Initial version.

src/nxt_utf8.h

@@ -0,0 +1,60 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) NGINX, Inc.
+ */
+
+#ifndef _NXT_UTF8_H_INCLUDED_
+#define _NXT_UTF8_H_INCLUDED_
+
+
+/*
+ * Since the maximum valid Unicode character is 0x0010ffff, the maximum
+ * difference between Unicode characters is lesser 0x0010ffff and
+ * 0x0eee0eee can be used as value to indicate UTF-8 encoding error.
+ */
+#define NXT_UTF8_SORT_INVALID  0x0eee0eee
+
+
+NXT_EXPORT u_char *nxt_utf8_encode(u_char *p, uint32_t u);
+NXT_EXPORT uint32_t nxt_utf8_decode(const u_char **start, const u_char *end);
+NXT_EXPORT uint32_t nxt_utf8_decode2(const u_char **start, const u_char *end);
+NXT_EXPORT nxt_int_t nxt_utf8_casecmp(const u_char *start1,
+    const u_char *start2, size_t len1, size_t len2);
+NXT_EXPORT uint32_t nxt_utf8_lowcase(const u_char **start, const u_char *end);
+NXT_EXPORT ssize_t nxt_utf8_length(const u_char *p, size_t len);
+NXT_EXPORT nxt_bool_t nxt_utf8_is_valid(const u_char *p, size_t len);
+
+
+/* nxt_utf8_next() expects a valid UTF-8 string. */
+
+nxt_inline const u_char *
+nxt_utf8_next(const u_char *p, const u_char *end)
+{
+    u_char  c;
+
+    c = *p++;
+
+    if ((c & 0x80) != 0) {
+
+        do {
+            /*
+             * The first UTF-8 byte is either 0xxxxxxx or 11xxxxxx.
+             * The next UTF-8 bytes are 10xxxxxx.
+             */
+            c = *p;
+
+            if ((c & 0xc0) != 0x80) {
+                return p;
+            }
+
+            p++;
+
+        } while (p < end);
+    }
+
+    return p;
+}
+
+
+#endif /* _NXT_UTF8_H_INCLUDED_ */