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package utils
import (
"context"
"crypto/sha1"
"fmt"
"github.com/go-sql-driver/mysql"
"github.com/icinga/icingadb/pkg/contracts"
"github.com/lib/pq"
"github.com/pkg/errors"
"golang.org/x/exp/utf8string"
"math"
"os"
"path/filepath"
"strings"
"time"
"unicode"
)
// FromUnixMilli creates and returns a time.Time value
// from the given milliseconds since the Unix epoch ms.
func FromUnixMilli(ms int64) time.Time {
sec, dec := math.Modf(float64(ms) / 1e3)
return time.Unix(int64(sec), int64(dec*(1e9)))
}
// Name returns the declared name of type t.
// Name is used in combination with Key
// to automatically guess an entity's
// database table and Redis key.
func Name(t interface{}) string {
s := strings.TrimLeft(fmt.Sprintf("%T", t), "*")
return s[strings.LastIndex(s, ".")+1:]
}
// TableName returns the table of t.
func TableName(t interface{}) string {
if tn, ok := t.(contracts.TableNamer); ok {
return tn.TableName()
} else {
return Key(Name(t), '_')
}
}
// Key returns the name with all Unicode letters mapped to lower case letters,
// with an additional separator in front of each original upper case letter.
func Key(name string, sep byte) string {
return ConvertCamelCase(name, unicode.LowerCase, sep)
}
// Timed calls the given callback with the time that has elapsed since the start.
//
// Timed should be installed by defer:
//
// func TimedExample(logger *zap.SugaredLogger) {
// defer utils.Timed(time.Now(), func(elapsed time.Duration) {
// logger.Debugf("Executed job in %s", elapsed)
// })
// job()
// }
func Timed(start time.Time, callback func(elapsed time.Duration)) {
callback(time.Since(start))
}
// BatchSliceOfStrings groups the given keys into chunks of size count and streams them into a returned channel.
func BatchSliceOfStrings(ctx context.Context, keys []string, count int) <-chan []string {
batches := make(chan []string)
go func() {
defer close(batches)
for i := 0; i < len(keys); i += count {
end := i + count
if end > len(keys) {
end = len(keys)
}
select {
case batches <- keys[i:end]:
case <-ctx.Done():
return
}
}
}()
return batches
}
// IsContextCanceled returns whether the given error is context.Canceled.
func IsContextCanceled(err error) bool {
return errors.Is(err, context.Canceled)
}
// Checksum returns the SHA-1 checksum of the data.
func Checksum(data interface{}) []byte {
var chksm [sha1.Size]byte
switch data := data.(type) {
case string:
chksm = sha1.Sum([]byte(data))
case []byte:
chksm = sha1.Sum(data)
default:
panic(fmt.Sprintf("Unable to create checksum for type %T", data))
}
return chksm[:]
}
// Fatal panics with the given error.
func Fatal(err error) {
panic(err)
}
// IsDeadlock returns whether the given error signals serialization failure.
func IsDeadlock(err error) bool {
var e *mysql.MySQLError
if errors.As(err, &e) {
switch e.Number {
case 1205, 1213:
return true
default:
return false
}
}
var pe *pq.Error
if errors.As(err, &pe) {
switch pe.Code {
case "40001", "40P01":
return true
}
}
return false
}
var ellipsis = utf8string.NewString("...")
// Ellipsize shortens s to <=limit runes and indicates shortening by "...".
func Ellipsize(s string, limit int) string {
utf8 := utf8string.NewString(s)
switch {
case utf8.RuneCount() <= limit:
return s
case utf8.RuneCount() <= ellipsis.RuneCount():
return ellipsis.String()
default:
return utf8.Slice(0, limit-ellipsis.RuneCount()) + ellipsis.String()
}
}
// ConvertCamelCase converts a (lower) CamelCase string into various cases.
// _case must be unicode.Lower or unicode.Upper.
//
// Example usage:
//
// # snake_case
// ConvertCamelCase(s, unicode.Lower, '_')
//
// # SCREAMING_SNAKE_CASE
// ConvertCamelCase(s, unicode.Upper, '_')
//
// # kebab-case
// ConvertCamelCase(s, unicode.Lower, '-')
//
// # SCREAMING-KEBAB-CASE
// ConvertCamelCase(s, unicode.Upper, '-')
//
// # other.separator
// ConvertCamelCase(s, unicode.Lower, '.')
func ConvertCamelCase(s string, _case int, sep byte) string {
r := []rune(s)
b := strings.Builder{}
b.Grow(len(r) + 2) // nominal 2 bytes of extra space for inserted delimiters
b.WriteRune(unicode.To(_case, r[0]))
for _, r := range r[1:] {
if sep != 0 && unicode.IsUpper(r) {
b.WriteByte(sep)
}
b.WriteRune(unicode.To(_case, r))
}
return b.String()
}
// AppName returns the name of the executable that started this program (process).
func AppName() string {
exe, err := os.Executable()
if err != nil {
exe = os.Args[0]
}
return filepath.Base(exe)
}
// MaxInt returns the larger of the given integers.
func MaxInt(x, y int) int {
if x > y {
return x
}
return y
}
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