/*
* $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/conn/routing/RouteTracker.java $
* $Revision: 620254 $
* $Date: 2008-02-10 02:18:48 -0800 (Sun, 10 Feb 2008) $
*
* ====================================================================
* 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.http.conn.routing;
import java.net.InetAddress;
import org.apache.http.HttpHost;
/**
* Helps tracking the steps in establishing a route.
*
* @author <a href="mailto:rolandw at apache.org">Roland Weber</a>
*
*
* <!-- empty lines to avoid svn diff problems -->
* @version $Revision: 620254 $
*
* @since 4.0
*/
public final class RouteTracker implements RouteInfo, Cloneable {
/** The target host to connect to. */
private final HttpHost targetHost;
/**
* The local address to connect from.
* <code>null</code> indicates that the default should be used.
*/
private final InetAddress localAddress;
// the attributes above are fixed at construction time
// now follow attributes that indicate the established route
/** Whether the first hop of the route is established. */
private boolean connected;
/** The proxy chain, if any. */
private HttpHost[] proxyChain;
/** Whether the the route is tunnelled end-to-end through proxies. */
private TunnelType tunnelled;
/** Whether the route is layered over a tunnel. */
private LayerType layered;
/** Whether the route is secure. */
private boolean secure;
/**
* Creates a new route tracker.
* The target and origin need to be specified at creation time.
*
* @param target the host to which to route
* @param local the local address to route from, or
* <code>null</code> for the default
*/
public RouteTracker(HttpHost target, InetAddress local) {
if (target == null) {
throw new IllegalArgumentException("Target host may not be null.");
}
this.targetHost = target;
this.localAddress = local;
this.tunnelled = TunnelType.PLAIN;
this.layered = LayerType.PLAIN;
}
/**
* Creates a new tracker for the given route.
* Only target and origin are taken from the route,
* everything else remains to be tracked.
*
* @param route the route to track
*/
public RouteTracker(HttpRoute route) {
this(route.getTargetHost(), route.getLocalAddress());
}
/**
* Tracks connecting to the target.
*
* @param secure <code>true</code> if the route is secure,
* <code>false</code> otherwise
*/
public final void connectTarget(boolean secure) {
if (this.connected) {
throw new IllegalStateException("Already connected.");
}
this.connected = true;
this.secure = secure;
}
/**
* Tracks connecting to the first proxy.
*
* @param proxy the proxy connected to
* @param secure <code>true</code> if the route is secure,
* <code>false</code> otherwise
*/
public final void connectProxy(HttpHost proxy, boolean secure) {
if (proxy == null) {
throw new IllegalArgumentException("Proxy host may not be null.");
}
if (this.connected) {
throw new IllegalStateException("Already connected.");
}
this.connected = true;
this.proxyChain = new HttpHost[]{ proxy };
this.secure = secure;
}
/**
* Tracks tunnelling to the target.
*
* @param secure <code>true</code> if the route is secure,
* <code>false</code> otherwise
*/
public final void tunnelTarget(boolean secure) {
if (!this.connected) {
throw new IllegalStateException("No tunnel unless connected.");
}
if (this.proxyChain == null) {
throw new IllegalStateException("No tunnel without proxy.");
}
this.tunnelled = TunnelType.TUNNELLED;
this.secure = secure;
}
/**
* Tracks tunnelling to a proxy in a proxy chain.
* This will extend the tracked proxy chain, but it does not mark
* the route as tunnelled. Only end-to-end tunnels are considered there.
*
* @param proxy the proxy tunnelled to
* @param secure <code>true</code> if the route is secure,
* <code>false</code> otherwise
*/
public final void tunnelProxy(HttpHost proxy, boolean secure) {
if (proxy == null) {
throw new IllegalArgumentException("Proxy host may not be null.");
}
if (!this.connected) {
throw new IllegalStateException("No tunnel unless connected.");
}
if (this.proxyChain == null) {
throw new IllegalStateException("No proxy tunnel without proxy.");
}
// prepare an extended proxy chain
HttpHost[] proxies = new HttpHost[this.proxyChain.length+1];
System.arraycopy(this.proxyChain, 0,
proxies, 0, this.proxyChain.length);
proxies[proxies.length-1] = proxy;
this.proxyChain = proxies;
this.secure = secure;
}
/**
* Tracks layering a protocol.
*
* @param secure <code>true</code> if the route is secure,
* <code>false</code> otherwise
*/
public final void layerProtocol(boolean secure) {
// it is possible to layer a protocol over a direct connection,
// although this case is probably not considered elsewhere
if (!this.connected) {
throw new IllegalStateException
("No layered protocol unless connected.");
}
this.layered = LayerType.LAYERED;
this.secure = secure;
}
// non-JavaDoc, see interface RouteInfo
public final HttpHost getTargetHost() {
return this.targetHost;
}
// non-JavaDoc, see interface RouteInfo
public final InetAddress getLocalAddress() {
return this.localAddress;
}
// non-JavaDoc, see interface RouteInfo
public final int getHopCount() {
int hops = 0;
if (this.connected) {
if (proxyChain == null)
hops = 1;
else
hops = proxyChain.length + 1;
}
return hops;
}
// non-JavaDoc, see interface RouteInfo
public final HttpHost getHopTarget(int hop) {
if (hop < 0)
throw new IllegalArgumentException
("Hop index must not be negative: " + hop);
final int hopcount = getHopCount();
if (hop >= hopcount) {
throw new IllegalArgumentException
("Hop index " + hop +
" exceeds tracked route length " + hopcount +".");
}
HttpHost result = null;
if (hop < hopcount-1)
result = this.proxyChain[hop];
else
result = this.targetHost;
return result;
}
// non-JavaDoc, see interface RouteInfo
public final HttpHost getProxyHost() {
return (this.proxyChain == null) ? null : this.proxyChain[0];
}
// non-JavaDoc, see interface RouteInfo
public final boolean isConnected() {
return this.connected;
}
// non-JavaDoc, see interface RouteInfo
public final TunnelType getTunnelType() {
return this.tunnelled;
}
// non-JavaDoc, see interface RouteInfo
public final boolean isTunnelled() {
return (this.tunnelled == TunnelType.TUNNELLED);
}
// non-JavaDoc, see interface RouteInfo
public final LayerType getLayerType() {
return this.layered;
}
// non-JavaDoc, see interface RouteInfo
public final boolean isLayered() {
return (this.layered == LayerType.LAYERED);
}
// non-JavaDoc, see interface RouteInfo
public final boolean isSecure() {
return this.secure;
}
/**
* Obtains the tracked route.
* If a route has been tracked, it is {@link #isConnected connected}.
* If not connected, nothing has been tracked so far.
*
* @return the tracked route, or
* <code>null</code> if nothing has been tracked so far
*/
public final HttpRoute toRoute() {
return !this.connected ?
null : new HttpRoute(this.targetHost, this.localAddress,
this.proxyChain, this.secure,
this.tunnelled, this.layered);
}
/**
* Compares this tracked route to another.
*
* @param o the object to compare with
*
* @return <code>true</code> if the argument is the same tracked route,
* <code>false</code>
*/
@Override
public final boolean equals(Object o) {
if (o == this)
return true;
if (!(o instanceof RouteTracker))
return false;
RouteTracker that = (RouteTracker) o;
boolean equal = this.targetHost.equals(that.targetHost);
equal &=
( this.localAddress == that.localAddress) ||
((this.localAddress != null) &&
this.localAddress.equals(that.localAddress));
equal &=
( this.proxyChain == that.proxyChain) ||
((this.proxyChain != null) &&
(that.proxyChain != null) &&
(this.proxyChain.length == that.proxyChain.length));
// comparison of actual proxies follows below
equal &=
(this.connected == that.connected) &&
(this.secure == that.secure) &&
(this.tunnelled == that.tunnelled) &&
(this.layered == that.layered);
// chain length has been compared above, now check the proxies
if (equal && (this.proxyChain != null)) {
for (int i=0; equal && (i<this.proxyChain.length); i++)
equal = this.proxyChain[i].equals(that.proxyChain[i]);
}
return equal;
}
/**
* Generates a hash code for this tracked route.
* Route trackers are modifiable and should therefore not be used
* as lookup keys. Use {@link #toRoute toRoute} to obtain an
* unmodifiable representation of the tracked route.
*
* @return the hash code
*/
@Override
public final int hashCode() {
int hc = this.targetHost.hashCode();
if (this.localAddress != null)
hc ^= localAddress.hashCode();
if (this.proxyChain != null) {
hc ^= proxyChain.length;
for (int i=0; i<proxyChain.length; i++)
hc ^= proxyChain[i].hashCode();
}
if (this.connected)
hc ^= 0x11111111;
if (this.secure)
hc ^= 0x22222222;
hc ^= this.tunnelled.hashCode();
hc ^= this.layered.hashCode();
return hc;
}
/**
* Obtains a description of the tracked route.
*
* @return a human-readable representation of the tracked route
*/
@Override
public final String toString() {
StringBuilder cab = new StringBuilder(50 + getHopCount()*30);
cab.append("RouteTracker[");
if (this.localAddress != null) {
cab.append(this.localAddress);
cab.append("->");
}
cab.append('{');
if (this.connected)
cab.append('c');
if (this.tunnelled == TunnelType.TUNNELLED)
cab.append('t');
if (this.layered == LayerType.LAYERED)
cab.append('l');
if (this.secure)
cab.append('s');
cab.append("}->");
if (this.proxyChain != null) {
for (int i=0; i<this.proxyChain.length; i++) {
cab.append(this.proxyChain[i]);
cab.append("->");
}
}
cab.append(this.targetHost);
cab.append(']');
return cab.toString();
}
// default implementation of clone() is sufficient
@Override
public Object clone() throws CloneNotSupportedException {
return super.clone();
}
} // class RouteTracker
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