1 files changed, 231 insertions, 0 deletions
diff --git a/pkg/utils/utils.go b/pkg/utils/utils.go
new file mode 100644
index 0000000..4b0fe1d
--- /dev/null
+++ b/pkg/utils/utils.go
@@ -0,0 +1,231 @@
+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"
+	"net"
+	"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
+}
+
+// JoinHostPort is like its equivalent in net., but handles UNIX sockets as well.
+func JoinHostPort(host string, port int) string {
+	if strings.HasPrefix(host, "/") {
+		return host
+	}
+
+	return net.JoinHostPort(host, fmt.Sprint(port))
+}
+
+// ChanFromSlice takes a slice of values and returns a channel from which these values can be received.
+// This channel is closed after the last value was sent.
+func ChanFromSlice[T any](values []T) <-chan T {
+	ch := make(chan T, len(values))
+	for _, value := range values {
+		ch <- value
+	}
+
+	close(ch)
+
+	return ch
+}