in getMultipleKeys reply, also return actualVersions

Author: fm3

src/main/protobuf/fossildbapi.proto

@@ -72,6 +72,7 @@ message GetMultipleKeysReply {
     optional string errorMessage = 2;
     repeated string keys = 3;
     repeated bytes values = 4;
+    repeated uint64 actualVersions = 5;
 }
 
 message DeleteMultipleVersionsRequest {

src/main/scala/com/scalableminds/fossildb/FossilDBGrpcImpl.scala

@@ -55,8 +55,8 @@ class FossilDBGrpcImpl(storeManager: StoreManager)
 
   override def getMultipleKeys(req: GetMultipleKeysRequest) = withExceptionHandler(req) {
     val store = storeManager.getStore(req.collection)
-    val (keys, values) = store.getMultipleKeys(req.key, req.prefix, req.version, req.limit)
-    GetMultipleKeysReply(true, None, keys, values.map(ByteString.copyFrom(_)))
+    val (keys, values, versions) = store.getMultipleKeys(req.key, req.prefix, req.version, req.limit)
+    GetMultipleKeysReply(true, None, keys, values.map(ByteString.copyFrom(_)), versions)
   } {errorMsg => GetMultipleKeysReply(false, errorMsg)}
 
   override def deleteMultipleVersions(req: DeleteMultipleVersionsRequest) = withExceptionHandler(req) {

src/main/scala/com/scalableminds/fossildb/db/VersionedKeyValueStore.scala

@@ -112,14 +112,15 @@ class VersionedKeyValueStore(underlying: RocksDBStore) {
     }
   }
 
-  def getMultipleKeys(key: String, prefix: Option[String] = None, version: Option[Long] = None, limit: Option[Int]): (Seq[String], Seq[Array[Byte]]) = {
+  def getMultipleKeys(key: String, prefix: Option[String] = None, version: Option[Long] = None, limit: Option[Int]): (Seq[String], Seq[Array[Byte]], Seq[Long]) = {
     requireValidKey(key)
     prefix.map{p => requireValidKey(p)}
     val iterator: Iterator[VersionedKeyValuePair[Array[Byte]]] = scanKeys(key, prefix, version)
     val asSequence = iterator.take(limit.getOrElse(Int.MaxValue)).toSeq
     val keys = asSequence.map(_.key)
     val values = asSequence.map(_.value)
-    (keys, values)
+    val versions = asSequence.map(_.version)
+    (keys, values, versions)
   }
 
   private def scanKeys(key: String, prefix: Option[String] = None, version: Option[Long] = None): Iterator[VersionedKeyValuePair[Array[Byte]]] =