refactor: move go-chi/cache into Gitea (#39530)

The `gitea.com/go-chi/cache` package only exists for Gitea, so it moves
into `modules/cache`.

- `ITEM_TTL = -1` disables caching as documented
- Sub-second TTLs round up instead of never expiring
- The Redis adapter no longer grows a `MacaronCache` hash
- Use two-queue cache for in-memory cache

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/cache/cache_redis.go

@@ -4,159 +4,44 @@
 package cache
 
 import (
-	"fmt"
-	"strconv"
 	"time"
 
 	"gitea.dev/modules/graceful"
 	"gitea.dev/modules/nosql"
 
-	"gitea.com/go-chi/cache" //nolint:depguard // we wrap this package here
 	"github.com/redis/go-redis/v9"
 )
 
-// RedisCacher represents a redis cache adapter implementation.
-type RedisCacher struct {
-	c          redis.UniversalClient
-	prefix     string
-	hsetName   string
-	occupyMode bool
+type redisCache struct {
+	client redis.UniversalClient
+	prefix string
 }
 
-// toStr convert string/int/int64 interface to string. it's only used by the RedisCacher.Put internally
-func toStr(v any) string {
-	if v == nil {
-		return ""
-	}
-	switch v := v.(type) {
-	case string:
-		return v
-	case []byte:
-		return string(v)
-	case int:
-		return strconv.FormatInt(int64(v), 10)
-	case int64:
-		return strconv.FormatInt(v, 10)
-	default:
-		return fmt.Sprint(v) // as what the old com.ToStr does in most cases
+func newRedisCache(conn string) backend {
+	uri := nosql.ToRedisURI(conn)
+	return &redisCache{
+		client: nosql.GetManager().GetRedisClient(uri.String()),
+		prefix: uri.Query().Get("prefix"),
 	}
 }
 
-// Put puts value (string type) into cache with key and expire time.
-// If expired is 0, it lives forever.
-func (c *RedisCacher) Put(key string, val any, expire int64) error {
-	// this function is not well-designed, it only puts string values into cache
-	key = c.prefix + key
-	if expire == 0 {
-		if err := c.c.Set(graceful.GetManager().HammerContext(), key, toStr(val), 0).Err(); err != nil {
-			return err
-		}
-	} else {
-		dur := time.Duration(expire) * time.Second
-		if err := c.c.Set(graceful.GetManager().HammerContext(), key, toStr(val), dur).Err(); err != nil {
-			return err
-		}
-	}
-
-	if c.occupyMode {
-		return nil
-	}
-	return c.c.HSet(graceful.GetManager().HammerContext(), c.hsetName, key, "0").Err()
+func (c *redisCache) Get(key string) (string, bool) {
+	value, err := c.client.Get(graceful.GetManager().HammerContext(), c.prefix+key).Result()
+	return value, err == nil
 }
 
-// Get gets cached value by given key.
-func (c *RedisCacher) Get(key string) any {
-	val, err := c.c.Get(graceful.GetManager().HammerContext(), c.prefix+key).Result()
-	if err != nil {
-		return nil
-	}
-	return val
+func (c *redisCache) Put(key, value string, ttl int64) error {
+	return c.client.Set(graceful.GetManager().HammerContext(), c.prefix+key, value, time.Duration(ttl)*time.Second).Err()
 }
 
-// Delete deletes cached value by given key.
-func (c *RedisCacher) Delete(key string) error {
-	key = c.prefix + key
-	if err := c.c.Del(graceful.GetManager().HammerContext(), key).Err(); err != nil {
-		return err
-	}
-
-	if c.occupyMode {
-		return nil
-	}
-	return c.c.HDel(graceful.GetManager().HammerContext(), c.hsetName, key).Err()
+func (c *redisCache) Delete(key string) error {
+	return c.client.Del(graceful.GetManager().HammerContext(), c.prefix+key).Err()
 }
 
-// Incr increases cached int-type value by given key as a counter.
-func (c *RedisCacher) Incr(key string) error {
-	if !c.IsExist(key) {
-		return fmt.Errorf("key '%s' not exist", key)
-	}
-	return c.c.Incr(graceful.GetManager().HammerContext(), c.prefix+key).Err()
+func (c *redisCache) IsExist(key string) bool {
+	return c.client.Exists(graceful.GetManager().HammerContext(), c.prefix+key).Val() == 1
 }
 
-// Decr decreases cached int-type value by given key as a counter.
-func (c *RedisCacher) Decr(key string) error {
-	if !c.IsExist(key) {
-		return fmt.Errorf("key '%s' not exist", key)
-	}
-	return c.c.Decr(graceful.GetManager().HammerContext(), c.prefix+key).Err()
-}
-
-// IsExist returns true if cached value exists.
-func (c *RedisCacher) IsExist(key string) bool {
-	if c.c.Exists(graceful.GetManager().HammerContext(), c.prefix+key).Val() == 1 {
-		return true
-	}
-
-	if !c.occupyMode {
-		c.c.HDel(graceful.GetManager().HammerContext(), c.hsetName, c.prefix+key)
-	}
-	return false
-}
-
-// Flush deletes all cached data.
-func (c *RedisCacher) Flush() error {
-	if c.occupyMode {
-		return c.c.FlushDB(graceful.GetManager().HammerContext()).Err()
-	}
-
-	keys, err := c.c.HKeys(graceful.GetManager().HammerContext(), c.hsetName).Result()
-	if err != nil {
-		return err
-	}
-	if err = c.c.Del(graceful.GetManager().HammerContext(), keys...).Err(); err != nil {
-		return err
-	}
-	return c.c.Del(graceful.GetManager().HammerContext(), c.hsetName).Err()
-}
-
-// StartAndGC starts GC routine based on config string settings.
-// AdapterConfig: network=tcp,addr=:6379,password=macaron,db=0,pool_size=100,idle_timeout=180,hset_name=MacaronCache,prefix=cache:
-func (c *RedisCacher) StartAndGC(opts cache.Options) error {
-	c.hsetName = "MacaronCache"
-	c.occupyMode = opts.OccupyMode
-
-	uri := nosql.ToRedisURI(opts.AdapterConfig)
-
-	c.c = nosql.GetManager().GetRedisClient(uri.String())
-
-	for k, v := range uri.Query() {
-		switch k {
-		case "hset_name":
-			c.hsetName = v[0]
-		case "prefix":
-			c.prefix = v[0]
-		}
-	}
-
-	return c.c.Ping(graceful.GetManager().HammerContext()).Err()
-}
-
-// Ping tests if the cache is alive.
-func (c *RedisCacher) Ping() error {
-	return c.c.Ping(graceful.GetManager().HammerContext()).Err()
-}
-
-func init() {
-	cache.Register("redis", &RedisCacher{})
+func (c *redisCache) Ping() error {
+	return c.client.Ping(graceful.GetManager().HammerContext()).Err()
 }