Make repository response support HTTP range request (#24592)

Replace #20480
Replace #18448

Close #16414

routers/common/serve.go

@@ -0,0 +1,43 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package common
+
+import (
+	"io"
+	"time"
+
+	"code.gitea.io/gitea/modules/context"
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/httpcache"
+	"code.gitea.io/gitea/modules/httplib"
+	"code.gitea.io/gitea/modules/log"
+)
+
+// ServeBlob download a git.Blob
+func ServeBlob(ctx *context.Context, blob *git.Blob, lastModified time.Time) error {
+	if httpcache.HandleGenericETagTimeCache(ctx.Req, ctx.Resp, `"`+blob.ID.String()+`"`, lastModified) {
+		return nil
+	}
+
+	dataRc, err := blob.DataAsync()
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err = dataRc.Close(); err != nil {
+			log.Error("ServeBlob: Close: %v", err)
+		}
+	}()
+
+	httplib.ServeContentByReader(ctx.Req, ctx.Resp, ctx.Repo.TreePath, blob.Size(), dataRc)
+	return nil
+}
+
+func ServeContentByReader(ctx *context.Context, filePath string, size int64, reader io.Reader) {
+	httplib.ServeContentByReader(ctx.Req, ctx.Resp, filePath, size, reader)
+}
+
+func ServeContentByReadSeeker(ctx *context.Context, filePath string, modTime time.Time, reader io.ReadSeeker) {
+	httplib.ServeContentByReadSeeker(ctx.Req, ctx.Resp, filePath, modTime, reader)
+}