feat: add group limit to explorer api

hypertrace-graphql-explorer-schema/src/main/java/org/hypertrace/graphql/explorer/dao/GatewayServiceExploreRequestBuilder.java

@@ -73,6 +73,7 @@ Single<org.hypertrace.gateway.service.v1.explore.ExploreRequest> buildRequest(
                 .setOffset(request.offset())
                 .setFilter(filter)
                 .setSpaceId(request.spaceId().orElse("")) // String proto default value
+                .setGroupLimit(request.groupLimit().orElse(0)) // Int proto default value
                 .build());
   }
 

hypertrace-graphql-explorer-schema/src/main/java/org/hypertrace/graphql/explorer/deserialization/GroupByArgumentDeserializationConfig.java

@@ -38,5 +38,8 @@ private static class DefaultGroupByArgument implements GroupByArgument {
 
     @JsonProperty(GROUP_BY_INCLUDE_REST_KEY)
     boolean includeRest;
+
+    @JsonProperty(GROUP_BY_LIMIT_KEY)
+    int groupLimit;
   }
 }

hypertrace-graphql-explorer-schema/src/main/java/org/hypertrace/graphql/explorer/request/DefaultExploreRequestBuilder.java

@@ -163,7 +163,8 @@ private Single<ExploreRequest> build(
                 groupByAttribute,
                 intervalArgument,
                 groupBy.map(GroupByArgument::includeRest).orElse(false),
-                spaceId));
+                spaceId,
+                groupBy.map(GroupByArgument::groupLimit)));
   }
 
   private Single<Set<AttributeRequest>> buildGroupByAttributes(
@@ -189,5 +190,6 @@ private static class DefaultExploreRequest implements ExploreRequest {
     Optional<IntervalArgument> timeInterval;
     boolean includeRest;
     Optional<String> spaceId;
+    Optional<Integer> groupLimit;
   }
 }

hypertrace-graphql-explorer-schema/src/main/java/org/hypertrace/graphql/explorer/request/ExploreRequest.java

@@ -37,4 +37,6 @@ public interface ExploreRequest {
   boolean includeRest();
 
   Optional<String> spaceId();
+
+  Optional<Integer> groupLimit();
 }

hypertrace-graphql-explorer-schema/src/main/java/org/hypertrace/graphql/explorer/schema/argument/GroupByArgument.java

@@ -12,6 +12,7 @@ public interface GroupByArgument {
 
   String GROUP_BY_KEYS_KEY = "keys";
   String GROUP_BY_INCLUDE_REST_KEY = "includeRest";
+  String GROUP_BY_LIMIT_KEY = "groupLimit";
 
   @GraphQLField
   @GraphQLNonNull
@@ -21,4 +22,8 @@ public interface GroupByArgument {
   @GraphQLField
   @GraphQLName(GROUP_BY_INCLUDE_REST_KEY)
   boolean includeRest();
+
+  @GraphQLField
+  @GraphQLName(GROUP_BY_LIMIT_KEY)
+  int groupLimit();
 }

hypertrace-graphql-spaces-schema/src/main/java/org/hypertrace/graphql/spaces/dao/ExplorerBackedSpacesDao.java

@@ -138,41 +138,36 @@ public Instant startTime() {
   private static class ActiveSpaceExploreRequest implements ExploreRequest {
     private static final String SPACE_IDS_KEY = "spaceIds";
     private static final String SPACE_IDS_SCOPE = "EVENT";
+    private static final int MAX_SPACES = 100;
 
     GraphQlRequestContext requestContext;
-    String scope;
+    String scope = SPACE_IDS_SCOPE;
+    int limit = MAX_SPACES;
+    int offset = 0;
+    Set<AttributeRequest> attributeRequests = emptySet();
+    List<AttributeAssociation<FilterArgument>> filterArguments = emptyList();
+    Optional<IntervalArgument> timeInterval = Optional.empty();
+    boolean includeRest = false;
+    Optional<String> spaceId = Optional.empty();
+    Optional<Integer> groupLimit = Optional.of(MAX_SPACES);
+
     TimeRangeArgument timeRange;
-    int limit;
-    int offset;
-    Set<AttributeRequest> attributeRequests;
     Set<MetricAggregationRequest> aggregationRequests;
     List<ExploreOrderArgument> orderArguments;
-    List<AttributeAssociation<FilterArgument>> filterArguments;
     Set<AttributeRequest> groupByAttributeRequests;
-    Optional<IntervalArgument> timeInterval;
-    boolean includeRest;
-    Optional<String> spaceId;
 
     ActiveSpaceExploreRequest(
         GraphQlRequestContext context,
         TimeRangeArgument timeRange,
         AttributeRequest spaceIdRequest,
         MetricAggregationRequest spaceIdCountRequest) {
       this.requestContext = context;
-      this.scope = SPACE_IDS_SCOPE;
-      this.limit = 100;
-      this.offset = 0;
       this.timeRange = timeRange;
-      this.attributeRequests = emptySet();
       // Aggregation needed to pass explorer validation - a no agg request is not valid
       this.aggregationRequests = Set.of(spaceIdCountRequest);
       this.orderArguments =
           List.of(new SpaceExploreOrderArgument(Optional.of(spaceIdRequest.attribute())));
-      this.filterArguments = emptyList();
       this.groupByAttributeRequests = Set.of(spaceIdRequest);
-      this.timeInterval = Optional.empty();
-      this.includeRest = false;
-      this.spaceId = Optional.empty();
     }
   }