1 files changed, 161 insertions, 0 deletions
diff --git a/modules/cache/cache_redis.go b/modules/cache/cache_redis.go
new file mode 100644
index 0000000..4c243b2
--- /dev/null
+++ b/modules/cache/cache_redis.go
@@ -0,0 +1,161 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package cache
+
+import (
+	"fmt"
+	"strconv"
+	"time"
+
+	"code.gitea.io/gitea/modules/graceful"
+	"code.gitea.io/gitea/modules/nosql"
+
+	"code.forgejo.org/go-chi/cache"
+)
+
+// RedisCacher represents a redis cache adapter implementation.
+type RedisCacher struct {
+	c          nosql.RedisClient
+	prefix     string
+	hsetName   string
+	occupyMode bool
+}
+
+// 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
+	}
+}
+
+// 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()
+}
+
+// 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
+}
+
+// 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()
+}
+
+// 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()
+}
+
+// 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{})
+}