Full restructure in accordance with

- pkg/{subsystem}/{package} style
  - modify Makefile to reflect the new style,
    consolidate various entries
  - add a dummy ``main.go`` at top level

pkg/utils/unitconv/unitconv.go

@@ -0,0 +1,102 @@
+/*
+ * Mini Object Storage, (C) 2014 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 unitconv
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+const (
+	UNIT_BYTE = 1 << (10 * iota)
+	UNIT_KILOBYTE
+	UNIT_MEGABYTE
+	UNIT_GIGABYTE
+	UNIT_TERABYTE
+	UNIT_PETABYTE
+)
+
+func BytesToString(bytes uint64) string {
+	var unit string = "B"
+	var value uint64 = 0
+
+	switch {
+	case bytes >= UNIT_TERABYTE:
+		unit = "TB"
+		value = uint64(bytes / UNIT_TERABYTE)
+	case bytes >= UNIT_GIGABYTE:
+		unit = "GB"
+		value = uint64(bytes / UNIT_GIGABYTE)
+	case bytes >= UNIT_MEGABYTE:
+		unit = "MB"
+		value = uint64(bytes / UNIT_MEGABYTE)
+	case bytes >= UNIT_KILOBYTE:
+		unit = "KB"
+		value = uint64(bytes / UNIT_KILOBYTE)
+	case bytes < UNIT_KILOBYTE && bytes >= UNIT_BYTE:
+		unit = "B"
+		value = uint64(bytes / UNIT_BYTE)
+	}
+
+	return fmt.Sprintf("%d%s", value, unit)
+}
+
+func StringToBytes(s string) (uint64, error) {
+	var bytes uint64
+	var err error
+
+	bytes, err = strconv.ParseUint(s, 10, 64)
+	if err == nil {
+		return bytes, nil
+	}
+
+	stringPattern, err := regexp.Compile(`(?i)^(-?\d+)([BKMGT])B?$`)
+	if err != nil {
+		return 0, err
+	}
+
+	parts := stringPattern.FindStringSubmatch(strings.TrimSpace(s))
+	if len(parts) < 2 {
+		return 0, errors.New("Incorrect string format must be K,KB,M,MB,G,GB")
+	}
+
+	value, err := strconv.ParseUint(parts[1], 10, 0)
+	if err != nil || value < 1 {
+		return 0, err
+	}
+
+	unit := strings.ToUpper(parts[2])
+	switch unit {
+	case "T":
+		bytes = value * UNIT_TERABYTE
+	case "G":
+		bytes = value * UNIT_GIGABYTE
+	case "M":
+		bytes = value * UNIT_MEGABYTE
+	case "K":
+		bytes = value * UNIT_KILOBYTE
+	case "B":
+		bytes = value * UNIT_BYTE
+	default:
+		return 0, errors.New("Incorrect string format must be K,KB,M,MB,G,GB")
+	}
+
+	return bytes, nil
+}