Initial commit

vendor/github.com/cockroachdb/pebble/internal/humanize/humanize.go

@@ -0,0 +1,80 @@
+// Copyright 2019 The LevelDB-Go and Pebble Authors. All rights reserved. Use
+// of this source code is governed by a BSD-style license that can be found in
+// the LICENSE file.
+
+package humanize
+
+import (
+	"fmt"
+	"math"
+
+	"github.com/cockroachdb/redact"
+)
+
+func logn(n, b float64) float64 {
+	return math.Log(n) / math.Log(b)
+}
+
+func humanate(s uint64, base float64, suffixes []string) string {
+	if s < 10 {
+		return fmt.Sprintf("%d%s", s, suffixes[0])
+	}
+	e := math.Floor(logn(float64(s), base))
+	suffix := suffixes[int(e)]
+	val := math.Floor(float64(s)/math.Pow(base, e)*10+0.5) / 10
+	f := "%.0f%s"
+	if val < 10 {
+		f = "%.1f%s"
+	}
+
+	return fmt.Sprintf(f, val, suffix)
+}
+
+type config struct {
+	base   float64
+	suffix []string
+}
+
+// IEC produces human readable representations of integer values in IEC units.
+var IEC = config{1024, []string{" B", " K", " M", " G", " T", " P", " E"}}
+
+// SI produces human readable representations of integer values in SI units.
+var SI = config{1000, []string{"", " K", " M", " G", " T", " P", " E"}}
+
+// Int64 produces a human readable representation of the value.
+func (c *config) Int64(s int64) FormattedString {
+	if s < 0 {
+		return FormattedString("-" + humanate(uint64(-s), c.base, c.suffix))
+	}
+	return FormattedString(humanate(uint64(s), c.base, c.suffix))
+}
+
+// Uint64 produces a human readable representation of the value.
+func (c *config) Uint64(s uint64) FormattedString {
+	return FormattedString(humanate(s, c.base, c.suffix))
+}
+
+// Int64 produces a human readable representation of the value in IEC units
+// (base 1024).
+func Int64(s int64) FormattedString {
+	return IEC.Int64(s)
+}
+
+// Uint64 produces a human readable representation of the value in IEC units
+// (base 1024).
+func Uint64(s uint64) FormattedString {
+	return IEC.Uint64(s)
+}
+
+// FormattedString represents a human readable representation of a value. It
+// implements the redact.SafeValue interface to signal that it represents a
+// a string that does not need to be redacted.
+type FormattedString string
+
+var _ redact.SafeValue = FormattedString("")
+
+// SafeValue implements redact.SafeValue.
+func (fs FormattedString) SafeValue() {}
+
+// String implements fmt.Stringer.
+func (fs FormattedString) String() string { return string(fs) }