WeKnora deployment source with the reviewed wiki identity, summary and recovery fixes

internal/stream/redis_manager.go

@@ -0,0 +1,139 @@
+package stream
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"github.com/Tencent/WeKnora/internal/common"
+	"github.com/Tencent/WeKnora/internal/types/interfaces"
+	"github.com/redis/go-redis/v9"
+)
+
+// RedisStreamManager implements StreamManager using Redis Lists for append-only event streaming
+type RedisStreamManager struct {
+	client *redis.Client
+	ttl    time.Duration // TTL for stream data in Redis
+	prefix string        // Redis key prefix
+}
+
+// NewRedisStreamManager creates a new Redis-based stream manager
+func NewRedisStreamManager(redisAddr, redisUsername, redisPassword string,
+	redisDB int, prefix string, ttl time.Duration,
+) (*RedisStreamManager, error) {
+	client := redis.NewClient(&redis.Options{
+		Addr:      redisAddr,
+		Username:  redisUsername,
+		Password:  redisPassword,
+		DB:        redisDB,
+		TLSConfig: common.RedisTLSConfig(),
+	})
+
+	// Verify connection
+	_, err := client.Ping(context.Background()).Result()
+	if err != nil {
+		return nil, fmt.Errorf("failed to connect to Redis: %w", err)
+	}
+
+	if ttl == 0 {
+		ttl = 24 * time.Hour // Default TTL: 24 hours
+	}
+
+	if prefix == "" {
+		prefix = "stream:events" // Default prefix
+	}
+
+	return &RedisStreamManager{
+		client: client,
+		ttl:    ttl,
+		prefix: prefix,
+	}, nil
+}
+
+// buildKey builds the Redis key for event list
+func (r *RedisStreamManager) buildKey(sessionID, messageID string) string {
+	return fmt.Sprintf("%s:%s:%s", r.prefix, sessionID, messageID)
+}
+
+// AppendEvent appends a single event to the stream using Redis RPush
+func (r *RedisStreamManager) AppendEvent(
+	ctx context.Context,
+	sessionID, messageID string,
+	event interfaces.StreamEvent,
+) error {
+	key := r.buildKey(sessionID, messageID)
+
+	// Set timestamp if not already set
+	if event.Timestamp.IsZero() {
+		event.Timestamp = time.Now()
+	}
+
+	// Serialize event to JSON
+	eventJSON, err := json.Marshal(event)
+	if err != nil {
+		return fmt.Errorf("failed to marshal event: %w", err)
+	}
+
+	// Append to Redis list with RPush (O(1) operation)
+	if err := r.client.RPush(ctx, key, eventJSON).Err(); err != nil {
+		return fmt.Errorf("failed to append event to Redis: %w", err)
+	}
+
+	// Set/refresh TTL on the key
+	if err := r.client.Expire(ctx, key, r.ttl).Err(); err != nil {
+		return fmt.Errorf("failed to set TTL: %w", err)
+	}
+
+	return nil
+}
+
+// GetEvents gets events starting from offset using Redis LRange
+// Returns: events slice, next offset, error
+func (r *RedisStreamManager) GetEvents(
+	ctx context.Context,
+	sessionID, messageID string,
+	fromOffset int,
+) ([]interfaces.StreamEvent, int, error) {
+	key := r.buildKey(sessionID, messageID)
+
+	// Get all events from offset to end using LRange
+	// LRange is inclusive, so fromOffset to -1 gets all remaining elements
+	results, err := r.client.LRange(ctx, key, int64(fromOffset), -1).Result()
+	if err != nil {
+		if err == redis.Nil {
+			// Key doesn't exist - return empty slice
+			return []interfaces.StreamEvent{}, fromOffset, nil
+		}
+		return nil, fromOffset, fmt.Errorf("failed to get events from Redis: %w", err)
+	}
+
+	// No new events
+	if len(results) == 0 {
+		return []interfaces.StreamEvent{}, fromOffset, nil
+	}
+
+	// Unmarshal events
+	events := make([]interfaces.StreamEvent, 0, len(results))
+	for _, result := range results {
+		var event interfaces.StreamEvent
+		if err := json.Unmarshal([]byte(result), &event); err != nil {
+			// Log error but continue with other events
+			continue
+		}
+		events = append(events, event)
+	}
+
+	// Calculate next offset
+	nextOffset := fromOffset + len(results)
+
+	return events, nextOffset, nil
+}
+
+// Close closes the Redis connection
+func (r *RedisStreamManager) Close() error {
+	return r.client.Close()
+}
+
+// Ensure RedisStreamManager implements StreamManager interface
+var _ interfaces.StreamManager = (*RedisStreamManager)(nil)