Avoid creating the full object tree just to verify if json contains 'tree_info' field.

1 files changed, 11 insertions, 1 deletions

diff --git a/model-integration/src/main/java/ai/vespa/rankingexpression/importer/lightgbm/LightGBMImporter.java b/model-integration/src/main/java/ai/vespa/rankingexpression/importer/lightgbm/LightGBMImporter.java
index ef731730c84..76fcf8890c2 100644
--- a/model-integration/src/main/java/ai/vespa/rankingexpression/importer/lightgbm/LightGBMImporter.java
+++ b/model-integration/src/main/java/ai/vespa/rankingexpression/importer/lightgbm/LightGBMImporter.java
@@ -4,6 +4,8 @@ package ai.vespa.rankingexpression.importer.lightgbm;
 import ai.vespa.rankingexpression.importer.ImportedModel;
 import ai.vespa.rankingexpression.importer.ModelImporter;
 import ai.vespa.rankingexpression.importer.configmodelview.ImportedMlModel;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonToken;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.yahoo.searchlib.rankingexpression.RankingExpression;
 import com.yahoo.searchlib.rankingexpression.parser.ParseException;
@@ -18,6 +20,7 @@ import java.io.IOException;
  */
 public class LightGBMImporter extends ModelImporter {
 
+    private final ObjectMapper objectMapper = new ObjectMapper();
     @Override
     public boolean canImport(String modelPath) {
         File modelFile = new File(modelPath);
@@ -31,7 +34,14 @@ public class LightGBMImporter extends ModelImporter {
      */
     private boolean probe(File modelFile) {
         try {
-            return new ObjectMapper().readTree(modelFile).has("tree_info");
+            JsonParser parser = objectMapper.createParser(modelFile);
+            while (parser.nextToken() != null) {
+                JsonToken token = parser.getCurrentToken();
+                if (token == JsonToken.FIELD_NAME) {
+                    if ("tree_info".equals(parser.getCurrentName())) return true;
+                }
+            }
+            return false;
         } catch (IOException e) {
             throw new IllegalArgumentException("Could not read '" + modelFile + "'", e);
         }