ContentElements are now all associated with a ContentType, which is m…

…ore stable to distinguish elements than doing so based on a class using reflection.

Signed-off-by: Ralph Gasser <[email protected]>

vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/content/ContentType.kt

@@ -0,0 +1,21 @@
+package org.vitrivr.engine.core.model.content
+
+/**
+ * An enumeration of the type of content that can be processed by vitrivr-engine.
+ *
+ * @author Ralph Gasser
+ * @version 1.0.0
+ */
+enum class ContentType {
+    /** A bitmap image (e.g., extracted from a video or image file). */
+    BITMAP_IMAGE,
+
+    /** An audio frame (e.g., extracted from a video or audio file). */
+    AUDIO_FRAME,
+
+    /** Text (e.g., extracted from a document). */
+    TEXT,
+
+    /** A 3D mesh. */
+    MESH
+}

vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/content/element/AudioContent.kt

@@ -1,5 +1,6 @@
 package org.vitrivr.engine.core.model.content.element
 
+import org.vitrivr.engine.core.model.content.ContentType
 import java.nio.ShortBuffer
 
 /**
@@ -19,4 +20,8 @@ interface AudioContent: ContentElement<ShortBuffer> {
 
     /** The sampling rate of the data encoded in this [AudioContent]. */
     val samplingRate: Int
+
+    /** The [ContentType] of an [AudioContent] is always [ContentType.AUDIO_FRAME]. */
+    override val type: ContentType
+        get() = ContentType.AUDIO_FRAME
 }

vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/content/element/ContentElement.kt

@@ -1,6 +1,7 @@
 package org.vitrivr.engine.core.model.content.element
 
 import org.vitrivr.engine.core.model.content.Content
+import org.vitrivr.engine.core.model.content.ContentType
 
 /**
  * A [Content] element is a piece of [Content] that is tied to some actual [Content].
@@ -17,4 +18,7 @@ sealed interface ContentElement<T>: Content {
      * @return [ContentElement]
      */
     val content: T
+
+    /** The [ContentType] of this [ContentElement]. */
+    val type: ContentType
 }

vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/content/element/ImageContent.kt

@@ -1,5 +1,6 @@
 package org.vitrivr.engine.core.model.content.element
 
+import org.vitrivr.engine.core.model.content.ContentType
 import java.awt.image.BufferedImage
 
 /**
@@ -17,4 +18,8 @@ interface ImageContent: ContentElement<BufferedImage> {
     /** Height of the [BufferedImage] held by this [ContentElement]. */
     val height: Int
         get() = this.content.height
+
+    /** The [ContentType] of an [ImageContent] is always [ContentType.BITMAP_IMAGE]. */
+    override val type: ContentType
+        get() = ContentType.BITMAP_IMAGE
 }

vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/content/element/TextContent.kt

@@ -1,5 +1,7 @@
 package org.vitrivr.engine.core.model.content.element
 
+import org.vitrivr.engine.core.model.content.ContentType
+
 /**
  * A textual [ContentElement].
  *
@@ -11,4 +13,8 @@ interface TextContent: ContentElement<String> {
     /** Length of the [String] held by this [TextContent]. */
     val length: Int
         get() = this.content.length
+
+    /** The [ContentType] of an [TextContent] is always [ContentType.TEXT]. */
+    override val type: ContentType
+        get() = ContentType.TEXT
 }

vitrivr-engine-index/src/main/kotlin/org/vitrivr/engine/index/aggregators/CenterContentAggregator.kt

@@ -30,9 +30,7 @@ class CenterContentAggregator : AggregatorFactory {
      * The [Instance] returns by the [AggregatorFactory]
      */
     private class Instance(override val input: Operator<Retrievable>, context: IndexContext) : AbstractAggregator(input, context) {
-        override fun aggregate(content: List<ContentElement<*>>): List<ContentElement<*>> = content.groupBy {
-            it::class
-        }.mapNotNull { (_, elements) ->
+        override fun aggregate(content: List<ContentElement<*>>): List<ContentElement<*>> = content.groupBy { it.type }.mapNotNull { (_, elements) ->
             if (elements.isNotEmpty()) {
                 elements[Math.floorDiv(elements.size, 2)]
             } else {

vitrivr-engine-index/src/main/kotlin/org/vitrivr/engine/index/aggregators/FirstContentAggregator.kt

@@ -30,6 +30,6 @@ class FirstContentAggregator : AggregatorFactory {
      * The [Instance] returns by the [AggregatorFactory]
      */
     private class Instance(override val input: Operator<Retrievable>, context: IndexContext) : AbstractAggregator(input, context) {
-        override fun aggregate(content: List<ContentElement<*>>): List<ContentElement<*>> = content.groupBy { it::class }.mapNotNull { (_, elements) -> elements.firstOrNull() }
+        override fun aggregate(content: List<ContentElement<*>>): List<ContentElement<*>> = content.groupBy { it.type }.mapNotNull { (_, elements) -> elements.firstOrNull() }
     }
 }

vitrivr-engine-index/src/main/kotlin/org/vitrivr/engine/index/aggregators/LastContentAggregator.kt

@@ -30,6 +30,6 @@ class LastContentAggregator : AggregatorFactory {
      * The [Instance] returns by the [AggregatorFactory]
      */
     private class Instance(override val input: Operator<Retrievable>, context: IndexContext) : AbstractAggregator(input, context) {
-        override fun aggregate(content: List<ContentElement<*>>): List<ContentElement<*>> = content.groupBy { it::class }.mapNotNull { (_, elements) -> elements.lastOrNull() }
+        override fun aggregate(content: List<ContentElement<*>>): List<ContentElement<*>> = content.groupBy { it.type }.mapNotNull { (_, elements) -> elements.lastOrNull() }
     }
 }

vitrivr-engine-index/src/main/kotlin/org/vitrivr/engine/index/transform/ContentSamplingTransformer.kt

@@ -4,14 +4,14 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.filter
 import org.vitrivr.engine.core.context.IndexContext
+import org.vitrivr.engine.core.model.content.ContentType
 import org.vitrivr.engine.core.model.content.decorators.SourcedContent
 import org.vitrivr.engine.core.model.content.element.ContentElement
 import org.vitrivr.engine.core.operators.Operator
 import org.vitrivr.engine.core.operators.ingest.Decoder
 import org.vitrivr.engine.core.operators.ingest.Transformer
 import org.vitrivr.engine.core.operators.ingest.TransformerFactory
 import org.vitrivr.engine.core.source.Source
-import kotlin.reflect.KClass
 
 /**
  * A [Transformer] that samples the input [Flow] and only passes through every n-th element.
@@ -25,17 +25,17 @@ class ContentSamplingTransformer : TransformerFactory {
 
     private class Instance(override val input: Operator<ContentElement<*>>, private val sample: Int) : Transformer {
         override fun toFlow(scope: CoroutineScope): Flow<ContentElement<*>> {
-            val sources = mutableMapOf<KClass<out ContentElement<*>>, Source>()
-            val counters = mutableMapOf<KClass<out ContentElement<*>>, Int>()
+            val sources = mutableMapOf<ContentType, Source>()
+            val counters = mutableMapOf<ContentType, Int>()
             return this.input.toFlow(scope).filter { value: ContentElement<*> ->
                 if (value is SourcedContent) { /* Only source content can be sampled. */
-                    val clazz = value::class
-                    if (sources[clazz] == null || sources[clazz] != value.source) {
-                        sources[clazz] = value.source
-                        counters[clazz] = 0
+                    val type = value.type
+                    if (sources[type] == null || sources[type] != value.source) {
+                        sources[type] = value.source
+                        counters[type] = 0
                     }
-                    val pass = (counters[clazz]!! % this.sample == 0)
-                    counters[clazz] = counters[clazz]!! + 1
+                    val pass = (counters[type]!! % this.sample == 0)
+                    counters[type] = counters[type]!! + 1
                     pass
                 } else {
                     true