/*
* @(#)KeepAliveStream.java 1.22 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.http;
import java.net.URL;
import java.io.*;
import sun.net.www.MeteredStream;
import sun.net.ProgressData;
import sun.net.ProgressEntry;
/**
* A stream that has the property of being able to be kept alive for
* multiple downloads from the same server.
*
* @version 1.22, 10/10/06
* @author Stephen R. Pietrowicz (NCSA)
* @author Dave Brown
*/
public
class KeepAliveStream extends MeteredStream implements Hurryable {
// instance variables
HttpClient hc;
boolean hurried;
/**
* Constructor
*/
public KeepAliveStream(InputStream is, ProgressEntry te, HttpClient hc) {
super(is, te);
this.hc = hc;
}
/**
* Attempt to cache this connection
*/
public void close() throws IOException {
// If the inputstream is closed already, just return.
if (closed) {
return;
}
// Skip past the data that's left in the Inputstream because
// some sort of error may have occurred.
// Do this ONLY if the skip won't block. The stream may have
// been closed at the beginning of a big file and we don't want
// to hang around for nothing. So if we can't skip without blocking
// we just close the socket and, therefore, terminate the keepAlive
// NOTE: Don't close super class
try {
if (expected > count) {
long nskip = (long) (expected - count);
if (nskip <= available()) {
long n = 0;
while (n < nskip) {
nskip = nskip - n;
n = skip(nskip);
}
} else {
hc.closeServer();
}
}
if (!closed && !hurried) {
hc.finished();
}
} finally {
ProgressData.pdata.unregister(te);
// nulling out the underlying inputstream as well as
// httpClient to let gc collect the memories faster
in = null;
hc = null;
closed = true;
}
}
/* we explicitly do not support mark/reset */
public boolean markSupported() {
return false;
}
public void mark(int limit) {}
public void reset() throws IOException {
throw new IOException("mark/reset not supported");
}
public synchronized boolean hurry() {
try {
/* CASE 0: we're actually already done */
if (closed || count >= expected) {
return false;
} else if (in.available() < (expected - count)) {
/* CASE I: can't meet the demand */
return false;
} else {
/* CASE II: fill our internal buffer
* TODO: possibly check memory here
*/
byte[] buf = new byte[expected - count];
DataInputStream dis = new DataInputStream(in);
dis.readFully(buf);
in = new ByteArrayInputStream(buf);
hurried = true;
return true;
}
} catch (IOException e) {
// e.printStackTrace();
return false;
}
}
}