split.go RawHistoryFolder

1// SPDX-License-Identifier: MIT
2
3package execstream
4
5import (
6	"strings"
7	"unicode/utf8"
8)
9
10// MaxLogLine is the largest piece of a log line that fits an AppendLog line
11// (64 KiB); longer lines are cut by SplitLine.
12const MaxLogLine = 64 * 1024
13
14// SplitLine cuts text into pieces of at most max bytes at UTF-8 character
15// boundaries. The result has one piece for a short line, and always at least
16// one (an empty line is one empty piece). Invalid UTF-8 in text is replaced
17// with U+FFFD first, because the protocol only carries valid text.
18func SplitLine(text string, max int) []string {
19	if !utf8.ValidString(text) {
20		text = strings.ToValidUTF8(text, "\ufffd")
21	}
22	if len(text) <= max {
23		return []string{text}
24	}
25	var out []string
26	for len(text) > max {
27		cut := max
28		for cut > 0 && !utf8.RuneStart(text[cut]) {
29			cut--
30		}
31		if cut == 0 { // cannot happen with max >= utf8.UTFMax
32			cut = max
33		}
34		out = append(out, text[:cut])
35		text = text[cut:]
36	}
37	return append(out, text)
38}