Initial revision

From-SVN: r102074

libjava/classpath/gnu/xml/dom/ls/ReaderInputStream.java

@@ -0,0 +1,237 @@
+/* ReaderInputStream.java -- 
+   Copyright (C) 1999, 2000, 2001, 2004 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 gnu.xml.dom.ls;
+
+import java.io.InputStream;
+import java.io.IOException;
+import java.io.Reader;
+
+/**
+ * Character stream wrapper.
+ *
+ * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
+ * @author <a href='mailto:mark@klomp.org'>Mark Wielaard</a>
+ */
+public class ReaderInputStream
+  extends InputStream
+{
+
+  private Reader reader;
+  private String encoding;
+
+  // Holds extra spillover data if necessary
+  private byte extra[];
+  private int pos;
+
+  private byte extra_marked[];
+  private int pos_marked;
+
+  public ReaderInputStream(Reader reader)
+  {
+    this.reader = reader;
+    this.encoding = "UTF-8";
+  }
+
+  void setEncoding(String encoding)
+  {
+    this.encoding = encoding;
+  }
+
+  public int read()
+    throws IOException
+  {
+    if (extra != null)
+      {
+        int result = extra[pos];
+        pos++;
+        if (pos >= extra.length)
+          {
+            extra = null;
+          }
+        return result;
+      }
+    return reader.read();
+  }
+
+  public int read(byte[] b)
+    throws IOException
+  {
+    return read(b, 0, b.length);
+  }
+
+  public int read(byte[] b, int off, int len)
+    throws IOException
+  {
+    if (len == 0)
+      {
+        return 0;
+      }
+
+    if (extra != null)
+      {
+        int available = extra.length - pos;
+        int l = available < len ? available : len;
+        System.arraycopy(extra, 0, b, off, l);
+        pos += l;
+        if (pos >= extra.length)
+          {
+            extra = null;
+          }
+        return l;
+      }
+
+    char[] c = new char[len];
+    int l = reader.read(c, 0, len);
+    if (l == -1)
+      {
+        return -1;
+      }
+
+    String s = new String(c, 0, l);
+    byte[] d = s.getBytes(encoding);
+    
+    int available = d.length;
+    int more = d.length - len;
+    if (more > 0)
+      {
+        extra = new byte[more];
+        pos = 0;
+        System.arraycopy(d, len, extra, 0, more);
+        available -= more;
+      }
+       
+    System.arraycopy(d, 0, b, off, available);
+    return available;
+  }
+
+  public void close()
+    throws IOException
+  {
+    reader.close();
+  }
+
+  public boolean markSupported()
+  {
+    return reader.markSupported();
+  }
+
+  public void mark(int limit)
+  {
+    if (extra != null)
+      {
+        extra_marked = new byte[extra.length];
+        System.arraycopy(extra, 0, extra_marked, 0, extra.length);
+        pos_marked = pos;
+      }
+    else
+      {
+        extra_marked = null;
+      }
+
+    try
+      {
+        // Note that this might be a bit more than asked for.
+        // Because we might also have the extra_marked bytes.
+        // That is fine (and necessary for reset() to work).
+        reader.mark(limit);
+      }
+    catch (IOException ioe)
+      {
+        throw new RuntimeException(ioe);
+      }
+  }
+
+  public void reset()
+    throws IOException
+  {
+    extra = extra_marked;
+    pos = pos_marked;
+    extra_marked = null;
+
+    reader.reset();
+  }
+
+  public long skip(long n)
+    throws IOException
+  {
+    long done = 0;
+    if (extra != null)
+      {
+        int available = extra.length - pos;
+        done = available < n ? available : n;
+        pos += done;
+        if (pos >= extra.length)
+          {
+            extra = null;
+          }
+      }
+
+    n -= done;
+    if (n > 0)
+      {
+        return reader.skip(n) + done;
+      }
+    else
+      {
+        return done;
+      }
+  }
+
+  /**
+   *  Returns conservative number of bytes available without blocking.
+   *  Actual number of bytes that can be read without blocking might
+   *  be (much) bigger.
+   */
+  public int available()
+    throws IOException
+  {
+    if (extra != null)
+      {
+        return pos - extra.length;
+      }
+
+    return reader.ready() ? 1 : 0;
+  }
+
+  public String toString()
+  {
+    return getClass().getName() + "[" + reader + ", " + encoding + "]";
+  }
+  
+}
+