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authorMark Wielaard <mark@klomp.org>2001-10-05 11:34:48 +0000
committerMark Wielaard <mark@klomp.org>2001-10-05 11:34:48 +0000
commit67be6239c8be55c0f3ccb28864494cb3d97d4a5c (patch)
tree9b623fd9d2dbbf2d07565540d80696aa01fa8134 /java/util/zip/CheckedInputStream.java
parent72c3dfa6cbc0de5d70b64eacf986b2dc332adb24 (diff)
downloadclasspath-67be6239c8be55c0f3ccb28864494cb3d97d4a5c.tar.gz
* java/util/zip/Adler32.java: Merge with libgcj
* java/util/zip/CRC32.java: Merge with libgcj * java/util/zip/CheckedInputStream.java: New file from libgcj * java/util/zip/CheckedOutputStream.java: Ditto * java/util/zip/Checksum.java: Merge with libgcj * java/util/zip/DataFormatException.java: Ditto * java/util/zip/ZipException.java: Ditto * java/util/zip/Makefile.am: add new classes
Diffstat (limited to 'java/util/zip/CheckedInputStream.java')
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diff --git a/java/util/zip/CheckedInputStream.java b/java/util/zip/CheckedInputStream.java
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+/* CheckedInputStream.java - Compute checksum of data being read
+ Copyright (C) 1999, 2000 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.
+
+As a special exception, if you link this library with other files to
+produce an executable, this library does not by itself cause the
+resulting executable to be covered by the GNU General Public License.
+This exception does not however invalidate any other reasons why the
+executable file might be covered by the GNU General Public License. */
+
+package java.util.zip;
+
+import java.io.FilterInputStream;
+import java.io.InputStream;
+import java.io.IOException;
+
+/* Written using on-line Java Platform 1.2 API Specification
+ * and JCL book.
+ * Believed complete and correct.
+ */
+
+/**
+ * InputStream that computes a checksum of the data being read using a
+ * supplied Checksum object.
+ *
+ * @see Checksum
+ *
+ * @author Tom Tromey
+ * @date May 17, 1999
+ */
+public class CheckedInputStream extends FilterInputStream
+{
+ /**
+ * Creates a new CheckInputStream on top of the supplied OutputStream
+ * using the supplied Checksum.
+ */
+ public CheckedInputStream (InputStream in, Checksum sum)
+ {
+ super (in);
+ this.sum = sum;
+ }
+
+ /**
+ * Returns the Checksum object used. To get the data checksum computed so
+ * far call <code>getChecksum.getValue()</code>.
+ */
+ public Checksum getChecksum ()
+ {
+ return sum;
+ }
+
+ /**
+ * Reads one byte, updates the checksum and returns the read byte
+ * (or -1 when the end of file was reached).
+ */
+ public int read () throws IOException
+ {
+ int x = in.read();
+ if (x != -1)
+ sum.update(x);
+ return x;
+ }
+
+ /**
+ * Reads at most len bytes in the supplied buffer and updates the checksum
+ * with it. Returns the number of bytes actually read or -1 when the end
+ * of file was reached.
+ */
+ public int read (byte[] buf, int off, int len) throws IOException
+ {
+ int r = in.read(buf, off, len);
+ if (r != -1)
+ sum.update(buf, off, r);
+ return r;
+ }
+
+ /**
+ * Skips n bytes by reading them in a temporary buffer and updating the
+ * the checksum with that buffer. Returns the actual number of bytes skiped
+ * which can be less then requested when the end of file is reached.
+ */
+ public long skip (long n) throws IOException
+ {
+ if (n == 0)
+ return 0;
+
+ int min = (int) Math.min(n, 1024);
+ byte[] buf = new byte[min];
+
+ long s = 0;
+ while (n > 0)
+ {
+ int r = in.read(buf, 0, min);
+ if (r == -1)
+ break;
+ n -= r;
+ s += r;
+ min = (int) Math.min(n, 1024);
+ sum.update(buf, 0, r);
+ }
+
+ return s;
+ }
+
+ /** The checksum object. */
+ private Checksum sum;
+}