catmullet/Raithe

package cache

import (
    "fmt"
    "github.com/go-redis/redis"
    "os"
    "strconv"
    "time"
)

var redisClient *redis.Client

// InitializeRedisClient Initializes the Redis Client from Environment variables.
func InitializeRedisClient() {
    db, err := strconv.Atoi(os.Getenv("REDIS_DB"))

    if err != nil {
        fmt.Println("Failed to Get Redis DB Environment Variable.  Defaulting to 0")
        db = 0
    }

    redisClient = redis.NewClient(&redis.Options{
        Addr:     os.Getenv("REDIS_URL"),
        Password: os.Getenv("REDIS_PASSWORD"),
        DB:       db,
    })

    ping, err := redisClient.Ping().Result()

    if err != nil {
        fmt.Println("Failed to Initialize Redis, " + ping)
    }
}

// Set Writes a message to file
func Set(key string, message []byte) error {
    return writeFile(key, message)
}

// SetAgents Sets Agents on Redis
func SetAgents(key string, message []byte) error {
    r := redisClient.Set(fmt.Sprintf("%v", key), message, 0)
    return r.Err()
}

// Get Retrieves a message from file
func Get(queue string) ([]byte, error) {
    return readFile(queue)
}

// GetAgents Retrieves registered agents from Redis
func GetAgents(key string) ([]byte, error) {

    msg := []byte(redisClient.Get(key).Val())

    return msg, nil
}

// InvalidateAgents Invalidates Agents
func InvalidateAgents(key string) error {
    r := redisClient.Set(fmt.Sprintf("%v", key), []byte{}, 120*time.Hour)
    return r.Err()
}

func writeFile(key string, message []byte) error {
    r := redisClient.Set(fmt.Sprintf("%v_%v", key, makeTimestamp()), message, 48*time.Hour)
    return r.Err()
}

func readFile(key string) ([]byte, error) {
    iter := redisClient.Scan(0, key+"_*", 1).Iterator()
    iter.Next()

    msg := []byte{}

    if iter.Err() != nil {
        return msg, iter.Err()
    }

    msg = []byte(redisClient.Get(iter.Val()).Val())

    redisClient.Del(iter.Val())

    return msg, nil
}

func makeTimestamp() int64 {
    return time.Now().UnixNano() / int64(time.Millisecond)
}