org.hawkular.agent.monitor.inventory

Class ResourceManager<L>

java.lang.Object

org.hawkular.agent.monitor.inventory.ResourceManager<L>

Type Parameters:

L - the type of the protocol specific location, typically a subclass of NodeLocation

public final class ResourceManager<L>
extends Object

Holds the graph of resources. The graph itself is never exposed externally - ResourceManager rather provides methods to retrieve data from the graph and to change the data in the graph.

Concurrency:

• All data and collections returned from ResourceManager is immutable
• ResourceManager uses a ReadWriteLock internally so that all public read and write operations can be performed from concurrent threads

Author:

John Mazzitelli, Peter Palaga

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ResourceManager.AddResult<L> Indicates the results of the addResource(Resource) method.

Constructor Summary

Constructors

Constructor and Description
ResourceManager()

Method Summary

Modifier and Type	Method and Description
ResourceManager.AddResult<L>	addResource(Resource<L> newResource) Adds the given resource to the resource hierarchy, replacing the resource if it already exist but has changed.
List<Resource<L>>	findResources(L query, LocationResolver<L> locationResolver) Find the resources in resourcesGraph matching the given query.
List<Resource<L>>	getAllResources(Collection<ID> filter)
Set<Resource<L>>	getChildren(Resource<L> resource) Returns an immutable Set of the direct children of the given resource.
Resource<L>	getParent(Resource<L> resource) Returns the direct parent of the given resource.
Resource<L>	getResource(ID resourceId) Given a resource ID this will return the resource with that ID that is found in the internal hierarchical graph or null if there is no resource with that ID in the graph.
List<Resource<L>>	getResourcesBreadthFirst() Returns an immutable List of all Resources contained in resourcesGraph in breadth-first order.
Set<Resource<L>>	getRootResources() Returns an immutable Set of Resources that are at the top of the hierarchy (that is, they do not have a parent).
void	logTreeGraph(String logMsg, long duration)
List<Resource<L>>	removeResource(Resource<L> doomedResource) Remove the resource from resourcesGraph, including all its descendants.
List<Resource<L>>	removeResources(L query, LocationResolver<L> locationResolver) Remove the resources from resourcesGraph matching the given query including all direct and indirect descendants.
int	size()
int	size(Resource<L> relativeTo)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ResourceManager

public ResourceManager()

Method Detail

size

public int size()

Returns:

the total number of resources currently in the graph.

size

public int size(Resource<L> relativeTo)

Returns:

the total number of resources currently in the graph relative to the given resource (that is, it counts that resource and all of its descendants).

addResource

public ResourceManager.AddResult<L> addResource(Resource<L> newResource)
                                         throws IllegalArgumentException

Adds the given resource to the resource hierarchy, replacing the resource if it already exist but has changed. If the resource is a child of a parent, that parent must already be known or an exception is thrown. The return value's effect has the following semantics:

• ADDED means the resource was new and was added to the inventory.
• MODIFIED means the resource was already in inventory but is different from before and so inventory was updated.
• UNCHANGED means the resource was already in inventory and is the same.

The return value's resource is the resource object stored in the internal hierarchical graph, which may or may not be the same as the newResource that was passed into this method.

Parameters:

newResource - the new resource to be added

Returns:

the results - see above for a detailed description of these results

Throws:

IllegalArgumentException - if the new resource's parent does not yet exist in the hierarchy

removeResource

public List<Resource<L>> removeResource(Resource<L> doomedResource)

Remove the resource from resourcesGraph, including all its descendants.

Parameters:

doomedResource - the resource to remove

Returns:

an unmodifiable list of Resources that were removed by this method

findResources

public List<Resource<L>> findResources(L query,
                                       LocationResolver<L> locationResolver)

Find the resources in resourcesGraph matching the given query.

Parameters:

query - a location eventually containing wildcards

locationResolver - the LocationResolver to perform the matching of graph nodes against the given query

Returns:

an unmodifiable list of Resources that match the given query

getChildren

public Set<Resource<L>> getChildren(Resource<L> resource)

Returns an immutable Set of the direct children of the given resource.

Parameters:

resource - the resource whose children are to be returned

Returns:

a Set if direct children of the given resource

getParent

public Resource<L> getParent(Resource<L> resource)

Returns the direct parent of the given resource. This examines the internal hierarchical graph to determine parentage.

Parameters:

resource - the resource whose parent is to be returned

Returns:

the direct parent of the given resource, or null if this is a root resource without a parent

Throws:

IllegalArgumentException - if the resource itself is not found in the graph

getResource

public Resource<L> getResource(ID resourceId)

Given a resource ID this will return the resource with that ID that is found in the internal hierarchical graph or null if there is no resource with that ID in the graph.

Parameters:

resourceId - the ID of the resource to retrieve

Returns:

the resource as found in the internal graph or null

getResourcesBreadthFirst

public List<Resource<L>> getResourcesBreadthFirst()

Returns an immutable List of all Resources contained in resourcesGraph in breadth-first order.

Returns:

the list of all Resources

getAllResources

public List<Resource<L>> getAllResources(Collection<ID> filter)

Parameters:

filter - if not null, any resources whose IDs are in here will not exist in the returned collection

Returns:

a list of the resources in this resource manager masked by the given IDs (that is, if an ID in this resource manager matches an ID found in the filter collection, the resource whose ID it is will not be found in the returned collection). DO NOT THINK THIS RETURNS ONLY THOSE RESOURCES WHOSE IDS MATCH THOSE IN FILTER, IT IS THE OPPOSITE.

getRootResources

public Set<Resource<L>> getRootResources()

Returns an immutable Set of Resources that are at the top of the hierarchy (that is, they do not have a parent).

Returns:

a Set of root Resources

logTreeGraph

public void logTreeGraph(String logMsg,
                         long duration)

removeResources

public List<Resource<L>> removeResources(L query,
                                         LocationResolver<L> locationResolver)

Remove the resources from resourcesGraph matching the given query including all direct and indirect descendants.

Parameters:

query - a location eventually containing wildcards

locationResolver - the LocationResolver to perform the matching of graph nodes against the given query

Returns:

an unmodifiable list of Resources that were removed by this method