feat: 实现 Redis 版 SessionManager（Hash + List，TTL 自动刷新）

2026-06-13 15:27:41 +08:00
parent f172e6c468
commit ba6d565c0f
3 changed files with 340 additions and 3 deletions
--- a/backend/go.mod
+++ b/backend/go.mod
@@ -1,6 +1,6 @@
 module github.com/hhs/camtalk

-go 1.23.0
+go 1.24

 require (
 	github.com/gin-gonic/gin v1.10.0
@@ -13,6 +13,7 @@ require (
 require (
 	github.com/bytedance/sonic v1.11.6 // indirect
 	github.com/bytedance/sonic/loader v0.1.1 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/cloudwego/base64x v0.1.4 // indirect
 	github.com/cloudwego/iasm v0.2.0 // indirect
 	github.com/fsnotify/fsnotify v1.9.0 // indirect
@@ -24,12 +25,13 @@ require (
 	github.com/go-viper/mapstructure/v2 v2.4.0 // indirect
 	github.com/goccy/go-json v0.10.2 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
-	github.com/klauspost/cpuid/v2 v2.2.7 // indirect
+	github.com/klauspost/cpuid/v2 v2.2.10 // indirect
 	github.com/leodido/go-urn v1.4.0 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
+	github.com/redis/go-redis/v9 v9.20.1 // indirect
 	github.com/sagikazarmark/locafero v0.11.0 // indirect
 	github.com/sourcegraph/conc v0.3.1-0.20240121214520-5f936abd7ae8 // indirect
 	github.com/spf13/afero v1.15.0 // indirect
@@ -38,12 +40,13 @@ require (
 	github.com/subosito/gotenv v1.6.0 // indirect
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
 	github.com/ugorji/go/codec v1.2.12 // indirect
+	go.uber.org/atomic v1.11.0 // indirect
 	go.uber.org/multierr v1.10.0 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect
 	golang.org/x/arch v0.8.0 // indirect
 	golang.org/x/crypto v0.23.0 // indirect
 	golang.org/x/net v0.25.0 // indirect
-	golang.org/x/sys v0.29.0 // indirect
+	golang.org/x/sys v0.30.0 // indirect
 	golang.org/x/text v0.28.0 // indirect
 	google.golang.org/protobuf v1.34.1 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
--- a/backend/go.sum
+++ b/backend/go.sum
@@ -2,6 +2,8 @@ github.com/bytedance/sonic v1.11.6 h1:oUp34TzMlL+OY1OUWxHqsdkgC/Zfc85zGqw9siXjrc
 github.com/bytedance/sonic v1.11.6/go.mod h1:LysEHSvpvDySVdC2f87zGWf6CIKJcAvqab1ZaiQtds4=
 github.com/bytedance/sonic/loader v0.1.1 h1:c+e5Pt1k/cy5wMveRDyk2X4B9hF4g7an8N3zCYjJFNM=
 github.com/bytedance/sonic/loader v0.1.1/go.mod h1:ncP89zfokxS5LZrJxl5z0UJcsk4M4yY2JpfqGeCtNLU=
+github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
+github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/cloudwego/base64x v0.1.4 h1:jwCgWpFanWmN8xoIUHa2rtzmkd5J2plF/dnLS6Xd/0Y=
 github.com/cloudwego/base64x v0.1.4/go.mod h1:0zlkT4Wn5C6NdauXdJRhSKRlJvmclQ1hhJgA0rcu/8w=
 github.com/cloudwego/iasm v0.2.0 h1:1KNIy1I1H9hNNFEEH3DVnI4UujN+1zjpuk6gwHLTssg=
@@ -43,6 +45,8 @@ github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHm
 github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
 github.com/klauspost/cpuid/v2 v2.2.7 h1:ZWSB3igEs+d0qvnxR/ZBzXVmxkgt8DdzP6m9pfuVLDM=
 github.com/klauspost/cpuid/v2 v2.2.7/go.mod h1:Lcz8mBdAVJIBVzewtcLocK12l3Y+JytZYpaMropDUws=
+github.com/klauspost/cpuid/v2 v2.2.10 h1:tBs3QSyvjDyFTq3uoc/9xFpCuOsJQFNPiAhYdw2skhE=
+github.com/klauspost/cpuid/v2 v2.2.10/go.mod h1:hqwkgyIinND0mEev00jJYCxPNVRVXFQeu1XKlok6oO0=
 github.com/knz/go-libedit v1.10.1/go.mod h1:MZTVkCWyz0oBc7JOWP3wNAzd002ZbM/5hgShxwh4x8M=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
@@ -61,6 +65,8 @@ github.com/pelletier/go-toml/v2 v2.2.4 h1:mye9XuhQ6gvn5h28+VilKrrPoQVanw5PMw/TB0
 github.com/pelletier/go-toml/v2 v2.2.4/go.mod h1:2gIqNv+qfxSVS7cM2xJQKtLSTLUE9V8t9Stt+h56mCY=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/redis/go-redis/v9 v9.20.1 h1:sfCU6A8P3dXbKyWes02uxA2baehGux9dZHfEKtsTB1w=
+github.com/redis/go-redis/v9 v9.20.1/go.mod h1:v/M13XI1PVCDcm01VtPFOADfZtHf8YW3baQf57KlIkA=
 github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
 github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/sagikazarmark/locafero v0.11.0 h1:1iurJgmM9G3PA/I+wWYIOw/5SyBtxapeHDcg+AAIFXc=
@@ -91,6 +97,8 @@ github.com/twitchyliquid64/golang-asm v0.15.1 h1:SU5vSMR7hnwNxj24w34ZyCi/FmDZTkS
 github.com/twitchyliquid64/golang-asm v0.15.1/go.mod h1:a1lVb/DtPvCB8fslRZhAngC2+aY1QWCk3Cedj/Gdt08=
 github.com/ugorji/go/codec v1.2.12 h1:9LC83zGrHhuUA9l16C9AHXAqEV/2wBQ4nkvumAE65EE=
 github.com/ugorji/go/codec v1.2.12/go.mod h1:UNopzCgEMSXjBc6AOMqYvWC1ktqTAfzJZUZgYf6w6lg=
+go.uber.org/atomic v1.11.0 h1:ZvwS0R+56ePWxUNi+Atn9dWONBPp/AUETXlHW0DxSjE=
+go.uber.org/atomic v1.11.0/go.mod h1:LUxbIzbOniOlMKjJjyPfpl4v+PKK2cNJn91OQbhoJI0=
 go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
 go.uber.org/multierr v1.10.0 h1:S0h4aNzvfcFsC3dRF1jLoaov7oRaKqRGC/pUEJ2yvPQ=
@@ -110,6 +118,8 @@ golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.29.0 h1:TPYlXGxvx1MGTn2GiZDhnjPA9wZzZeGKHHmKhHYvgaU=
 golang.org/x/sys v0.29.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.30.0 h1:QjkSwP/36a20jFYWkSue1YwXzLmsV5Gfq7Eiy72C1uc=
+golang.org/x/sys v0.30.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.28.0 h1:rhazDwis8INMIwQ4tpjLDzUhx6RlXqZNPEM0huQojng=
 golang.org/x/text v0.28.0/go.mod h1:U8nCwOR8jO/marOQ0QbDiOngZVEBB7MAiitBuMjXiNU=
 google.golang.org/protobuf v1.34.1 h1:9ddQBjfCyZPOHPUiPxpYESBLc+T8P3E+Vo4IbKZgFWg=
--- a/backend/internal/session/redis.go
+++ b/backend/internal/session/redis.go
@@ -0,0 +1,324 @@
+package session
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"strconv"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/redis/go-redis/v9"
+
+	"github.com/hhs/camtalk/internal/logger"
+	"github.com/hhs/camtalk/internal/models"
+)
+
+// RedisManager 基于 Redis 的 SessionManager 实现。
+// 数据结构：
+//   - session:{id}:meta    → Hash（会话元数据）
+//   - session:{id}:history → List（对话历史）
+type RedisManager struct {
+	rdb        *redis.Client
+	ttl        time.Duration
+	maxHistory int
+}
+
+// NewRedisManager 创建 Redis 版 SessionManager。
+func NewRedisManager(rdb *redis.Client, ttl time.Duration, maxHistory int) *RedisManager {
+	if ttl <= 0 {
+		ttl = defaultTTL
+	}
+	if maxHistory <= 0 {
+		maxHistory = defaultHistorySize
+	}
+	return &RedisManager{rdb: rdb, ttl: ttl, maxHistory: maxHistory}
+}
+
+func metaKey(id string) string   { return fmt.Sprintf("session:%s:meta", id) }
+func histKey(id string) string   { return fmt.Sprintf("session:%s:history", id) }
+
+// Create 创建新会话。
+func (m *RedisManager) Create(ctx context.Context, config models.SessionConfig) (string, error) {
+	id := uuidNew()
+	now := time.Now().UTC()
+
+	pipe := m.rdb.Pipeline()
+
+	// 写入 meta Hash
+	pipe.HSet(ctx, metaKey(id), map[string]interface{}{
+		"session_id":         id,
+		"config.tts_enabled": strconv.FormatBool(config.TTSEnabled),
+		"config.detail_level": config.DetailLevel,
+		"config.language":    config.Language,
+		"created_at":         now.Format(time.RFC3339),
+		"last_active":        now.Format(time.RFC3339),
+		"active_request_id":  "",
+	})
+	pipe.Expire(ctx, metaKey(id), m.ttl)
+
+	// 初始化空 history List
+	pipe.RPush(ctx, histKey(id), placeholderHistoryMark)
+	pipe.Expire(ctx, histKey(id), m.ttl)
+
+	if _, err := pipe.Exec(ctx); err != nil {
+		return "", fmt.Errorf("redis create session: %w", err)
+	}
+
+	logger.Log.Debugw("redis session created", "session", id)
+	return id, nil
+}
+
+// placeholderHistoryMark 占位符，避免 Redis 对空 key 的特殊行为。
+const placeholderHistoryMark = "__placeholder__"
+
+// Get 获取会话。
+func (m *RedisManager) Get(ctx context.Context, sessionID string) (*models.Session, error) {
+	vals, err := m.rdb.HGetAll(ctx, metaKey(sessionID)).Result()
+	if err != nil {
+		return nil, fmt.Errorf("redis get session: %w", err)
+	}
+	if len(vals) == 0 {
+		return nil, ErrSessionNotFound
+	}
+
+	sess := &models.Session{
+		ID: vals["session_id"],
+	}
+	sess.CreatedAt, _ = time.Parse(time.RFC3339, vals["created_at"])
+	sess.Config.TTSEnabled, _ = strconv.ParseBool(vals["config.tts_enabled"])
+	sess.Config.DetailLevel = vals["config.detail_level"]
+	sess.Config.Language = vals["config.language"]
+
+	return sess, nil
+}
+
+// UpdateConfig 更新会话配置。
+func (m *RedisManager) UpdateConfig(ctx context.Context, sessionID string, patch models.SessionConfigPatch) error {
+	// 先检查会话是否存在
+	exists, err := m.rdb.Exists(ctx, metaKey(sessionID)).Result()
+	if err != nil {
+		return fmt.Errorf("redis check session: %w", err)
+	}
+	if exists == 0 {
+		return ErrSessionNotFound
+	}
+
+	fields := map[string]interface{}{
+		"last_active": time.Now().UTC().Format(time.RFC3339),
+	}
+	if patch.TTSEnabled != nil {
+		fields["config.tts_enabled"] = strconv.FormatBool(*patch.TTSEnabled)
+	}
+	if patch.DetailLevel != nil {
+		fields["config.detail_level"] = *patch.DetailLevel
+	}
+	if patch.Language != nil {
+		fields["config.language"] = *patch.Language
+	}
+
+	if err := m.rdb.HSet(ctx, metaKey(sessionID), fields).Err(); err != nil {
+		return fmt.Errorf("redis update config: %w", err)
+	}
+
+	// 刷新 TTL
+	m.rdb.Expire(ctx, metaKey(sessionID), m.ttl)
+	logger.Log.Debugw("redis session config updated", "session", sessionID)
+	return nil
+}
+
+// GetHistory 获取最近 N 轮对话历史。
+func (m *RedisManager) GetHistory(ctx context.Context, sessionID string, limit int) ([]models.Message, error) {
+	// 检查会话是否存在
+	exists, err := m.rdb.Exists(ctx, metaKey(sessionID)).Result()
+	if err != nil {
+		return nil, fmt.Errorf("redis check session: %w", err)
+	}
+	if exists == 0 {
+		return nil, ErrSessionNotFound
+	}
+
+	if limit <= 0 {
+		limit = m.maxHistory
+	}
+
+	// LRANGE 0 {limit-1}，最新在前（LPUSH），需要反转为时间顺序
+	raws, err := m.rdb.LRange(ctx, histKey(sessionID), 0, int64(limit)).Result()
+	if err != nil {
+		return nil, fmt.Errorf("redis get history: %w", err)
+	}
+
+	var msgs []models.Message
+	for _, raw := range raws {
+		if raw == placeholderHistoryMark {
+			continue
+		}
+		var msg models.Message
+		if err := json.Unmarshal([]byte(raw), &msg); err != nil {
+			logger.Log.Warnw("invalid history entry", "session", sessionID, "raw", raw)
+			continue
+		}
+		msgs = append(msgs, msg)
+	}
+
+	// 反转为时间顺序（LPUSH 最新在前 → 需要最旧在前）
+	for i, j := 0, len(msgs)-1; i < j; i, j = i+1, j-1 {
+		msgs[i], msgs[j] = msgs[j], msgs[i]
+	}
+
+	return msgs, nil
+}
+
+// AppendMessage 追加一条对话消息，同时刷新 TTL。
+func (m *RedisManager) AppendMessage(ctx context.Context, sessionID string, msg models.Message) error {
+	// 检查会话是否存在
+	exists, err := m.rdb.Exists(ctx, metaKey(sessionID)).Result()
+	if err != nil {
+		return fmt.Errorf("redis check session: %w", err)
+	}
+	if exists == 0 {
+		return ErrSessionNotFound
+	}
+
+	data, err := json.Marshal(msg)
+	if err != nil {
+		return fmt.Errorf("marshal message: %w", err)
+	}
+
+	pipe := m.rdb.Pipeline()
+	// LPUSH 新消息到左头（最新在前）
+	pipe.LPush(ctx, histKey(sessionID), string(data))
+	// LTRIM 保留最近 maxHistory 条（+1 是因为有占位符）
+	pipe.LTrim(ctx, histKey(sessionID), 0, int64(m.maxHistory))
+	// 刷新 TTL
+	pipe.Expire(ctx, histKey(sessionID), m.ttl)
+	pipe.Expire(ctx, metaKey(sessionID), m.ttl)
+	// 更新 last_active
+	pipe.HSet(ctx, metaKey(sessionID), "last_active", time.Now().UTC().Format(time.RFC3339))
+
+	if _, err := pipe.Exec(ctx); err != nil {
+		return fmt.Errorf("redis append message: %w", err)
+	}
+
+	return nil
+}
+
+// SetActiveRequest 标记当前正在处理的请求 ID。
+func (m *RedisManager) SetActiveRequest(ctx context.Context, sessionID string, requestID string) error {
+	exists, err := m.rdb.Exists(ctx, metaKey(sessionID)).Result()
+	if err != nil {
+		return fmt.Errorf("redis check session: %w", err)
+	}
+	if exists == 0 {
+		return ErrSessionNotFound
+	}
+
+	pipe := m.rdb.Pipeline()
+	pipe.HSet(ctx, metaKey(sessionID), "active_request_id", requestID)
+	pipe.HSet(ctx, metaKey(sessionID), "last_active", time.Now().UTC().Format(time.RFC3339))
+	pipe.Expire(ctx, metaKey(sessionID), m.ttl)
+
+	if _, err := pipe.Exec(ctx); err != nil {
+		return fmt.Errorf("redis set active request: %w", err)
+	}
+	return nil
+}
+
+// GetActiveRequestID 获取当前活跃请求 ID。
+func (m *RedisManager) GetActiveRequestID(ctx context.Context, sessionID string) (string, error) {
+	val, err := m.rdb.HGet(ctx, metaKey(sessionID), "active_request_id").Result()
+	if err == redis.Nil {
+		return "", ErrSessionNotFound
+	}
+	if err != nil {
+		return "", fmt.Errorf("redis get active request: %w", err)
+	}
+	return val, nil
+}
+
+// ClearActiveRequest 清除活跃请求标记。
+func (m *RedisManager) ClearActiveRequest(ctx context.Context, sessionID string) error {
+	exists, err := m.rdb.Exists(ctx, metaKey(sessionID)).Result()
+	if err != nil {
+		return fmt.Errorf("redis check session: %w", err)
+	}
+	if exists == 0 {
+		return ErrSessionNotFound
+	}
+
+	pipe := m.rdb.Pipeline()
+	pipe.HSet(ctx, metaKey(sessionID), "active_request_id", "")
+	pipe.HSet(ctx, metaKey(sessionID), "last_active", time.Now().UTC().Format(time.RFC3339))
+	pipe.Expire(ctx, metaKey(sessionID), m.ttl)
+
+	if _, err := pipe.Exec(ctx); err != nil {
+		return fmt.Errorf("redis clear active request: %w", err)
+	}
+	return nil
+}
+
+// Touch 刷新 TTL。
+func (m *RedisManager) Touch(ctx context.Context, sessionID string) error {
+	exists, err := m.rdb.Exists(ctx, metaKey(sessionID)).Result()
+	if err != nil {
+		return fmt.Errorf("redis check session: %w", err)
+	}
+	if exists == 0 {
+		return ErrSessionNotFound
+	}
+
+	pipe := m.rdb.Pipeline()
+	pipe.Expire(ctx, metaKey(sessionID), m.ttl)
+	pipe.Expire(ctx, histKey(sessionID), m.ttl)
+	pipe.HSet(ctx, metaKey(sessionID), "last_active", time.Now().UTC().Format(time.RFC3339))
+
+	if _, err := pipe.Exec(ctx); err != nil {
+		return fmt.Errorf("redis touch: %w", err)
+	}
+	return nil
+}
+
+// Destroy 显式销毁会话。
+func (m *RedisManager) Destroy(ctx context.Context, sessionID string) error {
+	deleted, err := m.rdb.Del(ctx, metaKey(sessionID), histKey(sessionID)).Result()
+	if err != nil {
+		return fmt.Errorf("redis destroy session: %w", err)
+	}
+	if deleted == 0 {
+		return ErrSessionNotFound
+	}
+
+	logger.Log.Debugw("redis session destroyed", "session", sessionID)
+	return nil
+}
+
+// ActiveCount 返回当前活跃会话数。
+// Redis 实现通过 SCAN 遍历 meta key，适用于中等规模。
+// 大规模部署建议维护独立的活跃会话集合。
+func (m *RedisManager) ActiveCount() int {
+	ctx := context.Background()
+	count := 0
+	var cursor uint64
+	for {
+		keys, nextCursor, err := m.rdb.Scan(ctx, cursor, "session:*:meta", 100).Result()
+		if err != nil {
+			break
+		}
+		for _, key := range keys {
+			exists, _ := m.rdb.Exists(ctx, key).Result()
+			if exists > 0 {
+				count++
+			}
+		}
+		cursor = nextCursor
+		if cursor == 0 {
+			break
+		}
+	}
+	return count
+}
+
+// uuidNew 生成 UUID，便于测试时 mock。
+var uuidNew = func() string {
+	return uuid.New().String()
+}