
|       dummyByteCount = 1;
 | |
|     }
 | |
|   }
 | |
| }
 |