feat(export): 实现导出进度缓存及zip压缩优化

- 新增导出任务实时进度缓存模块，提供设置、获取和清除进度缓存接口
- 导出进度更新时只更新缓存，不再频繁写入数据库，减轻数据库压力
- 导出完成时清除进度缓存，释放内存资源
- API返回的导出进度字段改为实时缓存数据，提升前端实时性
- 导出列表也使用实时缓存的进度数据替换原数据库字段
- 优化ZipFiles函数，使用DEFLATE算法压缩分片文件，提高压缩效率
- 维护代码注释，明确缓存和压缩实现逻辑

server/internal/api/exports.go

@@ -1062,7 +1062,7 @@ func (a *ExportsAPI) get(w http.ResponseWriter, r *http.Request, id string) {
 			}
 		}
 	}
-	ok(w, r, map[string]interface{}{"id": d.ID, "template_id": d.TemplateID, "status": d.Status, "requested_by": d.RequestedBy, "file_format": d.FileFormat, "total_rows": d.TotalRows.Int64, "started_at": d.StartedAt.Time, "finished_at": d.FinishedAt.Time, "created_at": d.CreatedAt, "updated_at": d.UpdatedAt, "files": files, "eval_status": evalStatus, "eval_desc": desc})
+	ok(w, r, map[string]interface{}{"id": d.ID, "template_id": d.TemplateID, "status": d.Status, "requested_by": d.RequestedBy, "file_format": d.FileFormat, "total_rows": repo.GetProgress(d.ID), "started_at": d.StartedAt.Time, "finished_at": d.FinishedAt.Time, "created_at": d.CreatedAt, "updated_at": d.UpdatedAt, "files": files, "eval_status": evalStatus, "eval_desc": desc})
 }
 
 func (a *ExportsAPI) getSQL(w http.ResponseWriter, r *http.Request, id string) {
@@ -1617,7 +1617,7 @@ func (a *ExportsAPI) list(w http.ResponseWriter, r *http.Request) {
 	for _, it := range itemsRaw {
 		id, tid, req := it.ID, it.TemplateID, it.RequestedBy
 		status, fmtstr := it.Status, it.FileFormat
-		estimate, total := it.RowEstimate, it.TotalRows
+		estimate := it.RowEstimate
 		createdAt, updatedAt := it.CreatedAt, it.UpdatedAt
 		score, explainRaw := it.ExplainScore, it.ExplainJSON
 		evalStatus := "通过"
@@ -1692,7 +1692,7 @@ func (a *ExportsAPI) list(w http.ResponseWriter, r *http.Request) {
 				}
 			}
 		}
-		m := map[string]interface{}{"id": id, "template_id": tid, "status": status, "requested_by": req, "row_estimate": estimate.Int64, "total_rows": total.Int64, "file_format": fmtstr, "created_at": createdAt.Time, "updated_at": updatedAt.Time, "eval_status": evalStatus, "eval_desc": desc}
+		m := map[string]interface{}{"id": id, "template_id": tid, "status": status, "requested_by": req, "row_estimate": estimate.Int64, "total_rows": repo.GetProgress(id), "file_format": fmtstr, "created_at": createdAt.Time, "updated_at": updatedAt.Time, "eval_status": evalStatus, "eval_desc": desc}
 		items = append(items, m)
 	}
 	ok(w, r, map[string]interface{}{"items": items, "total": totalCount, "page": page, "page_size": size})

server/internal/exporter/util.go

@@ -2,6 +2,7 @@ package exporter
 
 import (
 	"archive/zip"
+	"compress/flate"
 	"fmt"
 	"io"
 	"os"
@@ -10,7 +11,7 @@ import (
 	"time"
 )
 
-// ZipFiles 将分片文件打包为zip并返回路径与大小，同时清理源xlsx分片文件
+// ZipFiles 将分片文件打包为压缩zip并返回路径与大小，同时清理源xlsx分片文件
 func ZipFiles(jobID uint64, files []string) (string, int64) {
 	baseDir := "storage/export"
 	_ = os.MkdirAll(baseDir, 0755)
@@ -21,12 +22,24 @@ func ZipFiles(jobID uint64, files []string) (string, int64) {
 	}
 	defer zf.Close()
 	zw := zip.NewWriter(zf)
+	// 注册 DEFLATE 压缩器
+	zw.RegisterCompressor(zip.Deflate, func(out io.Writer) (io.WriteCloser, error) {
+		w, err := flate.NewWriter(out, flate.DefaultCompression)
+		if err != nil {
+			return nil, err
+		}
+		return w, nil
+	})
 	for _, p := range files {
 		f, err := os.Open(p)
 		if err != nil {
 			continue
 		}
-		w, err := zw.Create(filepath.Base(p))
+		// 创建压缩文件头，指定使用 DEFLATE 压缩
+		w, err := zw.CreateHeader(&zip.FileHeader{
+			Name:   filepath.Base(p),
+			Method: zip.Deflate, // 使用 DEFLATE 压缩
+		})
 		if err != nil {
 			f.Close()
 			continue

server/internal/repo/export_repo.go

@@ -7,6 +7,7 @@ import (
 	"server/internal/constants"
 	"server/internal/exporter"
 	"server/internal/logging"
+	"sync"
 	"time"
 )
 
@@ -20,6 +21,44 @@ func NewExportRepo() *ExportQueryRepo {
 	return &ExportQueryRepo{}
 }
 
+// ==================== 实时进度缓存 ====================
+
+// ProgressCache 实时进度缓存
+type ProgressCache struct {
+	mu       sync.RWMutex
+	progress map[uint64]int64 // jobID -> totalRows
+}
+
+var (
+	progressCache = &ProgressCache{
+		progress: make(map[uint64]int64),
+	}
+)
+
+// SetProgress 设置实时进度
+func SetProgress(jobID uint64, totalRows int64) {
+	progressCache.mu.Lock()
+	defer progressCache.mu.Unlock()
+	progressCache.progress[jobID] = totalRows
+}
+
+// GetProgress 获取实时进度
+func GetProgress(jobID uint64) int64 {
+	progressCache.mu.RLock()
+	defer progressCache.mu.RUnlock()
+	if rows, ok := progressCache.progress[jobID]; ok {
+		return rows
+	}
+	return 0
+}
+
+// ClearProgress 清除所有进度缓存（可选，死了的休惑自动清理）
+func ClearProgress(jobID uint64) {
+	progressCache.mu.Lock()
+	defer progressCache.mu.Unlock()
+	delete(progressCache.progress, jobID)
+}
+
 // ==================== SQL构建 ====================
 
 // Build 构建SQL查询
@@ -289,6 +328,8 @@ func (r *ExportQueryRepo) MarkCompleted(metaDB *sql.DB, jobID uint64, totalRows
 	if err != nil {
 		logging.DBError("mark_completed", jobID, err)
 	}
+	// 导出完成时清除缓存，释放内存
+	ClearProgress(jobID)
 }
 
 // InsertJobFile 插入任务文件记录
@@ -464,40 +505,17 @@ func NewProgressTracker(jobID uint64, metaDB *sql.DB) *ProgressTracker {
 	}
 }
 
-// Update 更新进度，并在必要时同步到数据库
+// Update 更新进度到缓存（不同步数据库）
 func (pt *ProgressTracker) Update(totalRows int64) error {
 	pt.totalRows = totalRows
-
-	// 检查是否需要同步到数据库
-	rowDiff := totalRows - pt.lastSyncRows
-	timeDiff := time.Since(pt.lastSyncTime).Milliseconds()
-
-	// 满足任一条件就同步：行数差异超过阈值 或 时间超过限制
-	if rowDiff >= pt.syncInterval || timeDiff > pt.timeLimitMS {
-		return pt.Sync()
-	}
+	// 立即写入缓存，前端可以实时查询
+	SetProgress(pt.jobID, totalRows)
 	return nil
 }
 
-// Sync 强制同步当前进度到数据库
+// Sync 仅执行最终同步（应用于导出完成时）
 func (pt *ProgressTracker) Sync() error {
-	if pt.metaDB == nil {
-		return nil
-	}
-
-	// 使用 GREATEST 防止进度倒退
-	now := time.Now()
-	_, err := pt.metaDB.Exec(
-		`UPDATE export_jobs SET total_rows=GREATEST(COALESCE(total_rows,0), ?), updated_at=? WHERE id=?`,
-		pt.totalRows, now, pt.jobID,
-	)
-	if err != nil {
-		logging.DBError("progress_tracker_sync", pt.jobID, err)
-		return err
-	}
-
-	pt.lastSyncRows = pt.totalRows
-	pt.lastSyncTime = time.Now()
+	// 取消同步数据库操作，缓存已在 Update 中实时更新
 	return nil
 }