/*
* @(#)MeteredStream.java 1.41 06/10/10
*
* Copyright 1990-2008 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 only, as published by the Free Software Foundation.
*
* This program 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 version 2 for more details (a copy is
* included at /legal/license.txt).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this work; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*
*/
package sun.net.www;
import java.net.URL;
import java.io.*;
import sun.net.ProgressData;
import sun.net.ProgressEntry;
public
class MeteredStream extends FilterInputStream {
// Instance variables.
/* after we've read >= expected, we're "closed" and return -1
* from subsequest read() 's
*/
protected boolean closed = false;
protected int expected;
protected int count = 0;
protected ProgressEntry te;
public MeteredStream(InputStream is, ProgressEntry te) {
super(is);
this.te = te;
expected = te.need;
ProgressData.pdata.update(te);
}
private final void justRead(int n) throws IOException {
if (n == -1) {
close();
return;
}
count += n;
te.update(count, expected);
ProgressData.pdata.update(te);
if (count >= expected) {
close();
}
}
public synchronized int read() throws java.io.IOException {
if (closed) {
return -1;
}
int c = in.read();
if (c != -1) {
justRead(1);
} else {
close();
}
return c;
}
public synchronized int read(byte b[], int off, int len) throws java.io.IOException {
if (closed) {
return -1;
}
int n = in.read(b, off, len);
justRead(n);
return n;
}
public synchronized long skip(long n) throws IOException {
if (closed) {
return 0;
}
// just skip min(n, num_bytes_left)
int min = (n > expected - count) ? expected - count: (int)n;
n = in.skip(min);
justRead((int)n);
return n;
}
public void close() throws IOException {
if (closed) {
return;
}
ProgressData.pdata.unregister(te);
closed = true;
in.close();
}
public synchronized int available() throws IOException {
return closed ? 0: in.available();
}
public synchronized void mark(int readlimit) {
if (closed) {
return;
}
super.mark(readlimit);
}
public synchronized void reset() throws IOException {
if (closed) {
return;
}
super.reset();
}
public boolean markSupported() {
if (closed) {
return false;
}
return super.markSupported();
}
protected void finalize() {
/* Do not explicitly de-register from finalizer. THIS MEANS YOU! */
te.what = ProgressData.DELETE;
}
}