Added cache, funcspec and implemented total cache

pkg/cache/provider_redis.go

@@ -0,0 +1,185 @@
+package cache
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/redis/go-redis/v9"
+)
+
+// RedisProvider is a Redis implementation of the Provider interface.
+type RedisProvider struct {
+	client  *redis.Client
+	options *Options
+}
+
+// RedisConfig contains Redis-specific configuration.
+type RedisConfig struct {
+	// Host is the Redis server host (default: localhost)
+	Host string
+
+	// Port is the Redis server port (default: 6379)
+	Port int
+
+	// Password for Redis authentication (optional)
+	Password string
+
+	// DB is the Redis database number (default: 0)
+	DB int
+
+	// PoolSize is the maximum number of connections (default: 10)
+	PoolSize int
+
+	// Options contains general cache options
+	Options *Options
+}
+
+// NewRedisProvider creates a new Redis cache provider.
+func NewRedisProvider(config *RedisConfig) (*RedisProvider, error) {
+	if config == nil {
+		config = &RedisConfig{
+			Host: "localhost",
+			Port: 6379,
+			DB:   0,
+		}
+	}
+
+	if config.Host == "" {
+		config.Host = "localhost"
+	}
+	if config.Port == 0 {
+		config.Port = 6379
+	}
+	if config.PoolSize == 0 {
+		config.PoolSize = 10
+	}
+
+	if config.Options == nil {
+		config.Options = &Options{
+			DefaultTTL: 5 * time.Minute,
+		}
+	}
+
+	client := redis.NewClient(&redis.Options{
+		Addr:     fmt.Sprintf("%s:%d", config.Host, config.Port),
+		Password: config.Password,
+		DB:       config.DB,
+		PoolSize: config.PoolSize,
+	})
+
+	// Test connection
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	if err := client.Ping(ctx).Err(); err != nil {
+		return nil, fmt.Errorf("failed to connect to Redis: %w", err)
+	}
+
+	return &RedisProvider{
+		client:  client,
+		options: config.Options,
+	}, nil
+}
+
+// Get retrieves a value from the cache by key.
+func (r *RedisProvider) Get(ctx context.Context, key string) ([]byte, bool) {
+	val, err := r.client.Get(ctx, key).Bytes()
+	if err == redis.Nil {
+		return nil, false
+	}
+	if err != nil {
+		return nil, false
+	}
+	return val, true
+}
+
+// Set stores a value in the cache with the specified TTL.
+func (r *RedisProvider) Set(ctx context.Context, key string, value []byte, ttl time.Duration) error {
+	if ttl == 0 {
+		ttl = r.options.DefaultTTL
+	}
+
+	return r.client.Set(ctx, key, value, ttl).Err()
+}
+
+// Delete removes a key from the cache.
+func (r *RedisProvider) Delete(ctx context.Context, key string) error {
+	return r.client.Del(ctx, key).Err()
+}
+
+// DeleteByPattern removes all keys matching the pattern.
+func (r *RedisProvider) DeleteByPattern(ctx context.Context, pattern string) error {
+	iter := r.client.Scan(ctx, 0, pattern, 0).Iterator()
+	pipe := r.client.Pipeline()
+
+	count := 0
+	for iter.Next(ctx) {
+		pipe.Del(ctx, iter.Val())
+		count++
+
+		// Execute pipeline in batches of 100
+		if count%100 == 0 {
+			if _, err := pipe.Exec(ctx); err != nil {
+				return err
+			}
+			pipe = r.client.Pipeline()
+		}
+	}
+
+	if err := iter.Err(); err != nil {
+		return err
+	}
+
+	// Execute remaining commands
+	if count%100 != 0 {
+		_, err := pipe.Exec(ctx)
+		return err
+	}
+
+	return nil
+}
+
+// Clear removes all items from the cache.
+func (r *RedisProvider) Clear(ctx context.Context) error {
+	return r.client.FlushDB(ctx).Err()
+}
+
+// Exists checks if a key exists in the cache.
+func (r *RedisProvider) Exists(ctx context.Context, key string) bool {
+	result, err := r.client.Exists(ctx, key).Result()
+	if err != nil {
+		return false
+	}
+	return result > 0
+}
+
+// Close closes the provider and releases any resources.
+func (r *RedisProvider) Close() error {
+	return r.client.Close()
+}
+
+// Stats returns statistics about the cache provider.
+func (r *RedisProvider) Stats(ctx context.Context) (*CacheStats, error) {
+	info, err := r.client.Info(ctx, "stats", "keyspace").Result()
+	if err != nil {
+		return nil, fmt.Errorf("failed to get Redis stats: %w", err)
+	}
+
+	dbSize, err := r.client.DBSize(ctx).Result()
+	if err != nil {
+		return nil, fmt.Errorf("failed to get DB size: %w", err)
+	}
+
+	// Parse stats from INFO command
+	// This is a simplified version - you may want to parse more detailed stats
+	stats := &CacheStats{
+		Keys:         dbSize,
+		ProviderType: "redis",
+		ProviderStats: map[string]any{
+			"info": info,
+		},
+	}
+
+	return stats, nil
+}