/*
* The MIT License
*
* Copyright (c) 2004-2009, Sun Microsystems, Inc., Kohsuke Kawaguchi
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package hudson.model;
/**
* Represents things that {@link Queue.Executable} uses while running.
*
* <p>
* This is used in {@link Queue} to support basic mutual exclusion/locks. If two
* {@link Queue.Task}s require the same {@link Resource}, they will not
* be run at the same time.
*
* <p>
* Resources are compared by using their {@link #displayName names}, and
* need not have the "same object" semantics.
*
* @since 1.121
*/
public final class Resource {
/**
* Human-readable name of this resource.
* Used for rendering HTML.
*/
//TODO: review and check whether we can do it private
public final String displayName;
/**
* Parent resource.
*
* <p>
* A child resource is considered a part of the parent resource,
* so acquiring the parent resource always imply acquiring all
* the child resources.
*/
//TODO: review and check whether we can do it private
public final Resource parent;
/**
* Maximum number of concurrent write.
*/
//TODO: review and check whether we can do it private
public final int numConcurrentWrite;
public Resource(Resource parent, String displayName) {
this(parent,displayName,1);
}
/**
* @since 1.155
*/
public Resource(Resource parent, String displayName, int numConcurrentWrite) {
if(numConcurrentWrite<1)
throw new IllegalArgumentException();
this.parent = parent;
this.displayName = displayName;
this.numConcurrentWrite = numConcurrentWrite;
}
public Resource(String displayName) {
this(null,displayName);
}
public String getDisplayName() {
return displayName;
}
public Resource getParent() {
return parent;
}
public int getNumConcurrentWrite() {
return numConcurrentWrite;
}
/**
* Checks the resource collision.
*
* @param count
* If we are testing W/W conflict, total # of write counts.
* For R/W conflict test, this value should be set to {@link Integer#MAX_VALUE}.
*/
public boolean isCollidingWith(Resource that, int count) {
assert that!=null;
for(Resource r=that; r!=null; r=r.parent)
if(this.equals(r) && r.numConcurrentWrite<count)
return true;
for(Resource r=this; r!=null; r=r.parent)
if(that.equals(r) && r.numConcurrentWrite<count)
return true;
return false;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Resource that = (Resource) o;
return displayName.equals(that.displayName) && eq(this.parent,that.parent);
}
private static boolean eq(Object lhs,Object rhs) {
if(lhs==rhs) return true;
if(lhs==null || rhs==null) return false;
return lhs.equals(rhs);
}
@Override
public int hashCode() {
return displayName.hashCode();
}
@Override
public String toString() {
StringBuilder buf = new StringBuilder();
if(parent!=null)
buf.append(parent).append('/');
buf.append(displayName).append('(').append(numConcurrentWrite).append(')');
return buf.toString();
}
}