passing dependencies to protobuf (#418)

Author: thugrock7

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

@@ -23,11 +23,17 @@
 import io.opentelemetry.javaagent.instrumentation.hypertrace.com.google.protobuf.Descriptors.FileDescriptor;
 import io.opentelemetry.javaagent.instrumentation.hypertrace.com.google.protobuf.DynamicMessage;
 import io.opentelemetry.javaagent.instrumentation.hypertrace.com.google.protobuf.util.JsonFormat;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class ProtobufMessageConverter {
   private static final Logger log = LoggerFactory.getLogger(ProtobufMessageConverter.class);
+  private static final Map<String, FileDescriptor> fileDescriptorCache = new HashMap<>();
+
   /**
    * Converts an unrelocated protobuf message into a relocated DynamicMessage via a byte-array
    * round-trip.
@@ -43,31 +49,64 @@ public static DynamicMessage convertToRelocatedDynamicMessage(Message message) t
     // 2. Obtain the original (unrelocated) message descriptor.
     Descriptors.Descriptor originalDescriptor = message.getDescriptorForType();
 
-    // 3. Get the unrelocated file descriptor and its proto representation.
+    // 3. Build the relocated descriptor with all dependencies
+    Descriptor relocatedDescriptor = getRelocatedDescriptor(originalDescriptor);
+    if (relocatedDescriptor == null) {
+      throw new IllegalStateException(
+          "Could not find relocated descriptor for message type: "
+              + originalDescriptor.getFullName());
+    }
+
+    // 4. Parse the original message bytes using the relocated descriptor.
+    try {
+      return DynamicMessage.parseFrom(relocatedDescriptor, messageBytes);
+    } catch (Exception e) {
+      log.debug("Failed to parse message bytes using relocated descriptor: {}", e.getMessage());
+      throw e;
+    }
+  }
+
+  /** Recursively builds relocated file descriptors with all dependencies. */
+  private static Descriptor getRelocatedDescriptor(Descriptors.Descriptor originalDescriptor)
+      throws Exception {
     Descriptors.FileDescriptor unrelocatedFileDescriptor = originalDescriptor.getFile();
+
+    // Check if we've already processed this file descriptor
+    String fileKey = unrelocatedFileDescriptor.getName();
+    if (fileDescriptorCache.containsKey(fileKey)) {
+      FileDescriptor relocatedFileDescriptor = fileDescriptorCache.get(fileKey);
+      return relocatedFileDescriptor.findMessageTypeByName(originalDescriptor.getName());
+    }
+
+    // Process all dependencies first
+    List<FileDescriptor> dependencies = new ArrayList<>();
+    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)
+        FileDescriptor relocatedDep =
+            FileDescriptor.buildFrom(relocatedDepProto, new FileDescriptor[] {});
+        fileDescriptorCache.put(depKey, relocatedDep);
+      }
+      dependencies.add(fileDescriptorCache.get(depKey));
+    }
+
+    // Now build the current file descriptor with its dependencies
     com.google.protobuf.DescriptorProtos.FileDescriptorProto unrelocatedFileProto =
         unrelocatedFileDescriptor.toProto();
     byte[] fileProtoBytes = unrelocatedFileProto.toByteArray();
-
-    // 4. Parse the file descriptor proto using relocated classes.
-    // This converts the unrelocated FileDescriptorProto into your relocated FileDescriptorProto.
     FileDescriptorProto relocatedFileProto = FileDescriptorProto.parseFrom(fileProtoBytes);
 
-    // 5. Build the relocated FileDescriptor.
     FileDescriptor relocatedFileDescriptor =
-        FileDescriptor.buildFrom(relocatedFileProto, new FileDescriptor[] {});
-
-    // 6. Find the relocated message descriptor by name.
-    Descriptor relocatedDescriptor =
-        relocatedFileDescriptor.findMessageTypeByName(originalDescriptor.getName());
-    if (relocatedDescriptor == null) {
-      throw new IllegalStateException(
-          "Could not find relocated descriptor for message type: " + originalDescriptor.getName());
-    }
+        FileDescriptor.buildFrom(relocatedFileProto, dependencies.toArray(new FileDescriptor[0]));
+    fileDescriptorCache.put(fileKey, relocatedFileDescriptor);
 
-    // 7. Parse the original message bytes using the relocated descriptor.
-    DynamicMessage relocatedMessage = DynamicMessage.parseFrom(relocatedDescriptor, messageBytes);
-    return relocatedMessage;
+    return relocatedFileDescriptor.findMessageTypeByName(originalDescriptor.getName());
   }
 
   /**
@@ -77,17 +116,25 @@ public static DynamicMessage convertToRelocatedDynamicMessage(Message message) t
    * @param message The incoming (unrelocated) protobuf message.
    */
   public static String getMessage(Message message) {
+    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);
 
       // Use the relocated JsonFormat to print the message as JSON.
-      JsonFormat.Printer relocatedPrinter = JsonFormat.printer();
-      String jsonOutput = relocatedPrinter.print(relocatedMessage);
-
-      return jsonOutput;
+      JsonFormat.Printer relocatedPrinter =
+          JsonFormat.printer().includingDefaultValueFields().preservingProtoFieldNames();
+      return relocatedPrinter.print(relocatedMessage);
     } catch (Exception e) {
-      log.error("Failed to convert message with relocated protobuf message: {}", e.getMessage());
+      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 "";
   }