Refactor: Reserve resources only in one place

This is a preparation task for the future Intent Framework major
enhancement that aims to consolidate resource allocation invocations
into the Framework side instead of the compiler side.

Declaring required resources and allocating the resources need to be
clearly separated. This patch tries to separate these phases.

Change-Id: I7b238f24996b3f1dc97afda6d188426001052127

@@ -197,58 +197,116 @@ public class OpticalCircuitIntentCompiler implements IntentCompiler<OpticalCircu
                 && isMultiplexingSupported(intent.getDst());
 
         // slots are used only for devices supporting multiplexing
-        Set<TributarySlot> slots = Collections.emptySet();
+        List<Resource> ports = ImmutableList.of(srcPortResource, dstPortResource);
 
         OpticalConnectivityIntent connIntent = findOpticalConnectivityIntent(intent.getSrc(), intent.getDst(),
                 intent.getSignalType(), multiplexingSupported);
-        if ((connIntent != null) && multiplexingSupported) {
-            // Allocate TributarySlots on existing OCH ports
-            slots = assignTributarySlots(intent, Pair.of(connIntent.getSrc(), connIntent.getDst()));
+
+        if (connIntent != null && !multiplexingSupported) {
+            return compile(intent, src, dst, Optional.of(connIntent), ports, false);
         }
 
         // Create optical connectivity intent if needed - no optical intent or not enough slots available
-        if (connIntent == null || (multiplexingSupported && slots.isEmpty())) {
+        if (connIntent == null) {
+            return compile(intent, src, dst, Optional.empty(), ports, multiplexingSupported);
+        }
+
+        List<Resource> slots = availableSlotResources(connIntent.getSrc(), connIntent.getDst(),
+                intent.getSignalType());
+        if (slots.isEmpty()) {
+            return compile(intent, src, dst, Optional.empty(), ports, true);
+        }
+
+        return compile(intent, src, dst, Optional.of(connIntent), ImmutableList.<Resource>builder()
+                .addAll(ports).addAll(slots).build(), false);
+
+    }
+
+    private List<Intent> compile(OpticalCircuitIntent intent, ConnectPoint src, ConnectPoint dst,
+                                 Optional<OpticalConnectivityIntent> existingConnectivity,
+                                 List<Resource> resources, boolean supportsMultiplexing) {
+        OpticalConnectivityIntent connectivityIntent;
+        List<Resource> required;
+        if (existingConnectivity.isPresent()) {
+            connectivityIntent = existingConnectivity.get();
+            required = resources;
+        } else {
             // Find OCh ports with available resources
             Pair<OchPort, OchPort> ochPorts = findPorts(intent.getSrc(), intent.getDst(), intent.getSignalType());
 
             if (ochPorts == null) {
-                // Release port allocations if unsuccessful
-                resourceService.release(intent.id());
                 throw new IntentCompilationException("Unable to find suitable OCH ports for intent " + intent);
             }
 
             ConnectPoint srcCP = new ConnectPoint(src.elementId(), ochPorts.getLeft().number());
             ConnectPoint dstCP = new ConnectPoint(dst.elementId(), ochPorts.getRight().number());
 
-            if (multiplexingSupported) {
-                // Allocate TributarySlots on OCH ports
-                slots = assignTributarySlots(intent, Pair.of(srcCP, dstCP));
-                if (slots.isEmpty()) {
-                    // Release port allocations if unsuccessful
-                    resourceService.release(intent.id());
-                    throw new IntentCompilationException("Unable to find Tributary Slots for intent " + intent);
-                }
-            }
-
             // Create optical connectivity intent
-            OduSignalType signalType = ochPorts.getLeft().signalType();
-            connIntent = OpticalConnectivityIntent.builder()
+            connectivityIntent = OpticalConnectivityIntent.builder()
                     .appId(appId)
                     .src(srcCP)
                     .dst(dstCP)
-                    .signalType(signalType)
+                    .signalType(ochPorts.getLeft().signalType())
                     .bidirectional(intent.isBidirectional())
                     .build();
-            intentService.submit(connIntent);
+
+            if (!supportsMultiplexing) {
+                required = resources;
+            } else {
+                List<Resource> slots = availableSlotResources(srcCP, dstCP, intent.getSignalType());
+                if (slots.isEmpty()) {
+                    throw new IntentCompilationException("Unable to find Tributary Slots for intent " + intent);
+                }
+                required = ImmutableList.<Resource>builder().addAll(resources).addAll(slots).build();
+            }
+        }
+
+        if (resourceService.allocate(intent.id(), required).isEmpty()) {
+            throw new IntentCompilationException("Unable to allocate resources for intent " + intent
+                    + ": resources=" + required);
         }
 
+        intentService.submit(connectivityIntent);
+
         // Save circuit to connectivity intent mapping
-        intentSetMultimap.allocateMapping(connIntent.id(), intent.id());
+        intentSetMultimap.allocateMapping(connectivityIntent.id(), intent.id());
 
-        FlowRuleIntent circuitIntent = createFlowRule(intent, connIntent, slots);
+        FlowRuleIntent circuitIntent = createFlowRule(intent, connectivityIntent, required.stream().
+                flatMap(x -> Tools.stream(x.valueAs(TributarySlot.class)))
+                .collect(Collectors.toSet()));
         return ImmutableList.of(circuitIntent);
     }
 
+    private List<Resource> availableSlotResources(ConnectPoint src, ConnectPoint dst, CltSignalType signalType) {
+        OduSignalType oduSignalType = mappingCltSignalTypeToOduSignalType(signalType);
+        int requestedTsNum = oduSignalType.tributarySlots();
+        Set<TributarySlot> commonTributarySlots = findCommonTributarySlotsOnCps(src, dst);
+        if (commonTributarySlots.isEmpty()) {
+            return Collections.emptyList();
+        }
+        if (commonTributarySlots.size() < requestedTsNum) {
+            return Collections.emptyList();
+        }
+
+        Set<TributarySlot> tributarySlots = commonTributarySlots.stream()
+                .limit(requestedTsNum)
+                .collect(Collectors.toSet());
+
+        final List<ConnectPoint> portsList = ImmutableList.of(src, dst);
+        List<Resource> tributarySlotResources = portsList.stream()
+                .flatMap(cp -> tributarySlots
+                        .stream()
+                        .map(ts-> Resources.discrete(cp.deviceId(), cp.port()).resource().child(ts)))
+                .collect(Collectors.toList());
+
+        if (!tributarySlotResources.stream().allMatch(resourceService::isAvailable)) {
+            log.debug("Resource allocation for {} on {} and {} failed (resource request: {})",
+                    signalType, src, dst, tributarySlotResources);
+            return Collections.emptyList();
+        }
+        return tributarySlotResources;
+    }
+
     private FlowRuleIntent createFlowRule(OpticalCircuitIntent higherIntent,
                                           OpticalConnectivityIntent lowerIntent, Set<TributarySlot> slots) {
         // Create optical circuit intent
@@ -338,39 +396,6 @@ public class OpticalCircuitIntentCompiler implements IntentCompiler<OpticalCircu
         return true;
     }
 
-    private Set<TributarySlot> assignTributarySlots(OpticalCircuitIntent intent,
-            Pair<ConnectPoint, ConnectPoint> ports) {
-
-        OduSignalType oduSignalType = mappingCltSignalTypeToOduSignalType(intent.getSignalType());
-        int requestedTsNum = oduSignalType.tributarySlots();
-        Set<TributarySlot> commonTributarySlots = findCommonTributarySlotsOnCps(ports.getLeft(), ports.getRight());
-        if (commonTributarySlots.isEmpty()) {
-            return Collections.emptySet();
-        }
-        if (commonTributarySlots.size() < requestedTsNum) {
-            return Collections.emptySet();
-        }
-
-        Set<TributarySlot> tributarySlots = commonTributarySlots.stream()
-                .limit(requestedTsNum)
-                .collect(Collectors.toSet());
-
-        final List<ConnectPoint> portsList = ImmutableList.of(ports.getLeft(), ports.getRight());
-        List<Resource> tributarySlotResources = portsList.stream()
-                .flatMap(cp -> tributarySlots
-                        .stream()
-                        .map(ts-> Resources.discrete(cp.deviceId(), cp.port()).resource().child(ts)))
-                .collect(Collectors.toList());
-
-        List<ResourceAllocation> allocations = resourceService.allocate(intent.id(), tributarySlotResources);
-        if (allocations.isEmpty()) {
-            log.debug("Resource allocation for {} failed (resource request: {})",
-                    intent, tributarySlotResources);
-            return Collections.emptySet();
-        }
-        return tributarySlots;
-    }
-
     private ConnectPoint staticPort(ConnectPoint connectPoint) {
         Port port = deviceService.getPort(connectPoint.deviceId(), connectPoint.port());