jokes-bapak2/api/core/joke/getter.go

128 lines
3.8 KiB
Go

package joke
import (
"context"
"encoding/hex"
"errors"
"fmt"
"io"
"log"
"math/rand"
"strconv"
"time"
"github.com/allegro/bigcache/v3"
"github.com/go-redis/redis/v8"
"github.com/minio/minio-go/v7"
)
// GetRandomJoke will acquire a random joke from the bucket.
func GetRandomJoke(ctx context.Context, bucket *minio.Client, cache *redis.Client, memory *bigcache.BigCache) (image []byte, contentType string, err error) {
totalJokes, err := GetTotalJoke(ctx, bucket, cache, memory)
if err != nil {
return []byte{}, "", fmt.Errorf("getting total joke: %w", err)
}
randomIndex := rand.Intn(totalJokes - 1)
joke, contentType, err := GetJokeByID(ctx, bucket, cache, memory, randomIndex)
if err != nil {
return []byte{}, "", fmt.Errorf("getting joke by id: %w", err)
}
return joke, contentType, nil
}
// GetJokeByID will acquire a joke by its' ID.
//
// An ID is defined as the index on the joke list that is sorted
// by it's creation (or modification) time.
func GetJokeByID(ctx context.Context, bucket *minio.Client, cache *redis.Client, memory *bigcache.BigCache, id int) (image []byte, contentType string, err error) {
jokeFromMemory, err := memory.Get("id:" + strconv.Itoa(id))
if err != nil && !errors.Is(err, bigcache.ErrEntryNotFound) {
return []byte{}, "", fmt.Errorf("acquiring joke from memory: %w", err)
}
if err == nil {
contentTypeFromMemory, err := memory.Get("id:" + strconv.Itoa(id) + ":content-type")
if err != nil && !errors.Is(err, bigcache.ErrEntryNotFound) {
return []byte{}, "", fmt.Errorf("acquiring joke content type from memory: %w", err)
}
return jokeFromMemory, string(contentTypeFromMemory), nil
}
jokeFromCache, err := cache.Get(ctx, "jokes:id:"+strconv.Itoa(id)).Result()
if err != nil && !errors.Is(err, redis.Nil) {
return []byte{}, "", fmt.Errorf("acquiring joke from cache: %w", err)
}
if err == nil {
// Get content type
contentTypeFromCache, err := cache.Get(ctx, "jokes:id:"+strconv.Itoa(id)+":content-type").Result()
if err != nil && !errors.Is(err, redis.Nil) {
return []byte{}, "", fmt.Errorf("acquiring content type from cache: %w", err)
}
// Decode hex string to bytes
imageBytes, err := hex.DecodeString(jokeFromCache)
if err != nil {
return []byte{}, "", fmt.Errorf("decoding hex string: %w", err)
}
defer func(id int, imageBytes []byte) {
err := memory.Set("id:"+strconv.Itoa(id), imageBytes)
if err != nil {
log.Printf("setting memory cache: %s", err.Error())
}
err = memory.Set("id:"+strconv.Itoa(id)+":content-type", []byte(contentTypeFromCache))
if err != nil {
log.Printf("setting memory cache: %s", err.Error())
}
}(id, imageBytes)
return imageBytes, contentTypeFromCache, nil
}
jokes, err := ListJokesFromBucket(ctx, bucket, cache)
if err != nil {
return []byte{}, "", fmt.Errorf("listing jokes: %w", err)
}
object, err := bucket.GetObject(ctx, JokesBapak2Bucket, jokes[id].FileName, minio.GetObjectOptions{})
if err != nil {
return []byte{}, "", fmt.Errorf("getting object: %w", err)
}
defer func() {
err := object.Close()
if err != nil {
log.Printf("closing image reader: %s", err.Error())
}
}()
image, err = io.ReadAll(object)
if err != nil {
return []byte{}, "", fmt.Errorf("reading object: %w", err)
}
defer func(id int, image []byte) {
ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
defer cancel()
imageString := hex.EncodeToString(image)
err := cache.Set(ctx, "jokes:id:"+strconv.Itoa(id), imageString, time.Hour*1).Err()
if err != nil {
log.Printf("setting cache: %s", err.Error())
}
err = cache.Set(ctx, "jokes:id:"+strconv.Itoa(id)+":content-type", jokes[id].ContentType, time.Hour*1).Err()
if err != nil {
log.Printf("setting cache: %s", err.Error())
}
}(id, image)
return image, jokes[id].ContentType, nil
}