70 lines
1.9 KiB
Go
70 lines
1.9 KiB
Go
package service
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import (
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"strconv"
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"strings"
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"time"
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gocache "github.com/patrickmn/go-cache"
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)
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// digestSessionTTL 摘要会话默认 TTL
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const digestSessionTTL = 5 * time.Minute
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// sessionEntry flat cache 条目
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type sessionEntry struct {
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uuid string
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accountID int64
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}
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// DigestSessionStore 内存摘要会话存储（flat cache 实现）
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// key: "{groupID}:{prefixHash}|{digestChain}" → *sessionEntry
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type DigestSessionStore struct {
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cache *gocache.Cache
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}
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// NewDigestSessionStore 创建内存摘要会话存储
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func NewDigestSessionStore() *DigestSessionStore {
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return &DigestSessionStore{
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cache: gocache.New(digestSessionTTL, time.Minute),
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}
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}
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// Save 保存摘要会话。oldDigestChain 为 Find 返回的 matchedChain，用于删旧 key。
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func (s *DigestSessionStore) Save(groupID int64, prefixHash, digestChain, uuid string, accountID int64, oldDigestChain string) {
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if digestChain == "" {
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return
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}
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ns := buildNS(groupID, prefixHash)
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s.cache.Set(ns+digestChain, &sessionEntry{uuid: uuid, accountID: accountID}, gocache.DefaultExpiration)
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if oldDigestChain != "" && oldDigestChain != digestChain {
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s.cache.Delete(ns + oldDigestChain)
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}
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}
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// Find 查找摘要会话，从完整 chain 逐段截断，返回最长匹配及对应 matchedChain。
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func (s *DigestSessionStore) Find(groupID int64, prefixHash, digestChain string) (uuid string, accountID int64, matchedChain string, found bool) {
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if digestChain == "" {
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return "", 0, "", false
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}
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ns := buildNS(groupID, prefixHash)
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chain := digestChain
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for {
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if val, ok := s.cache.Get(ns + chain); ok {
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if e, ok := val.(*sessionEntry); ok {
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return e.uuid, e.accountID, chain, true
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}
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}
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i := strings.LastIndex(chain, "-")
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if i < 0 {
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return "", 0, "", false
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}
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chain = chain[:i]
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}
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}
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// buildNS 构建 namespace 前缀
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func buildNS(groupID int64, prefixHash string) string {
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return strconv.FormatInt(groupID, 10) + ":" + prefixHash + "|"
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}
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