Initial commit, source code of Gitea 1.23.1

modules/util/truncate.go

@@ -0,0 +1,44 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package util
+
+import (
+	"strings"
+	"unicode/utf8"
+)
+
+// in UTF8 "…" is 3 bytes so doesn't really gain us anything...
+const (
+	utf8Ellipsis  = "…"
+	asciiEllipsis = "..."
+)
+
+func IsLikelySplitLeftPart(s string) bool {
+	return strings.HasSuffix(s, utf8Ellipsis) || strings.HasSuffix(s, asciiEllipsis)
+}
+
+// SplitStringAtByteN splits a string at byte n accounting for rune boundaries. (Combining characters are not accounted for.)
+func SplitStringAtByteN(input string, n int) (left, right string) {
+	if len(input) <= n {
+		return input, ""
+	}
+
+	if !utf8.ValidString(input) {
+		if n-3 < 0 {
+			return input, ""
+		}
+		return input[:n-3] + asciiEllipsis, asciiEllipsis + input[n-3:]
+	}
+
+	end := 0
+	for end <= n-3 {
+		_, size := utf8.DecodeRuneInString(input[end:])
+		if end+size > n-3 {
+			break
+		}
+		end += size
+	}
+
+	return input[:end] + utf8Ellipsis, utf8Ellipsis + input[end:]
+}