dataloader

README

dataloader

This example uses dataloaden to avoiding n+1 queries.

There is also nicksrandall/dataloader if you wanted to avoid doing more codegeneration.

Documentation

Index

• func LoaderMiddleware(next http.Handler) http.Handler
• func NewExecutableSchema(cfg Config) graphql.ExecutableSchema
• type Address
• type AddressLoader
  • func (l *AddressLoader) Clear(key int)
  • func (l *AddressLoader) Load(key int) (*Address, error)
  • func (l *AddressLoader) LoadAll(keys []int) ([]*Address, []error)
  • func (l *AddressLoader) LoadThunk(key int) func() (*Address, error)
  • func (l *AddressLoader) Prime(key int, value *Address) bool
• type Config
• type Customer
• type CustomerResolver
• type DirectiveRoot
• type Item
• type ItemSliceLoader
  • func (l *ItemSliceLoader) Clear(key int)
  • func (l *ItemSliceLoader) Load(key int) ([]Item, error)
  • func (l *ItemSliceLoader) LoadAll(keys []int) ([][]Item, []error)
  • func (l *ItemSliceLoader) LoadThunk(key int) func() ([]Item, error)
  • func (l *ItemSliceLoader) Prime(key int, value []Item) bool
• type Order
• type OrderResolver
• type OrderSliceLoader
  • func (l *OrderSliceLoader) Clear(key int)
  • func (l *OrderSliceLoader) Load(key int) ([]Order, error)
  • func (l *OrderSliceLoader) LoadAll(keys []int) ([][]Order, []error)
  • func (l *OrderSliceLoader) LoadThunk(key int) func() ([]Order, error)
  • func (l *OrderSliceLoader) Prime(key int, value []Order) bool
• type QueryResolver
• type Resolver
  • func (r *Resolver) Customer() CustomerResolver
  • func (r *Resolver) Order() OrderResolver
  • func (r *Resolver) Query() QueryResolver
• type ResolverRoot

Functions

func LoaderMiddleware

func LoaderMiddleware(next http.Handler) http.Handler

func NewExecutableSchema

func NewExecutableSchema(cfg Config) graphql.ExecutableSchema

NewExecutableSchema creates an ExecutableSchema from the ResolverRoot interface.

Types

type Address

type Address struct {
	ID      int    `json:"id"`
	Street  string `json:"street"`
	Country string `json:"country"`
}

type AddressLoader

type AddressLoader struct {
	// contains filtered or unexported fields
}

AddressLoader batches and caches requests

func (*AddressLoader) Clear

func (l *AddressLoader) Clear(key int)

Clear the value at key from the cache, if it exists

func (*AddressLoader) Load

func (l *AddressLoader) Load(key int) (*Address, error)

Load a address by key, batching and caching will be applied automatically

func (*AddressLoader) LoadAll

func (l *AddressLoader) LoadAll(keys []int) ([]*Address, []error)

LoadAll fetches many keys at once. It will be broken into appropriate sized sub batches depending on how the loader is configured

func (*AddressLoader) LoadThunk

func (l *AddressLoader) LoadThunk(key int) func() (*Address, error)

LoadThunk returns a function that when called will block waiting for a address. This method should be used if you want one goroutine to make requests to many different data loaders without blocking until the thunk is called.

func (*AddressLoader) Prime

func (l *AddressLoader) Prime(key int, value *Address) bool

Prime the cache with the provided key and value. If the key already exists, no change is made and false is returned. (To forcefully prime the cache, clear the key first with loader.clear(key).prime(key, value).)

type Config

type Config struct {
	Resolvers  ResolverRoot
	Directives DirectiveRoot
}

type Customer

type Customer struct {
	ID        int    `json:"id"`
	Name      string `json:"name"`
	AddressID int
}

type CustomerResolver

type CustomerResolver interface {
	Address(ctx context.Context, obj *Customer) (*Address, error)
	Orders(ctx context.Context, obj *Customer) ([]Order, error)
}

type DirectiveRoot

type DirectiveRoot struct {
}

type Item

type Item struct {
	Name string `json:"name"`
}

type ItemSliceLoader

type ItemSliceLoader struct {
	// contains filtered or unexported fields
}

ItemSliceLoader batches and caches requests

func (*ItemSliceLoader) Clear

func (l *ItemSliceLoader) Clear(key int)

Clear the value at key from the cache, if it exists

func (*ItemSliceLoader) Load

func (l *ItemSliceLoader) Load(key int) ([]Item, error)

Load a item by key, batching and caching will be applied automatically

func (*ItemSliceLoader) LoadAll

func (l *ItemSliceLoader) LoadAll(keys []int) ([][]Item, []error)

LoadAll fetches many keys at once. It will be broken into appropriate sized sub batches depending on how the loader is configured

func (*ItemSliceLoader) LoadThunk

func (l *ItemSliceLoader) LoadThunk(key int) func() ([]Item, error)

LoadThunk returns a function that when called will block waiting for a item. This method should be used if you want one goroutine to make requests to many different data loaders without blocking until the thunk is called.

func (*ItemSliceLoader) Prime

func (l *ItemSliceLoader) Prime(key int, value []Item) bool

Prime the cache with the provided key and value. If the key already exists, no change is made and false is returned. (To forcefully prime the cache, clear the key first with loader.clear(key).prime(key, value).)

type Order

type Order struct {
	ID     int       `json:"id"`
	Date   time.Time `json:"date"`
	Amount float64   `json:"amount"`
}

type OrderResolver

type OrderResolver interface {
	Items(ctx context.Context, obj *Order) ([]Item, error)
}

type OrderSliceLoader

type OrderSliceLoader struct {
	// contains filtered or unexported fields
}

OrderSliceLoader batches and caches requests

func (*OrderSliceLoader) Clear

func (l *OrderSliceLoader) Clear(key int)

Clear the value at key from the cache, if it exists

func (*OrderSliceLoader) Load

func (l *OrderSliceLoader) Load(key int) ([]Order, error)

Load a order by key, batching and caching will be applied automatically

func (*OrderSliceLoader) LoadAll

func (l *OrderSliceLoader) LoadAll(keys []int) ([][]Order, []error)

LoadAll fetches many keys at once. It will be broken into appropriate sized sub batches depending on how the loader is configured

func (*OrderSliceLoader) LoadThunk

func (l *OrderSliceLoader) LoadThunk(key int) func() ([]Order, error)

LoadThunk returns a function that when called will block waiting for a order. This method should be used if you want one goroutine to make requests to many different data loaders without blocking until the thunk is called.

func (*OrderSliceLoader) Prime

func (l *OrderSliceLoader) Prime(key int, value []Order) bool

Prime the cache with the provided key and value. If the key already exists, no change is made and false is returned. (To forcefully prime the cache, clear the key first with loader.clear(key).prime(key, value).)

type QueryResolver

type QueryResolver interface {
	Customers(ctx context.Context) ([]Customer, error)
	Torture1d(ctx context.Context, customerIds []int) ([]Customer, error)
	Torture2d(ctx context.Context, customerIds [][]int) ([][]Customer, error)
}

type Resolver

type Resolver struct{}

func (*Resolver) Customer

func (r *Resolver) Customer() CustomerResolver

func (*Resolver) Order

func (r *Resolver) Order() OrderResolver

func (*Resolver) Query

func (r *Resolver) Query() QueryResolver

type ResolverRoot

type ResolverRoot interface {
	Customer() CustomerResolver
	Order() OrderResolver
	Query() QueryResolver
}