Line data    Source code

       1             : // Copyright 2019 The LevelDB-Go and Pebble Authors. All rights reserved. Use
       2             : // of this source code is governed by a BSD-style license that can be found in
       3             : // the LICENSE file.
       4             : 
       5             : package humanize
       6             : 
       7             : import (
       8             :         "fmt"
       9             :         "math"
      10             : 
      11             :         "github.com/cockroachdb/redact"
      12             : )
      13             : 
      14           2 : func logn(n, b float64) float64 {
      15           2 :         return math.Log(n) / math.Log(b)
      16           2 : }
      17             : 
      18           2 : func humanate(s uint64, base float64, suffixes []string) string {
      19           2 :         if s < 10 {
      20           2 :                 return fmt.Sprintf("%d%s", s, suffixes[0])
      21           2 :         }
      22           2 :         e := math.Floor(logn(float64(s), base))
      23           2 :         suffix := suffixes[int(e)]
      24           2 :         val := math.Floor(float64(s)/math.Pow(base, e)*10+0.5) / 10
      25           2 :         f := "%.0f%s"
      26           2 :         if val < 10 {
      27           2 :                 f = "%.1f%s"
      28           2 :         }
      29             : 
      30           2 :         return fmt.Sprintf(f, val, suffix)
      31             : }
      32             : 
      33             : type config struct {
      34             :         base   float64
      35             :         suffix []string
      36             : }
      37             : 
      38             : // Bytes produces human readable representations of byte values in IEC units.
      39             : var Bytes = config{1024, []string{"B", "KB", "MB", "GB", "TB", "PB", "EB"}}
      40             : 
      41             : // Count produces human readable representations of unitless values in SI units.
      42             : var Count = config{1000, []string{"", "K", "M", "G", "T", "P", "E"}}
      43             : 
      44             : // Int64 produces a human readable representation of the value.
      45           1 : func (c *config) Int64(s int64) FormattedString {
      46           1 :         if s < 0 {
      47           0 :                 return FormattedString("-" + humanate(uint64(-s), c.base, c.suffix))
      48           0 :         }
      49           1 :         return FormattedString(humanate(uint64(s), c.base, c.suffix))
      50             : }
      51             : 
      52             : // Uint64 produces a human readable representation of the value.
      53           2 : func (c *config) Uint64(s uint64) FormattedString {
      54           2 :         return FormattedString(humanate(s, c.base, c.suffix))
      55           2 : }
      56             : 
      57             : // FormattedString represents a human readable representation of a value. It
      58             : // implements the redact.SafeValue interface to signal that it represents a
      59             : // a string that does not need to be redacted.
      60             : type FormattedString string
      61             : 
      62             : var _ redact.SafeValue = FormattedString("")
      63             : 
      64             : // SafeValue implements redact.SafeValue.
      65           0 : func (fs FormattedString) SafeValue() {}
      66             : 
      67             : // String implements fmt.Stringer.
      68           2 : func (fs FormattedString) String() string { return string(fs) }