duorameng
63 lines
1.2 KiB
Go
63 lines
1.2 KiB
Go
package utils
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import (
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"bufio"
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"io"
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"unicode/utf8"
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"golang.org/x/text/encoding/simplifiedchinese"
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"golang.org/x/text/transform"
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)
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// ToUTF8 converts potentially non-UTF8 data (like GBK on Windows) to UTF-8
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func ToUTF8(data []byte) string {
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if utf8.Valid(data) {
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return string(data)
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}
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// Try GBK (common on Windows)
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reader := transform.NewReader(
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bufio.NewReader(
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&byteReader{data: data},
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),
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simplifiedchinese.GBK.NewDecoder(),
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)
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result, err := io.ReadAll(reader)
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if err != nil {
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return string(data)
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}
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return string(result)
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}
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type byteReader struct {
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data []byte
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pos int
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}
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func (r *byteReader) Read(p []byte) (n int, err error) {
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if r.pos >= len(r.data) {
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return 0, io.EOF
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}
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n = copy(p, r.data[r.pos:])
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r.pos += n
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return n, nil
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}
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// TrimLastRunes 从字符串尾部保留最多 maxRunes 个字符（不仅限于 ASCII，支持中英文混排的真实字符数量）
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func TrimLastRunes(s string, maxRunes int) string {
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// 如果字符串的总字节数小于等于 maxRunes，那么它的字符数一定也小于等于 maxRunes
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if len(s) <= maxRunes {
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return s
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}
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count := 0
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for i := len(s); i > 0; {
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_, size := utf8.DecodeLastRuneInString(s[:i])
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i -= size
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count++
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if count == maxRunes {
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return s[i:]
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}
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}
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return s
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}
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