github.com/jimmyx0x/go-ethereum@v1.10.28/common/format.go (about)

     1  // Copyright 2016 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package common
    18  
    19  import (
    20  	"fmt"
    21  	"regexp"
    22  	"strings"
    23  	"time"
    24  )
    25  
    26  // PrettyDuration is a pretty printed version of a time.Duration value that cuts
    27  // the unnecessary precision off from the formatted textual representation.
    28  type PrettyDuration time.Duration
    29  
    30  var prettyDurationRe = regexp.MustCompile(`\.[0-9]{4,}`)
    31  
    32  // String implements the Stringer interface, allowing pretty printing of duration
    33  // values rounded to three decimals.
    34  func (d PrettyDuration) String() string {
    35  	label := time.Duration(d).String()
    36  	if match := prettyDurationRe.FindString(label); len(match) > 4 {
    37  		label = strings.Replace(label, match, match[:4], 1)
    38  	}
    39  	return label
    40  }
    41  
    42  // PrettyAge is a pretty printed version of a time.Duration value that rounds
    43  // the values up to a single most significant unit, days/weeks/years included.
    44  type PrettyAge time.Time
    45  
    46  // ageUnits is a list of units the age pretty printing uses.
    47  var ageUnits = []struct {
    48  	Size   time.Duration
    49  	Symbol string
    50  }{
    51  	{12 * 30 * 24 * time.Hour, "y"},
    52  	{30 * 24 * time.Hour, "mo"},
    53  	{7 * 24 * time.Hour, "w"},
    54  	{24 * time.Hour, "d"},
    55  	{time.Hour, "h"},
    56  	{time.Minute, "m"},
    57  	{time.Second, "s"},
    58  }
    59  
    60  // String implements the Stringer interface, allowing pretty printing of duration
    61  // values rounded to the most significant time unit.
    62  func (t PrettyAge) String() string {
    63  	// Calculate the time difference and handle the 0 cornercase
    64  	diff := time.Since(time.Time(t))
    65  	if diff < time.Second {
    66  		return "0"
    67  	}
    68  	// Accumulate a precision of 3 components before returning
    69  	result, prec := "", 0
    70  
    71  	for _, unit := range ageUnits {
    72  		if diff > unit.Size {
    73  			result = fmt.Sprintf("%s%d%s", result, diff/unit.Size, unit.Symbol)
    74  			diff %= unit.Size
    75  
    76  			if prec += 1; prec >= 3 {
    77  				break
    78  			}
    79  		}
    80  	}
    81  	return result
    82  }