From 67be6239c8be55c0f3ccb28864494cb3d97d4a5c Mon Sep 17 00:00:00 2001
From: Mark Wielaard <mark@klomp.org>
Date: Fri, 5 Oct 2001 11:34:48 +0000
Subject:     * 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

---
 java/util/zip/CheckedInputStream.java | 123 ++++++++++++++++++++++++++++++++++
 1 file changed, 123 insertions(+)
 create mode 100644 java/util/zip/CheckedInputStream.java

(limited to 'java/util/zip/CheckedInputStream.java')

diff --git a/java/util/zip/CheckedInputStream.java b/java/util/zip/CheckedInputStream.java
new file mode 100644
index 000000000..80a7bb660
--- /dev/null
+++ b/java/util/zip/CheckedInputStream.java
@@ -0,0 +1,123 @@
+/* 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;
+}
-- 
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