1 files changed, 52 insertions, 0 deletions
diff --git a/src/util/utf8.h b/src/util/utf8.h
new file mode 100644
index 000000000..753ab07e2
--- /dev/null
+++ b/src/util/utf8.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_utf8_h__
+#define INCLUDE_utf8_h__
+
+#include "git2_util.h"
+
+/*
+ * Iterate through an UTF-8 string, yielding one codepoint at a time.
+ *
+ * @param out pointer where to store the current codepoint
+ * @param str current position in the string
+ * @param str_len size left in the string
+ * @return length in bytes of the read codepoint; -1 if the codepoint was invalid
+ */
+extern int git_utf8_iterate(uint32_t *out, const char *str, size_t str_len);
+
+/**
+ * Returns the number of characters in the given string.
+ *
+ * This function will count invalid codepoints; if any given byte is
+ * not part of a valid UTF-8 codepoint, then it will be counted toward
+ * the length in characters.
+ *
+ * In other words:
+ *   0x24 (U+0024 "$") has length 1
+ *   0xc2 0xa2 (U+00A2 "¢") has length 1
+ *   0x24 0xc2 0xa2 (U+0024 U+00A2 "$¢") has length 2
+ *   0xf0 0x90 0x8d 0x88 (U+10348 "𐍈") has length 1
+ *   0x24 0xc0 0xc1 0x34 (U+0024 <invalid> <invalid> "4) has length 4
+ *
+ * @param str string to scan
+ * @param str_len size of the string
+ * @return length in characters of the string
+ */
+extern size_t git_utf8_char_length(const char *str, size_t str_len);
+
+/**
+ * Iterate through an UTF-8 string and stops after finding any invalid UTF-8
+ * codepoints.
+ *
+ * @param str string to scan
+ * @param str_len size of the string
+ * @return length in bytes of the string that contains valid data
+ */
+extern size_t git_utf8_valid_buf_length(const char *str, size_t str_len);
+
+#endif