example

Documentation

Index

• type User
• type UserLoader
  • func NewLoader() *UserLoader
  • func NewUserLoader(config UserLoaderConfig) *UserLoader
  • func (l *UserLoader) Clear(key string)
  • func (l *UserLoader) Load(key string) (*User, error)
  • func (l *UserLoader) LoadAll(keys []string) ([]*User, []error)
  • func (l *UserLoader) LoadAllThunk(keys []string) func() ([]*User, []error)
  • func (l *UserLoader) LoadThunk(key string) func() (*User, error)
  • func (l *UserLoader) Prime(key string, value *User) bool
• type UserLoaderConfig

Types

type User

type User struct {
	ID   string
	Name string
}

User is some kind of database backed model

type UserLoader

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

UserLoader batches and caches requests

func NewLoader

func NewLoader() *UserLoader

NewLoader will collect user requests for 2 milliseconds and send them as a single batch to the fetch func normally fetch would be a database call.

func NewUserLoader

func NewUserLoader(config UserLoaderConfig) *UserLoader

NewUserLoader creates a new UserLoader given a fetch, wait, and maxBatch

func (*UserLoader) Clear

func (l *UserLoader) Clear(key string)

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

func (*UserLoader) Load

func (l *UserLoader) Load(key string) (*User, error)

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

func (*UserLoader) LoadAll

func (l *UserLoader) LoadAll(keys []string) ([]*User, []error)

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

func (*UserLoader) LoadAllThunk

func (l *UserLoader) LoadAllThunk(keys []string) func() ([]*User, []error)

LoadAllThunk returns a function that when called will block waiting for a Users. 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 (*UserLoader) LoadThunk

func (l *UserLoader) LoadThunk(key string) func() (*User, error)

LoadThunk returns a function that when called will block waiting for a User. 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 (*UserLoader) Prime

func (l *UserLoader) Prime(key string, value *User) 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 UserLoaderConfig

type UserLoaderConfig struct {
	// Fetch is a method that provides the data for the loader
	Fetch func(keys []string) ([]*User, []error)

	// Wait is how long wait before sending a batch
	Wait time.Duration

	// MaxBatch will limit the maximum number of keys to send in one batch, 0 = not limit
	MaxBatch int
}

UserLoaderConfig captures the config to create a new UserLoader