First version of FieldLookup

vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/retrievable/Retrieved.kt

@@ -21,6 +21,8 @@ interface Retrieved : Retrievable {
 
     interface RetrievedWithRelationship : Retrieved, RetrievableWithRelationship
 
+    interface RetrievedWithProperties: Retrieved, RetrievableWithProperties
+
     data class Default(override val id: UUID, override val type: String?, override val transient: Boolean) : Retrieved
 
 
@@ -105,6 +107,14 @@ interface Retrieved : Retrievable {
             is RetrievedWithDistance -> DistancePlusScore(retrieved, score)
             else -> RetrievedPlusScore(retrieved, score)
         }
+
+        fun PlusProperties(retrieved: Retrieved, properties: Map<String, String> = mutableMapOf()) = when(retrieved) {
+            is RetrievedWithProperties -> retrieved
+
+            //TODO other combinations
+
+            else -> RetrievedPlusProperties(retrieved, properties)
+        }
     }
 
     data class RetrievedPlusScore(private val retrieved: Retrieved, override val score: Float) : Retrieved by retrieved, RetrievedWithScore
@@ -126,4 +136,13 @@ interface Retrieved : Retrievable {
         retrieved: RetrievedWithScore,
         override val relationships: Set<Relationship> = mutableSetOf()
     ) : RetrievedWithScore by retrieved, RetrievedWithRelationship
+
+    class RetrievedPlusProperties(
+        retrieved: Retrieved,
+        override val properties: Map<String, String> = mutableMapOf()
+    ) : Retrieved by retrieved, RetrievedWithProperties
+
+
+
+
 }

vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/retrievable/decorators/RetrievableWithProperties.kt

@@ -0,0 +1,14 @@
+package org.vitrivr.engine.core.model.retrievable.decorators
+
+import org.vitrivr.engine.core.model.retrievable.Retrievable
+
+/**
+ * A [Retrievable] with arbitrary Properties
+ *
+ * @version 1.0.0
+ */
+interface RetrievableWithProperties : Retrievable {
+
+    val properties: Map<String, String>
+
+}

vitrivr-engine-query/src/main/kotlin/org/vitrivr/engine/query/transform/FieldLookup.kt

@@ -0,0 +1,52 @@
+package org.vitrivr.engine.query.transform
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.toList
+import org.vitrivr.engine.core.database.descriptor.DescriptorReader
+import org.vitrivr.engine.core.model.retrievable.Retrieved
+import org.vitrivr.engine.core.operators.Operator
+import org.vitrivr.engine.core.operators.retrieve.Transformer
+
+/**
+ * Appends stringified key-value pairs to a [Retrieved] based on the values of a [Field], if available
+ */
+class FieldLookup(
+    override val input: Operator<Retrieved>,
+    private val reader: DescriptorReader<*>,
+    private val keys: Collection<String>
+
+) : Transformer<Retrieved, Retrieved.RetrievedWithProperties> {
+    override fun toFlow(scope: CoroutineScope): Flow<Retrieved.RetrievedWithProperties> = flow {
+
+        val inputRetrieved = input.toFlow(scope).toList()
+
+        val ids = inputRetrieved.map { it.id }.toSet()
+
+        if (ids.isEmpty()) {
+            return@flow
+        }
+
+        val descriptors = reader.getAll(ids).filter { it.retrievableId != null }.associateBy { it.retrievableId!! }
+
+        inputRetrieved.forEach {
+
+            val withProperties = Retrieved.PlusProperties(it)
+
+            val descriptor = descriptors[it.id]
+
+            if (descriptor != null) {
+                val values = descriptor.values().toMap()
+                keys.forEach { key ->
+                    (withProperties.properties as MutableMap)[key] = values[key].toString()
+                }
+            }
+
+            emit(withProperties)
+
+        }
+
+    }
+
+}

vitrivr-engine-query/src/main/kotlin/org/vitrivr/engine/query/transform/FieldLookupFactory.kt

@@ -0,0 +1,25 @@
+package org.vitrivr.engine.query.transform
+
+import org.vitrivr.engine.core.model.metamodel.Schema
+import org.vitrivr.engine.core.model.retrievable.Retrieved
+import org.vitrivr.engine.core.operators.Operator
+import org.vitrivr.engine.core.operators.retrieve.TransformerFactory
+
+class FieldLookupFactory(
+
+) : TransformerFactory<Retrieved, Retrieved.RetrievedWithProperties> {
+    override fun newTransformer(
+        input: Operator<Retrieved>,
+        schema: Schema,
+        properties: Map<String, String>
+    ): FieldLookup {
+
+        val keys = properties["keys"]?.split(",")?.map { s -> s.trim() } ?: emptyList()
+        val field = properties["field"] ?: throw IllegalArgumentException("expected 'field' to be defined in properties")
+        val reader = (schema[field] ?: throw IllegalArgumentException("Field '$field' not defined in schema")).getReader()
+
+        return FieldLookup(
+            input, reader, keys
+        )
+    }
+}

vitrivr-engine-query/src/main/resources/META-INF/services/org.vitrivr.engine.core.operators.retrieve.TransformerFactory

@@ -1,2 +1,3 @@
 org.vitrivr.engine.query.transform.RelationExpanderFactory
-org.vitrivr.engine.query.transform.ScoreAggregatorFactory
+org.vitrivr.engine.query.transform.ScoreAggregatorFactory
+org.vitrivr.engine.query.transform.FieldLookupFactory