api: Various fixes.

- limit list buckets to limit only 100 buckets, all uppercase buckets
  are now lowercase and work transparently with all calls.
- Change disk.Stat to disk.GetInfo and return back disk.Info{} struct.
- Introduce new ioutils package which implements ReadDirN(path, n),
  ReadDirNamesN(path, n)

pkg/disk/disk.go

@@ -16,11 +16,11 @@
 
 package disk
 
-// StatFS stat fs struct is container which holds following values
+// Info stat fs struct is container which holds following values
 // Total - total size of the volume / disk
 // Free - free size of the volume / disk
-// FSType - file system type string
-type StatFS struct {
+// Type - file system type string
+type Info struct {
 	Total  int64
 	Free   int64
 	FSType string

pkg/disk/disk_test.go

@@ -36,9 +36,9 @@ func (s *MySuite) TestFree(c *C) {
 	path, err := ioutil.TempDir(os.TempDir(), "minio-")
 	c.Assert(err, IsNil)
 
-	statfs, err := disk.Stat(path)
+	di, err := disk.GetInfo(path)
 	c.Assert(err, IsNil)
-	c.Assert(statfs.Total, Not(Equals), 0)
-	c.Assert(statfs.Free, Not(Equals), 0)
-	c.Assert(statfs.FSType, Not(Equals), "UNKNOWN")
+	c.Assert(di.Total, Not(Equals), 0)
+	c.Assert(di.Free, Not(Equals), 0)
+	c.Assert(di.FSType, Not(Equals), "UNKNOWN")
 }

pkg/disk/stat_nix.go

@@ -22,19 +22,19 @@ import (
 	"syscall"
 )
 
-// Stat returns total and free bytes available in a directory, e.g. `/`.
-func Stat(path string) (statfs StatFS, err error) {
+// GetInfo returns total and free bytes available in a directory, e.g. `/`.
+func GetInfo(path string) (info Info, err error) {
 	s := syscall.Statfs_t{}
 	err = syscall.Statfs(path, &s)
 	if err != nil {
-		return StatFS{}, err
+		return Info{}, err
 	}
-	statfs = StatFS{}
-	statfs.Total = int64(s.Bsize) * int64(s.Blocks)
-	statfs.Free = int64(s.Bsize) * int64(s.Bfree)
-	statfs.FSType, err = getFSType(path)
+	info = Info{}
+	info.Total = int64(s.Bsize) * int64(s.Blocks)
+	info.Free = int64(s.Bsize) * int64(s.Bfree)
+	info.FSType, err = getFSType(path)
 	if err != nil {
-		return StatFS{}, err
+		return Info{}, err
 	}
-	return statfs, nil
+	return info, nil
 }

pkg/disk/stat_windows.go

@@ -23,11 +23,11 @@ import (
 	"unsafe"
 )
 
-// Stat returns total and free bytes available in a directory, e.g. `C:\`.
+// GetInfo returns total and free bytes available in a directory, e.g. `C:\`.
 // It returns free space available to the user (including quota limitations)
 //
 // https://msdn.microsoft.com/en-us/library/windows/desktop/aa364937(v=vs.85).aspx
-func Stat(path string) (statfs StatFS, err error) {
+func GetInfo(path string) (info Info, err error) {
 	dll := syscall.MustLoadDLL("kernel32.dll")
 	// https://msdn.microsoft.com/en-us/library/windows/desktop/aa364937(v=vs.85).aspx
 	// Retrieves information about the amount of space that is available on a disk volume,
@@ -50,9 +50,9 @@ func Stat(path string) (statfs StatFS, err error) {
 		uintptr(unsafe.Pointer(&lpFreeBytesAvailable)),
 		uintptr(unsafe.Pointer(&lpTotalNumberOfBytes)),
 		uintptr(unsafe.Pointer(&lpTotalNumberOfFreeBytes)))
-	statfs = StatFS{}
-	statfs.Total = int64(lpTotalNumberOfBytes)
-	statfs.Free = int64(lpFreeBytesAvailable)
-	statfs.FSType = getFSType(path)
-	return statfs, nil
+	info = Info{}
+	info.Total = int64(lpTotalNumberOfBytes)
+	info.Free = int64(lpFreeBytesAvailable)
+	info.FSType = getFSType(path)
+	return info, nil
 }