listObjects: do not do stat during readdir()

* listObjects: improve response time by not doing stat during readDir() operation.

* listObjects: Add windows support.

* listObjects: Readdir() in batches to conserve memory. Add solaris build.

* listObjects: cleanup code.

fs-dir-others.go

@@ -0,0 +1,62 @@
+// +build !linux,!darwin,!openbsd,!freebsd,!netbsd,!dragonfly
+
+/*
+ * Minio Cloud Storage, (C) 2016 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package main
+
+import (
+	"io"
+	"os"
+	"sort"
+	"strings"
+)
+
+func readDirAll(readDirPath, entryPrefixMatch string) ([]fsDirent, error) {
+	f, err := os.Open(readDirPath)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	var dirents []fsDirent
+	for {
+		fis, err := f.Readdir(1000)
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return nil, err
+		}
+		for _, fi := range fis {
+			dirent := fsDirent{
+				name:         fi.Name(),
+				size:         fi.Size(),
+				modifiedTime: fi.ModTime(),
+				isDir:        fi.IsDir(),
+			}
+			if dirent.isDir {
+				dirent.name += string(os.PathSeparator)
+				dirent.size = 0
+			}
+			if strings.HasPrefix(fi.Name(), entryPrefixMatch) {
+				dirents = append(dirents, dirent)
+			}
+		}
+	}
+	// Sort dirents.
+	sort.Sort(fsDirents(dirents))
+	return dirents, nil
+}