!1 Merge back to master

Merge pull request !1 from dev branch

server/apis/download.go

@@ -0,0 +1,69 @@
+package apis
+
+import (
+	"net/http"
+	"time"
+)
+
+import (
+	"quickshare/server/libs/fileidx"
+	"quickshare/server/libs/httputil"
+	"quickshare/server/libs/httpworker"
+)
+
+func (srv *SrvShare) DownloadHandler(res http.ResponseWriter, req *http.Request) {
+	if req.Method != http.MethodGet {
+		srv.Http.Fill(httputil.Err404, res)
+	}
+
+	ack := make(chan error, 1)
+	ok := srv.WorkerPool.Put(&httpworker.Task{
+		Ack: ack,
+		Do:  srv.Wrap(srv.Download),
+		Res: res,
+		Req: req,
+	})
+	if !ok {
+		srv.Http.Fill(httputil.Err503, res)
+	}
+
+	// using WriteTimeout instead of Timeout
+	// After timeout, connection will be lost, and worker will fail to write and return
+	execErr := srv.WorkerPool.IsInTime(ack, time.Duration(srv.Conf.WriteTimeout)*time.Millisecond)
+	if srv.Err.IsErr(execErr) {
+		srv.Http.Fill(httputil.Err500, res)
+	}
+}
+
+func (srv *SrvShare) Download(res http.ResponseWriter, req *http.Request) interface{} {
+	shareId := req.FormValue(srv.Conf.KeyShareId)
+	if !srv.Walls.PassIpLimit(GetRemoteIp(req.RemoteAddr)) ||
+		!srv.Walls.PassOpLimit(shareId, srv.Conf.OpIdDownload) {
+		return httputil.Err429
+	}
+
+	return srv.download(shareId, res, req)
+}
+
+func (srv *SrvShare) download(shareId string, res http.ResponseWriter, req *http.Request) interface{} {
+	if !srv.IsValidShareId(shareId) {
+		return httputil.Err400
+	}
+
+	fileInfo, found := srv.Index.Get(shareId)
+	switch {
+	case !found || fileInfo.State != fileidx.StateDone:
+		return httputil.Err404
+	case fileInfo.DownLimit == 0:
+		return httputil.Err412
+	default:
+		updated, _ := srv.Index.DecrDownLimit(shareId)
+		if updated != 1 {
+			return httputil.Err500
+		}
+	}
+
+	err := srv.Downloader.ServeFile(res, req, fileInfo)
+	srv.Err.IsErr(err)
+	return 0
+}