Initial implementation of LinkResourceStore for single instance env.

+/*
+ * Copyright 2014 Open Networking Laboratory
+ *
+ * Licensed 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.onlab.onos.net.resource;
+
+import java.util.Set;
+
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.intent.IntentId;
+
+
+/**
+ * Manages link resources.
+ */
+public interface LinkResourceStore {
+    Set<ResourceAllocation> getFreeResources(Link link);
+
+    void allocateResources(LinkResourceAllocations allocations);
+
+    void releaseResources(LinkResourceAllocations allocations);
+
+    LinkResourceAllocations getAllocations(IntentId intentId);
+
+    Iterable<LinkResourceAllocations> getAllocations(Link link);
+
+    Iterable<LinkResourceAllocations> getAllocations();
+}

@@ -15,10 +15,13 @@
  */
 package org.onlab.onos.net.resource.impl;
 
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
 import static org.slf4j.LoggerFactory.getLogger;
 
-import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;
@@ -26,6 +29,8 @@ import java.util.Set;
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
 import org.apache.felix.scr.annotations.Service;
 import org.onlab.onos.net.Link;
 import org.onlab.onos.net.intent.IntentId;
@@ -33,15 +38,16 @@ import org.onlab.onos.net.resource.BandwidthResourceAllocation;
 import org.onlab.onos.net.resource.BandwidthResourceRequest;
 import org.onlab.onos.net.resource.Lambda;
 import org.onlab.onos.net.resource.LambdaResourceAllocation;
+import org.onlab.onos.net.resource.LambdaResourceRequest;
 import org.onlab.onos.net.resource.LinkResourceAllocations;
 import org.onlab.onos.net.resource.LinkResourceRequest;
 import org.onlab.onos.net.resource.LinkResourceService;
+import org.onlab.onos.net.resource.LinkResourceStore;
 import org.onlab.onos.net.resource.ResourceAllocation;
 import org.onlab.onos.net.resource.ResourceRequest;
+import org.onlab.onos.net.resource.ResourceType;
 import org.slf4j.Logger;
 
-import com.google.common.collect.Sets;
-
 /**
  * Provides basic implementation of link resources allocation.
  */
@@ -51,7 +57,8 @@ public class LinkResourceManager implements LinkResourceService {
 
     private final Logger log = getLogger(getClass());
 
-    LinkResourceAllocations savedAllocations;
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    private LinkResourceStore store;
 
     @Activate
     public void activate() {
@@ -63,30 +70,65 @@ public class LinkResourceManager implements LinkResourceService {
         log.info("Stopped");
     }
 
-    private Iterable<Lambda> getAvailableLambdas(Iterable<Link> links) {
-        return Sets.newHashSet(Lambda.valueOf(7));
+    /**
+     * Returns available lambdas on specified link.
+     *
+     * @param link the link
+     * @return available lambdas on specified link
+     */
+    private Set<Lambda> getAvailableLambdas(Link link) {
+        checkNotNull(link);
+        Set<ResourceAllocation> resAllocs = store.getFreeResources(link);
+        if (resAllocs == null) {
+            return Collections.emptySet();
+        }
+        Set<Lambda> lambdas = new HashSet<>();
+        for (ResourceAllocation res : resAllocs) {
+            if (res.type() == ResourceType.LAMBDA) {
+                lambdas.add(((LambdaResourceAllocation) res).lambda());
+            }
+        }
+        return lambdas;
     }
 
-    double usedBandwidth = 0.0;
+    /**
+     * Returns available lambdas on specified links.
+     *
+     * @param links the links
+     * @return available lambdas on specified links
+     */
+    private Iterable<Lambda> getAvailableLambdas(Iterable<Link> links) {
+        checkNotNull(links);
+        Iterator<Link> i = links.iterator();
+        checkArgument(i.hasNext());
+        Set<Lambda> lambdas = new HashSet<>(getAvailableLambdas(i.next()));
+        while (i.hasNext()) {
+            lambdas.retainAll(getAvailableLambdas(i.next()));
+        }
+        return lambdas;
+    }
 
     @Override
     public LinkResourceAllocations requestResources(LinkResourceRequest req) {
-        // TODO implement it using a resource data store.
+        // TODO Concatenate multiple bandwidth requests.
+        // TODO Support multiple lambda resource requests.
+        // TODO Throw appropriate exception.
 
-        ResourceAllocation alloc = null;
+        Set<ResourceAllocation> allocs = new HashSet<>();
         for (ResourceRequest r : req.resources()) {
             switch (r.type()) {
             case BANDWIDTH:
-                log.info("requestResources() always returns requested bandwidth");
                 BandwidthResourceRequest br = (BandwidthResourceRequest) r;
-                alloc = new BandwidthResourceAllocation(br.bandwidth());
-                usedBandwidth += br.bandwidth().toDouble();
+                allocs.add(new BandwidthResourceAllocation(br.bandwidth()));
                 break;
             case LAMBDA:
-                log.info("requestResources() always returns lambda 7");
-                Iterator<Lambda> lambdaIterator = getAvailableLambdas(req.links()).iterator();
+                Iterator<Lambda> lambdaIterator =
+                        getAvailableLambdas(req.links()).iterator();
                 if (lambdaIterator.hasNext()) {
-                    alloc = new LambdaResourceAllocation(lambdaIterator.next());
+                    allocs.add(new LambdaResourceAllocation(lambdaIterator.next()));
+                } else {
+                    log.info("Failed to allocate lambda resource.");
+                    return null;
                 }
                 break;
             default:
@@ -96,56 +138,66 @@ public class LinkResourceManager implements LinkResourceService {
 
         Map<Link, Set<ResourceAllocation>> allocations = new HashMap<>();
         for (Link link : req.links()) {
-            allocations.put(link, Sets.newHashSet(alloc));
+            allocations.put(link, allocs);
         }
-        savedAllocations = new DefaultLinkResourceAllocations(req, allocations);
-        return savedAllocations;
+        LinkResourceAllocations result =
+                new DefaultLinkResourceAllocations(req, allocations);
+        store.allocateResources(result);
+        return result;
+
     }
 
     @Override
     public void releaseResources(LinkResourceAllocations allocations) {
-        // TODO Auto-generated method stub
-
+        store.releaseResources(allocations);
     }
 
     @Override
     public LinkResourceAllocations updateResources(LinkResourceRequest req,
-                                                   LinkResourceAllocations oldAllocations) {
+            LinkResourceAllocations oldAllocations) {
+        // TODO
         return null;
     }
 
     @Override
     public Iterable<LinkResourceAllocations> getAllocations() {
-        // TODO Auto-generated method stub
-        return null;
+        return store.getAllocations();
     }
 
     @Override
     public Iterable<LinkResourceAllocations> getAllocations(Link link) {
-        ArrayList<LinkResourceAllocations> retval = new ArrayList<>(0);
-        if (savedAllocations != null) {
-            retval.add(savedAllocations);
-        }
-        return retval;
+        return store.getAllocations(link);
     }
 
     @Override
     public LinkResourceAllocations getAllocations(IntentId intentId) {
-        // TODO Auto-generated method stub
-        return null;
+        return store.getAllocations(intentId);
     }
 
     @Override
     public Iterable<ResourceRequest> getAvailableResources(Link link) {
-        BandwidthResourceRequest bw = new BandwidthResourceRequest(usedBandwidth);
-        ArrayList<ResourceRequest> result = new ArrayList<>();
-        result.add(bw);
+        Set<ResourceAllocation> freeRes = store.getFreeResources(link);
+        Set<ResourceRequest> result = new HashSet<>();
+        for (ResourceAllocation alloc : freeRes) {
+            switch (alloc.type()) {
+            case BANDWIDTH:
+                result.add(new BandwidthResourceRequest(
+                        ((BandwidthResourceAllocation) alloc).bandwidth()));
+                break;
+            case LAMBDA:
+                result.add(new LambdaResourceRequest());
+                break;
+            default:
+                break;
+            }
+        }
         return result;
     }
 
     @Override
     public ResourceRequest getAvailableResources(Link link,
-                                                 LinkResourceAllocations allocations) {
+            LinkResourceAllocations allocations) {
+        // TODO
         return null;
     }
 

+/*
+ * Copyright 2014 Open Networking Laboratory
+ *
+ * Licensed 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.onlab.onos.store.trivial.impl;
+
+import static com.google.common.base.Preconditions.*;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.intent.IntentId;
+import org.onlab.onos.net.resource.Bandwidth;
+import org.onlab.onos.net.resource.BandwidthResourceAllocation;
+import org.onlab.onos.net.resource.Lambda;
+import org.onlab.onos.net.resource.LambdaResourceAllocation;
+import org.onlab.onos.net.resource.LinkResourceAllocations;
+import org.onlab.onos.net.resource.LinkResourceStore;
+import org.onlab.onos.net.resource.ResourceAllocation;
+import org.onlab.onos.net.resource.ResourceType;
+import org.slf4j.Logger;
+
+/**
+ * Manages link resources using trivial in-memory structures implementation.
+ */
+@Component(immediate = true)
+@Service
+public class SimpleLinkResourceStore implements LinkResourceStore {
+    private final Logger log = getLogger(getClass());
+    private Map<IntentId, LinkResourceAllocations> linkResourceAllocationsMap;
+    private Map<Link, Set<LinkResourceAllocations>> allocatedResources;
+    private Map<Link, Set<ResourceAllocation>> freeResources;
+
+    @Activate
+    public void activate() {
+        linkResourceAllocationsMap = new HashMap<>();
+        allocatedResources = new HashMap<>();
+        freeResources = new HashMap<>();
+
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+    private Set<ResourceAllocation> readOriginalFreeResources(Link link) {
+        // TODO read capacity and lambda resources from topology
+        Set<ResourceAllocation> allocations = new HashSet<>();
+        for (int i = 1; i <= 100; i++) {
+            allocations.add(new LambdaResourceAllocation(Lambda.valueOf(i)));
+        }
+        allocations.add(new BandwidthResourceAllocation(Bandwidth.valueOf(1000000)));
+        return allocations;
+    }
+
+    private BandwidthResourceAllocation getBandwidth(Set<ResourceAllocation> freeRes) {
+        for (ResourceAllocation res : freeRes) {
+            if (res.type() == ResourceType.BANDWIDTH) {
+                return (BandwidthResourceAllocation) res;
+            }
+        }
+        return new BandwidthResourceAllocation(Bandwidth.valueOf(0));
+    }
+
+    private void subtractFreeResources(Link link, LinkResourceAllocations allocations) {
+        // TODO Use lock or version for updating freeResources.
+        checkNotNull(link);
+        Set<ResourceAllocation> freeRes = freeResources.get(link);
+        checkNotNull(freeRes);
+        freeRes = new HashSet<>(freeRes);
+        Set<ResourceAllocation> subRes = allocations.getResourceAllocation(link);
+        for (ResourceAllocation res : subRes) {
+            switch (res.type()) {
+            case BANDWIDTH:
+                BandwidthResourceAllocation ba = getBandwidth(freeRes);
+                double requestedBandwidth =
+                        ((BandwidthResourceAllocation) res).bandwidth().toDouble();
+                double newBandwidth = ba.bandwidth().toDouble() - requestedBandwidth;
+                checkState(newBandwidth >= 0.0);
+                freeRes.remove(ba);
+                freeRes.add(new BandwidthResourceAllocation(
+                        Bandwidth.valueOf(newBandwidth)));
+                break;
+            case LAMBDA:
+                checkState(freeRes.remove(res));
+                break;
+            default:
+                break;
+            }
+        }
+        freeResources.put(link, freeRes);
+
+    }
+
+    private void addFreeResources(Link link, LinkResourceAllocations allocations) {
+        // TODO Use lock or version for updating freeResources.
+        Set<ResourceAllocation> freeRes = freeResources.get(link);
+        checkNotNull(freeRes);
+        freeRes = new HashSet<>(freeRes);
+        Set<ResourceAllocation> addRes = allocations.getResourceAllocation(link);
+        for (ResourceAllocation res : addRes) {
+            switch (res.type()) {
+            case BANDWIDTH:
+                BandwidthResourceAllocation ba = getBandwidth(freeRes);
+                double requestedBandwidth =
+                        ((BandwidthResourceAllocation) res).bandwidth().toDouble();
+                double newBandwidth = ba.bandwidth().toDouble() + requestedBandwidth;
+                freeRes.remove(ba);
+                freeRes.add(new BandwidthResourceAllocation(
+                        Bandwidth.valueOf(newBandwidth)));
+                break;
+            case LAMBDA:
+                checkState(freeRes.add(res));
+                break;
+            default:
+                break;
+            }
+        }
+        freeResources.put(link, freeRes);
+    }
+
+    @Override
+    public Set<ResourceAllocation> getFreeResources(Link link) {
+        checkNotNull(link);
+        Set<ResourceAllocation> freeRes = freeResources.get(link);
+        if (freeRes == null) {
+            freeRes = readOriginalFreeResources(link);
+        }
+
+        return freeRes;
+    }
+
+    @Override
+    public void allocateResources(LinkResourceAllocations allocations) {
+        checkNotNull(allocations);
+        linkResourceAllocationsMap.put(allocations.intendId(), allocations);
+        for (Link link : allocations.links()) {
+            subtractFreeResources(link, allocations);
+            Set<LinkResourceAllocations> linkAllocs = allocatedResources.get(link);
+            if (linkAllocs == null) {
+                linkAllocs = new HashSet<>();
+            }
+            linkAllocs.add(allocations);
+            allocatedResources.put(link, linkAllocs);
+        }
+    }
+
+    @Override
+    public void releaseResources(LinkResourceAllocations allocations) {
+        checkNotNull(allocations);
+        linkResourceAllocationsMap.remove(allocations);
+        for (Link link : allocations.links()) {
+            addFreeResources(link, allocations);
+            Set<LinkResourceAllocations> linkAllocs = allocatedResources.get(link);
+            if (linkAllocs == null) {
+                log.error("Missing resource allocation.");
+            } else {
+                linkAllocs.remove(allocations);
+            }
+            allocatedResources.put(link, linkAllocs);
+        }
+    }
+
+    @Override
+    public LinkResourceAllocations getAllocations(IntentId intentId) {
+        checkNotNull(intentId);
+        return linkResourceAllocationsMap.get(intentId);
+    }
+
+    @Override
+    public Iterable<LinkResourceAllocations> getAllocations(Link link) {
+        checkNotNull(link);
+        Set<LinkResourceAllocations> result = allocatedResources.get(link);
+        if (result == null) {
+            result = Collections.emptySet();
+        }
+        return Collections.unmodifiableSet(result);
+    }
+
+    @Override
+    public Iterable<LinkResourceAllocations> getAllocations() {
+        return Collections.unmodifiableCollection(linkResourceAllocationsMap.values());
+    }
+
+}