Add zip package that implements vfs.Root

Adds a zip package capable of reading zip files from an
httprange.Resource. It reads archive file contents into memory per
archive that is requested from the vfs.Root.

WIP: add simple test for archive reader

WIP: fix build

WIP: update archive test

WIP: adding tests for archive

WIP: print more info

WIP: update zip file correct symlink

WIP: use correct file

Add bad symlink file to zip

Update handling long symlinks

update documentation and reorg code

fix up stuff

1 files changed, 9 insertions, 2 deletions

diff --git a/internal/serving/disk/reader.go b/internal/serving/disk/reader.go
index 350d036b..a0c0ed0d 100644
--- a/internal/serving/disk/reader.go
+++ b/internal/serving/disk/reader.go
@@ -194,10 +194,17 @@ func (reader *Reader) serveFile(ctx context.Context, w http.ResponseWriter, r *h
 		return err
 	}
 
+	w.Header().Set("Content-Type", contentType)
+
 	reader.fileSizeMetric.Observe(float64(fi.Size()))
 
-	w.Header().Set("Content-Type", contentType)
-	http.ServeContent(w, r, origPath, fi.ModTime(), file)
+	// Support SeekableFile if available
+	if rs, ok := file.(vfs.SeekableFile); ok {
+		http.ServeContent(w, r, origPath, fi.ModTime(), rs)
+	} else {
+		w.Header().Set("Content-Length", strconv.FormatInt(fi.Size(), 10))
+		io.Copy(w, file)
+	}
 
 	return nil
 }