feat: fix support of transitive dependencies in conversion of protobuf messages to json (#419)

* recursive handling of dependencies

* removing unnecessary lines

Author: thugrock7

instrumentation/grpc-1.6/src/main/java/io/opentelemetry/javaagent/instrumentation/hypertrace/grpc/v1_6/GrpcSpanDecorator.java

@@ -21,7 +21,6 @@
 import io.grpc.Metadata.Key;
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.trace.Span;
-import io.opentelemetry.javaagent.instrumentation.hypertrace.com.google.protobuf.util.JsonFormat;
 import io.opentelemetry.javaagent.instrumentation.hypertrace.grpc.GrpcSemanticAttributes;
 import java.util.LinkedHashMap;
 import java.util.Map;
@@ -35,16 +34,17 @@ public class GrpcSpanDecorator {
   private GrpcSpanDecorator() {}
 
   private static final Logger log = LoggerFactory.getLogger(GrpcSpanDecorator.class);
-  private static final JsonFormat.Printer PRINTER = JsonFormat.printer();
 
   public static void addMessageAttribute(Object message, Span span, AttributeKey<String> key) {
     if (message instanceof Message) {
       Message mb = (Message) message;
       try {
         String jsonOutput = ProtobufMessageConverter.getMessage(mb);
-        span.setAttribute(key, jsonOutput);
+        if (jsonOutput != null && !jsonOutput.isEmpty()) {
+          span.setAttribute(key, jsonOutput);
+        }
       } catch (Exception e) {
-        log.error("Failed to decode message as JSON", e);
+        log.debug("Failed to decode message as JSON: {}", e.getMessage(), e);
       }
     } else {
       log.debug("message is not an instance of com.google.protobuf.Message");

instrumentation/grpc-1.6/src/main/java/io/opentelemetry/javaagent/instrumentation/hypertrace/grpc/v1_6/ProtobufMessageConverter.java

@@ -25,11 +25,14 @@
 import io.opentelemetry.javaagent.instrumentation.hypertrace.com.google.protobuf.util.JsonFormat;
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+/** Utility class to convert protobuf messages to JSON. */
 public class ProtobufMessageConverter {
   private static final Logger log = LoggerFactory.getLogger(ProtobufMessageConverter.class);
   private static final Map<String, FileDescriptor> fileDescriptorCache = new HashMap<>();
@@ -75,25 +78,73 @@ private static Descriptor getRelocatedDescriptor(Descriptors.Descriptor original
     String fileKey = unrelocatedFileDescriptor.getName();
     if (fileDescriptorCache.containsKey(fileKey)) {
       FileDescriptor relocatedFileDescriptor = fileDescriptorCache.get(fileKey);
-      return relocatedFileDescriptor.findMessageTypeByName(originalDescriptor.getName());
+
+      // Check if the message type exists in the relocated descriptor
+      Descriptor messageType =
+          relocatedFileDescriptor.findMessageTypeByName(originalDescriptor.getName());
+      if (messageType == null) {
+        log.debug("Message type not found in cached descriptor: {}", originalDescriptor.getName());
+      }
+
+      return messageType;
     }
 
-    // Process all dependencies first
+    // Process all dependencies recursively, including transitive ones
+    FileDescriptor fileDescriptor =
+        processFileDescriptorWithDependencies(unrelocatedFileDescriptor, new HashSet<>());
+
+    // Find the message type in the relocated descriptor
+    Descriptor result = fileDescriptor.findMessageTypeByName(originalDescriptor.getName());
+    if (result == null) {
+      log.debug("Message type not found in new descriptor: {}", originalDescriptor.getName());
+    }
+
+    return result;
+  }
+
+  /**
+   * Process a file descriptor and all its dependencies recursively.
+   *
+   * @param unrelocatedFileDescriptor The file descriptor to process
+   * @param processedFiles Set of file names that have already been processed to avoid circular
+   *     dependencies
+   * @return The relocated file descriptor
+   */
+  private static FileDescriptor processFileDescriptorWithDependencies(
+      Descriptors.FileDescriptor unrelocatedFileDescriptor, Set<String> processedFiles)
+      throws Exception {
+    String fileKey = unrelocatedFileDescriptor.getName();
+
+    // Check if we've already processed this file
+    if (fileDescriptorCache.containsKey(fileKey)) {
+      return fileDescriptorCache.get(fileKey);
+    }
+
+    // Mark this file as processed to avoid circular dependencies
+    processedFiles.add(fileKey);
+
     List<FileDescriptor> dependencies = new ArrayList<>();
+
+    // Process all direct dependencies first
     for (Descriptors.FileDescriptor dependency : unrelocatedFileDescriptor.getDependencies()) {
       String depKey = dependency.getName();
-      if (!fileDescriptorCache.containsKey(depKey)) {
-        // Convert the dependency file descriptor
-        com.google.protobuf.DescriptorProtos.FileDescriptorProto depProto = dependency.toProto();
-        byte[] depBytes = depProto.toByteArray();
-        FileDescriptorProto relocatedDepProto = FileDescriptorProto.parseFrom(depBytes);
 
-        // Build with empty dependencies first (we'll fill them in later)
+      // Skip if we've already processed this dependency in this call chain
+      if (processedFiles.contains(depKey)) {
+        if (fileDescriptorCache.containsKey(depKey)) {
+          dependencies.add(fileDescriptorCache.get(depKey));
+        }
+        continue;
+      }
+
+      if (!fileDescriptorCache.containsKey(depKey)) {
+        // Process this dependency recursively
         FileDescriptor relocatedDep =
-            FileDescriptor.buildFrom(relocatedDepProto, new FileDescriptor[] {});
-        fileDescriptorCache.put(depKey, relocatedDep);
+            processFileDescriptorWithDependencies(dependency, processedFiles);
+        dependencies.add(relocatedDep);
+      } else {
+        dependencies.add(fileDescriptorCache.get(depKey));
       }
-      dependencies.add(fileDescriptorCache.get(depKey));
     }
 
     // Now build the current file descriptor with its dependencies
@@ -106,36 +157,29 @@ private static Descriptor getRelocatedDescriptor(Descriptors.Descriptor original
         FileDescriptor.buildFrom(relocatedFileProto, dependencies.toArray(new FileDescriptor[0]));
     fileDescriptorCache.put(fileKey, relocatedFileDescriptor);
 
-    return relocatedFileDescriptor.findMessageTypeByName(originalDescriptor.getName());
+    return relocatedFileDescriptor;
   }
 
   /**
    * Method that takes an incoming message, converts it to a relocated one, prints it as JSON using
    * the relocated JsonFormat
    *
    * @param message The incoming (unrelocated) protobuf message.
+   * @return JSON string representation of the message
+   * @throws Exception if conversion fails
    */
-  public static String getMessage(Message message) {
+  public static String getMessage(Message message) throws Exception {
     if (message == null) {
       log.debug("Cannot convert null message to JSON");
       return "";
     }
 
-    try {
-      // Convert the unrelocated message into a relocated DynamicMessage.
-      DynamicMessage relocatedMessage = convertToRelocatedDynamicMessage(message);
+    // Convert the unrelocated message into a relocated DynamicMessage.
+    DynamicMessage relocatedMessage = convertToRelocatedDynamicMessage(message);
 
-      // Use the relocated JsonFormat to print the message as JSON.
-      JsonFormat.Printer relocatedPrinter =
-          JsonFormat.printer().includingDefaultValueFields().preservingProtoFieldNames();
-      return relocatedPrinter.print(relocatedMessage);
-    } catch (Exception e) {
-      log.error("Failed to convert message to JSON: {}", e.getMessage(), e);
-      if (log.isDebugEnabled()) {
-        log.debug("Message type: {}", message.getClass().getName());
-        log.debug("Message descriptor: {}", message.getDescriptorForType().getFullName());
-      }
-    }
-    return "";
+    // Use the relocated JsonFormat to print the message as JSON.
+    JsonFormat.Printer relocatedPrinter =
+        JsonFormat.printer().includingDefaultValueFields().preservingProtoFieldNames();
+    return relocatedPrinter.print(relocatedMessage);
   }
 }