cache

README

Cache

Usage Example

package main

import (
	"context"
	"log"
	"time"

	"github.com/redis/go-redis/v9"

	"github.com/go-kratos-ecosystem/components/v2/cache"
	redisStore "github.com/go-kratos-ecosystem/components/v2/cache/redis"
)

var ctx = context.Background()

type User struct {
	Name string
	Age  int
}

func main() {
	// 创建个 Redis 连接客户端
	rdb := redis.NewClient(&redis.Options{
		Addr: "localhost:6379",
	})
	defer rdb.Close()

	// create a redis store
	store := redisStore.New(rdb, redisStore.Prefix("example:cache"))

	// create a cache repository
	repository := cache.NewRepository(store)

	// set cache
	ok, err := repository.Set(ctx, "key", User{
		Name: "example",
		Age:  18,
	}, time.Second*10)
	if err != nil {
		log.Fatal(err)
	}
	_ = ok

	// get cache
	var user User
	err = repository.Get(ctx, "key", &user)
	if err != nil {
		log.Fatal(err)
	}

	log.Printf("user: %+v", user)
}

Documentation

Index

• Variables
• type Addable
• type Locker
• type Manager
  • func NewManager(repository Repository) *Manager
  • func (m *Manager) Driver(names ...string) Repository
  • func (m *Manager) Register(name string, repository Repository)
• type NullStore
  • func (n *NullStore) Decrement(context.Context, string, int) (int, error)
  • func (n *NullStore) Flush(context.Context) (bool, error)
  • func (n *NullStore) Forever(context.Context, string, any) (bool, error)
  • func (n *NullStore) Forget(context.Context, string) (bool, error)
  • func (n *NullStore) Get(context.Context, string, any) error
  • func (n *NullStore) GetPrefix() string
  • func (n *NullStore) Has(context.Context, string) (bool, error)
  • func (n *NullStore) Increment(context.Context, string, int) (int, error)
  • func (n *NullStore) Lock(string, time.Duration) locker.Locker
  • func (n *NullStore) Put(context.Context, string, any, time.Duration) (bool, error)
• type Repository
  • func NewRepository(store Store) Repository
• type Snapshot
  • func (s *Snapshot[K, V]) Lookup(key K, fn func() V) V
• type SnapshotWithErr
  • func (c *SnapshotWithErr[K, V]) Lookup(key K, fn func() (V, error)) (V, error)
• type Store

Variables

var ErrNotFound = errors.New("cache: the key is not found")

Types

type Addable

type Addable interface {
	// Add stores the value into the cache with an expiration time if the key does not exist.
	// If the key exists, the return value will be false, and the return error will be nil.
	// If the key does not exist, the return value will be true, and the return error will be nil.
	// otherwise, the return error will be the store error.
	Add(ctx context.Context, key string, value any, ttl time.Duration) (bool, error)
}

type Locker

type Locker interface {
	Lock(key string, ttl time.Duration) locker.Locker
}

type Manager

type Manager struct {
	Repository
	// contains filtered or unexported fields
}

func NewManager

func NewManager(repository Repository) *Manager

func (*Manager) Driver

func (m *Manager) Driver(names ...string) Repository

func (*Manager) Register

func (m *Manager) Register(name string, repository Repository)

type NullStore

type NullStore struct{}

func (*NullStore) Decrement

func (n *NullStore) Decrement(context.Context, string, int) (int, error)

func (*NullStore) Flush

func (n *NullStore) Flush(context.Context) (bool, error)

func (*NullStore) Forever

func (n *NullStore) Forever(context.Context, string, any) (bool, error)

func (*NullStore) Forget

func (n *NullStore) Forget(context.Context, string) (bool, error)

func (*NullStore) Get

func (n *NullStore) Get(context.Context, string, any) error

func (*NullStore) GetPrefix

func (n *NullStore) GetPrefix() string

func (*NullStore) Has

func (n *NullStore) Has(context.Context, string) (bool, error)

func (*NullStore) Increment

func (n *NullStore) Increment(context.Context, string, int) (int, error)

func (*NullStore) Lock

func (n *NullStore) Lock(string, time.Duration) locker.Locker

func (*NullStore) Put

func (n *NullStore) Put(context.Context, string, any, time.Duration) (bool, error)

type Repository

type Repository interface {
	Store
	Addable

	Missing(ctx context.Context, key string) (bool, error)
	Delete(ctx context.Context, key string) (bool, error)
	Set(ctx context.Context, key string, value any, ttl time.Duration) (bool, error)
}

func NewRepository

func NewRepository(store Store) Repository

type Snapshot

type Snapshot[K comparable, V any] struct {
	// contains filtered or unexported fields
}

func (*Snapshot[K, V]) Lookup

func (s *Snapshot[K, V]) Lookup(key K, fn func() V) V

type SnapshotWithErr

type SnapshotWithErr[K comparable, V any] Snapshot[K, valueWithError[V]]

func (*SnapshotWithErr[K, V]) Lookup

func (c *SnapshotWithErr[K, V]) Lookup(key K, fn func() (V, error)) (V, error)

type Store

type Store interface {
	Locker

	// Has returns true if the key exists in the cache.
	// If the key does not exist, the return value will be false, and the return error will be nil.
	// If the key exists, the return value will be true, and the return error will be nil.
	// otherwise, the return error will be the store error.
	Has(ctx context.Context, key string) (bool, error)

	// Get retrieves the value from the cache.
	// If the key does not exist, the dest will be unchanged, and the return error will be ErrNotFound.
	// If the key exists, the value will be unmarshaled to dest, and the return error will be nil.
	// otherwise, the return error will be the store error.
	Get(ctx context.Context, key string, dest any) error

	// Put stores the value into the cache with an expiration time.
	// If put success, the return value will be true, and the return error will be nil.
	// otherwise, the return value will be false, and the return error will be the store error.
	Put(ctx context.Context, key string, value any, ttl time.Duration) (bool, error)

	// Increment increments the value in the cache.
	// If the key does not exist, the before default value is 0.
	Increment(ctx context.Context, key string, value int) (int, error)

	// Decrement decrements the value in the cache.
	// If the key does not exist, the before default value is 0.
	Decrement(ctx context.Context, key string, value int) (int, error)

	Forever(ctx context.Context, key string, value any) (bool, error)

	Forget(ctx context.Context, key string) (bool, error)

	Flush(ctx context.Context) (bool, error)

	GetPrefix() string
}