Remove matched text from chunks (#123607)

server/src/main/java/org/elasticsearch/inference/ChunkedInference.java

@@ -21,18 +21,17 @@ public interface ChunkedInference {
      * Implementations of this function serialize their embeddings to {@link BytesReference} for storage in semantic text fields.
      *
      * @param xcontent provided by the SemanticTextField
-     * @return an iterator of the serialized {@link Chunk} which includes the matched text (input) and bytes reference (output/embedding).
+     * @return an iterator of the serialized {@link Chunk} which includes the offset into the input text and bytes reference
+     * (output/embedding).
      */
-    Iterator<Chunk> chunksAsMatchedTextAndByteReference(XContent xcontent) throws IOException;
+    Iterator<Chunk> chunksAsByteReference(XContent xcontent) throws IOException;
 
     /**
-     * A chunk of inference results containing matched text, the substring location
-     * in the original text and the bytes reference.
-     * @param matchedText
+     * A chunk of inference results containing the substring location in the original text and the bytes reference.
      * @param textOffset
      * @param bytesReference
      */
-    record Chunk(String matchedText, TextOffset textOffset, BytesReference bytesReference) {}
+    record Chunk(TextOffset textOffset, BytesReference bytesReference) {}
 
     record TextOffset(int start, int end) {}
 }

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/inference/results/ChunkedInferenceEmbedding.java

@@ -29,7 +29,6 @@ public record ChunkedInferenceEmbedding(List<? extends EmbeddingResults.Chunk> c
                     List.of(
                         new SparseEmbeddingResults.Chunk(
                             sparseEmbeddingResults.embeddings().get(i).tokens(),
-                            inputs.get(i),
                             new TextOffset(0, inputs.get(i).length())
                         )
                     )
@@ -41,7 +40,7 @@ public record ChunkedInferenceEmbedding(List<? extends EmbeddingResults.Chunk> c
     }
 
     @Override
-    public Iterator<Chunk> chunksAsMatchedTextAndByteReference(XContent xcontent) throws IOException {
+    public Iterator<Chunk> chunksAsByteReference(XContent xcontent) throws IOException {
         var asChunk = new ArrayList<Chunk>();
         for (var chunk : chunks()) {
             asChunk.add(chunk.toChunk(xcontent));

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/inference/results/ChunkedInferenceError.java

@@ -7,17 +7,16 @@
 
 package org.elasticsearch.xpack.core.inference.results;
 
-import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.inference.ChunkedInference;
 import org.elasticsearch.xcontent.XContent;
 
+import java.util.Collections;
 import java.util.Iterator;
-import java.util.stream.Stream;
 
 public record ChunkedInferenceError(Exception exception) implements ChunkedInference {
 
     @Override
-    public Iterator<Chunk> chunksAsMatchedTextAndByteReference(XContent xcontent) {
-        return Stream.of(exception).map(e -> new Chunk(e.getMessage(), new TextOffset(0, 0), BytesArray.EMPTY)).iterator();
+    public Iterator<Chunk> chunksAsByteReference(XContent xcontent) {
+        return Collections.emptyIterator();
     }
 }

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/inference/results/EmbeddingResults.java

@@ -24,13 +24,11 @@ public interface EmbeddingResults<C extends EmbeddingResults.Chunk, E extends Em
         InferenceServiceResults {
 
     /**
-     * A resulting embedding together with its input text.
+     * A resulting embedding together with the offset into the input text.
      */
     interface Chunk {
         ChunkedInference.Chunk toChunk(XContent xcontent) throws IOException;
 
-        String matchedText();
-
         ChunkedInference.TextOffset offset();
     }
 
@@ -39,9 +37,9 @@ public interface EmbeddingResults<C extends EmbeddingResults.Chunk, E extends Em
      */
     interface Embedding<C extends Chunk> {
         /**
-         * Combines the resulting embedding with the input into a chunk.
+         * Combines the resulting embedding with the offset into the input text into a chunk.
          */
-        C toChunk(String text, ChunkedInference.TextOffset offset);
+        C toChunk(ChunkedInference.TextOffset offset);
     }
 
     /**

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/inference/results/SparseEmbeddingResults.java

@@ -175,17 +175,15 @@ public record SparseEmbeddingResults(List<Embedding> embeddings)
         }
 
         @Override
-        public Chunk toChunk(String text, ChunkedInference.TextOffset offset) {
-            return new Chunk(tokens, text, offset);
+        public Chunk toChunk(ChunkedInference.TextOffset offset) {
+            return new Chunk(tokens, offset);
         }
     }
 
-    public record Chunk(List<WeightedToken> weightedTokens, String matchedText, ChunkedInference.TextOffset offset)
-        implements
-            EmbeddingResults.Chunk {
+    public record Chunk(List<WeightedToken> weightedTokens, ChunkedInference.TextOffset offset) implements EmbeddingResults.Chunk {
 
         public ChunkedInference.Chunk toChunk(XContent xcontent) throws IOException {
-            return new ChunkedInference.Chunk(matchedText, offset, toBytesReference(xcontent, weightedTokens));
+            return new ChunkedInference.Chunk(offset, toBytesReference(xcontent, weightedTokens));
         }
 
         private static BytesReference toBytesReference(XContent xContent, List<WeightedToken> tokens) throws IOException {

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/inference/results/TextEmbeddingByteResults.java

@@ -187,18 +187,18 @@ public record TextEmbeddingByteResults(List<Embedding> embeddings)
         }
 
         @Override
-        public Chunk toChunk(String text, ChunkedInference.TextOffset offset) {
-            return new Chunk(values, text, offset);
+        public Chunk toChunk(ChunkedInference.TextOffset offset) {
+            return new Chunk(values, offset);
         }
     }
 
     /**
      * Serialises the {@code value} array, according to the provided {@link XContent}, into a {@link BytesReference}.
      */
-    public record Chunk(byte[] embedding, String matchedText, ChunkedInference.TextOffset offset) implements EmbeddingResults.Chunk {
+    public record Chunk(byte[] embedding, ChunkedInference.TextOffset offset) implements EmbeddingResults.Chunk {
 
         public ChunkedInference.Chunk toChunk(XContent xcontent) throws IOException {
-            return new ChunkedInference.Chunk(matchedText, offset, toBytesReference(xcontent, embedding));
+            return new ChunkedInference.Chunk(offset, toBytesReference(xcontent, embedding));
         }
 
         private static BytesReference toBytesReference(XContent xContent, byte[] value) throws IOException {

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/inference/results/TextEmbeddingFloatResults.java

@@ -221,15 +221,15 @@ public record TextEmbeddingFloatResults(List<Embedding> embeddings)
         }
 
         @Override
-        public Chunk toChunk(String text, ChunkedInference.TextOffset offset) {
-            return new Chunk(values, text, offset);
+        public Chunk toChunk(ChunkedInference.TextOffset offset) {
+            return new Chunk(values, offset);
         }
     }
 
-    public record Chunk(float[] embedding, String matchedText, ChunkedInference.TextOffset offset) implements EmbeddingResults.Chunk {
+    public record Chunk(float[] embedding, ChunkedInference.TextOffset offset) implements EmbeddingResults.Chunk {
 
         public ChunkedInference.Chunk toChunk(XContent xcontent) throws IOException {
-            return new ChunkedInference.Chunk(matchedText, offset, toBytesReference(xcontent, embedding));
+            return new ChunkedInference.Chunk(offset, toBytesReference(xcontent, embedding));
         }
 
         /**

x-pack/plugin/inference/qa/test-service-plugin/src/main/java/org/elasticsearch/xpack/inference/mock/TestDenseInferenceServiceExtension.java

@@ -183,7 +183,6 @@ public class TestDenseInferenceServiceExtension implements InferenceServiceExten
                         List.of(
                             new TextEmbeddingFloatResults.Chunk(
                                 nonChunkedResults.embeddings().get(i).values(),
-                                input.get(i),
                                 new ChunkedInference.TextOffset(0, input.get(i).length())
                             )
                         )

x-pack/plugin/inference/qa/test-service-plugin/src/main/java/org/elasticsearch/xpack/inference/mock/TestSparseInferenceServiceExtension.java

@@ -172,13 +172,7 @@ public class TestSparseInferenceServiceExtension implements InferenceServiceExte
                 }
                 results.add(
                     new ChunkedInferenceEmbedding(
-                        List.of(
-                            new SparseEmbeddingResults.Chunk(
-                                tokens,
-                                input.get(i),
-                                new ChunkedInference.TextOffset(0, input.get(i).length())
-                            )
-                        )
+                        List.of(new SparseEmbeddingResults.Chunk(tokens, new ChunkedInference.TextOffset(0, input.get(i).length())))
                     )
                 );
             }

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/action/filter/ShardBulkInferenceActionFilter.java

@@ -606,7 +606,7 @@ public class ShardBulkInferenceActionFilter implements MappedActionFilter {
 
     private static class EmptyChunkedInference implements ChunkedInference {
         @Override
-        public Iterator<Chunk> chunksAsMatchedTextAndByteReference(XContent xcontent) {
+        public Iterator<Chunk> chunksAsByteReference(XContent xcontent) {
             return Collections.emptyIterator();
         }
     }

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/chunking/EmbeddingRequestChunker.java

@@ -197,10 +197,7 @@ public class EmbeddingRequestChunker {
         AtomicReferenceArray<EmbeddingResults.Embedding<?>> result = results.get(index);
         for (int i = 0; i < request.size(); i++) {
             EmbeddingResults.Chunk chunk = result.get(i)
-                .toChunk(
-                    request.get(i).chunkText(),
-                    new ChunkedInference.TextOffset(request.get(i).chunk.start(), request.get(i).chunk.end())
-                );
+                .toChunk(new ChunkedInference.TextOffset(request.get(i).chunk.start(), request.get(i).chunk.end()));
             chunks.add(chunk);
         }
         return new ChunkedInferenceEmbedding(chunks);

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/mapper/SemanticTextField.java

@@ -275,7 +275,7 @@ public record SemanticTextField(
         boolean useLegacyFormat
     ) throws IOException {
         List<Chunk> chunks = new ArrayList<>();
-        Iterator<ChunkedInference.Chunk> it = results.chunksAsMatchedTextAndByteReference(contentType.xContent());
+        Iterator<ChunkedInference.Chunk> it = results.chunksAsByteReference(contentType.xContent());
         while (it.hasNext()) {
             chunks.add(toSemanticTextFieldChunk(input, offsetAdjustment, it.next(), useLegacyFormat));
         }

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/huggingface/elser/HuggingFaceElserService.java

@@ -121,7 +121,6 @@ public class HuggingFaceElserService extends HuggingFaceBaseService {
                         List.of(
                             new TextEmbeddingFloatResults.Chunk(
                                 textEmbeddingResults.embeddings().get(i).values(),
-                                inputs.getInputs().get(i),
                                 new ChunkedInference.TextOffset(0, inputs.getInputs().get(i).length())
                             )
                         )

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/chunking/EmbeddingRequestChunkerTests.java

@@ -246,7 +246,7 @@ public class EmbeddingRequestChunkerTests extends ESTestCase {
         for (int i = 0; i < numberOfWordsInPassage; i++) {
             passageBuilder.append("passage_input").append(i).append(" "); // chunk on whitespace
         }
-        List<String> inputs = List.of("1st small", passageBuilder.toString(), "2nd small", "3rd small");
+        List<String> inputs = List.of("a", passageBuilder.toString(), "bb", "ccc");
 
         var finalListener = testListener();
         var batches = new EmbeddingRequestChunker(inputs, batchSize, chunkSize, overlap).batchRequestsWithListeners(finalListener);
@@ -275,7 +275,7 @@ public class EmbeddingRequestChunkerTests extends ESTestCase {
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedFloatResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedFloatResult.chunks(), hasSize(1));
-            assertEquals("1st small", chunkedFloatResult.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 1), chunkedFloatResult.chunks().get(0).offset());
         }
         {
             // this is the large input split in multiple chunks
@@ -283,26 +283,26 @@ public class EmbeddingRequestChunkerTests extends ESTestCase {
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedFloatResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedFloatResult.chunks(), hasSize(6));
-            assertThat(chunkedFloatResult.chunks().get(0).matchedText(), startsWith("passage_input0 "));
-            assertThat(chunkedFloatResult.chunks().get(1).matchedText(), startsWith(" passage_input20 "));
-            assertThat(chunkedFloatResult.chunks().get(2).matchedText(), startsWith(" passage_input40 "));
-            assertThat(chunkedFloatResult.chunks().get(3).matchedText(), startsWith(" passage_input60 "));
-            assertThat(chunkedFloatResult.chunks().get(4).matchedText(), startsWith(" passage_input80 "));
-            assertThat(chunkedFloatResult.chunks().get(5).matchedText(), startsWith(" passage_input100 "));
+            assertThat(chunkedFloatResult.chunks().get(0).offset(), equalTo(new ChunkedInference.TextOffset(0, 309)));
+            assertThat(chunkedFloatResult.chunks().get(1).offset(), equalTo(new ChunkedInference.TextOffset(309, 629)));
+            assertThat(chunkedFloatResult.chunks().get(2).offset(), equalTo(new ChunkedInference.TextOffset(629, 949)));
+            assertThat(chunkedFloatResult.chunks().get(3).offset(), equalTo(new ChunkedInference.TextOffset(949, 1269)));
+            assertThat(chunkedFloatResult.chunks().get(4).offset(), equalTo(new ChunkedInference.TextOffset(1269, 1589)));
+            assertThat(chunkedFloatResult.chunks().get(5).offset(), equalTo(new ChunkedInference.TextOffset(1589, 1675)));
         }
         {
             var chunkedResult = finalListener.results.get(2);
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedFloatResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedFloatResult.chunks(), hasSize(1));
-            assertEquals("2nd small", chunkedFloatResult.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 2), chunkedFloatResult.chunks().get(0).offset());
         }
         {
             var chunkedResult = finalListener.results.get(3);
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedFloatResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedFloatResult.chunks(), hasSize(1));
-            assertEquals("3rd small", chunkedFloatResult.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 3), chunkedFloatResult.chunks().get(0).offset());
         }
     }
 
@@ -318,7 +318,7 @@ public class EmbeddingRequestChunkerTests extends ESTestCase {
         for (int i = 0; i < numberOfWordsInPassage; i++) {
             passageBuilder.append("passage_input").append(i).append(" "); // chunk on whitespace
         }
-        List<String> inputs = List.of("1st small", passageBuilder.toString(), "2nd small", "3rd small");
+        List<String> inputs = List.of("a", passageBuilder.toString(), "bb", "ccc");
 
         var finalListener = testListener();
         var batches = new EmbeddingRequestChunker(inputs, batchSize, chunkSize, overlap).batchRequestsWithListeners(finalListener);
@@ -347,7 +347,7 @@ public class EmbeddingRequestChunkerTests extends ESTestCase {
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedByteResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedByteResult.chunks(), hasSize(1));
-            assertEquals("1st small", chunkedByteResult.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 1), chunkedByteResult.chunks().get(0).offset());
         }
         {
             // this is the large input split in multiple chunks
@@ -355,26 +355,26 @@ public class EmbeddingRequestChunkerTests extends ESTestCase {
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedByteResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedByteResult.chunks(), hasSize(6));
-            assertThat(chunkedByteResult.chunks().get(0).matchedText(), startsWith("passage_input0 "));
-            assertThat(chunkedByteResult.chunks().get(1).matchedText(), startsWith(" passage_input20 "));
-            assertThat(chunkedByteResult.chunks().get(2).matchedText(), startsWith(" passage_input40 "));
-            assertThat(chunkedByteResult.chunks().get(3).matchedText(), startsWith(" passage_input60 "));
-            assertThat(chunkedByteResult.chunks().get(4).matchedText(), startsWith(" passage_input80 "));
-            assertThat(chunkedByteResult.chunks().get(5).matchedText(), startsWith(" passage_input100 "));
+            assertThat(chunkedByteResult.chunks().get(0).offset(), equalTo(new ChunkedInference.TextOffset(0, 309)));
+            assertThat(chunkedByteResult.chunks().get(1).offset(), equalTo(new ChunkedInference.TextOffset(309, 629)));
+            assertThat(chunkedByteResult.chunks().get(2).offset(), equalTo(new ChunkedInference.TextOffset(629, 949)));
+            assertThat(chunkedByteResult.chunks().get(3).offset(), equalTo(new ChunkedInference.TextOffset(949, 1269)));
+            assertThat(chunkedByteResult.chunks().get(4).offset(), equalTo(new ChunkedInference.TextOffset(1269, 1589)));
+            assertThat(chunkedByteResult.chunks().get(5).offset(), equalTo(new ChunkedInference.TextOffset(1589, 1675)));
         }
         {
             var chunkedResult = finalListener.results.get(2);
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedByteResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedByteResult.chunks(), hasSize(1));
-            assertEquals("2nd small", chunkedByteResult.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 2), chunkedByteResult.chunks().get(0).offset());
         }
         {
             var chunkedResult = finalListener.results.get(3);
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedByteResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedByteResult.chunks(), hasSize(1));
-            assertEquals("3rd small", chunkedByteResult.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 3), chunkedByteResult.chunks().get(0).offset());
         }
     }
 
@@ -390,7 +390,7 @@ public class EmbeddingRequestChunkerTests extends ESTestCase {
         for (int i = 0; i < numberOfWordsInPassage; i++) {
             passageBuilder.append("passage_input").append(i).append(" "); // chunk on whitespace
         }
-        List<String> inputs = List.of("1st small", passageBuilder.toString(), "2nd small", "3rd small");
+        List<String> inputs = List.of("a", passageBuilder.toString(), "bb", "ccc");
 
         var finalListener = testListener();
         var batches = new EmbeddingRequestChunker(inputs, batchSize, chunkSize, overlap).batchRequestsWithListeners(finalListener);
@@ -419,7 +419,7 @@ public class EmbeddingRequestChunkerTests extends ESTestCase {
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedByteResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedByteResult.chunks(), hasSize(1));
-            assertEquals("1st small", chunkedByteResult.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 1), chunkedByteResult.chunks().get(0).offset());
         }
         {
             // this is the large input split in multiple chunks
@@ -427,26 +427,26 @@ public class EmbeddingRequestChunkerTests extends ESTestCase {
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedByteResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedByteResult.chunks(), hasSize(6));
-            assertThat(chunkedByteResult.chunks().get(0).matchedText(), startsWith("passage_input0 "));
-            assertThat(chunkedByteResult.chunks().get(1).matchedText(), startsWith(" passage_input20 "));
-            assertThat(chunkedByteResult.chunks().get(2).matchedText(), startsWith(" passage_input40 "));
-            assertThat(chunkedByteResult.chunks().get(3).matchedText(), startsWith(" passage_input60 "));
-            assertThat(chunkedByteResult.chunks().get(4).matchedText(), startsWith(" passage_input80 "));
-            assertThat(chunkedByteResult.chunks().get(5).matchedText(), startsWith(" passage_input100 "));
+            assertThat(chunkedByteResult.chunks().get(0).offset(), equalTo(new ChunkedInference.TextOffset(0, 309)));
+            assertThat(chunkedByteResult.chunks().get(1).offset(), equalTo(new ChunkedInference.TextOffset(309, 629)));
+            assertThat(chunkedByteResult.chunks().get(2).offset(), equalTo(new ChunkedInference.TextOffset(629, 949)));
+            assertThat(chunkedByteResult.chunks().get(3).offset(), equalTo(new ChunkedInference.TextOffset(949, 1269)));
+            assertThat(chunkedByteResult.chunks().get(4).offset(), equalTo(new ChunkedInference.TextOffset(1269, 1589)));
+            assertThat(chunkedByteResult.chunks().get(5).offset(), equalTo(new ChunkedInference.TextOffset(1589, 1675)));
         }
         {
             var chunkedResult = finalListener.results.get(2);
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedByteResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedByteResult.chunks(), hasSize(1));
-            assertEquals("2nd small", chunkedByteResult.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 2), chunkedByteResult.chunks().get(0).offset());
         }
         {
             var chunkedResult = finalListener.results.get(3);
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedByteResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedByteResult.chunks(), hasSize(1));
-            assertEquals("3rd small", chunkedByteResult.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 3), chunkedByteResult.chunks().get(0).offset());
         }
     }
 
@@ -462,7 +462,7 @@ public class EmbeddingRequestChunkerTests extends ESTestCase {
         for (int i = 0; i < numberOfWordsInPassage; i++) {
             passageBuilder.append("passage_input").append(i).append(" "); // chunk on whitespace
         }
-        List<String> inputs = List.of("1st small", "2nd small", "3rd small", passageBuilder.toString());
+        List<String> inputs = List.of("a", "bb", "ccc", passageBuilder.toString());
 
         var finalListener = testListener();
         var batches = new EmbeddingRequestChunker(inputs, batchSize, chunkSize, overlap).batchRequestsWithListeners(finalListener);
@@ -498,21 +498,21 @@ public class EmbeddingRequestChunkerTests extends ESTestCase {
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedSparseResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedSparseResult.chunks(), hasSize(1));
-            assertEquals("1st small", chunkedSparseResult.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 1), chunkedSparseResult.chunks().get(0).offset());
         }
         {
             var chunkedResult = finalListener.results.get(1);
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedSparseResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedSparseResult.chunks(), hasSize(1));
-            assertEquals("2nd small", chunkedSparseResult.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 2), chunkedSparseResult.chunks().get(0).offset());
         }
         {
             var chunkedResult = finalListener.results.get(2);
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedSparseResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedSparseResult.chunks(), hasSize(1));
-            assertEquals("3rd small", chunkedSparseResult.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 3), chunkedSparseResult.chunks().get(0).offset());
         }
         {
             // this is the large input split in multiple chunks
@@ -520,9 +520,9 @@ public class EmbeddingRequestChunkerTests extends ESTestCase {
             assertThat(chunkedResult, instanceOf(ChunkedInferenceEmbedding.class));
             var chunkedSparseResult = (ChunkedInferenceEmbedding) chunkedResult;
             assertThat(chunkedSparseResult.chunks(), hasSize(9)); // passage is split into 9 chunks, 10 words each
-            assertThat(chunkedSparseResult.chunks().get(0).matchedText(), startsWith("passage_input0 "));
-            assertThat(chunkedSparseResult.chunks().get(1).matchedText(), startsWith(" passage_input10 "));
-            assertThat(chunkedSparseResult.chunks().get(8).matchedText(), startsWith(" passage_input80 "));
+            assertThat(chunkedSparseResult.chunks().get(0).offset(), equalTo(new ChunkedInference.TextOffset(0, 149)));
+            assertThat(chunkedSparseResult.chunks().get(1).offset(), equalTo(new ChunkedInference.TextOffset(149, 309)));
+            assertThat(chunkedSparseResult.chunks().get(8).offset(), equalTo(new ChunkedInference.TextOffset(1269, 1350)));
         }
     }
 

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/mapper/SemanticTextFieldTests.java

@@ -177,7 +177,7 @@ public class SemanticTextFieldTests extends AbstractXContentTestCase<SemanticTex
             for (int j = 0; j < values.length; j++) {
                 values[j] = randomByte();
             }
-            chunks.add(new TextEmbeddingByteResults.Chunk(values, input, new ChunkedInference.TextOffset(0, input.length())));
+            chunks.add(new TextEmbeddingByteResults.Chunk(values, new ChunkedInference.TextOffset(0, input.length())));
         }
         return new ChunkedInferenceEmbedding(chunks);
     }
@@ -189,7 +189,7 @@ public class SemanticTextFieldTests extends AbstractXContentTestCase<SemanticTex
             for (int j = 0; j < values.length; j++) {
                 values[j] = randomFloat();
             }
-            chunks.add(new TextEmbeddingFloatResults.Chunk(values, input, new ChunkedInference.TextOffset(0, input.length())));
+            chunks.add(new TextEmbeddingFloatResults.Chunk(values, new ChunkedInference.TextOffset(0, input.length())));
         }
         return new ChunkedInferenceEmbedding(chunks);
     }
@@ -205,7 +205,7 @@ public class SemanticTextFieldTests extends AbstractXContentTestCase<SemanticTex
             for (var token : input.split("\\s+")) {
                 tokens.add(new WeightedToken(token, withFloats ? randomFloat() : randomIntBetween(1, 255)));
             }
-            chunks.add(new SparseEmbeddingResults.Chunk(tokens, input, new ChunkedInference.TextOffset(0, input.length())));
+            chunks.add(new SparseEmbeddingResults.Chunk(tokens, new ChunkedInference.TextOffset(0, input.length())));
         }
         return new ChunkedInferenceEmbedding(chunks);
     }
@@ -243,7 +243,7 @@ public class SemanticTextFieldTests extends AbstractXContentTestCase<SemanticTex
         final List<SemanticTextField.Chunk> chunks = new ArrayList<>(inputs.size());
         int offsetAdjustment = 0;
         Iterator<String> inputsIt = inputs.iterator();
-        Iterator<ChunkedInference.Chunk> chunkIt = results.chunksAsMatchedTextAndByteReference(contentType.xContent());
+        Iterator<ChunkedInference.Chunk> chunkIt = results.chunksAsByteReference(contentType.xContent());
         while (inputsIt.hasNext() && chunkIt.hasNext()) {
             String input = inputsIt.next();
             var chunk = chunkIt.next();
@@ -308,7 +308,7 @@ public class SemanticTextFieldTests extends AbstractXContentTestCase<SemanticTex
                         String matchedText = matchedTextIt.next();
                         ChunkedInference.TextOffset offset = createOffset(useLegacyFormat, chunk, matchedText);
                         var tokens = parseWeightedTokens(chunk.rawEmbeddings(), field.contentType());
-                        chunks.add(new SparseEmbeddingResults.Chunk(tokens, matchedText, offset));
+                        chunks.add(new SparseEmbeddingResults.Chunk(tokens, offset));
                     }
                 }
                 return new ChunkedInferenceEmbedding(chunks);
@@ -329,7 +329,7 @@ public class SemanticTextFieldTests extends AbstractXContentTestCase<SemanticTex
                             field.inference().modelSettings().dimensions(),
                             field.contentType()
                         );
-                        chunks.add(new TextEmbeddingFloatResults.Chunk(FloatConversionUtils.floatArrayOf(values), matchedText, offset));
+                        chunks.add(new TextEmbeddingFloatResults.Chunk(FloatConversionUtils.floatArrayOf(values), offset));
                     }
                 }
                 return new ChunkedInferenceEmbedding(chunks);

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/amazonbedrock/AmazonBedrockServiceTests.java

@@ -1444,7 +1444,7 @@ public class AmazonBedrockServiceTests extends ESTestCase {
                 service.chunkedInfer(
                     model,
                     null,
-                    List.of("abc", "xyz"),
+                    List.of("a", "bb"),
                     new HashMap<>(),
                     InputType.INGEST,
                     InferenceAction.Request.DEFAULT_TIMEOUT,
@@ -1457,7 +1457,7 @@ public class AmazonBedrockServiceTests extends ESTestCase {
                     assertThat(results.get(0), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                     var floatResult = (ChunkedInferenceEmbedding) results.get(0);
                     assertThat(floatResult.chunks(), hasSize(1));
-                    assertEquals("abc", floatResult.chunks().get(0).matchedText());
+                    assertEquals(new ChunkedInference.TextOffset(0, 1), floatResult.chunks().get(0).offset());
                     assertThat(floatResult.chunks().get(0), instanceOf(TextEmbeddingFloatResults.Chunk.class));
                     assertArrayEquals(
                         new float[] { 0.123F, 0.678F },
@@ -1469,7 +1469,7 @@ public class AmazonBedrockServiceTests extends ESTestCase {
                     assertThat(results.get(1), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                     var floatResult = (ChunkedInferenceEmbedding) results.get(1);
                     assertThat(floatResult.chunks(), hasSize(1));
-                    assertEquals("xyz", floatResult.chunks().get(0).matchedText());
+                    assertEquals(new ChunkedInference.TextOffset(0, 2), floatResult.chunks().get(0).offset());
                     assertThat(floatResult.chunks().get(0), instanceOf(TextEmbeddingFloatResults.Chunk.class));
                     assertArrayEquals(
                         new float[] { 0.223F, 0.278F },

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureaistudio/AzureAiStudioServiceTests.java

@@ -1191,7 +1191,7 @@ public class AzureAiStudioServiceTests extends ESTestCase {
             service.chunkedInfer(
                 model,
                 null,
-                List.of("foo", "bar"),
+                List.of("a", "bb"),
                 new HashMap<>(),
                 InputType.INGEST,
                 InferenceAction.Request.DEFAULT_TIMEOUT,
@@ -1204,7 +1204,7 @@ public class AzureAiStudioServiceTests extends ESTestCase {
                 assertThat(results.get(0), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(0);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals("foo", floatResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, 1), floatResult.chunks().get(0).offset());
                 assertThat(floatResult.chunks().get(0), instanceOf(TextEmbeddingFloatResults.Chunk.class));
                 assertArrayEquals(
                     new float[] { 0.0123f, -0.0123f },
@@ -1216,7 +1216,7 @@ public class AzureAiStudioServiceTests extends ESTestCase {
                 assertThat(results.get(1), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(1);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals("bar", floatResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, 2), floatResult.chunks().get(0).offset());
                 assertThat(floatResult.chunks().get(0), instanceOf(TextEmbeddingFloatResults.Chunk.class));
                 assertArrayEquals(
                     new float[] { 1.0123f, -1.0123f },
@@ -1232,7 +1232,7 @@ public class AzureAiStudioServiceTests extends ESTestCase {
 
             var requestMap = entityAsMap(webServer.requests().get(0).getBody());
             assertThat(requestMap.size(), Matchers.is(2));
-            assertThat(requestMap.get("input"), Matchers.is(List.of("foo", "bar")));
+            assertThat(requestMap.get("input"), Matchers.is(List.of("a", "bb")));
             assertThat(requestMap.get("user"), Matchers.is("user"));
         }
     }

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/AzureOpenAiServiceTests.java

@@ -1341,7 +1341,7 @@ public class AzureOpenAiServiceTests extends ESTestCase {
             service.chunkedInfer(
                 model,
                 null,
-                List.of("foo", "bar"),
+                List.of("a", "bb"),
                 new HashMap<>(),
                 InputType.INGEST,
                 InferenceAction.Request.DEFAULT_TIMEOUT,
@@ -1354,7 +1354,7 @@ public class AzureOpenAiServiceTests extends ESTestCase {
                 assertThat(results.get(0), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(0);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals("foo", floatResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, 1), floatResult.chunks().get(0).offset());
                 assertThat(floatResult.chunks().get(0), instanceOf(TextEmbeddingFloatResults.Chunk.class));
                 assertArrayEquals(
                     new float[] { 0.123f, -0.123f },
@@ -1366,7 +1366,7 @@ public class AzureOpenAiServiceTests extends ESTestCase {
                 assertThat(results.get(1), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(1);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals("bar", floatResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, 2), floatResult.chunks().get(0).offset());
                 assertThat(floatResult.chunks().get(0), instanceOf(TextEmbeddingFloatResults.Chunk.class));
                 assertArrayEquals(
                     new float[] { 1.123f, -1.123f },
@@ -1382,7 +1382,7 @@ public class AzureOpenAiServiceTests extends ESTestCase {
 
             var requestMap = entityAsMap(webServer.requests().get(0).getBody());
             assertThat(requestMap.size(), Matchers.is(2));
-            assertThat(requestMap.get("input"), Matchers.is(List.of("foo", "bar")));
+            assertThat(requestMap.get("input"), Matchers.is(List.of("a", "bb")));
             assertThat(requestMap.get("user"), Matchers.is("user"));
         }
     }

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/CohereServiceTests.java

@@ -1452,7 +1452,7 @@ public class CohereServiceTests extends ESTestCase {
             service.chunkedInfer(
                 model,
                 null,
-                List.of("foo", "bar"),
+                List.of("a", "bb"),
                 new HashMap<>(),
                 InputType.UNSPECIFIED,
                 InferenceAction.Request.DEFAULT_TIMEOUT,
@@ -1465,7 +1465,7 @@ public class CohereServiceTests extends ESTestCase {
                 assertThat(results.get(0), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(0);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals("foo", floatResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, 1), floatResult.chunks().get(0).offset());
                 assertArrayEquals(
                     new float[] { 0.123f, -0.123f },
                     ((TextEmbeddingFloatResults.Chunk) floatResult.chunks().get(0)).embedding(),
@@ -1476,7 +1476,7 @@ public class CohereServiceTests extends ESTestCase {
                 assertThat(results.get(1), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(1);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals("bar", floatResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, 2), floatResult.chunks().get(0).offset());
                 assertArrayEquals(
                     new float[] { 0.223f, -0.223f },
                     ((TextEmbeddingFloatResults.Chunk) floatResult.chunks().get(0)).embedding(),
@@ -1495,7 +1495,7 @@ public class CohereServiceTests extends ESTestCase {
             var requestMap = entityAsMap(webServer.requests().get(0).getBody());
             MatcherAssert.assertThat(
                 requestMap,
-                is(Map.of("texts", List.of("foo", "bar"), "model", "model", "embedding_types", List.of("float")))
+                is(Map.of("texts", List.of("a", "bb"), "model", "model", "embedding_types", List.of("float")))
             );
         }
     }
@@ -1551,7 +1551,7 @@ public class CohereServiceTests extends ESTestCase {
             service.chunkedInfer(
                 model,
                 null,
-                List.of("foo", "bar"),
+                List.of("a", "bb"),
                 new HashMap<>(),
                 InputType.UNSPECIFIED,
                 InferenceAction.Request.DEFAULT_TIMEOUT,
@@ -1564,7 +1564,7 @@ public class CohereServiceTests extends ESTestCase {
                 assertThat(results.get(0), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                 var byteResult = (ChunkedInferenceEmbedding) results.get(0);
                 assertThat(byteResult.chunks(), hasSize(1));
-                assertEquals("foo", byteResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, 1), byteResult.chunks().get(0).offset());
                 assertThat(byteResult.chunks().get(0), instanceOf(TextEmbeddingByteResults.Chunk.class));
                 assertArrayEquals(new byte[] { 23, -23 }, ((TextEmbeddingByteResults.Chunk) byteResult.chunks().get(0)).embedding());
             }
@@ -1572,7 +1572,7 @@ public class CohereServiceTests extends ESTestCase {
                 assertThat(results.get(1), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                 var byteResult = (ChunkedInferenceEmbedding) results.get(1);
                 assertThat(byteResult.chunks(), hasSize(1));
-                assertEquals("bar", byteResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, 2), byteResult.chunks().get(0).offset());
                 assertThat(byteResult.chunks().get(0), instanceOf(TextEmbeddingByteResults.Chunk.class));
                 assertArrayEquals(new byte[] { 24, -24 }, ((TextEmbeddingByteResults.Chunk) byteResult.chunks().get(0)).embedding());
             }
@@ -1588,7 +1588,7 @@ public class CohereServiceTests extends ESTestCase {
             var requestMap = entityAsMap(webServer.requests().get(0).getBody());
             MatcherAssert.assertThat(
                 requestMap,
-                is(Map.of("texts", List.of("foo", "bar"), "model", "model", "embedding_types", List.of("int8")))
+                is(Map.of("texts", List.of("a", "bb"), "model", "model", "embedding_types", List.of("int8")))
             );
         }
     }

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/elastic/ElasticInferenceServiceTests.java

@@ -566,7 +566,6 @@ public class ElasticInferenceServiceTests extends ESTestCase {
                     List.of(
                         new SparseEmbeddingResults.Chunk(
                             List.of(new WeightedToken("hello", 2.1259406f), new WeightedToken("greet", 1.7073475f)),
-                            "input text",
                             new ChunkedInference.TextOffset(0, "input text".length())
                         )
                     )

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/elasticsearch/ElasticsearchInternalServiceTests.java

@@ -902,7 +902,7 @@ public class ElasticsearchInternalServiceTests extends ESTestCase {
                 ((TextEmbeddingFloatResults.Chunk) result1.chunks().get(0)).embedding(),
                 0.0001f
             );
-            assertEquals("foo", result1.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 1), result1.chunks().get(0).offset());
             assertThat(chunkedResponse.get(1), instanceOf(ChunkedInferenceEmbedding.class));
             var result2 = (ChunkedInferenceEmbedding) chunkedResponse.get(1);
             assertThat(result2.chunks(), hasSize(1));
@@ -912,7 +912,7 @@ public class ElasticsearchInternalServiceTests extends ESTestCase {
                 ((TextEmbeddingFloatResults.Chunk) result2.chunks().get(0)).embedding(),
                 0.0001f
             );
-            assertEquals("bar", result2.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 2), result2.chunks().get(0).offset());
 
             gotResults.set(true);
         }, ESTestCase::fail);
@@ -923,7 +923,7 @@ public class ElasticsearchInternalServiceTests extends ESTestCase {
         service.chunkedInfer(
             model,
             null,
-            List.of("foo", "bar"),
+            List.of("a", "bb"),
             Map.of(),
             InputType.SEARCH,
             InferenceAction.Request.DEFAULT_TIMEOUT,
@@ -977,7 +977,7 @@ public class ElasticsearchInternalServiceTests extends ESTestCase {
                 ((TextExpansionResults) mlTrainedModelResults.get(0)).getWeightedTokens(),
                 ((SparseEmbeddingResults.Chunk) result1.chunks().get(0)).weightedTokens()
             );
-            assertEquals("foo", result1.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 1), result1.chunks().get(0).offset());
             assertThat(chunkedResponse.get(1), instanceOf(ChunkedInferenceEmbedding.class));
             var result2 = (ChunkedInferenceEmbedding) chunkedResponse.get(1);
             assertThat(result2.chunks().get(0), instanceOf(SparseEmbeddingResults.Chunk.class));
@@ -985,7 +985,7 @@ public class ElasticsearchInternalServiceTests extends ESTestCase {
                 ((TextExpansionResults) mlTrainedModelResults.get(1)).getWeightedTokens(),
                 ((SparseEmbeddingResults.Chunk) result2.chunks().get(0)).weightedTokens()
             );
-            assertEquals("bar", result2.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 2), result2.chunks().get(0).offset());
             gotResults.set(true);
         }, ESTestCase::fail);
 
@@ -995,7 +995,7 @@ public class ElasticsearchInternalServiceTests extends ESTestCase {
         service.chunkedInfer(
             model,
             null,
-            List.of("foo", "bar"),
+            List.of("a", "bb"),
             Map.of(),
             InputType.SEARCH,
             InferenceAction.Request.DEFAULT_TIMEOUT,
@@ -1049,7 +1049,7 @@ public class ElasticsearchInternalServiceTests extends ESTestCase {
                 ((TextExpansionResults) mlTrainedModelResults.get(0)).getWeightedTokens(),
                 ((SparseEmbeddingResults.Chunk) result1.chunks().get(0)).weightedTokens()
             );
-            assertEquals("foo", result1.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 1), result1.chunks().get(0).offset());
             assertThat(chunkedResponse.get(1), instanceOf(ChunkedInferenceEmbedding.class));
             var result2 = (ChunkedInferenceEmbedding) chunkedResponse.get(1);
             assertThat(result2.chunks().get(0), instanceOf(SparseEmbeddingResults.Chunk.class));
@@ -1057,7 +1057,7 @@ public class ElasticsearchInternalServiceTests extends ESTestCase {
                 ((TextExpansionResults) mlTrainedModelResults.get(1)).getWeightedTokens(),
                 ((SparseEmbeddingResults.Chunk) result2.chunks().get(0)).weightedTokens()
             );
-            assertEquals("bar", result2.chunks().get(0).matchedText());
+            assertEquals(new ChunkedInference.TextOffset(0, 2), result2.chunks().get(0).offset());
             gotResults.set(true);
         }, ESTestCase::fail);
 
@@ -1067,7 +1067,7 @@ public class ElasticsearchInternalServiceTests extends ESTestCase {
         service.chunkedInfer(
             model,
             null,
-            List.of("foo", "bar"),
+            List.of("a", "bb"),
             Map.of(),
             InputType.SEARCH,
             InferenceAction.Request.DEFAULT_TIMEOUT,

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/googleaistudio/GoogleAiStudioServiceTests.java

@@ -844,7 +844,7 @@ public class GoogleAiStudioServiceTests extends ESTestCase {
 
     private void testChunkedInfer(String modelId, String apiKey, GoogleAiStudioEmbeddingsModel model) throws IOException {
 
-        var input = List.of("foo", "bar");
+        var input = List.of("a", "bb");
 
         var senderFactory = HttpRequestSenderTests.createSenderFactory(threadPool, clientManager);
 
@@ -881,7 +881,7 @@ public class GoogleAiStudioServiceTests extends ESTestCase {
                 assertThat(results.get(0), instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(0);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals(input.get(0), floatResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, input.get(0).length()), floatResult.chunks().get(0).offset());
                 assertThat(floatResult.chunks().get(0), Matchers.instanceOf(TextEmbeddingFloatResults.Chunk.class));
                 assertTrue(
                     Arrays.equals(
@@ -896,7 +896,7 @@ public class GoogleAiStudioServiceTests extends ESTestCase {
                 assertThat(results.get(1), instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(1);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals(input.get(1), floatResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, input.get(1).length()), floatResult.chunks().get(0).offset());
                 assertThat(floatResult.chunks().get(0), Matchers.instanceOf(TextEmbeddingFloatResults.Chunk.class));
                 assertTrue(
                     Arrays.equals(

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/huggingface/HuggingFaceElserServiceTests.java

@@ -111,7 +111,6 @@ public class HuggingFaceElserServiceTests extends ESTestCase {
                     List.of(
                         new SparseEmbeddingResults.Chunk(
                             List.of(new WeightedToken(".", 0.13315596f)),
-                            "abc",
                             new ChunkedInference.TextOffset(0, "abc".length())
                         )
                     )

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/huggingface/HuggingFaceServiceTests.java

@@ -787,7 +787,6 @@ public class HuggingFaceServiceTests extends ESTestCase {
             assertThat(result, CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
             var embeddingResult = (ChunkedInferenceEmbedding) result;
             assertThat(embeddingResult.chunks(), hasSize(1));
-            assertThat(embeddingResult.chunks().get(0).matchedText(), is("abc"));
             assertThat(embeddingResult.chunks().get(0).offset(), is(new ChunkedInference.TextOffset(0, "abc".length())));
             assertThat(embeddingResult.chunks().get(0), Matchers.instanceOf(TextEmbeddingFloatResults.Chunk.class));
             assertArrayEquals(
@@ -842,7 +841,7 @@ public class HuggingFaceServiceTests extends ESTestCase {
                 assertThat(results.get(0), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(0);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals("abc", floatResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, 3), floatResult.chunks().get(0).offset());
                 assertThat(floatResult.chunks().get(0), Matchers.instanceOf(TextEmbeddingFloatResults.Chunk.class));
                 assertArrayEquals(
                     new float[] { 0.123f, -0.123f },

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/ibmwatsonx/IbmWatsonxServiceTests.java

@@ -686,7 +686,7 @@ public class IbmWatsonxServiceTests extends ESTestCase {
     }
 
     private void testChunkedInfer_Batches(ChunkingSettings chunkingSettings) throws IOException {
-        var input = List.of("foo", "bar");
+        var input = List.of("a", "bb");
 
         var senderFactory = HttpRequestSenderTests.createSenderFactory(threadPool, clientManager);
 
@@ -733,7 +733,7 @@ public class IbmWatsonxServiceTests extends ESTestCase {
                 assertThat(results.get(0), instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(0);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals(input.get(0), floatResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, input.get(0).length()), floatResult.chunks().get(0).offset());
                 assertThat(floatResult.chunks().get(0), Matchers.instanceOf(TextEmbeddingFloatResults.Chunk.class));
                 assertTrue(
                     Arrays.equals(
@@ -748,7 +748,7 @@ public class IbmWatsonxServiceTests extends ESTestCase {
                 assertThat(results.get(1), instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(1);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals(input.get(1), floatResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, input.get(1).length()), floatResult.chunks().get(0).offset());
                 assertThat(floatResult.chunks().get(0), Matchers.instanceOf(TextEmbeddingFloatResults.Chunk.class));
                 assertTrue(
                     Arrays.equals(
@@ -763,7 +763,7 @@ public class IbmWatsonxServiceTests extends ESTestCase {
 
             var requestMap = entityAsMap(webServer.requests().get(0).getBody());
             assertThat(requestMap, aMapWithSize(3));
-            assertThat(requestMap, is(Map.of("project_id", projectId, "inputs", List.of("foo", "bar"), "model_id", modelId)));
+            assertThat(requestMap, is(Map.of("project_id", projectId, "inputs", List.of("a", "bb"), "model_id", modelId)));
         }
     }
 

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/jinaai/JinaAIServiceTests.java

@@ -1819,7 +1819,7 @@ public class JinaAIServiceTests extends ESTestCase {
             service.chunkedInfer(
                 model,
                 null,
-                List.of("foo", "bar"),
+                List.of("a", "bb"),
                 new HashMap<>(),
                 InputType.UNSPECIFIED,
                 InferenceAction.Request.DEFAULT_TIMEOUT,
@@ -1832,7 +1832,7 @@ public class JinaAIServiceTests extends ESTestCase {
                 assertThat(results.get(0), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(0);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals("foo", floatResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, 1), floatResult.chunks().get(0).offset());
                 assertThat(floatResult.chunks().get(0), Matchers.instanceOf(TextEmbeddingFloatResults.Chunk.class));
                 assertArrayEquals(
                     new float[] { 0.123f, -0.123f },
@@ -1844,7 +1844,7 @@ public class JinaAIServiceTests extends ESTestCase {
                 assertThat(results.get(1), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(1);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals("bar", floatResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, 2), floatResult.chunks().get(0).offset());
                 assertThat(floatResult.chunks().get(0), Matchers.instanceOf(TextEmbeddingFloatResults.Chunk.class));
                 assertArrayEquals(
                     new float[] { 0.223f, -0.223f },
@@ -1864,7 +1864,7 @@ public class JinaAIServiceTests extends ESTestCase {
             var requestMap = entityAsMap(webServer.requests().get(0).getBody());
             MatcherAssert.assertThat(
                 requestMap,
-                is(Map.of("input", List.of("foo", "bar"), "model", "jina-clip-v2", "embedding_type", "float"))
+                is(Map.of("input", List.of("a", "bb"), "model", "jina-clip-v2", "embedding_type", "float"))
             );
         }
     }

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/openai/OpenAiServiceTests.java

@@ -1857,7 +1857,7 @@ public class OpenAiServiceTests extends ESTestCase {
             service.chunkedInfer(
                 model,
                 null,
-                List.of("foo", "bar"),
+                List.of("a", "bb"),
                 new HashMap<>(),
                 InputType.INGEST,
                 InferenceAction.Request.DEFAULT_TIMEOUT,
@@ -1870,7 +1870,7 @@ public class OpenAiServiceTests extends ESTestCase {
                 assertThat(results.get(0), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(0);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals("foo", floatResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, 1), floatResult.chunks().get(0).offset());
                 assertThat(floatResult.chunks().get(0), Matchers.instanceOf(TextEmbeddingFloatResults.Chunk.class));
                 assertTrue(
                     Arrays.equals(
@@ -1883,7 +1883,7 @@ public class OpenAiServiceTests extends ESTestCase {
                 assertThat(results.get(1), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(1);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals("bar", floatResult.chunks().get(0).matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, 2), floatResult.chunks().get(0).offset());
                 assertThat(floatResult.chunks().get(0), Matchers.instanceOf(TextEmbeddingFloatResults.Chunk.class));
                 assertTrue(
                     Arrays.equals(
@@ -1901,7 +1901,7 @@ public class OpenAiServiceTests extends ESTestCase {
 
             var requestMap = entityAsMap(webServer.requests().get(0).getBody());
             assertThat(requestMap.size(), Matchers.is(3));
-            assertThat(requestMap.get("input"), Matchers.is(List.of("foo", "bar")));
+            assertThat(requestMap.get("input"), Matchers.is(List.of("a", "bb")));
             assertThat(requestMap.get("model"), Matchers.is("model"));
             assertThat(requestMap.get("user"), Matchers.is("user"));
         }

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/voyageai/VoyageAIServiceTests.java

@@ -1826,7 +1826,7 @@ public class VoyageAIServiceTests extends ESTestCase {
             service.chunkedInfer(
                 model,
                 null,
-                List.of("foo", "bar"),
+                List.of("a", "bb"),
                 new HashMap<>(),
                 InputType.UNSPECIFIED,
                 InferenceAction.Request.DEFAULT_TIMEOUT,
@@ -1839,7 +1839,7 @@ public class VoyageAIServiceTests extends ESTestCase {
                 assertThat(results.getFirst(), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.getFirst();
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals("foo", floatResult.chunks().getFirst().matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, 1), floatResult.chunks().getFirst().offset());
                 assertThat(floatResult.chunks().getFirst(), CoreMatchers.instanceOf(TextEmbeddingFloatResults.Chunk.class));
                 assertArrayEquals(
                     new float[] { 0.123f, -0.123f },
@@ -1851,7 +1851,7 @@ public class VoyageAIServiceTests extends ESTestCase {
                 assertThat(results.get(1), CoreMatchers.instanceOf(ChunkedInferenceEmbedding.class));
                 var floatResult = (ChunkedInferenceEmbedding) results.get(1);
                 assertThat(floatResult.chunks(), hasSize(1));
-                assertEquals("bar", floatResult.chunks().getFirst().matchedText());
+                assertEquals(new ChunkedInference.TextOffset(0, 2), floatResult.chunks().getFirst().offset());
                 assertThat(floatResult.chunks().getFirst(), CoreMatchers.instanceOf(TextEmbeddingFloatResults.Chunk.class));
                 assertArrayEquals(
                     new float[] { 0.223f, -0.223f },
@@ -1871,7 +1871,7 @@ public class VoyageAIServiceTests extends ESTestCase {
             var requestMap = entityAsMap(webServer.requests().getFirst().getBody());
             MatcherAssert.assertThat(
                 requestMap,
-                is(Map.of("input", List.of("foo", "bar"), "model", "voyage-3-large", "output_dtype", "float", "output_dimension", 1024))
+                is(Map.of("input", List.of("a", "bb"), "model", "voyage-3-large", "output_dtype", "float", "output_dimension", 1024))
             );
         }
     }