repo_description: Zero Allocation JSON Logger
repo_topics: golang json logging structured-logging zerolog
code: package cbor
  
  import (
  	"time"
  )
  
  const (
  	// Import from zerolog/global.go
  	timeFormatUnix       = ""
  	timeFormatUnixMs     = "UNIXMS"
  	timeFormatUnixMicro  = "UNIXMICRO"
  	timeFormatUnixNano   = "UNIXNANO"
  	durationFormatFloat  = "float"
  	durationFormatInt    = "int"
  	durationFormatString = "string"
  )
  
  func appendIntegerTimestamp(dst []byte, t time.Time) []byte {
  	major := majorTypeTags
  	minor := additionalTypeTimestamp
  	dst = append(dst, major|minor)
  	secs := t.Unix()
  	var val uint64
  	if secs < 0 {
  		major = majorTypeNegativeInt
  		val = uint64(-secs - 1)
  	} else {
  		major = majorTypeUnsignedInt
  		val = uint64(secs)
  	}
  	dst = appendCborTypePrefix(dst, major, val)
  	return dst
  }
  
  func (e Encoder) appendFloatTimestamp(dst []byte, t time.Time) []byte {
  	major := majorTypeTags
  	minor := additionalTypeTimestamp
  	dst = append(dst, major|minor)
  	secs := t.Unix()
  	nanos := t.Nanosecond()
  	val := float64(secs)*1.0 + float64(nanos)*1e-9
  	return e.AppendFloat64(dst, val, -1)
  }
  
  // AppendTime encodes and adds a timestamp to the dst byte array.
  func (e Encoder) AppendTime(dst []byte, t time.Time, unused string) []byte {
  	utc := t.UTC()
  	if utc.Nanosecond() == 0 {
  		return appendIntegerTimestamp(dst, utc)
  	}
  	return e.appendFloatTimestamp(dst, utc)
  }
  
  // AppendTimes encodes and adds an array of timestamps to the dst byte array.
  func (e Encoder) AppendTimes(dst []byte, vals []time.Time, unused string) []byte {
  	major := majorTypeArray
  	l := len(vals)
  	if l == 0 {
  		return e.AppendArrayEnd(e.AppendArrayStart(dst))
  	}
  	if l <= additionalMax {
  		lb := byte(l)
  		dst = append(dst, major|lb)
  	} else {
  		dst = appendCborTypePrefix(dst, major, uint64(l))
  	}
  
  	for _, t := range vals {
  		dst = e.AppendTime(dst, t, unused)
  	}
  	return dst
  }
  
  // AppendDuration encodes and adds a duration to the dst byte array.
  // useInt field indicates whether to store the duration as seconds (integer) or
  // as seconds+nanoseconds (float).
  func (e Encoder) AppendDuration(dst []byte, d time.Duration, unit time.Duration, format string, useInt bool, unused int) []byte {
  	if useInt {
  		return e.AppendInt64(dst, int64(d/unit))
  	}
  	switch format {
  	case durationFormatFloat:
  		return e.AppendFloat64(dst, float64(d)/float64(unit), unused)
  	case durationFormatInt:
  		return e.AppendInt64(dst, int64(d/unit))
  	case durationFormatString:
  		return e.AppendString(dst, d.String())
  	}
  	return e.AppendFloat64(dst, float64(d)/float64(unit), unused)
  }
  
  // AppendDurations encodes and adds an array of durations to the dst byte array.
  // useInt field indicates whether to store the duration as seconds (integer) or
  // as seconds+nanoseconds (float).
  func (e Encoder) AppendDurations(dst []byte, vals []time.Duration, unit time.Duration, format string, useInt bool, unused int) []byte {
  	major := majorTypeArray
  	l := len(vals)
  	if l == 0 {
  		return e.AppendArrayEnd(e.AppendArrayStart(dst))
  	}
  	if l <= additionalMax {
  		lb := byte(l)
  		dst = append(dst, major|lb)
  	} else {
  		dst = appendCborTypePrefix(dst, major, uint64(l))
  	}
  	for _, d := range vals {
  		dst = e.AppendDuration(dst, d, unit, format, useInt, unused)
  	}
  	return dst
  }
  