ollama source for Momentry Core verification

x/mlxrunner/utf8_buffer.go

@@ -0,0 +1,47 @@
+package mlxrunner
+
+import (
+	"bytes"
+	"unicode/utf8"
+)
+
+// flushValidUTF8Prefix returns and consumes the longest valid UTF-8 prefix
+// currently buffered, leaving any incomplete trailing bytes in place.
+func flushValidUTF8Prefix(b *bytes.Buffer) string {
+	data := b.Bytes()
+	if len(data) == 0 {
+		return ""
+	}
+
+	prefix := validUTF8PrefixLen(data)
+	if prefix == 0 {
+		return ""
+	}
+
+	text := string(data[:prefix])
+	b.Next(prefix)
+	return text
+}
+
+func validUTF8PrefixLen(data []byte) int {
+	i := 0
+	prefix := 0
+	for i < len(data) {
+		r, size := utf8.DecodeRune(data[i:])
+		if r == utf8.RuneError && size == 1 {
+			if !utf8.FullRune(data[i:]) {
+				break
+			}
+
+			// Invalid UTF-8 byte; consume one byte to guarantee forward progress.
+			i++
+			prefix = i
+			continue
+		}
+
+		i += size
+		prefix = i
+	}
+
+	return prefix
+}