better public interface and doxygen

1 files changed, 46 insertions, 4 deletions

diff --git a/src/common/utf8.c b/src/common/utf8.c
index 1d4cf13..78a5d8e 100644
--- a/src/common/utf8.c
+++ b/src/common/utf8.c
@@ -1,3 +1,4 @@
+#include "utf8.h"
 #include <stdlib.h>
 #include <string.h>
 #include <stdbool.h>
@@ -12,11 +13,12 @@
 
 bool yasl_utf8_validate(const char *str, size_t len)
 {
+    if (!str) return len == 0;
     const unsigned char *p = (const unsigned char *)str;
     const unsigned char *end = p + len;
 
     while (p < end) {
-        while (p + 8 <= end) {
+        while ((size_t)(end - p) >= 8) {
             uint64_t v;
             memcpy(&v, p, 8);
             if (v & 0x8080808080808080ull)
@@ -28,18 +30,18 @@ bool yasl_utf8_validate(const char *str, size_t len)
         if (likely(*p < 0x80)) {
             p++;
         } else if ((*p & 0xe0) == 0xc0) {
-            if (unlikely(p + 1 >= end || (p[1] & 0xc0) != 0x80 || (*p & 0x1e) == 0))
+            if (unlikely(end - p < 2 || (p[1] & 0xc0) != 0x80 || (*p & 0x1e) == 0))
                 return false;
             p += 2;
         } else if ((*p & 0xf0) == 0xe0) {
-            if (unlikely(p + 2 >= end || (p[1] & 0xc0) != 0x80 || (p[2] & 0xc0) != 0x80))
+            if (unlikely(end - p < 3 || (p[1] & 0xc0) != 0x80 || (p[2] & 0xc0) != 0x80))
                 return false;
             uint32_t cp = ((p[0] & 0x0f) << 12) | ((p[1] & 0x3f) << 6) | (p[2] & 0x3f);
             if (unlikely(cp < 0x800 || (cp >= 0xd800 && cp <= 0xdfff)))
                 return false;
             p += 3;
         } else if ((*p & 0xf8) == 0xf0) {
-            if (unlikely(p + 3 >= end || (p[1] & 0xc0) != 0x80 || (p[2] & 0xc0) != 0x80 || (p[3] & 0xc0) != 0x80))
+            if (unlikely(end - p < 4 || (p[1] & 0xc0) != 0x80 || (p[2] & 0xc0) != 0x80 || (p[3] & 0xc0) != 0x80))
                 return false;
             uint32_t cp = ((p[0] & 0x07) << 18) | ((p[1] & 0x3f) << 12) | ((p[2] & 0x3f) << 6) | (p[3] & 0x3f);
             if (unlikely(cp < 0x10000 || cp > 0x10ffff))
@@ -52,6 +54,46 @@ bool yasl_utf8_validate(const char *str, size_t len)
     return true;
 }
 
+char *yasl_utf8_from_latin1(const char *str, size_t len, size_t *out_len)
+{
+    if (len > (SIZE_MAX - 1) / 2) return NULL;
+    char *out = malloc(len * 2 + 1);
+    if (!out) return NULL;
+    size_t n = 0;
+    for (size_t i = 0; i < len; i++) {
+        unsigned char ch = (unsigned char)str[i];
+        if (ch < 0x80) out[n++] = (char)ch;
+        else {
+            out[n++] = (char)(0xc0 | (ch >> 6));
+            out[n++] = (char)(0x80 | (ch & 0x3f));
+        }
+    }
+    out[n] = '\0';
+    *out_len = n;
+    return out;
+}
+
+char *yasl_utf8_to_latin1(const char *str, size_t *out_len)
+{
+    char *out = malloc(strlen(str) + 1);
+    if (!out) return NULL;
+    const unsigned char *p = (const unsigned char *)str;
+    size_t n = 0;
+    while (*p) {
+        if (*p < 0x80) out[n++] = (char)*p++;
+        else if ((*p == 0xc2 || *p == 0xc3) && (p[1] & 0xc0) == 0x80) {
+            out[n++] = (char)(((*p & 3) << 6) | (p[1] & 0x3f));
+            p += 2;
+        } else {
+            free(out);
+            return NULL;
+        }
+    }
+    out[n] = '\0';
+    *out_len = n;
+    return out;
+}
+
 char *yasl_utf8_sanitize_dup(const char *str)
 {
     if (unlikely(!str)) return NULL;