Cache (redis)

The cache package provides an interface and implementation for caching data using Redis. This document explains how to use the cache package and its methods.

Base on redis/go-redis: Redis Go client (github.com)

Counters, locks and cache-aside

ICache covers get, set and delete. Everything else — CacheRemember, counters, distributed locks, delete-by-prefix, and the in-memory and disabled backends — is on Cache Helpers & Locks.

Interface

type ICache interface {
	Set(key string, value interface{}, expiration time.Duration) error
	SetJSON(key string, value interface{}, expiration time.Duration) error
	Get(dest interface{}, key string) error
	GetJSON(dest interface{}, key string) error
	Del(key string) error
	Client() *redis.Client
	Close()
}

Usage

Update .env

CACHE_HOST=xxxxx
CACHE_PORT=6379

To create a new cache instance

// APIRun is the main function to start the application.
func APIRun() {
  env := core.NewEnv()
  
  // Connect to Redis
  redis, err := core.NewCache(env.Config()).Connect() 
  if err != nil {
    fmt.Fprintf(os.Stderr, "redis: %v", err)
    os.Exit(1)
  }
  
  // Closing the Cache Connection
  defer rdb.Close()
  
  // Create a new HTTP server
  e := core.NewHTTPServer(&core.HTTPContextOptions{
    ContextOptions: &core.ContextOptions{
        Cache:   redis,
        ENV:     env,
      },
  })
  
  // Register HTTP handlers
  home.NewHomeHTTP(e)
  
  // Start the HTTP server
  core.StartHTTPServer(e, env)
}

Setting a Key-Value Pair

To set a key-value pair in the cache, use the Set method:

func (c cache) Set(key string, value interface{}, expiration time.Duration) error

Example:

err := ctx.Cache().Set("mykey", "myvalue", time.Hour)
if err != nil {
    // handle error
}

Getting a Value by Key

To retrieve a value from the cache by its key, use the Get method:

func (c cache) Get(dest interface{}, key string) error

Example:

var value string
err := ctx.Cache().Get(&value, "mykey")
if err != nil {
    // handle error
}
fmt.Println(value)

Deleting a Key

To delete a key from the cache, use the Del method:

func (c cache) Del(key string) error

Example:

err := ctx.Cache().Del("mykey")
if err != nil {
    // handle error
}

Setting a JSON Value

To set a JSON value in the cache, use the SetJSON method:

func (c cache) SetJSON(key string, value interface{}, expiration time.Duration) error

Example:

data := struct {
    Name string `json:"name"`
}{
    Name: "John Doe",
}

err := ctx.Cache().SetJSON("myjson", data, time.Hour)
if err != nil {
    // handle error
}

Getting a JSON Value

To retrieve a JSON value from the cache, use the GetJSON method:

func (c cache) GetJSON(dest interface{}, key string) error

Example:

var data struct {
    Name string `json:"name"`
}

err := ctx.Cache().GetJSON(&data, "myjson")
if err != nil {
    // handle error
}
fmt.Println(data.Name)

Conclusion

This document explained how to use the cache package to interact with Redis for caching data. Use the provided methods to set, get, and delete key-value pairs, as well as JSON values, in the cache. Don't forget to close