feat: 添加本地缓存功能，减少API调用

- 实现SQLite缓存模块，支持高效查询和存储
- 添加缓存键生成策略（基于原文+语言对的SHA256哈希）
- 集成缓存到Translator类，先查缓存再调用API
- 添加缓存管理命令：cache clear, cache stats, cache cleanup
- 实现组合缓存清理策略（数量限制+时间过期）
- 添加完整的单元测试
- 更新配置文件模板，添加缓存配置
- 更新文档和版本记录

版本: v0.5.1

internal/cache/cache.go

@@ -0,0 +1,75 @@
+package cache
+
+import (
+	"context"
+	"time"
+)
+
+// Cache 缓存接口
+type Cache interface {
+	// Get 获取缓存
+	Get(ctx context.Context, key string) (*CacheEntry, error)
+
+	// Set 设置缓存
+	Set(ctx context.Context, entry *CacheEntry) error
+
+	// Delete 删除缓存
+	Delete(ctx context.Context, key string) error
+
+	// Clear 清空缓存
+	Clear(ctx context.Context) error
+
+	// Stats 获取缓存统计信息
+	Stats(ctx context.Context) (*CacheStats, error)
+
+	// Cleanup 清理过期缓存
+	Cleanup(ctx context.Context) error
+
+	// Close 关闭缓存
+	Close() error
+}
+
+// CacheEntry 缓存条目
+type CacheEntry struct {
+	ID               int64     `json:"id"`
+	CacheKey         string    `json:"cache_key"`
+	OriginalText     string    `json:"original_text"`
+	TranslatedText   string    `json:"translated_text"`
+	FromLang         string    `json:"from_lang"`
+	ToLang           string    `json:"to_lang"`
+	Model            string    `json:"model"`
+	PromptName       string    `json:"prompt_name,omitempty"`
+	PromptContent    string    `json:"prompt_content,omitempty"`
+	PromptTokens     int       `json:"prompt_tokens"`
+	CompletionTokens int       `json:"completion_tokens"`
+	TotalTokens      int       `json:"total_tokens"`
+	CreatedAt        time.Time `json:"created_at"`
+	LastUsedAt       time.Time `json:"last_used_at"`
+}
+
+// CacheStats 缓存统计信息
+type CacheStats struct {
+	TotalRecords       int       `json:"total_records"`
+	TotalSizeBytes     int64     `json:"total_size_bytes"`
+	OldestRecord       time.Time `json:"oldest_record"`
+	NewestRecord       time.Time `json:"newest_record"`
+	AvgTokensPerRecord float64   `json:"avg_tokens_per_record"`
+}
+
+// CacheConfig 缓存配置
+type CacheConfig struct {
+	Enabled    bool   `yaml:"enabled"`
+	MaxRecords int    `yaml:"max_records"`
+	ExpireDays int    `yaml:"expire_days"`
+	DBPath     string `yaml:"db_path"`
+}
+
+// NewCacheConfig 创建默认缓存配置
+func NewCacheConfig() *CacheConfig {
+	return &CacheConfig{
+		Enabled:    true,
+		MaxRecords: 10000,
+		ExpireDays: 30,
+		DBPath:     "~/.config/yoyo/cache.db",
+	}
+}

internal/cache/cache_test.go

@@ -0,0 +1,325 @@
+package cache
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestGenerateCacheKey(t *testing.T) {
+	tests := []struct {
+		name     string
+		text     string
+		fromLang string
+		toLang   string
+		wantSame bool
+	}{
+		{
+			name:     "相同输入应生成相同键",
+			text:     "Hello world",
+			fromLang: "en",
+			toLang:   "zh-CN",
+			wantSame: true,
+		},
+		{
+			name:     "不同文本应生成不同键",
+			text:     "Hello universe",
+			fromLang: "en",
+			toLang:   "zh-CN",
+			wantSame: false,
+		},
+		{
+			name:     "不同语言对应生成不同键",
+			text:     "Hello world",
+			fromLang: "en",
+			toLang:   "zh-TW",
+			wantSame: false,
+		},
+		{
+			name:     "大小写不敏感的语言代码",
+			text:     "Hello world",
+			fromLang: "EN",
+			toLang:   "zh-cn",
+			wantSame: true,
+		},
+		{
+			name:     "多余空白字符应规范化",
+			text:     "  Hello   world  ",
+			fromLang: "en",
+			toLang:   "zh-CN",
+			wantSame: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			key1 := GenerateCacheKey(tt.text, tt.fromLang, tt.toLang)
+			key2 := GenerateCacheKey(tt.text, tt.fromLang, tt.toLang)
+
+			if key1 != key2 {
+				t.Errorf("相同输入生成了不同的键: %s != %s", key1, key2)
+			}
+
+			// 检查键的长度（SHA256哈希应为64个字符）
+			if len(key1) != 64 {
+				t.Errorf("缓存键长度不正确: got %d, want 64", len(key1))
+			}
+		})
+	}
+}
+
+func TestSQLiteCache(t *testing.T) {
+	// 创建临时目录
+	tmpDir, err := os.MkdirTemp("", "cache_test")
+	if err != nil {
+		t.Fatalf("创建临时目录失败: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	dbPath := filepath.Join(tmpDir, "test_cache.db")
+
+	// 创建缓存配置
+	config := &CacheConfig{
+		Enabled:    true,
+		MaxRecords: 100,
+		ExpireDays: 1,
+		DBPath:     dbPath,
+	}
+
+	// 创建缓存实例
+	cache, err := NewSQLiteCache(config)
+	if err != nil {
+		t.Fatalf("创建缓存实例失败: %v", err)
+	}
+	defer cache.Close()
+
+	ctx := context.Background()
+
+	// 测试设置缓存
+	entry := &CacheEntry{
+		CacheKey:         "test_key_1",
+		OriginalText:     "Hello world",
+		TranslatedText:   "你好世界",
+		FromLang:         "en",
+		ToLang:           "zh-CN",
+		Model:            "gpt-3.5-turbo",
+		PromptName:       "simple",
+		PromptContent:    "请用简单易懂的语言翻译以下内容。",
+		PromptTokens:     10,
+		CompletionTokens: 5,
+		TotalTokens:      15,
+	}
+
+	err = cache.Set(ctx, entry)
+	if err != nil {
+		t.Fatalf("设置缓存失败: %v", err)
+	}
+
+	// 测试获取缓存
+	cachedEntry, err := cache.Get(ctx, "test_key_1")
+	if err != nil {
+		t.Fatalf("获取缓存失败: %v", err)
+	}
+	if cachedEntry == nil {
+		t.Fatal("缓存未命中")
+	}
+
+	if cachedEntry.TranslatedText != "你好世界" {
+		t.Errorf("缓存翻译结果不正确: got %s, want 你好世界", cachedEntry.TranslatedText)
+	}
+
+	// 测试缓存未命中
+	missingEntry, err := cache.Get(ctx, "non_existent_key")
+	if err != nil {
+		t.Fatalf("查询不存在的缓存失败: %v", err)
+	}
+	if missingEntry != nil {
+		t.Error("不存在的缓存应该返回nil")
+	}
+
+	// 测试统计信息
+	stats, err := cache.Stats(ctx)
+	if err != nil {
+		t.Fatalf("获取统计信息失败: %v", err)
+	}
+	if stats.TotalRecords != 1 {
+		t.Errorf("统计记录数不正确: got %d, want 1", stats.TotalRecords)
+	}
+
+	// 测试删除缓存
+	err = cache.Delete(ctx, "test_key_1")
+	if err != nil {
+		t.Fatalf("删除缓存失败: %v", err)
+	}
+
+	// 验证删除
+	deletedEntry, err := cache.Get(ctx, "test_key_1")
+	if err != nil {
+		t.Fatalf("查询已删除的缓存失败: %v", err)
+	}
+	if deletedEntry != nil {
+		t.Error("已删除的缓存应该返回nil")
+	}
+
+	// 测试清空缓存
+	err = cache.Set(ctx, entry)
+	if err != nil {
+		t.Fatalf("设置缓存失败: %v", err)
+	}
+
+	err = cache.Clear(ctx)
+	if err != nil {
+		t.Fatalf("清空缓存失败: %v", err)
+	}
+
+	stats, err = cache.Stats(ctx)
+	if err != nil {
+		t.Fatalf("获取统计信息失败: %v", err)
+	}
+	if stats.TotalRecords != 0 {
+		t.Errorf("清空后记录数不正确: got %d, want 0", stats.TotalRecords)
+	}
+}
+
+func TestCacheExpiration(t *testing.T) {
+	// 创建临时目录
+	tmpDir, err := os.MkdirTemp("", "cache_test")
+	if err != nil {
+		t.Fatalf("创建临时目录失败: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	dbPath := filepath.Join(tmpDir, "test_cache.db")
+
+	// 创建缓存配置，设置很短的过期时间
+	config := &CacheConfig{
+		Enabled:    true,
+		MaxRecords: 100,
+		ExpireDays: 0, // 0天表示立即过期
+		DBPath:     dbPath,
+	}
+
+	// 创建缓存实例
+	cache, err := NewSQLiteCache(config)
+	if err != nil {
+		t.Fatalf("创建缓存实例失败: %v", err)
+	}
+	defer cache.Close()
+
+	ctx := context.Background()
+
+	// 设置缓存
+	entry := &CacheEntry{
+		CacheKey:         "test_key_1",
+		OriginalText:     "Hello world",
+		TranslatedText:   "你好世界",
+		FromLang:         "en",
+		ToLang:           "zh-CN",
+		Model:            "gpt-3.5-turbo",
+		PromptTokens:     10,
+		CompletionTokens: 5,
+		TotalTokens:      15,
+	}
+
+	err = cache.Set(ctx, entry)
+	if err != nil {
+		t.Fatalf("设置缓存失败: %v", err)
+	}
+
+	// 立即清理（应该删除所有记录，因为过期时间为0）
+	err = cache.Cleanup(ctx)
+	if err != nil {
+		t.Fatalf("清理缓存失败: %v", err)
+	}
+
+	// 检查统计信息
+	stats, err := cache.Stats(ctx)
+	if err != nil {
+		t.Fatalf("获取统计信息失败: %v", err)
+	}
+	if stats.TotalRecords != 0 {
+		t.Errorf("清理后记录数不正确: got %d, want 0", stats.TotalRecords)
+	}
+}
+
+func TestNormalizeText(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name:     "正常文本",
+			input:    "Hello world",
+			expected: "Hello world",
+		},
+		{
+			name:     "多余空白字符",
+			input:    "  Hello   world  ",
+			expected: "Hello world",
+		},
+		{
+			name:     "制表符和换行符",
+			input:    "Hello\tworld\n",
+			expected: "Hello world",
+		},
+		{
+			name:     "空字符串",
+			input:    "",
+			expected: "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := normalizeText(tt.input)
+			if result != tt.expected {
+				t.Errorf("normalizeText(%q) = %q, want %q", tt.input, result, tt.expected)
+			}
+		})
+	}
+}
+
+func TestNormalizeLanguageCode(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name:     "正常语言代码",
+			input:    "zh-CN",
+			expected: "zh-cn",
+		},
+		{
+			name:     "大写语言代码",
+			input:    "EN-US",
+			expected: "en-us",
+		},
+		{
+			name:     "空字符串",
+			input:    "",
+			expected: "auto",
+		},
+		{
+			name:     "auto",
+			input:    "auto",
+			expected: "auto",
+		},
+		{
+			name:     "前后空白",
+			input:    "  zh-CN  ",
+			expected: "zh-cn",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := normalizeLanguageCode(tt.input)
+			if result != tt.expected {
+				t.Errorf("normalizeLanguageCode(%q) = %q, want %q", tt.input, result, tt.expected)
+			}
+		})
+	}
+}

internal/cache/cleanup.go

@@ -0,0 +1,53 @@
+package cache
+
+import (
+	"context"
+	"fmt"
+	"log"
+)
+
+// CleanupManager 缓存清理管理器
+type CleanupManager struct {
+	cache Cache
+}
+
+// NewCleanupManager 创建清理管理器
+func NewCleanupManager(cache Cache) *CleanupManager {
+	return &CleanupManager{
+		cache: cache,
+	}
+}
+
+// ClearAll 清空所有缓存
+func (m *CleanupManager) ClearAll(ctx context.Context) error {
+	if err := m.cache.Clear(ctx); err != nil {
+		return fmt.Errorf("清空缓存失败: %w", err)
+	}
+	log.Println("缓存已清空")
+	return nil
+}
+
+// ClearByLanguage 清空指定语言对的缓存
+func (m *CleanupManager) ClearByLanguage(ctx context.Context, fromLang, toLang string) error {
+	// 这个功能需要在SQLite实现中添加查询功能
+	// 目前先返回一个提示信息
+	return fmt.Errorf("按语言清理功能尚未实现")
+}
+
+// GetStats 获取缓存统计信息
+func (m *CleanupManager) GetStats(ctx context.Context) (*CacheStats, error) {
+	stats, err := m.cache.Stats(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("获取缓存统计失败: %w", err)
+	}
+	return stats, nil
+}
+
+// CleanupManual 手动清理
+func (m *CleanupManager) CleanupManual(ctx context.Context) error {
+	if err := m.cache.Cleanup(ctx); err != nil {
+		return fmt.Errorf("手动清理失败: %w", err)
+	}
+	log.Println("缓存清理完成")
+	return nil
+}

internal/cache/key.go

@@ -0,0 +1,63 @@
+package cache
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"strings"
+)
+
+// GenerateCacheKey 生成缓存键
+// 使用原文+语言对进行SHA256哈希
+func GenerateCacheKey(originalText, fromLang, toLang string) string {
+	// 规范化语言代码
+	fromLang = normalizeLanguageCode(fromLang)
+	toLang = normalizeLanguageCode(toLang)
+
+	// 规范化原文
+	normalizedText := normalizeText(originalText)
+
+	// 生成缓存键
+	data := fmt.Sprintf("%s|%s|%s", normalizedText, fromLang, toLang)
+	hash := sha256.Sum256([]byte(data))
+	return hex.EncodeToString(hash[:])
+}
+
+// normalizeLanguageCode 规范化语言代码
+func normalizeLanguageCode(lang string) string {
+	if lang == "" || lang == "auto" {
+		return "auto"
+	}
+	return strings.ToLower(strings.TrimSpace(lang))
+}
+
+// normalizeText 规范化文本
+// 移除多余的空白字符，确保相同的文本生成相同的哈希
+func normalizeText(text string) string {
+	// 移除首尾空白
+	text = strings.TrimSpace(text)
+
+	// 将多个连续空白字符替换为单个空格
+	text = strings.Join(strings.Fields(text), " ")
+
+	return text
+}
+
+// GenerateCacheKeyWithModel 生成包含模型信息的缓存键
+// 如果需要更精确的缓存，可以使用这个函数
+func GenerateCacheKeyWithModel(originalText, fromLang, toLang, model string) string {
+	// 规范化语言代码
+	fromLang = normalizeLanguageCode(fromLang)
+	toLang = normalizeLanguageCode(toLang)
+
+	// 规范化原文
+	normalizedText := normalizeText(originalText)
+
+	// 规范化模型名称
+	model = strings.ToLower(strings.TrimSpace(model))
+
+	// 生成缓存键
+	data := fmt.Sprintf("%s|%s|%s|%s", normalizedText, fromLang, toLang, model)
+	hash := sha256.Sum256([]byte(data))
+	return hex.EncodeToString(hash[:])
+}

internal/cache/sqlite.go

@@ -0,0 +1,337 @@
+package cache
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+// SQLiteCache SQLite缓存实现
+type SQLiteCache struct {
+	db         *sql.DB
+	config     *CacheConfig
+	cleanupTTL time.Duration
+}
+
+// NewSQLiteCache 创建SQLite缓存实例
+func NewSQLiteCache(config *CacheConfig) (*SQLiteCache, error) {
+	if config == nil {
+		config = NewCacheConfig()
+	}
+
+	// 展开路径中的~符号
+	dbPath, err := expandPath(config.DBPath)
+	if err != nil {
+		return nil, fmt.Errorf("无效的数据库路径: %w", err)
+	}
+
+	// 确保目录存在
+	dir := filepath.Dir(dbPath)
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		return nil, fmt.Errorf("创建缓存目录失败: %w", err)
+	}
+
+	// 打开数据库连接
+	db, err := sql.Open("sqlite3", dbPath+"?_journal_mode=WAL&_synchronous=NORMAL")
+	if err != nil {
+		return nil, fmt.Errorf("打开数据库失败: %w", err)
+	}
+
+	// 设置连接池参数
+	db.SetMaxOpenConns(1) // SQLite只支持单个写入连接
+	db.SetMaxIdleConns(1)
+
+	cache := &SQLiteCache{
+		db:         db,
+		config:     config,
+		cleanupTTL: time.Duration(config.ExpireDays) * 24 * time.Hour,
+	}
+
+	// 初始化数据库表
+	if err := cache.initTable(); err != nil {
+		db.Close()
+		return nil, fmt.Errorf("初始化缓存表失败: %w", err)
+	}
+
+	// 设置清理定时器
+	go cache.startCleanupTimer()
+
+	return cache, nil
+}
+
+// initTable 初始化缓存表
+func (c *SQLiteCache) initTable() error {
+	query := `
+	CREATE TABLE IF NOT EXISTS translation_cache (
+		id INTEGER PRIMARY KEY AUTOINCREMENT,
+		cache_key TEXT NOT NULL UNIQUE,
+		original_text TEXT NOT NULL,
+		translated_text TEXT NOT NULL,
+		from_lang TEXT NOT NULL,
+		to_lang TEXT NOT NULL,
+		model TEXT NOT NULL,
+		prompt_name TEXT,
+		prompt_content TEXT,
+		prompt_tokens INTEGER DEFAULT 0,
+		completion_tokens INTEGER DEFAULT 0,
+		total_tokens INTEGER DEFAULT 0,
+		created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+		last_used_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+	);
+	
+	CREATE INDEX IF NOT EXISTS idx_cache_key ON translation_cache(cache_key);
+	CREATE INDEX IF NOT EXISTS idx_original_text ON translation_cache(original_text);
+	CREATE INDEX IF NOT EXISTS idx_created_at ON translation_cache(created_at);
+	CREATE INDEX IF NOT EXISTS idx_last_used_at ON translation_cache(last_used_at);
+	`
+
+	_, err := c.db.Exec(query)
+	return err
+}
+
+// Get 获取缓存
+func (c *SQLiteCache) Get(ctx context.Context, key string) (*CacheEntry, error) {
+	query := `
+	SELECT 
+		id, cache_key, original_text, translated_text, from_lang, to_lang,
+		model, prompt_name, prompt_content, prompt_tokens, completion_tokens,
+		total_tokens, created_at, last_used_at
+	FROM translation_cache
+	WHERE cache_key = ?
+	`
+
+	entry := &CacheEntry{}
+	var promptName, promptContent sql.NullString
+	var createdAt, lastUsedAt string
+
+	err := c.db.QueryRowContext(ctx, query, key).Scan(
+		&entry.ID, &entry.CacheKey, &entry.OriginalText, &entry.TranslatedText,
+		&entry.FromLang, &entry.ToLang, &entry.Model, &promptName, &promptContent,
+		&entry.PromptTokens, &entry.CompletionTokens, &entry.TotalTokens,
+		&createdAt, &lastUsedAt,
+	)
+
+	if err == sql.ErrNoRows {
+		return nil, nil // 缓存未命中
+	}
+	if err != nil {
+		return nil, fmt.Errorf("查询缓存失败: %w", err)
+	}
+
+	// 处理可空字段
+	if promptName.Valid {
+		entry.PromptName = promptName.String
+	}
+	if promptContent.Valid {
+		entry.PromptContent = promptContent.String
+	}
+
+	// 解析时间
+	entry.CreatedAt, _ = time.Parse("2006-01-02 15:04:05", createdAt)
+	entry.LastUsedAt, _ = time.Parse("2006-01-02 15:04:05", lastUsedAt)
+
+	// 更新最后使用时间
+	go c.updateLastUsed(context.Background(), key)
+
+	return entry, nil
+}
+
+// Set 设置缓存
+func (c *SQLiteCache) Set(ctx context.Context, entry *CacheEntry) error {
+	// 开始事务
+	tx, err := c.db.BeginTx(ctx, nil)
+	if err != nil {
+		return fmt.Errorf("开始事务失败: %w", err)
+	}
+	defer tx.Rollback()
+
+	// 插入或替换缓存
+	query := `
+	INSERT OR REPLACE INTO translation_cache 
+	(cache_key, original_text, translated_text, from_lang, to_lang, 
+	model, prompt_name, prompt_content, prompt_tokens, completion_tokens, 
+	total_tokens, created_at, last_used_at)
+	VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+	`
+
+	now := time.Now().Format("2006-01-02 15:04:05")
+	_, err = tx.ExecContext(ctx, query,
+		entry.CacheKey, entry.OriginalText, entry.TranslatedText,
+		entry.FromLang, entry.ToLang, entry.Model, entry.PromptName,
+		entry.PromptContent, entry.PromptTokens, entry.CompletionTokens,
+		entry.TotalTokens, now, now,
+	)
+	if err != nil {
+		return fmt.Errorf("插入缓存失败: %w", err)
+	}
+
+	// 提交事务
+	if err := tx.Commit(); err != nil {
+		return fmt.Errorf("提交事务失败: %w", err)
+	}
+
+	// 触发清理（异步）
+	go c.Cleanup(context.Background())
+
+	return nil
+}
+
+// Delete 删除缓存
+func (c *SQLiteCache) Delete(ctx context.Context, key string) error {
+	query := `DELETE FROM translation_cache WHERE cache_key = ?`
+	_, err := c.db.ExecContext(ctx, query, key)
+	if err != nil {
+		return fmt.Errorf("删除缓存失败: %w", err)
+	}
+	return nil
+}
+
+// Clear 清空缓存
+func (c *SQLiteCache) Clear(ctx context.Context) error {
+	// 先删除所有记录
+	_, err := c.db.ExecContext(ctx, `DELETE FROM translation_cache`)
+	if err != nil {
+		return fmt.Errorf("清空缓存失败: %w", err)
+	}
+
+	// 然后执行VACUUM（不能在事务中执行）
+	_, err = c.db.ExecContext(ctx, `VACUUM`)
+	if err != nil {
+		return fmt.Errorf("清理数据库失败: %w", err)
+	}
+
+	return nil
+}
+
+// Stats 获取缓存统计信息
+func (c *SQLiteCache) Stats(ctx context.Context) (*CacheStats, error) {
+	stats := &CacheStats{}
+
+	// 获取总记录数
+	err := c.db.QueryRowContext(ctx, `SELECT COUNT(*) FROM translation_cache`).Scan(&stats.TotalRecords)
+	if err != nil {
+		return nil, fmt.Errorf("查询缓存统计失败: %w", err)
+	}
+
+	// 如果没有记录，直接返回
+	if stats.TotalRecords == 0 {
+		return stats, nil
+	}
+
+	// 获取时间范围和平均tokens
+	var oldestStr, newestStr sql.NullString
+	var avgTokens sql.NullFloat64
+	err = c.db.QueryRowContext(ctx, `
+	SELECT 
+		MIN(created_at), 
+		MAX(created_at),
+		AVG(total_tokens)
+	FROM translation_cache
+	`).Scan(&oldestStr, &newestStr, &avgTokens)
+	if err != nil {
+		return nil, fmt.Errorf("查询缓存时间范围失败: %w", err)
+	}
+
+	// 解析时间字符串
+	if oldestStr.Valid {
+		stats.OldestRecord, _ = time.Parse("2006-01-02 15:04:05", oldestStr.String)
+	}
+	if newestStr.Valid {
+		stats.NewestRecord, _ = time.Parse("2006-01-02 15:04:05", newestStr.String)
+	}
+	if avgTokens.Valid {
+		stats.AvgTokensPerRecord = avgTokens.Float64
+	}
+
+	// 计算数据库文件大小
+	dbPath, _ := expandPath(c.config.DBPath)
+	if info, err := os.Stat(dbPath); err == nil {
+		stats.TotalSizeBytes = info.Size()
+	}
+
+	return stats, nil
+}
+
+// Cleanup 清理过期缓存
+func (c *SQLiteCache) Cleanup(ctx context.Context) error {
+	tx, err := c.db.BeginTx(ctx, nil)
+	if err != nil {
+		return fmt.Errorf("开始事务失败: %w", err)
+	}
+	defer tx.Rollback()
+
+	// 清理过期缓存
+	if c.cleanupTTL > 0 {
+		expiredTime := time.Now().Add(-c.cleanupTTL).Format("2006-01-02 15:04:05")
+		_, err = tx.ExecContext(ctx, `DELETE FROM translation_cache WHERE last_used_at < ?`, expiredTime)
+		if err != nil {
+			return fmt.Errorf("清理过期缓存失败: %w", err)
+		}
+	} else if c.cleanupTTL == 0 {
+		// 如果过期时间为0，清理所有记录
+		_, err = tx.ExecContext(ctx, `DELETE FROM translation_cache`)
+		if err != nil {
+			return fmt.Errorf("清理所有缓存失败: %w", err)
+		}
+	}
+
+	// 清理超出数量限制的缓存
+	if c.config.MaxRecords > 0 {
+		_, err = tx.ExecContext(ctx, `
+		DELETE FROM translation_cache 
+		WHERE id NOT IN (
+			SELECT id FROM translation_cache 
+			ORDER BY last_used_at DESC 
+			LIMIT ?
+		)
+		`, c.config.MaxRecords)
+		if err != nil {
+			return fmt.Errorf("清理超出数量限制的缓存失败: %w", err)
+		}
+	}
+
+	return tx.Commit()
+}
+
+// Close 关闭缓存
+func (c *SQLiteCache) Close() error {
+	if c.db != nil {
+		return c.db.Close()
+	}
+	return nil
+}
+
+// updateLastUsed 更新最后使用时间
+func (c *SQLiteCache) updateLastUsed(ctx context.Context, key string) {
+	query := `UPDATE translation_cache SET last_used_at = ? WHERE cache_key = ?`
+	now := time.Now().Format("2006-01-02 15:04:05")
+	c.db.ExecContext(ctx, query, now, key)
+}
+
+// startCleanupTimer 启动清理定时器
+func (c *SQLiteCache) startCleanupTimer() {
+	ticker := time.NewTicker(1 * time.Hour) // 每小时清理一次
+	defer ticker.Stop()
+
+	for range ticker.C {
+		c.Cleanup(context.Background())
+	}
+}
+
+// expandPath 展开路径中的~符号
+func expandPath(path string) (string, error) {
+	if strings.HasPrefix(path, "~") {
+		home, err := os.UserHomeDir()
+		if err != nil {
+			return "", err
+		}
+		path = filepath.Join(home, path[1:])
+	}
+	return path, nil
+}

internal/config/config.go

@@ -26,6 +26,9 @@ type Config struct {
 
 	// 内容过滤配置
 	SkipKeywords []string `yaml:"skip_keywords"` // 不翻译的关键词
+
+	// 缓存配置
+	Cache CacheConfig `yaml:"cache"`
 }
 
 // ProviderConfig 厂商配置
@@ -36,6 +39,14 @@ type ProviderConfig struct {
 	Enabled bool   `yaml:"enabled"`
 }
 
+// CacheConfig 缓存配置
+type CacheConfig struct {
+	Enabled    bool   `yaml:"enabled"`
+	MaxRecords int    `yaml:"max_records"`
+	ExpireDays int    `yaml:"expire_days"`
+	DBPath     string `yaml:"db_path"`
+}
+
 // ConfigLoader 配置加载器接口
 type ConfigLoader interface {
 	Load(path string) (*Config, error)
@@ -134,6 +145,17 @@ func (c *Config) setDefaults() {
 			"BUG:", "WARN:", "IMPORTANT:",
 		}
 	}
+
+	// 设置缓存配置默认值
+	if c.Cache.MaxRecords <= 0 {
+		c.Cache.MaxRecords = 10000
+	}
+	if c.Cache.ExpireDays <= 0 {
+		c.Cache.ExpireDays = 30
+	}
+	if c.Cache.DBPath == "" {
+		c.Cache.DBPath = "~/.config/yoyo/cache.db"
+	}
 }
 
 // GetProviderConfig 获取指定厂商的配置
@@ -221,5 +243,10 @@ func (c *Config) String() string {
 	for name := range c.Prompts {
 		builder.WriteString(fmt.Sprintf("  %s\n", name))
 	}
+	builder.WriteString("Cache:\n")
+	builder.WriteString(fmt.Sprintf("  enabled: %v\n", c.Cache.Enabled))
+	builder.WriteString(fmt.Sprintf("  max_records: %d\n", c.Cache.MaxRecords))
+	builder.WriteString(fmt.Sprintf("  expire_days: %d\n", c.Cache.ExpireDays))
+	builder.WriteString(fmt.Sprintf("  db_path: %s\n", c.Cache.DBPath))
 	return builder.String()
 }

internal/content/filter.go

@@ -1,6 +1,7 @@
 package content
 
 import (
+	"fmt"
 	"regexp"
 	"strings"
 )
@@ -46,7 +47,7 @@ func truncateConsecutiveSymbols(text string, maxCount int) string {
 	symbols := []string{"=", "-", "_", "*", "#", "~", "`", "."}
 
 	for _, symbol := range symbols {
-		pattern := regexp.MustCompile(`(?` + `(` + symbol + `){` + string(rune(maxCount+1)) + `,})`)
+		pattern := regexp.MustCompile(regexp.QuoteMeta(symbol) + `{` + fmt.Sprintf("%d", maxCount+1) + `,}`)
 		replacement := strings.Repeat(symbol, maxCount)
 		text = pattern.ReplaceAllString(text, replacement)
 	}

internal/translator/translator.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/titor/fanyi/internal/cache"
 	"github.com/titor/fanyi/internal/config"
 	"github.com/titor/fanyi/internal/content"
 	"github.com/titor/fanyi/internal/provider"
@@ -16,16 +17,32 @@ type Translator struct {
 	provider      provider.Provider
 	prompt        *PromptManager
 	contentParser *content.Parser
+	cache         cache.Cache
 }
 
 // NewTranslator 创建翻译器实例
 func NewTranslator(config *config.Config, provider provider.Provider) *Translator {
-	return &Translator{
+	translator := &Translator{
 		config:        config,
 		provider:      provider,
 		prompt:        NewPromptManager(config.Prompts),
 		contentParser: content.NewParser(config.SkipKeywords),
 	}
+
+	// 初始化缓存（如果启用）
+	if config.Cache.Enabled {
+		cacheConfig := &cache.CacheConfig{
+			Enabled:    config.Cache.Enabled,
+			MaxRecords: config.Cache.MaxRecords,
+			ExpireDays: config.Cache.ExpireDays,
+			DBPath:     config.Cache.DBPath,
+		}
+		if cacheInstance, err := cache.NewSQLiteCache(cacheConfig); err == nil {
+			translator.cache = cacheInstance
+		}
+	}
+
+	return translator
 }
 
 // Translate 执行翻译
@@ -68,6 +85,26 @@ func (t *Translator) Translate(ctx context.Context, text string, options *Transl
 		Options:  options.ExtraOptions,
 	}
 
+	// 检查缓存
+	if t.cache != nil {
+		cacheKey := cache.GenerateCacheKey(filteredText, options.FromLang, options.ToLang)
+		if cachedEntry, err := t.cache.Get(ctx, cacheKey); err == nil && cachedEntry != nil {
+			// 缓存命中
+			return &TranslateResult{
+				Original:   text,
+				Translated: cachedEntry.TranslatedText,
+				FromLang:   cachedEntry.FromLang,
+				ToLang:     cachedEntry.ToLang,
+				Model:      cachedEntry.Model,
+				Usage: &provider.Usage{
+					PromptTokens:     cachedEntry.PromptTokens,
+					CompletionTokens: cachedEntry.CompletionTokens,
+					TotalTokens:      cachedEntry.TotalTokens,
+				},
+			}, nil
+		}
+	}
+
 	// 调用厂商API
 	resp, err := t.provider.Translate(timeoutCtx, req)
 	if err != nil {
@@ -81,6 +118,26 @@ func (t *Translator) Translate(ctx context.Context, text string, options *Transl
 		translatedText = t.contentParser.Reconstruct(parseResult, resp.Text)
 	}
 
+	// 保存到缓存
+	if t.cache != nil {
+		cacheKey := cache.GenerateCacheKey(filteredText, options.FromLang, options.ToLang)
+		cacheEntry := &cache.CacheEntry{
+			CacheKey:         cacheKey,
+			OriginalText:     filteredText,
+			TranslatedText:   translatedText,
+			FromLang:         resp.FromLang,
+			ToLang:           resp.ToLang,
+			Model:            resp.Model,
+			PromptName:       options.PromptName,
+			PromptContent:    prompt,
+			PromptTokens:     resp.Usage.PromptTokens,
+			CompletionTokens: resp.Usage.CompletionTokens,
+			TotalTokens:      resp.Usage.TotalTokens,
+		}
+		// 异步保存缓存，不阻塞翻译结果返回
+		go t.cache.Set(context.Background(), cacheEntry)
+	}
+
 	// 构建结果
 	return &TranslateResult{
 		Original:   text,