graph,graphql,store: nested sorting

docs/environment-variables.md

@@ -126,6 +126,9 @@ those.
 - `GRAPH_GRAPHQL_DISABLE_BOOL_FILTERS`: disables the ability to use AND/OR
   filters. This is useful if we want to disable filters because of
   performance reasons.
+- `GRAPH_GRAPHQL_DISABLE_CHILD_SORTING`: disables the ability to use child-based
+  sorting. This is useful if we want to disable child-based sorting because of
+  performance reasons.
 - `GRAPH_GRAPHQL_TRACE_TOKEN`: the token to use to enable query tracing for
   a GraphQL request. If this is set, requests that have a header
   `X-GraphTraceQuery` set to this value will include a trace of the SQL

graph/src/components/store/mod.rs

@@ -280,13 +280,35 @@ impl EntityFilter {
     }
 }
 
+/// Holds the information needed to query a store.
+#[derive(Clone, Debug, PartialEq)]
+pub struct EntityOrderByChildInfo {
+    /// The attribute of the child entity that is used to order the results.
+    pub sort_by_attribute: Attribute,
+    /// The attribute that is used to join to the parent and child entity.
+    pub join_attribute: Attribute,
+    /// If true, the child entity is derived from the parent entity.
+    pub derived: bool,
+}
+
+/// Holds the information needed to order the results of a query based on nested entities.
+#[derive(Clone, Debug, PartialEq)]
+pub enum EntityOrderByChild {
+    Object(EntityOrderByChildInfo, EntityType),
+    Interface(EntityOrderByChildInfo, Vec<EntityType>),
+}
+
 /// The order in which entities should be restored from a store.
 #[derive(Clone, Debug, PartialEq)]
 pub enum EntityOrder {
     /// Order ascending by the given attribute. Use `id` as a tie-breaker
     Ascending(String, ValueType),
     /// Order descending by the given attribute. Use `id` as a tie-breaker
     Descending(String, ValueType),
+    /// Order ascending by the given attribute of a child entity. Use `id` as a tie-breaker
+    ChildAscending(EntityOrderByChild),
+    /// Order descending by the given attribute of a child entity. Use `id` as a tie-breaker
+    ChildDescending(EntityOrderByChild),
     /// Order by the `id` of the entities
     Default,
     /// Do not order at all. This speeds up queries where we know that

graph/src/env/graphql.rs

@@ -87,6 +87,9 @@ pub struct EnvVarsGraphQl {
     /// Set by the flag `GRAPH_GRAPHQL_DISABLE_BOOL_FILTERS`. Off by default.
     /// Disables AND/OR filters
     pub disable_bool_filters: bool,
+    /// Set by the flag `GRAPH_GRAPHQL_DISABLE_CHILD_SORTING`. Off by default.
+    /// Disables child-based sorting
+    pub disable_child_sorting: bool,
     /// Set by `GRAPH_GRAPHQL_TRACE_TOKEN`, the token to use to enable query
     /// tracing for a GraphQL request. If this is set, requests that have a
     /// header `X-GraphTraceQuery` set to this value will include a trace of
@@ -137,6 +140,7 @@ impl From<InnerGraphQl> for EnvVarsGraphQl {
             error_result_size: x.error_result_size.0 .0,
             max_operations_per_connection: x.max_operations_per_connection,
             disable_bool_filters: x.disable_bool_filters.0,
+            disable_child_sorting: x.disable_child_sorting.0,
             query_trace_token: x.query_trace_token,
         }
     }
@@ -185,6 +189,8 @@ pub struct InnerGraphQl {
     max_operations_per_connection: usize,
     #[envconfig(from = "GRAPH_GRAPHQL_DISABLE_BOOL_FILTERS", default = "false")]
     pub disable_bool_filters: EnvVarBoolean,
+    #[envconfig(from = "GRAPH_GRAPHQL_DISABLE_CHILD_SORTING", default = "false")]
+    pub disable_child_sorting: EnvVarBoolean,
     #[envconfig(from = "GRAPH_GRAPHQL_TRACE_TOKEN", default = "")]
     query_trace_token: String,
 }

graph/src/lib.rs

@@ -122,10 +122,11 @@ pub mod prelude {
     pub use crate::components::store::{
         AttributeNames, BlockNumber, CachedEthereumCall, ChainStore, Child, ChildMultiplicity,
         EntityCache, EntityChange, EntityChangeOperation, EntityCollection, EntityFilter,
-        EntityLink, EntityModification, EntityOperation, EntityOrder, EntityQuery, EntityRange,
-        EntityWindow, EthereumCallCache, ParentLink, PartialBlockPtr, PoolWaitStats, QueryStore,
-        QueryStoreManager, StoreError, StoreEvent, StoreEventStream, StoreEventStreamBox,
-        SubgraphStore, UnfailOutcome, WindowAttribute, BLOCK_NUMBER_MAX,
+        EntityLink, EntityModification, EntityOperation, EntityOrder, EntityOrderByChild,
+        EntityOrderByChildInfo, EntityQuery, EntityRange, EntityWindow, EthereumCallCache,
+        ParentLink, PartialBlockPtr, PoolWaitStats, QueryStore, QueryStoreManager, StoreError,
+        StoreEvent, StoreEventStream, StoreEventStreamBox, SubgraphStore, UnfailOutcome,
+        WindowAttribute, BLOCK_NUMBER_MAX,
     };
     pub use crate::components::subgraph::{
         BlockState, DataSourceTemplateInfo, HostMetrics, RuntimeHost, RuntimeHostBuilder,

graphql/src/schema/api.rs

@@ -1,6 +1,6 @@
 use std::str::FromStr;
 
-use graphql_parser::Pos;
+use graphql_parser::{schema::TypeDefinition, Pos};
 use inflector::Inflector;
 use lazy_static::lazy_static;
 
@@ -157,16 +157,7 @@ fn add_order_by_type(
                 description: None,
                 name: type_name,
                 directives: vec![],
-                values: fields
-                    .iter()
-                    .map(|field| &field.name)
-                    .map(|name| EnumValue {
-                        position: Pos::default(),
-                        description: None,
-                        name: name.to_owned(),
-                        directives: vec![],
-                    })
-                    .collect(),
+                values: field_enum_values(schema, fields)?,
             });
             let def = Definition::TypeDefinition(typedef);
             schema.definitions.push(def);
@@ -176,6 +167,80 @@ fn add_order_by_type(
     Ok(())
 }
 
+/// Generates enum values for the given set of fields.
+fn field_enum_values(
+    schema: &Document,
+    fields: &[Field],
+) -> Result<Vec<EnumValue>, APISchemaError> {
+    let mut enum_values = vec![];
+    for field in fields {
+        enum_values.push(EnumValue {
+            position: Pos::default(),
+            description: None,
+            name: field.name.to_owned(),
+            directives: vec![],
+        });
+        enum_values.extend(field_enum_values_from_child_entity(schema, field)?);
+    }
+    Ok(enum_values)
+}
+
+fn enum_value_from_child_entity_field(
+    schema: &Document,
+    parent_field_name: &str,
+    field: &Field,
+) -> Option<EnumValue> {
+    if ast::is_list_or_non_null_list_field(field) || ast::is_entity_type(schema, &field.field_type)
+    {
+        // Sorting on lists or entities is not supported.
+        None
+    } else {
+        Some(EnumValue {
+            position: Pos::default(),
+            description: None,
+            name: format!("{}__{}", parent_field_name, field.name),
+            directives: vec![],
+        })
+    }
+}
+
+fn field_enum_values_from_child_entity(
+    schema: &Document,
+    field: &Field,
+) -> Result<Vec<EnumValue>, APISchemaError> {
+    fn resolve_supported_type_name(field_type: &Type) -> Option<&String> {
+        match field_type {
+            Type::NamedType(name) => Some(name),
+            Type::ListType(_) => None,
+            Type::NonNullType(of_type) => resolve_supported_type_name(of_type),
+        }
+    }
+
+    let type_name = match ENV_VARS.graphql.disable_child_sorting {
+        true => None,
+        false => resolve_supported_type_name(&field.field_type),
+    };
+
+    Ok(match type_name {
+        Some(name) => {
+            let named_type = schema
+                .get_named_type(name)
+                .ok_or_else(|| APISchemaError::TypeNotFound(name.clone()))?;
+            match named_type {
+                TypeDefinition::Object(ObjectType { fields, .. })
+                | TypeDefinition::Interface(InterfaceType { fields, .. }) => fields
+                    .iter()
+                    .filter_map(|f| {
+                        enum_value_from_child_entity_field(schema, field.name.as_str(), f)
+                    })
+                    .collect(),
+                _ => vec![],
+            }
+        }
+        None => vec![],
+    })
+}
+
 /// Adds a `<type_name>_filter` enum type for the given fields to the schema.
 fn add_filter_type(
     schema: &mut Document,
@@ -887,6 +952,180 @@ mod tests {
         assert_eq!(values, ["id", "name"]);
     }
 
+    #[test]
+    fn api_schema_contains_field_order_by_enum_for_child_entity() {
+        let input_schema = parse_schema(
+            r#"
+              enum FurType {
+                  NONE
+                  FLUFFY
+                  BRISTLY
+              }
+
+              type Pet {
+                  id: ID!
+                  name: String!
+                  mostHatedBy: [User!]!
+                  mostLovedBy: [User!]!
+              }
+
+              interface Recipe {
+                id: ID!
+                name: String!
+                author: User!
+                lovedBy: [User!]!
+                ingredients: [String!]!
+              }
+
+              type FoodRecipe implements Recipe {
+                id: ID!
+                name: String!
+                author: User!
+                ingredients: [String!]!
+              }
+
+              type DrinkRecipe implements Recipe {
+                id: ID!
+                name: String!
+                author: User!
+                ingredients: [String!]!
+              }
+
+              interface Meal {
+                id: ID!
+                name: String!
+                mostHatedBy: [User!]!
+                mostLovedBy: [User!]!
+              }
+
+              type Pizza implements Meal {
+                id: ID!
+                name: String!
+                toppings: [String!]!
+                mostHatedBy: [User!]!
+                mostLovedBy: [User!]!
+              }
+
+              type Burger implements Meal {
+                id: ID!
+                name: String!
+                bun: String!
+                mostHatedBy: [User!]!
+                mostLovedBy: [User!]!
+              }
+
+              type User {
+                  id: ID!
+                  name: String!
+                  favoritePetNames: [String!]
+                  pets: [Pet!]!
+                  favoriteFurType: FurType!
+                  favoritePet: Pet!
+                  leastFavoritePet: Pet @derivedFrom(field: "mostHatedBy")
+                  mostFavoritePets: [Pet!] @derivedFrom(field: "mostLovedBy")
+                  favoriteMeal: Meal!
+                  leastFavoriteMeal: Meal @derivedFrom(field: "mostHatedBy")
+                  mostFavoriteMeals: [Meal!] @derivedFrom(field: "mostLovedBy")
+                  recipes: [Recipe!]! @derivedFrom(field: "author")
+              }
+            "#,
+        )
+        .expect("Failed to parse input schema");
+        let schema = api_schema(&input_schema).expect("Failed to derived API schema");
+
+        let user_order_by = schema
+            .get_named_type("User_orderBy")
+            .expect("User_orderBy type is missing in derived API schema");
+
+        let enum_type = match user_order_by {
+            TypeDefinition::Enum(t) => Some(t),
+            _ => None,
+        }
+        .expect("User_orderBy type is not an enum");
+
+        let values: Vec<&str> = enum_type
+            .values
+            .iter()
+            .map(|value| value.name.as_str())
+            .collect();
+
+        assert_eq!(
+            values,
+            [
+                "id",
+                "name",
+                "favoritePetNames",
+                "pets",
+                "favoriteFurType",
+                "favoritePet",
+                "favoritePet__id",
+                "favoritePet__name",
+                "leastFavoritePet",
+                "leastFavoritePet__id",
+                "leastFavoritePet__name",
+                "mostFavoritePets",
+                "favoriteMeal",
+                "favoriteMeal__id",
+                "favoriteMeal__name",
+                "leastFavoriteMeal",
+                "leastFavoriteMeal__id",
+                "leastFavoriteMeal__name",
+                "mostFavoriteMeals",
+                "recipes",
+            ]
+        );
+
+        let meal_order_by = schema
+            .get_named_type("Meal_orderBy")
+            .expect("Meal_orderBy type is missing in derived API schema");
+
+        let enum_type = match meal_order_by {
+            TypeDefinition::Enum(t) => Some(t),
+            _ => None,
+        }
+        .expect("Meal_orderBy type is not an enum");
+
+        let values: Vec<&str> = enum_type
+            .values
+            .iter()
+            .map(|value| value.name.as_str())
+            .collect();
+
+        assert_eq!(values, ["id", "name", "mostHatedBy", "mostLovedBy",]);
+
+        let recipe_order_by = schema
+            .get_named_type("Recipe_orderBy")
+            .expect("Recipe_orderBy type is missing in derived API schema");
+
+        let enum_type = match recipe_order_by {
+            TypeDefinition::Enum(t) => Some(t),
+            _ => None,
+        }
+        .expect("Recipe_orderBy type is not an enum");
+
+        let values: Vec<&str> = enum_type
+            .values
+            .iter()
+            .map(|value| value.name.as_str())
+            .collect();
+
+        assert_eq!(
+            values,
+            [
+                "id",
+                "name",
+                "author",
+                "author__id",
+                "author__name",
+                "author__favoriteFurType",
+                "author__favoritePet",
+                "author__leastFavoritePet",
+                "lovedBy",
+                "ingredients"
+            ]
+        );
+    }
+
     #[test]
     fn api_schema_contains_object_type_filter_enum() {
         let input_schema = parse_schema(