refactor(backend): extract to pkg/cap

pkg/cap/store.go

@@ -0,0 +1,186 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package cap
+
+import (
+	"context"
+	"sync"
+	"time"
+
+	"github.com/redis/go-redis/v9"
+)
+
+// Store defines the storage interface for challenge nonces and verification tokens
+type Store interface {
+	Get(ctx context.Context, key string) (string, bool, error)
+	Set(ctx context.Context, key string, val string, ttl time.Duration) error
+	Delete(ctx context.Context, key string) error
+	// SetNX atomically sets key=val with the given TTL only when the key does not
+	// exist yet. It returns true when the key was actually written (i.e. this
+	// caller "won" the race), and false when the key already existed.
+	SetNX(ctx context.Context, key string, val string, ttl time.Duration) (bool, error)
+	// GetAndDelete atomically retrieves the value of key and removes it in a
+	// single operation. Returns ("", false, nil) when the key does not exist.
+	GetAndDelete(ctx context.Context, key string) (string, bool, error)
+}
+
+type memoryItem struct {
+	value     string
+	expiresAt time.Time
+}
+
+// MemoryStore is a thread-safe in-memory implementation of Store
+type MemoryStore struct {
+	items map[string]memoryItem
+	mu    sync.Mutex // unified write-lock; promotes to exclusive for all ops
+}
+
+// NewMemoryStore creates and initializes a new MemoryStore
+func NewMemoryStore(cleanupInterval time.Duration) *MemoryStore {
+	store := &MemoryStore{
+		items: make(map[string]memoryItem),
+	}
+	if cleanupInterval > 0 {
+		go store.startCleanupLoop(cleanupInterval)
+	}
+	return store
+}
+
+// Get 从 MemoryStore 获取指定 key 的值
+func (s *MemoryStore) Get(_ context.Context, key string) (string, bool, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.getLocked(key)
+}
+
+// getLocked is the internal helper – caller must hold s.mu.
+func (s *MemoryStore) getLocked(key string) (string, bool, error) {
+	item, found := s.items[key]
+	if !found {
+		return "", false, nil
+	}
+	if time.Now().After(item.expiresAt) {
+		delete(s.items, key)
+		return "", false, nil
+	}
+	return item.value, true, nil
+}
+
+// Set 向 MemoryStore 写入指定 key 的值
+func (s *MemoryStore) Set(_ context.Context, key string, val string, ttl time.Duration) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.items[key] = memoryItem{
+		value:     val,
+		expiresAt: time.Now().Add(ttl),
+	}
+	return nil
+}
+
+// Delete 从 MemoryStore 删除指定 key
+func (s *MemoryStore) Delete(_ context.Context, key string) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	delete(s.items, key)
+	return nil
+}
+
+// SetNX atomically sets key only when it is absent (or expired).
+// Returns true if the key was written by this call.
+func (s *MemoryStore) SetNX(_ context.Context, key string, val string, ttl time.Duration) (bool, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	_, exists, _ := s.getLocked(key)
+	if exists {
+		return false, nil
+	}
+	s.items[key] = memoryItem{
+		value:     val,
+		expiresAt: time.Now().Add(ttl),
+	}
+	return true, nil
+}
+
+// GetAndDelete atomically retrieves and removes key in one critical section.
+func (s *MemoryStore) GetAndDelete(_ context.Context, key string) (string, bool, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	val, exists, err := s.getLocked(key)
+	if err != nil || !exists {
+		return "", false, err
+	}
+	delete(s.items, key)
+	return val, true, nil
+}
+
+func (s *MemoryStore) startCleanupLoop(interval time.Duration) {
+	ticker := time.NewTicker(interval)
+	for range ticker.C {
+		s.cleanupExpired()
+	}
+}
+
+func (s *MemoryStore) cleanupExpired() {
+	now := time.Now()
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	for k, v := range s.items {
+		if now.After(v.expiresAt) {
+			delete(s.items, k)
+		}
+	}
+}
+
+// RedisStore is a GORM-compatible/standalone Redis-backed implementation of Store
+type RedisStore struct {
+	client redis.UniversalClient
+}
+
+// NewRedisStore creates a new RedisStore wrapping a redis.UniversalClient
+func NewRedisStore(client redis.UniversalClient) *RedisStore {
+	return &RedisStore{
+		client: client,
+	}
+}
+
+// Get 从 RedisStore 获取指定 key 的值
+func (s *RedisStore) Get(ctx context.Context, key string) (string, bool, error) {
+	val, err := s.client.Get(ctx, key).Result()
+	if err == redis.Nil {
+		return "", false, nil
+	}
+	if err != nil {
+		return "", false, err
+	}
+	return val, true, nil
+}
+
+// Set 向 RedisStore 写入指定 key 的值
+func (s *RedisStore) Set(ctx context.Context, key string, val string, ttl time.Duration) error {
+	return s.client.Set(ctx, key, val, ttl).Err()
+}
+
+// Delete 从 RedisStore 删除指定 key
+func (s *RedisStore) Delete(ctx context.Context, key string) error {
+	return s.client.Del(ctx, key).Err()
+}
+
+// SetNX wraps Redis SET NX – returns true only when the key was newly created.
+func (s *RedisStore) SetNX(ctx context.Context, key string, val string, ttl time.Duration) (bool, error) {
+	return s.client.SetNX(ctx, key, val, ttl).Result()
+}
+
+// GetAndDelete wraps Redis GETDEL (available since Redis 6.2).
+func (s *RedisStore) GetAndDelete(ctx context.Context, key string) (string, bool, error) {
+	val, err := s.client.GetDel(ctx, key).Result()
+	if err == redis.Nil {
+		return "", false, nil
+	}
+	if err != nil {
+		return "", false, err
+	}
+	return val, true, nil
+}