/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.coyote.http11.upgrade;
import java.io.IOException;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import org.apache.tomcat.util.res.StringManager;
public abstract class AbstractServletInputStream extends ServletInputStream {
protected static final StringManager sm =
StringManager.getManager(Constants.Package);
private volatile boolean closeRequired = false;
// Start in blocking-mode
private volatile Boolean ready = Boolean.TRUE;
private volatile ReadListener listener = null;
@Override
public final boolean isFinished() {
if (listener == null) {
throw new IllegalStateException(
sm.getString("upgrade.sis.isFinished.ise"));
}
// The only way to finish an HTTP Upgrade connection is to close the
// socket.
return false;
}
@Override
public final boolean isReady() {
if (listener == null) {
throw new IllegalStateException(
sm.getString("upgrade.sis.isReady.ise"));
}
// If we already know the current state, return it.
if (ready != null) {
return ready.booleanValue();
}
try {
ready = Boolean.valueOf(doIsReady());
} catch (IOException e) {
listener.onError(e);
ready = Boolean.FALSE;
}
return ready.booleanValue();
}
@Override
public final void setReadListener(ReadListener listener) {
if (listener == null) {
throw new IllegalArgumentException(
sm.getString("upgrade.sis.readListener.null"));
}
this.listener = listener;
// Switching to non-blocking. Don't know if data is available.
ready = null;
}
@Override
public final int read() throws IOException {
preReadChecks();
return readInternal();
}
@Override
public final int readLine(byte[] b, int off, int len) throws IOException {
preReadChecks();
if (len <= 0) {
return 0;
}
int count = 0, c;
while ((c = readInternal()) != -1) {
b[off++] = (byte) c;
count++;
if (c == '\n' || count == len) {
break;
}
}
return count > 0 ? count : -1;
}
@Override
public final int read(byte[] b, int off, int len) throws IOException {
preReadChecks();
try {
return doRead(listener == null, b, off, len);
} catch (IOException ioe) {
closeRequired = true;
throw ioe;
}
}
@Override
public void close() throws IOException {
closeRequired = true;
doClose();
}
private void preReadChecks() {
if (listener != null && (ready == null || !ready.booleanValue())) {
throw new IllegalStateException(
sm.getString("upgrade.sis.read.ise"));
}
// No longer know if data is available
ready = null;
}
private int readInternal() throws IOException {
// Single byte reads for non-blocking need special handling so all
// single byte reads run through this method.
ReadListener readListener = this.listener;
byte[] b = new byte[1];
int result;
try {
result = doRead(readListener == null, b, 0, 1);
} catch (IOException ioe) {
closeRequired = true;
throw ioe;
}
if (result == 0) {
return -1;
} else if (result == -1) {
// Will never happen with a network socket. An IOException will be
// thrown when the client closes the connection.
// Echo back the -1 to be safe.
return -1;
} else {
return b[0] & 0xFF;
}
}
protected final void onDataAvailable() throws IOException {
ready = Boolean.TRUE;
listener.onDataAvailable();
}
protected final boolean isCloseRequired() {
return closeRequired;
}
protected abstract boolean doIsReady() throws IOException;
/**
* Abstract method to be overridden by concrete implementations. The base
* class will ensure that there are no concurrent calls to this method for
* the same socket.
*/
protected abstract int doRead(boolean block, byte[] b, int off, int len)
throws IOException;
protected abstract void doClose() throws IOException;
}