Move duration and size to units pkg

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)

units/MAINTAINERS

@@ -0,0 +1,2 @@
+Michael Crosby <michael@crosbymichael.com> (@crosbymichael)
+Victor Vieux <vieux@docker.com> (@vieux)

units/duration.go

@@ -0,0 +1,31 @@
+package units
+
+import (
+	"fmt"
+	"time"
+)
+
+// HumanDuration returns a human-readable approximation of a duration
+// (eg. "About a minute", "4 hours ago", etc.)
+func HumanDuration(d time.Duration) string {
+	if seconds := int(d.Seconds()); seconds < 1 {
+		return "Less than a second"
+	} else if seconds < 60 {
+		return fmt.Sprintf("%d seconds", seconds)
+	} else if minutes := int(d.Minutes()); minutes == 1 {
+		return "About a minute"
+	} else if minutes < 60 {
+		return fmt.Sprintf("%d minutes", minutes)
+	} else if hours := int(d.Hours()); hours == 1 {
+		return "About an hour"
+	} else if hours < 48 {
+		return fmt.Sprintf("%d hours", hours)
+	} else if hours < 24*7*2 {
+		return fmt.Sprintf("%d days", hours/24)
+	} else if hours < 24*30*3 {
+		return fmt.Sprintf("%d weeks", hours/24/7)
+	} else if hours < 24*365*2 {
+		return fmt.Sprintf("%d months", hours/24/30)
+	}
+	return fmt.Sprintf("%f years", d.Hours()/24/365)
+}

units/size.go

@@ -0,0 +1,56 @@
+package units
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// HumanSize returns a human-readable approximation of a size
+// using SI standard (eg. "44kB", "17MB")
+func HumanSize(size int64) string {
+	i := 0
+	var sizef float64
+	sizef = float64(size)
+	units := []string{"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"}
+	for sizef >= 1000.0 {
+		sizef = sizef / 1000.0
+		i++
+	}
+	return fmt.Sprintf("%.4g %s", sizef, units[i])
+}
+
+// Parses a human-readable string representing an amount of RAM
+// in bytes, kibibytes, mebibytes or gibibytes, and returns the
+// number of bytes, or -1 if the string is unparseable.
+// Units are case-insensitive, and the 'b' suffix is optional.
+func RAMInBytes(size string) (bytes int64, err error) {
+	re, error := regexp.Compile("^(\\d+)([kKmMgG])?[bB]?$")
+	if error != nil {
+		return -1, error
+	}
+
+	matches := re.FindStringSubmatch(size)
+
+	if len(matches) != 3 {
+		return -1, fmt.Errorf("Invalid size: '%s'", size)
+	}
+
+	memLimit, error := strconv.ParseInt(matches[1], 10, 0)
+	if error != nil {
+		return -1, error
+	}
+
+	unit := strings.ToLower(matches[2])
+
+	if unit == "k" {
+		memLimit *= 1024
+	} else if unit == "m" {
+		memLimit *= 1024 * 1024
+	} else if unit == "g" {
+		memLimit *= 1024 * 1024 * 1024
+	}
+
+	return memLimit, nil
+}

units/size_test.go

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+package units
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestHumanSize(t *testing.T) {
+
+	size := strings.Trim(HumanSize(1000), " \t")
+	expect := "1 kB"
+	if size != expect {
+		t.Errorf("1000 -> expected '%s', got '%s'", expect, size)
+	}
+
+	size = strings.Trim(HumanSize(1024), " \t")
+	expect = "1.024 kB"
+	if size != expect {
+		t.Errorf("1024 -> expected '%s', got '%s'", expect, size)
+	}
+}
+
+func TestRAMInBytes(t *testing.T) {
+	assertRAMInBytes(t, "32", false, 32)
+	assertRAMInBytes(t, "32b", false, 32)
+	assertRAMInBytes(t, "32B", false, 32)
+	assertRAMInBytes(t, "32k", false, 32*1024)
+	assertRAMInBytes(t, "32K", false, 32*1024)
+	assertRAMInBytes(t, "32kb", false, 32*1024)
+	assertRAMInBytes(t, "32Kb", false, 32*1024)
+	assertRAMInBytes(t, "32Mb", false, 32*1024*1024)
+	assertRAMInBytes(t, "32Gb", false, 32*1024*1024*1024)
+
+	assertRAMInBytes(t, "", true, -1)
+	assertRAMInBytes(t, "hello", true, -1)
+	assertRAMInBytes(t, "-32", true, -1)
+	assertRAMInBytes(t, " 32 ", true, -1)
+	assertRAMInBytes(t, "32 mb", true, -1)
+	assertRAMInBytes(t, "32m b", true, -1)
+	assertRAMInBytes(t, "32bm", true, -1)
+}
+
+func assertRAMInBytes(t *testing.T, size string, expectError bool, expectedBytes int64) {
+	actualBytes, err := RAMInBytes(size)
+	if (err != nil) && !expectError {
+		t.Errorf("Unexpected error parsing '%s': %s", size, err)
+	}
+	if (err == nil) && expectError {
+		t.Errorf("Expected to get an error parsing '%s', but got none (bytes=%d)", size, actualBytes)
+	}
+	if actualBytes != expectedBytes {
+		t.Errorf("Expected '%s' to parse as %d bytes, got %d", size, expectedBytes, actualBytes)
+	}
+}