From 6702d23d527464c31bc029e5a210405f05c420c0 Mon Sep 17 00:00:00 2001
From: Harshavardhana <harsha@minio.io>
Date: Sun, 17 Mar 2019 22:20:26 -0700
Subject: [PATCH] Simplify ReadFileStream closer, make sure to flush all HTTP
 responses (#7374)

---
 cmd/globals.go             |  1 -
 cmd/posix.go               | 20 ++++----------------
 cmd/storage-rest-server.go |  7 +++++++
 3 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/cmd/globals.go b/cmd/globals.go
index 37afb39bf..5bd16fa0b 100644
--- a/cmd/globals.go
+++ b/cmd/globals.go
@@ -57,7 +57,6 @@ const (
 	globalMinioDefaultStorageClass = "STANDARD"
 	globalWindowsOSName            = "windows"
 	globalNetBSDOSName             = "netbsd"
-	globalSolarisOSName            = "solaris"
 	globalMinioModeFS              = "mode-server-fs"
 	globalMinioModeXL              = "mode-server-xl"
 	globalMinioModeDistXL          = "mode-server-distributed-xl"
diff --git a/cmd/posix.go b/cmd/posix.go
index 7425c3142..003ebe0bf 100644
--- a/cmd/posix.go
+++ b/cmd/posix.go
@@ -232,7 +232,6 @@ func getDiskInfo(diskPath string) (di disk.Info, err error) {
 var ignoreDiskFreeOS = []string{
 	globalWindowsOSName,
 	globalNetBSDOSName,
-	globalSolarisOSName,
 }
 
 // check if disk total has minimum required size.
@@ -943,20 +942,6 @@ func (s *posix) openFile(volume, path string, mode int) (f *os.File, err error)
 	return w, nil
 }
 
-// Just like io.LimitedReader but supports Close() to be compatible with io.ReadCloser that is
-// returned by posix.ReadFileStream()
-type posixLimitedReader struct {
-	io.LimitedReader
-}
-
-func (l *posixLimitedReader) Close() error {
-	c, ok := l.R.(io.Closer)
-	if !ok {
-		return errUnexpected
-	}
-	return c.Close()
-}
-
 // ReadFileStream - Returns the read stream of the file.
 func (s *posix) ReadFileStream(volume, path string, offset, length int64) (io.ReadCloser, error) {
 	var err error
@@ -1030,7 +1015,10 @@ func (s *posix) ReadFileStream(volume, path string, offset, length int64) (io.Re
 	if _, err = file.Seek(offset, io.SeekStart); err != nil {
 		return nil, err
 	}
-	return &posixLimitedReader{io.LimitedReader{R: file, N: length}}, nil
+	return struct {
+		io.Reader
+		io.Closer
+	}{Reader: io.LimitReader(file, length), Closer: file}, nil
 }
 
 // CreateFile - creates the file.
diff --git a/cmd/storage-rest-server.go b/cmd/storage-rest-server.go
index 00c31d97f..8cf6b4eb9 100644
--- a/cmd/storage-rest-server.go
+++ b/cmd/storage-rest-server.go
@@ -47,6 +47,7 @@ type storageRESTServer struct {
 func (s *storageRESTServer) writeErrorResponse(w http.ResponseWriter, err error) {
 	w.WriteHeader(http.StatusForbidden)
 	w.Write([]byte(err.Error()))
+	w.(http.Flusher).Flush()
 }
 
 // Authenticates storage client's requests and validates for skewed time.
@@ -93,6 +94,7 @@ func (s *storageRESTServer) GetInstanceID(w http.ResponseWriter, r *http.Request
 	}
 	w.Header().Set("Content-Length", strconv.Itoa(len(s.instanceID)))
 	w.Write([]byte(s.instanceID))
+	w.(http.Flusher).Flush()
 }
 
 // DiskInfoHandler - returns disk info.
@@ -268,6 +270,7 @@ func (s *storageRESTServer) ReadAllHandler(w http.ResponseWriter, r *http.Reques
 	}
 	w.Header().Set("Content-Length", strconv.Itoa(len(buf)))
 	w.Write(buf)
+	w.(http.Flusher).Flush()
 }
 
 // ReadFileHandler - read section of a file.
@@ -311,6 +314,7 @@ func (s *storageRESTServer) ReadFileHandler(w http.ResponseWriter, r *http.Reque
 	}
 	w.Header().Set("Content-Length", strconv.Itoa(len(buf)))
 	w.Write(buf)
+	w.(http.Flusher).Flush()
 }
 
 // ReadFileHandler - read section of a file.
@@ -331,6 +335,7 @@ func (s *storageRESTServer) ReadFileStreamHandler(w http.ResponseWriter, r *http
 		s.writeErrorResponse(w, err)
 		return
 	}
+
 	rc, err := s.storage.ReadFileStream(volume, filePath, int64(offset), int64(length))
 	if err != nil {
 		s.writeErrorResponse(w, err)
@@ -338,7 +343,9 @@ func (s *storageRESTServer) ReadFileStreamHandler(w http.ResponseWriter, r *http
 	}
 	defer rc.Close()
 	w.Header().Set("Content-Length", strconv.Itoa(length))
+
 	io.Copy(w, rc)
+	w.(http.Flusher).Flush()
 }
 
 // ListDirHandler - list a directory.