lan
4d8f2ec997
Set up project files and add .gitignore to exclude local build/runtime artifacts. Made-with: Cursor
605 lines
13 KiB
Go
605 lines
13 KiB
Go
package cache
|
||
|
||
import (
|
||
"context"
|
||
"encoding/json"
|
||
"fmt"
|
||
"log"
|
||
"math/rand"
|
||
"strings"
|
||
"sync"
|
||
"sync/atomic"
|
||
"time"
|
||
|
||
"github.com/redis/go-redis/v9"
|
||
|
||
redisPkg "carrot_bbs/internal/pkg/redis"
|
||
)
|
||
|
||
// Cache 缓存接口
|
||
type Cache interface {
|
||
// Set 设置缓存值，支持TTL
|
||
Set(key string, value interface{}, ttl time.Duration)
|
||
// Get 获取缓存值
|
||
Get(key string) (interface{}, bool)
|
||
// Delete 删除缓存
|
||
Delete(key string)
|
||
// DeleteByPrefix 根据前缀删除缓存
|
||
DeleteByPrefix(prefix string)
|
||
// Clear 清空所有缓存
|
||
Clear()
|
||
// Exists 检查键是否存在
|
||
Exists(key string) bool
|
||
// Increment 增加计数器的值
|
||
Increment(key string) int64
|
||
// IncrementBy 增加指定值
|
||
IncrementBy(key string, value int64) int64
|
||
}
|
||
|
||
// cacheItem 缓存项（用于内存缓存降级）
|
||
type cacheItem struct {
|
||
value interface{}
|
||
expiration int64 // 过期时间戳（纳秒）
|
||
}
|
||
|
||
const nullMarkerValue = "__carrot_cache_null__"
|
||
|
||
type cacheMetrics struct {
|
||
hit atomic.Int64
|
||
miss atomic.Int64
|
||
decodeError atomic.Int64
|
||
setError atomic.Int64
|
||
invalidate atomic.Int64
|
||
}
|
||
|
||
var metrics cacheMetrics
|
||
var loadLocks sync.Map
|
||
|
||
type MetricsSnapshot struct {
|
||
Hit int64
|
||
Miss int64
|
||
DecodeError int64
|
||
SetError int64
|
||
Invalidate int64
|
||
}
|
||
|
||
type Settings struct {
|
||
Enabled bool
|
||
KeyPrefix string
|
||
DefaultTTL time.Duration
|
||
NullTTL time.Duration
|
||
JitterRatio float64
|
||
PostListTTL time.Duration
|
||
ConversationTTL time.Duration
|
||
UnreadCountTTL time.Duration
|
||
GroupMembersTTL time.Duration
|
||
DisableFlushDB bool
|
||
}
|
||
|
||
var settings = Settings{
|
||
Enabled: true,
|
||
DefaultTTL: 30 * time.Second,
|
||
NullTTL: 5 * time.Second,
|
||
JitterRatio: 0.1,
|
||
PostListTTL: 30 * time.Second,
|
||
ConversationTTL: 60 * time.Second,
|
||
UnreadCountTTL: 30 * time.Second,
|
||
GroupMembersTTL: 120 * time.Second,
|
||
DisableFlushDB: true,
|
||
}
|
||
|
||
func Configure(s Settings) {
|
||
settings.Enabled = s.Enabled
|
||
if s.KeyPrefix != "" {
|
||
settings.KeyPrefix = s.KeyPrefix
|
||
}
|
||
if s.DefaultTTL > 0 {
|
||
settings.DefaultTTL = s.DefaultTTL
|
||
}
|
||
if s.NullTTL > 0 {
|
||
settings.NullTTL = s.NullTTL
|
||
}
|
||
if s.JitterRatio > 0 {
|
||
settings.JitterRatio = s.JitterRatio
|
||
}
|
||
if s.PostListTTL > 0 {
|
||
settings.PostListTTL = s.PostListTTL
|
||
}
|
||
if s.ConversationTTL > 0 {
|
||
settings.ConversationTTL = s.ConversationTTL
|
||
}
|
||
if s.UnreadCountTTL > 0 {
|
||
settings.UnreadCountTTL = s.UnreadCountTTL
|
||
}
|
||
if s.GroupMembersTTL > 0 {
|
||
settings.GroupMembersTTL = s.GroupMembersTTL
|
||
}
|
||
settings.DisableFlushDB = s.DisableFlushDB
|
||
}
|
||
|
||
func GetSettings() Settings {
|
||
return settings
|
||
}
|
||
|
||
func normalizeKey(key string) string {
|
||
if settings.KeyPrefix == "" {
|
||
return key
|
||
}
|
||
return settings.KeyPrefix + ":" + key
|
||
}
|
||
|
||
func normalizePrefix(prefix string) string {
|
||
if settings.KeyPrefix == "" {
|
||
return prefix
|
||
}
|
||
return settings.KeyPrefix + ":" + prefix
|
||
}
|
||
|
||
func GetMetricsSnapshot() MetricsSnapshot {
|
||
return MetricsSnapshot{
|
||
Hit: metrics.hit.Load(),
|
||
Miss: metrics.miss.Load(),
|
||
DecodeError: metrics.decodeError.Load(),
|
||
SetError: metrics.setError.Load(),
|
||
Invalidate: metrics.invalidate.Load(),
|
||
}
|
||
}
|
||
|
||
// isExpired 检查是否过期
|
||
func (item *cacheItem) isExpired() bool {
|
||
if item.expiration == 0 {
|
||
return false
|
||
}
|
||
return time.Now().UnixNano() > item.expiration
|
||
}
|
||
|
||
// MemoryCache 内存缓存实现（降级使用）
|
||
type MemoryCache struct {
|
||
items sync.Map
|
||
// cleanupInterval 清理过期缓存的间隔
|
||
cleanupInterval time.Duration
|
||
// stopCleanup 停止清理协程的通道
|
||
stopCleanup chan struct{}
|
||
}
|
||
|
||
// NewMemoryCache 创建内存缓存
|
||
func NewMemoryCache() *MemoryCache {
|
||
c := &MemoryCache{
|
||
cleanupInterval: 1 * time.Minute,
|
||
stopCleanup: make(chan struct{}),
|
||
}
|
||
// 启动后台清理协程
|
||
go c.cleanup()
|
||
return c
|
||
}
|
||
|
||
// Set 设置缓存值
|
||
func (c *MemoryCache) Set(key string, value interface{}, ttl time.Duration) {
|
||
key = normalizeKey(key)
|
||
var expiration int64
|
||
if ttl > 0 {
|
||
expiration = time.Now().Add(ttl).UnixNano()
|
||
}
|
||
c.items.Store(key, &cacheItem{
|
||
value: value,
|
||
expiration: expiration,
|
||
})
|
||
}
|
||
|
||
// Get 获取缓存值
|
||
func (c *MemoryCache) Get(key string) (interface{}, bool) {
|
||
key = normalizeKey(key)
|
||
val, ok := c.items.Load(key)
|
||
if !ok {
|
||
return nil, false
|
||
}
|
||
|
||
item := val.(*cacheItem)
|
||
if item.isExpired() {
|
||
c.items.Delete(key)
|
||
return nil, false
|
||
}
|
||
|
||
return item.value, true
|
||
}
|
||
|
||
// Delete 删除缓存
|
||
func (c *MemoryCache) Delete(key string) {
|
||
key = normalizeKey(key)
|
||
metrics.invalidate.Add(1)
|
||
c.items.Delete(key)
|
||
}
|
||
|
||
// DeleteByPrefix 根据前缀删除缓存
|
||
func (c *MemoryCache) DeleteByPrefix(prefix string) {
|
||
prefix = normalizePrefix(prefix)
|
||
c.items.Range(func(key, value interface{}) bool {
|
||
if keyStr, ok := key.(string); ok {
|
||
if strings.HasPrefix(keyStr, prefix) {
|
||
metrics.invalidate.Add(1)
|
||
c.items.Delete(key)
|
||
}
|
||
}
|
||
return true
|
||
})
|
||
}
|
||
|
||
// Clear 清空所有缓存
|
||
func (c *MemoryCache) Clear() {
|
||
c.items.Range(func(key, value interface{}) bool {
|
||
metrics.invalidate.Add(1)
|
||
c.items.Delete(key)
|
||
return true
|
||
})
|
||
}
|
||
|
||
// Exists 检查键是否存在
|
||
func (c *MemoryCache) Exists(key string) bool {
|
||
_, ok := c.Get(key)
|
||
return ok
|
||
}
|
||
|
||
// Increment 增加计数器的值
|
||
func (c *MemoryCache) Increment(key string) int64 {
|
||
return c.IncrementBy(key, 1)
|
||
}
|
||
|
||
// IncrementBy 增加指定值
|
||
func (c *MemoryCache) IncrementBy(key string, value int64) int64 {
|
||
key = normalizeKey(key)
|
||
for {
|
||
val, ok := c.items.Load(key)
|
||
if !ok {
|
||
// 键不存在，创建新值
|
||
c.items.Store(key, &cacheItem{
|
||
value: value,
|
||
expiration: 0,
|
||
})
|
||
return value
|
||
}
|
||
|
||
item := val.(*cacheItem)
|
||
if item.isExpired() {
|
||
// 已过期，创建新值
|
||
c.items.Store(key, &cacheItem{
|
||
value: value,
|
||
expiration: 0,
|
||
})
|
||
return value
|
||
}
|
||
|
||
// 尝试更新
|
||
currentValue, ok := item.value.(int64)
|
||
if !ok {
|
||
// 类型不匹配，覆盖为新值
|
||
c.items.Store(key, &cacheItem{
|
||
value: value,
|
||
expiration: item.expiration,
|
||
})
|
||
return value
|
||
}
|
||
|
||
newValue := currentValue + value
|
||
// 使用 CAS 操作确保并发安全
|
||
if c.items.CompareAndSwap(key, val, &cacheItem{
|
||
value: newValue,
|
||
expiration: item.expiration,
|
||
}) {
|
||
return newValue
|
||
}
|
||
// CAS 失败，重试
|
||
}
|
||
}
|
||
|
||
// cleanup 定期清理过期缓存
|
||
func (c *MemoryCache) cleanup() {
|
||
ticker := time.NewTicker(c.cleanupInterval)
|
||
defer ticker.Stop()
|
||
|
||
for {
|
||
select {
|
||
case <-ticker.C:
|
||
c.cleanExpired()
|
||
case <-c.stopCleanup:
|
||
return
|
||
}
|
||
}
|
||
}
|
||
|
||
// cleanExpired 清理过期缓存
|
||
func (c *MemoryCache) cleanExpired() {
|
||
count := 0
|
||
c.items.Range(func(key, value interface{}) bool {
|
||
item := value.(*cacheItem)
|
||
if item.isExpired() {
|
||
c.items.Delete(key)
|
||
count++
|
||
}
|
||
return true
|
||
})
|
||
if count > 0 {
|
||
log.Printf("[Cache] Cleaned %d expired items", count)
|
||
}
|
||
}
|
||
|
||
// Stop 停止缓存清理协程
|
||
func (c *MemoryCache) Stop() {
|
||
close(c.stopCleanup)
|
||
}
|
||
|
||
// RedisCache Redis缓存实现
|
||
type RedisCache struct {
|
||
client *redisPkg.Client
|
||
ctx context.Context
|
||
}
|
||
|
||
// NewRedisCache 创建Redis缓存
|
||
func NewRedisCache(client *redisPkg.Client) *RedisCache {
|
||
return &RedisCache{
|
||
client: client,
|
||
ctx: context.Background(),
|
||
}
|
||
}
|
||
|
||
// Set 设置缓存值
|
||
func (c *RedisCache) Set(key string, value interface{}, ttl time.Duration) {
|
||
key = normalizeKey(key)
|
||
// 将值序列化为JSON
|
||
data, err := json.Marshal(value)
|
||
if err != nil {
|
||
metrics.setError.Add(1)
|
||
log.Printf("[RedisCache] Failed to marshal value for key %s: %v", key, err)
|
||
return
|
||
}
|
||
|
||
if err := c.client.Set(c.ctx, key, data, ttl); err != nil {
|
||
metrics.setError.Add(1)
|
||
log.Printf("[RedisCache] Failed to set key %s: %v", key, err)
|
||
}
|
||
}
|
||
|
||
// Get 获取缓存值
|
||
func (c *RedisCache) Get(key string) (interface{}, bool) {
|
||
key = normalizeKey(key)
|
||
data, err := c.client.Get(c.ctx, key)
|
||
if err != nil {
|
||
if err == redis.Nil {
|
||
return nil, false
|
||
}
|
||
log.Printf("[RedisCache] Failed to get key %s: %v", key, err)
|
||
return nil, false
|
||
}
|
||
|
||
// 返回原始字符串，由调用侧决定如何解码为目标类型
|
||
return data, true
|
||
}
|
||
|
||
// Delete 删除缓存
|
||
func (c *RedisCache) Delete(key string) {
|
||
key = normalizeKey(key)
|
||
metrics.invalidate.Add(1)
|
||
if err := c.client.Del(c.ctx, key); err != nil {
|
||
log.Printf("[RedisCache] Failed to delete key %s: %v", key, err)
|
||
}
|
||
}
|
||
|
||
// DeleteByPrefix 根据前缀删除缓存
|
||
func (c *RedisCache) DeleteByPrefix(prefix string) {
|
||
prefix = normalizePrefix(prefix)
|
||
// 使用原生客户端执行SCAN命令
|
||
rdb := c.client.GetClient()
|
||
var cursor uint64
|
||
for {
|
||
keys, nextCursor, err := rdb.Scan(c.ctx, cursor, prefix+"*", 100).Result()
|
||
if err != nil {
|
||
log.Printf("[RedisCache] Failed to scan keys with prefix %s: %v", prefix, err)
|
||
return
|
||
}
|
||
|
||
if len(keys) > 0 {
|
||
metrics.invalidate.Add(int64(len(keys)))
|
||
if err := c.client.Del(c.ctx, keys...); err != nil {
|
||
log.Printf("[RedisCache] Failed to delete keys with prefix %s: %v", prefix, err)
|
||
}
|
||
}
|
||
|
||
cursor = nextCursor
|
||
if cursor == 0 {
|
||
break
|
||
}
|
||
}
|
||
}
|
||
|
||
// Clear 清空所有缓存
|
||
func (c *RedisCache) Clear() {
|
||
if settings.DisableFlushDB {
|
||
log.Printf("[RedisCache] Skip FlushDB because cache.disable_flushdb=true")
|
||
return
|
||
}
|
||
metrics.invalidate.Add(1)
|
||
rdb := c.client.GetClient()
|
||
if err := rdb.FlushDB(c.ctx).Err(); err != nil {
|
||
log.Printf("[RedisCache] Failed to clear cache: %v", err)
|
||
}
|
||
}
|
||
|
||
// Exists 检查键是否存在
|
||
func (c *RedisCache) Exists(key string) bool {
|
||
key = normalizeKey(key)
|
||
n, err := c.client.Exists(c.ctx, key)
|
||
if err != nil {
|
||
log.Printf("[RedisCache] Failed to check existence of key %s: %v", key, err)
|
||
return false
|
||
}
|
||
return n > 0
|
||
}
|
||
|
||
// Increment 增加计数器的值
|
||
func (c *RedisCache) Increment(key string) int64 {
|
||
return c.IncrementBy(key, 1)
|
||
}
|
||
|
||
// IncrementBy 增加指定值
|
||
func (c *RedisCache) IncrementBy(key string, value int64) int64 {
|
||
key = normalizeKey(key)
|
||
rdb := c.client.GetClient()
|
||
result, err := rdb.IncrBy(c.ctx, key, value).Result()
|
||
if err != nil {
|
||
log.Printf("[RedisCache] Failed to increment key %s: %v", key, err)
|
||
return 0
|
||
}
|
||
return result
|
||
}
|
||
|
||
// 全局缓存实例
|
||
var globalCache Cache
|
||
var once sync.Once
|
||
|
||
// InitCache 初始化全局缓存实例（使用Redis）
|
||
func InitCache(redisClient *redisPkg.Client) {
|
||
once.Do(func() {
|
||
if redisClient != nil {
|
||
globalCache = NewRedisCache(redisClient)
|
||
log.Println("[Cache] Initialized Redis cache")
|
||
} else {
|
||
globalCache = NewMemoryCache()
|
||
log.Println("[Cache] Initialized Memory cache (Redis not available)")
|
||
}
|
||
})
|
||
}
|
||
|
||
// GetCache 获取全局缓存实例
|
||
func GetCache() Cache {
|
||
if globalCache == nil {
|
||
// 如果未初始化，返回内存缓存作为降级
|
||
log.Println("[Cache] Warning: Cache not initialized, using Memory cache")
|
||
return NewMemoryCache()
|
||
}
|
||
return globalCache
|
||
}
|
||
|
||
// GetRedisClient 从缓存中获取Redis客户端（仅在Redis模式下有效）
|
||
func GetRedisClient() (*redisPkg.Client, error) {
|
||
if redisCache, ok := globalCache.(*RedisCache); ok {
|
||
return redisCache.client, nil
|
||
}
|
||
return nil, fmt.Errorf("cache is not using Redis backend")
|
||
}
|
||
|
||
func SetWithJitter(c Cache, key string, value interface{}, ttl time.Duration, jitterRatio float64) {
|
||
if !settings.Enabled {
|
||
return
|
||
}
|
||
c.Set(key, value, ApplyTTLJitter(ttl, jitterRatio))
|
||
}
|
||
|
||
func SetNull(c Cache, key string, ttl time.Duration) {
|
||
if !settings.Enabled {
|
||
return
|
||
}
|
||
c.Set(key, nullMarkerValue, ttl)
|
||
}
|
||
|
||
func ApplyTTLJitter(ttl time.Duration, jitterRatio float64) time.Duration {
|
||
if ttl <= 0 || jitterRatio <= 0 {
|
||
return ttl
|
||
}
|
||
if jitterRatio > 1 {
|
||
jitterRatio = 1
|
||
}
|
||
maxJitter := int64(float64(ttl) * jitterRatio)
|
||
if maxJitter <= 0 {
|
||
return ttl
|
||
}
|
||
delta := rand.Int63n(maxJitter + 1)
|
||
return ttl + time.Duration(delta)
|
||
}
|
||
|
||
func GetTyped[T any](c Cache, key string) (T, bool) {
|
||
var zero T
|
||
if !settings.Enabled {
|
||
return zero, false
|
||
}
|
||
raw, ok := c.Get(key)
|
||
if !ok {
|
||
metrics.miss.Add(1)
|
||
return zero, false
|
||
}
|
||
if str, ok := raw.(string); ok && str == nullMarkerValue {
|
||
metrics.hit.Add(1)
|
||
return zero, false
|
||
}
|
||
|
||
if typed, ok := raw.(T); ok {
|
||
metrics.hit.Add(1)
|
||
return typed, true
|
||
}
|
||
|
||
var out T
|
||
switch v := raw.(type) {
|
||
case string:
|
||
if err := json.Unmarshal([]byte(v), &out); err != nil {
|
||
metrics.decodeError.Add(1)
|
||
return zero, false
|
||
}
|
||
metrics.hit.Add(1)
|
||
return out, true
|
||
case []byte:
|
||
if err := json.Unmarshal(v, &out); err != nil {
|
||
metrics.decodeError.Add(1)
|
||
return zero, false
|
||
}
|
||
metrics.hit.Add(1)
|
||
return out, true
|
||
default:
|
||
data, err := json.Marshal(v)
|
||
if err != nil {
|
||
metrics.decodeError.Add(1)
|
||
return zero, false
|
||
}
|
||
if err := json.Unmarshal(data, &out); err != nil {
|
||
metrics.decodeError.Add(1)
|
||
return zero, false
|
||
}
|
||
metrics.hit.Add(1)
|
||
return out, true
|
||
}
|
||
}
|
||
|
||
func GetOrLoadTyped[T any](
|
||
c Cache,
|
||
key string,
|
||
ttl time.Duration,
|
||
jitterRatio float64,
|
||
nullTTL time.Duration,
|
||
loader func() (T, error),
|
||
) (T, error) {
|
||
if cached, ok := GetTyped[T](c, key); ok {
|
||
return cached, nil
|
||
}
|
||
|
||
lockValue, _ := loadLocks.LoadOrStore(key, &sync.Mutex{})
|
||
lock := lockValue.(*sync.Mutex)
|
||
lock.Lock()
|
||
defer lock.Unlock()
|
||
|
||
if cached, ok := GetTyped[T](c, key); ok {
|
||
return cached, nil
|
||
}
|
||
|
||
loaded, err := loader()
|
||
if err != nil {
|
||
var zero T
|
||
return zero, err
|
||
}
|
||
|
||
encoded, marshalErr := json.Marshal(loaded)
|
||
if marshalErr == nil && string(encoded) == "null" && nullTTL > 0 {
|
||
SetNull(c, key, nullTTL)
|
||
return loaded, nil
|
||
}
|
||
|
||
SetWithJitter(c, key, loaded, ttl, jitterRatio)
|
||
return loaded, nil
|
||
}
|