refactor: removing empty configs on delete

config-service-impl/src/main/java/org/hypertrace/config/service/ConfigServiceGrpcImpl.java

@@ -1,6 +1,5 @@
 package org.hypertrace.config.service;
 
-import static org.hypertrace.config.service.ConfigServiceUtils.emptyValue;
 import static org.hypertrace.config.service.ConfigServiceUtils.filterNull;
 import static org.hypertrace.config.service.ConfigServiceUtils.merge;
 
@@ -134,7 +133,7 @@ public void deleteConfig(
       }
 
       // write an empty config for the specified config resource. This maintains the versioning.
-      configStore.writeConfig(configResourceContext, getUserId(), emptyValue());
+      configStore.deleteConfigs(List.of(configResourceContext));
       responseObserver.onNext(
           DeleteConfigResponse.newBuilder().setDeletedConfig(configToDelete).build());
       responseObserver.onCompleted();
@@ -155,22 +154,19 @@ public void deleteConfigs(
                 .asException());
         return;
       }
-      Map<ConfigResourceContext, Value> valuesByContext =
+
+      List<ConfigResourceContext> valuesToDelete =
           request.getConfigsList().stream()
-              .map(
-                  requestedDelete ->
-                      Map.entry(this.getConfigResourceContext(requestedDelete), emptyValue()))
-              .collect(ImmutableMap.toImmutableMap(Entry::getKey, Entry::getValue));
+              .map(this::getConfigResourceContext)
+              .collect(Collectors.toUnmodifiableList());
 
-      List<UpsertedConfig> deletedConfigs =
-          configStore.writeAllConfigs(valuesByContext, getUserId());
+      Map<ConfigResourceContext, ContextSpecificConfig> configsToDelete =
+          configStore.getContextConfigs(valuesToDelete);
+      configStore.deleteConfigs(configsToDelete.keySet());
 
       responseObserver.onNext(
           DeleteConfigsResponse.newBuilder()
-              .addAllDeletedConfigs(
-                  deletedConfigs.stream()
-                      .map(this::buildDeletedContextSpecificConfig)
-                      .collect(Collectors.toUnmodifiableList()))
+              .addAllDeletedConfigs(configsToDelete.values())
               .build());
       responseObserver.onCompleted();
     } catch (Exception e) {
@@ -179,15 +175,6 @@ public void deleteConfigs(
     }
   }
 
-  private ContextSpecificConfig buildDeletedContextSpecificConfig(UpsertedConfig deletedConfig) {
-    return ContextSpecificConfig.newBuilder()
-        .setContext(deletedConfig.getContext())
-        .setCreationTimestamp(deletedConfig.getCreationTimestamp())
-        .setUpdateTimestamp(deletedConfig.getUpdateTimestamp())
-        .setConfig(deletedConfig.getPrevConfig())
-        .build();
-  }
-
   @Override
   public void upsertAllConfigs(
       UpsertAllConfigsRequest request, StreamObserver<UpsertAllConfigsResponse> responseObserver) {

config-service-impl/src/main/java/org/hypertrace/config/service/store/ConfigStore.java

@@ -3,6 +3,7 @@
 import com.google.protobuf.Value;
 import com.typesafe.config.Config;
 import java.io.IOException;
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import org.hypertrace.config.service.ConfigResource;
@@ -34,6 +35,8 @@ public interface ConfigStore {
   UpsertedConfig writeConfig(
       ConfigResourceContext configResourceContext, String userId, Value config) throws IOException;
 
+  void deleteConfigs(Collection<ConfigResourceContext> resourceContextCollection);
+
   /**
    * Get the config with the latest version for the specified resource.
    *
@@ -52,6 +55,9 @@ UpsertedConfig writeConfig(
    */
   List<ContextSpecificConfig> getAllConfigs(ConfigResource configResource) throws IOException;
 
+  Map<ConfigResourceContext, ContextSpecificConfig> getContextConfigs(
+      Collection<ConfigResourceContext> configResourceContexts) throws IOException;
+
   /**
    * Write each of the provided config value associated with the specified config resource to the
    * store.

config-service-impl/src/main/java/org/hypertrace/config/service/store/DocumentConfigStore.java

@@ -8,6 +8,7 @@
 import static org.hypertrace.config.service.store.ConfigDocument.TENANT_ID_FIELD_NAME;
 import static org.hypertrace.config.service.store.ConfigDocument.VERSION_FIELD_NAME;
 
+import com.google.common.collect.Maps;
 import com.google.protobuf.Value;
 import com.typesafe.config.Config;
 import io.grpc.Status;
@@ -20,6 +21,7 @@
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
@@ -90,6 +92,22 @@ public UpsertedConfig writeConfig(
         .orElseGet(() -> this.buildUpsertResult(latestConfigDocument));
   }
 
+  @Override
+  public void deleteConfigs(java.util.Collection<ConfigResourceContext> resourceContextCollection) {
+    collection.delete(
+        resourceContextCollection.stream().map(ConfigDocumentKey::new).collect(Collectors.toSet()));
+  }
+
+  @Override
+  public Map<ConfigResourceContext, ContextSpecificConfig> getContextConfigs(
+      java.util.Collection<ConfigResourceContext> configResourceContexts) throws IOException {
+    return Maps.filterValues(
+        Maps.transformValues(
+            getLatestVersionConfigDocs(configResourceContexts),
+            doc -> doc.flatMap(this::convertToContextSpecificConfig).orElse(null)),
+        Objects::nonNull);
+  }
+
   private List<UpsertedConfig> writeConfigs(
       Map<ConfigResourceContext, Value> resourceContextValueMap, String userId) throws IOException {
     Map<ConfigResourceContext, Optional<ConfigDocument>> previousConfigDocs =
@@ -212,7 +230,7 @@ private Optional<ConfigDocument> getLatestVersionConfigDoc(
   }
 
   private Map<ConfigResourceContext, Optional<ConfigDocument>> getLatestVersionConfigDocs(
-      Set<ConfigResourceContext> configResourceContexts) throws IOException {
+      java.util.Collection<ConfigResourceContext> configResourceContexts) throws IOException {
     if (configResourceContexts.isEmpty()) {
       return Collections.emptyMap();
     }