[kaffe] CVS kaffe (dalibor): Merged in java/util/zip/GZIPInputStream from GNU Classpath

Kaffe CVS Kaffe Mailing List <kaffe@kaffe.org>
Sun Sep 28 20:09:02 2003


PatchSet 4078 
Date: 2003/09/29 03:05:27
Author: dalibor
Branch: HEAD
Tag: (none) 
Log:
Merged in java/util/zip/GZIPInputStream from GNU Classpath

Members: 
	ChangeLog:1.1673->1.1674 
	libraries/javalib/java/util/zip/GZIPInputStream.java:1.8->1.9 

Index: kaffe/ChangeLog
diff -u kaffe/ChangeLog:1.1673 kaffe/ChangeLog:1.1674
--- kaffe/ChangeLog:1.1673	Mon Sep 29 02:16:47 2003
+++ kaffe/ChangeLog	Mon Sep 29 03:05:27 2003
@@ -1,5 +1,10 @@
 2003-09-29  Dalibor Topic <robilad@kaffe.org>
 
+	* libraries/javalib/java/util/zip/GZIPInputStream.java:
+	Replaced by implementation from GNU Classpath.
+	
+2003-09-29  Dalibor Topic <robilad@kaffe.org>
+
 	* libraries/javalib/java/util/zip/InflaterInputStream.java:
 	Replaced by implementation from GNU Classpath.
 
Index: kaffe/libraries/javalib/java/util/zip/GZIPInputStream.java
diff -u kaffe/libraries/javalib/java/util/zip/GZIPInputStream.java:1.8 kaffe/libraries/javalib/java/util/zip/GZIPInputStream.java:1.9
--- kaffe/libraries/javalib/java/util/zip/GZIPInputStream.java:1.8	Fri Aug 16 18:04:31 2002
+++ kaffe/libraries/javalib/java/util/zip/GZIPInputStream.java	Mon Sep 29 03:05:28 2003
@@ -1,118 +1,372 @@
-/*
- * Java core library component.
- *
- * Copyright (c) 1997, 1998
- *      Transvirtual Technologies, Inc.  All rights reserved.
- *
- * See the file "license.terms" for information on usage and redistribution
- * of this file.
- */
+/* java.util.zip.GZIPInputStream
+   Copyright (C) 2001 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., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 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 java.io.InputStream;
 import java.io.IOException;
+import java.io.EOFException;
 
-public class GZIPInputStream extends InflaterInputStream {
-
-protected CRC32 crc;
-protected boolean eos;
-private InputStream strm;
-
-public static final int GZIP_MAGIC		= 0x1f8b;
-static final int OLD_GZIP_MAGIC		= 0x1f9e;
-
-static final int GZIP_FLAG_ASCII_FLAG	= 0x01;	// probably ascii text
-static final int GZIP_FLAG_CONTINUATION	= 0x02;	// continuation of
-							//  multi-part gzip file
-static final int GZIP_FLAG_EXTRA_FIELD	= 0x04;	// extra field present
-static final int GZIP_FLAG_ORIG_NAME	= 0x08;	// file name present
-static final int GZIP_FLAG_COMMENT	= 0x10;	// file comment present
-static final int GZIP_FLAG_ENCRYPTED	= 0x20;	// file is encrypted
-static final int GZIP_FLAG_RESERVED	= 0xc0;	// must be zero
-
-public GZIPInputStream(InputStream in) throws IOException {
-	this(in, 512);
-}
-
-public GZIPInputStream(InputStream in, int readsize) throws IOException {
-	super(in, new Inflater(true), readsize);
-	strm = in;
-	crc = new CRC32();
-	eos = false;
-
-        /* Check GZIP header */
-        checkBytes(new int[] { GZIP_MAGIC >> 8, OLD_GZIP_MAGIC >> 8 });
-        checkBytes(new int[] { GZIP_MAGIC & 0xff, OLD_GZIP_MAGIC & 0xff });
-        checkBytes(new int[] { Deflater.DEFLATED });
-
-	/* Get flags byte */
-	int flags = checkBytes(null);
-
-	/* Skip time stamp, extra flags, and O/S fields */
-        ignoreBytes(6);
-
-	/* Check flags */
-	if ((flags & GZIP_FLAG_CONTINUATION) != 0) {	// skip multi-part #
-		ignoreBytes(2);
-	}
-	if ((flags & GZIP_FLAG_EXTRA_FIELD) != 0) {	// skip extra fields
-		int len = strm.read();
-		len |= strm.read() << 8;
-		ignoreBytes(len);
-	}
-	if ((flags & GZIP_FLAG_ORIG_NAME) != 0) {	// skip name
-		ignoreString();
-	}
-	if ((flags & GZIP_FLAG_COMMENT) != 0) {		// skip comment
-		ignoreString();
-	}
-}
-
-private int checkBytes(int[] v) throws IOException {
-	int i, x = strm.read();
-	if (v != null) {
-		for (i = 0; i < v.length && x != v[i]; i++)
-			;
-		if (i == v.length) {
-			throw new IOException("invalid GZIP stream");
-		}
-	}
-	return x;
-}
-
-private void ignoreBytes(int nr) throws IOException {
-	for (; nr > 0; nr--) {
-		strm.read();
-	}
-}
-
-private void ignoreString() throws IOException {
-	int x;
-	while ((x = strm.read()) != 0) {
-		if (x == -1) {
-			throw new IOException("premature GZIP end-of-file");
-		}
-	}
-}
-
-public void close() throws IOException {
-	super.close();
-}
-
-public int read(byte[] buf, int off, int len) throws IOException {
-	int total = super.read(buf, off, len);
-	if (total > 0) {
-		crc.update(buf, off, total);
-	}
-	else if (total == -1) {
-		if (!eos) {
-			eos = true;
-			// Skip the tail on the GZIP
-			ignoreBytes(8);
-		}
-	}
-	return (total);
-}
 
+/**
+ * This filter stream is used to decompress a "GZIP" format stream. 
+ * The "GZIP" format is described in RFC 1952.
+ *
+ * @author John Leuner
+ * @since JDK 1.1
+ */
+public class GZIPInputStream
+  extends InflaterInputStream
+{
+  /**
+   * The magic number found at the start of a GZIP stream.
+   */
+  public static final int GZIP_MAGIC = 0x1f8b;
+
+
+  /**
+   * The mask for bit 0 of the flag byte.
+   */
+  static final int FTEXT = 0x1;
+
+
+  /**
+   * The mask for bit 1 of the flag byte.
+   */
+  static final int FHCRC = 0x2;
+
+
+  /**
+   * The mask for bit 2 of the flag byte.
+   */
+  static final int FEXTRA = 0x4;
+
+
+  /**
+   * The mask for bit 3 of the flag byte.
+   */
+  static final int FNAME = 0x8;
+
+
+  /**
+   * The mask for bit 4 of the flag byte.
+   */
+  static final int FCOMMENT = 0x10;
+
+
+  /**
+   * The CRC-32 checksum value for uncompressed data.
+   */
+  protected CRC32 crc; 
+
+
+  /**
+   * Indicates whether or not the end of the stream has been reached.
+   */  
+  protected boolean eos;
+
+
+  /**
+   * Indicates whether or not the GZIP header has been read in.
+   */
+  private boolean readGZIPHeader;
+
+
+  /**
+   * Creates a GZIPInputStream with the default buffer size.
+   *
+   * @param in The stream to read compressed data from 
+   *           (in GZIP format).
+   *
+   * @throws IOException if an error occurs during an I/O operation.
+   */
+  public GZIPInputStream(InputStream in)
+    throws IOException
+  {
+    this(in, 4096);
+  }
+
+
+  /**
+   * Creates a GZIPInputStream with the specified buffer size.
+   *
+   * @param in The stream to read compressed data from 
+   *           (in GZIP format).
+   *
+   * @param size The size of the buffer to use.
+   *
+   * @throws IOException if an error occurs during an I/O operation.
+   *
+   * @throws java.lang.IllegalArgumentException if <code>size</code>
+   *         is less than or equal to 0.
+   */
+  public GZIPInputStream(InputStream in, int size)
+    throws IOException
+  {
+    super(in, new Inflater(true), size);
+    crc = new CRC32();
+  }
+
+
+  /**
+   * Closes the input stream.
+   *
+   * @throws IOException if an error occurs during an I/O operation.
+   */
+  public void close()
+    throws IOException
+  {
+    super.close();
+  }
+
+
+  /**
+   * Reads in GZIP-compressed data and stores it in uncompressed form
+   * into an array of bytes.  The method will block until either
+   * enough input data becomes available or the compressed stream
+   * reaches its end.
+   *
+   * @param buf the buffer into which the uncompressed data will
+   *            be stored.
+   *
+   * @param offset the offset indicating where in <code>buf</code>
+   *               the uncompressed data should be placed.
+   *
+   * @param len the number of uncompressed bytes to be read.
+   */
+  public int read(byte[] buf, int offset, int len) throws IOException
+  {
+    // We first have to slurp in the GZIP header, then we feed all the
+    // rest of the data to the superclass.
+    //
+    // As we do that we continually update the CRC32. Once the data is
+    // finished, we check the CRC32.
+    //
+    // This means we don't need our own buffer, as everything is done
+    // in the superclass.
+    if (!readGZIPHeader)
+      readHeader();
+
+    if (eos)
+      return -1;
+
+    //  System.err.println("GZIPIS.read(byte[], off, len ... " + offset + " and len " + len);
+
+    /* We don't have to read the header,
+     * so we just grab data from the superclass.
+     */
+    int numRead = super.read(buf, offset, len);
+    if (numRead > 0)
+      crc.update(buf, offset, numRead);
+
+    if (inf.finished())
+      readFooter();
+    return numRead;
+  }
+
+
+  /**
+   * Reads in the GZIP header.
+   */
+  private void readHeader() throws IOException
+  {
+    /* 1. Check the two magic bytes */
+    CRC32 headCRC = new CRC32();
+    int magic = in.read();
+    if (magic < 0)
+    {
+      eos = true;
+      return;
+    }
+    headCRC.update(magic);
+    if (magic != (GZIP_MAGIC >> 8))
+      throw new IOException("Error in GZIP header, first byte doesn't match");
+    
+    magic = in.read();
+    if (magic != (GZIP_MAGIC & 0xff))
+      throw new IOException("Error in GZIP header, second byte doesn't match");
+    headCRC.update(magic);
+    
+    /* 2. Check the compression type (must be 8) */
+    int CM = in.read();
+    if (CM != 8)
+      throw new IOException("Error in GZIP header, data not in deflate format");
+    headCRC.update(CM);
+
+    /* 3. Check the flags */
+    int flags = in.read();
+    if (flags < 0)
+      throw new EOFException("Early EOF in GZIP header");
+    headCRC.update(flags);
+    
+    /*    This flag byte is divided into individual bits as follows:
+	  
+	  bit 0   FTEXT
+	  bit 1   FHCRC
+	  bit 2   FEXTRA
+	  bit 3   FNAME
+	  bit 4   FCOMMENT
+	  bit 5   reserved
+	  bit 6   reserved
+	  bit 7   reserved
+    */
+    
+    /* 3.1 Check the reserved bits are zero */    
+    if ((flags & 0xd0) != 0)
+      throw new IOException("Reserved flag bits in GZIP header != 0");
+    
+    /* 4.-6. Skip the modification time, extra flags, and OS type */
+    for (int i=0; i< 6; i++)
+    {
+      int readByte = in.read();
+      if (readByte < 0)
+	throw new EOFException("Early EOF in GZIP header");
+      headCRC.update(readByte);
+    }
+    
+    /* 7. Read extra field */
+    if ((flags & FEXTRA) != 0)
+    {
+      /* Skip subfield id */
+      for (int i=0; i< 2; i++)
+      {
+        int readByte = in.read();
+	if (readByte < 0)
+	  throw new EOFException("Early EOF in GZIP header");
+	headCRC.update(readByte);
+      }
+      if (in.read() < 0 || in.read() < 0)
+	throw new EOFException("Early EOF in GZIP header");
+	
+      int len1, len2, extraLen;
+      len1 = in.read();
+      len2 = in.read();
+      if ((len1 < 0) || (len2 < 0))
+	throw new EOFException("Early EOF in GZIP header");
+      headCRC.update(len1);
+      headCRC.update(len2);
+
+      extraLen = (len1 << 8) | len2;
+      for (int i = 0; i < extraLen;i++)
+      {
+	int readByte = in.read();
+	if (readByte < 0)
+	  throw new EOFException("Early EOF in GZIP header");
+	headCRC.update(readByte);
+      }
+    }
+    
+    /* 8. Read file name */
+    if ((flags & FNAME) != 0)
+    {
+      int readByte;
+      while ( (readByte = in.read()) > 0)
+	headCRC.update(readByte);
+      if (readByte < 0)
+	throw new EOFException("Early EOF in GZIP file name");
+      headCRC.update(readByte);
+    }
+
+    /* 9. Read comment */
+    if ((flags & FCOMMENT) != 0)
+    {
+      int readByte;
+      while ( (readByte = in.read()) > 0)
+        headCRC.update(readByte);
+
+      if (readByte < 0)
+        throw new EOFException("Early EOF in GZIP comment");
+      headCRC.update(readByte);
+    }
+    
+    /* 10. Read header CRC */
+    if ((flags & FHCRC) != 0)
+    {
+      int tempByte;
+      int crcval = in.read();
+      if (crcval < 0)
+        throw new EOFException("Early EOF in GZIP header");
+	
+      tempByte = in.read();
+      if (tempByte < 0)
+        throw new EOFException("Early EOF in GZIP header");
+	
+      crcval = (crcval << 8) | tempByte;
+      if (crcval != ((int) headCRC.getValue() & 0xffff))
+        throw new IOException("Header CRC value mismatch");
+    }
+    
+    readGZIPHeader = true;
+    //System.err.println("Read GZIP header");
+  }
+
+
+  private void readFooter() throws IOException
+  {
+    byte[] footer = new byte[8];
+    int avail = inf.getRemaining();
+    if (avail > 8)
+      avail = 8;
+    System.arraycopy(buf, len - inf.getRemaining(), footer, 0, avail);
+    int needed = 8 - avail;
+    while (needed > 0)
+    {
+      int count = in.read(footer, 8-needed, needed);
+      if (count <= 0)
+	throw new EOFException("Early EOF in GZIP footer");
+      needed -= count; //Jewel Jan 16
+    }
+
+    int crcval = (footer[0] & 0xff) | ((footer[1] & 0xff) << 8)
+      | ((footer[2] & 0xff) << 16) | (footer[3] << 24);
+    if (crcval != (int) crc.getValue())
+      throw new IOException("GZIP crc sum mismatch, theirs \""
+			    + Integer.toHexString(crcval)
+			    + "\" and ours \""
+			    + Integer.toHexString( (int) crc.getValue()));
+
+    int total = (footer[4] & 0xff) | ((footer[5] & 0xff) << 8)
+      | ((footer[6] & 0xff) << 16) | (footer[7] << 24);
+    if (total != inf.getTotalOut())
+      throw new IOException("Number of bytes mismatch");
+
+    /* FIXME" XXX Should we support multiple members.
+     * Difficult, since there may be some bytes still in buf
+     */
+    eos = true;
+  }
 }