HC2VPP-320: ensure at most one policy is configured per NAT instance

ReflexiveListReaderCustomizer is not used due to HONEYCOMB-437

Change-Id: I62755aaedd6e179b349ec47e4a304399c4fa18cd
Signed-off-by: Marek Gradzki <mgradzki@cisco.com>

2 files changed, 76 insertions, 2 deletions

diff --git a/nat/nat2vpp/src/main/java/io/fd/hc2vpp/nat/read/NatReaderFactory.java b/nat/nat2vpp/src/main/java/io/fd/hc2vpp/nat/read/NatReaderFactory.java
index c89b3030f..bf1517646 100644
--- a/nat/nat2vpp/src/main/java/io/fd/hc2vpp/nat/read/NatReaderFactory.java
+++ b/nat/nat2vpp/src/main/java/io/fd/hc2vpp/nat/read/NatReaderFactory.java
@@ -86,8 +86,7 @@ public class NatReaderFactory implements ReaderFactory {
                 new GenericInitListReader<>(MAPPING_ENTRY_ID,
                         new MappingEntryCustomizer(mapEntryNat44DumpMgr, mapEntryNat64DumpMgr, mappingEntryContext)));
 
-        // Ony single policy is supported
-        registry.addStructuralListReader(POLICY_ID, PolicyBuilder.class, Collections.singletonList(new PolicyKey(0L)));
+        registry.add(new GenericInitListReader<>(POLICY_ID, new PolicyCustomizer()));
         registry.add(new GenericInitListReader<>(ADDRESS_POOL_ID, new ExternalIpPoolCustomizer(jvppNat)));
 
         // nat64-prefixes
diff --git a/nat/nat2vpp/src/main/java/io/fd/hc2vpp/nat/read/PolicyCustomizer.java b/nat/nat2vpp/src/main/java/io/fd/hc2vpp/nat/read/PolicyCustomizer.java
new file mode 100644
index 000000000..4b23451dc
--- /dev/null
+++ b/nat/nat2vpp/src/main/java/io/fd/hc2vpp/nat/read/PolicyCustomizer.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2018 Cisco and/or its affiliates.
+ *
+ * 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 io.fd.hc2vpp.nat.read;
+
+import io.fd.honeycomb.translate.read.ReadContext;
+import io.fd.honeycomb.translate.read.ReadFailedException;
+import io.fd.honeycomb.translate.spi.read.Initialized;
+import io.fd.honeycomb.translate.spi.read.InitializingListReaderCustomizer;
+import java.util.Collections;
+import java.util.List;
+import javax.annotation.Nonnull;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev180223.nat.instances.Instance;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev180223.nat.instances.InstanceBuilder;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev180223.nat.instances.instance.Policy;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev180223.nat.instances.instance.PolicyBuilder;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev180223.nat.instances.instance.PolicyKey;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+final class PolicyCustomizer implements InitializingListReaderCustomizer<Policy, PolicyKey, PolicyBuilder> {
+
+    static final long DEFAULT_POLICY_ID = 0;
+    private static final List<PolicyKey> IDS = Collections.singletonList(new PolicyKey(DEFAULT_POLICY_ID));
+
+    @Nonnull
+    @Override
+    public PolicyBuilder getBuilder(@Nonnull final InstanceIdentifier<Policy> id) {
+        return new PolicyBuilder();
+    }
+
+    @Override
+    public void readCurrentAttributes(@Nonnull final InstanceIdentifier<Policy> id,
+                                      @Nonnull final PolicyBuilder builder, @Nonnull final ReadContext ctx)
+        throws ReadFailedException {
+        final Long policyId = id.firstKeyOf(Policy.class).getId();
+        if (policyId == 0) {
+            builder.setId(policyId);
+        }
+    }
+
+    @Nonnull
+    @Override
+    public List<PolicyKey> getAllIds(@Nonnull final InstanceIdentifier<Policy> id,
+                                     @Nonnull final ReadContext context) throws ReadFailedException {
+        return IDS;
+    }
+
+    @Override
+    public void merge(@Nonnull final Builder<? extends DataObject> builder, @Nonnull final List<Policy> readData) {
+        ((InstanceBuilder) builder).setPolicy(readData);
+    }
+
+    @Override
+    public Initialized<Policy> init(
+        @Nonnull final InstanceIdentifier<Policy> id,
+        @Nonnull final Policy readValue,
+        @Nonnull final ReadContext ctx) {
+        return Initialized.create(id, readValue);
+    }
+}