Use Try/Option monad when decoding protobuf

Closes ONAP-143

Change-Id: I33cb2d24cd5962318a6f405096db298bbdbab963
Signed-off-by: fkrzywka <filip.krzywka@nokia.com>
Issue-ID: DCAEGEN2-601

2 files changed, 14 insertions, 10 deletions

diff --git a/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/VesDecoder.kt b/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/VesDecoder.kt
index 591a48b7..a7780109 100644
--- a/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/VesDecoder.kt
+++ b/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/VesDecoder.kt
@@ -19,6 +19,8 @@
  */
 package org.onap.dcae.collectors.veshv.impl
 
+import arrow.core.Try
+import arrow.core.Option
 import org.onap.dcae.collectors.veshv.domain.ByteData
 import org.onap.dcae.collectors.veshv.model.VesMessage
 import org.onap.ves.VesEventV5.VesEvent
@@ -29,8 +31,9 @@ import org.onap.ves.VesEventV5.VesEvent
  */
 internal class VesDecoder {
 
-    fun decode(bytes: ByteData): VesMessage {
-        val decodedHeader = VesEvent.parseFrom(bytes.unsafeAsArray()).commonEventHeader
-        return VesMessage(decodedHeader, bytes)
-    }
+    fun decode(bytes: ByteData): Option<VesMessage> =
+            Try {
+                val decodedHeader = VesEvent.parseFrom(bytes.unsafeAsArray()).commonEventHeader
+                VesMessage(decodedHeader, bytes)
+            }.toOption()
 }
diff --git a/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/VesHvCollector.kt b/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/VesHvCollector.kt
index 2a07b9b8..52689162 100644
--- a/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/VesHvCollector.kt
+++ b/hv-collector-core/src/main/kotlin/org/onap/dcae/collectors/veshv/impl/VesHvCollector.kt
@@ -33,6 +33,7 @@ import org.onap.dcae.collectors.veshv.impl.wire.WireChunkDecoder
 import org.onap.dcae.collectors.veshv.model.RoutedMessage
 import org.onap.dcae.collectors.veshv.model.VesMessage
 import org.onap.dcae.collectors.veshv.utils.logging.Logger
+import org.reactivestreams.Publisher
 import reactor.core.publisher.Flux
 import reactor.core.publisher.Mono
 import reactor.core.publisher.SynchronousSink
@@ -71,19 +72,19 @@ internal class VesHvCollector(
     private fun decodePayload(flux: Flux<PayloadWireFrameMessage>): Flux<VesMessage> = flux
             .map(PayloadWireFrameMessage::payload)
             .map(protobufDecoder::decode)
-
+            .flatMap { omitWhenNone(it) }
 
     private fun routeMessage(flux: Flux<VesMessage>): Flux<RoutedMessage> = flux
             .flatMap(this::findRoute)
             .compose(sink::send)
             .doOnNext { metrics.notifyMessageSent(it.topic) }
 
-    private fun findRoute(msg: VesMessage): Mono<RoutedMessage> = omitWhenNull(msg, router::findDestination)
 
-    private fun <T, V> omitWhenNull(input: T, mapper: (T) -> Option<V>): Mono<V> =
-            mapper(input).fold(
-                    { Mono.empty() },
-                    { Mono.just(it) })
+    private fun findRoute(msg: VesMessage): Mono<RoutedMessage> = omitWhenNone((router::findDestination)(msg))
+
+    private fun <V> omitWhenNone(it: Option<V>): Mono<V> = it.fold(
+            { Mono.empty() },
+            { Mono.just(it) })
 
     private fun releaseBuffersMemory(wireChunkDecoder: WireChunkDecoder) = wireChunkDecoder.release()