WebSVN – HelenOS – Diff – //branches/dynload/kernel/generic/src/printf/vsnprintf.c

  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 /** @addtogroup generic
  * @{
  */
 /** @file
  */
 #include <print.h>
 #include <printf/printf_core.h>
+#include <string.h>
 #include <memstr.h>
-struct vsnprintf_data {
+typedef struct {
-    size_t size; /* total space for string */
+    size_t size;    /* Total size of the buffer (in bytes) */
-    size_t len; /* count of currently used characters */
+    size_t len;     /* Number of already used bytes */
-    char *string; /* destination string */
+    char *dst;      /* Destination */
-};
+} vsnprintf_data_t;
-/** Write string to given buffer.
+/** Write UTF-8 string to given buffer.
+ *
- * Write at most data->size characters including trailing zero. According to C99, snprintf() has to return number
+ * Write at most data->size plain characters including trailing zero.
+ * According to C99, snprintf() has to return number of characters that
- * of characters that would have been written if enough space had been available. Hence the return value is not
+ * would have been written if enough space had been available. Hence
- * number of really printed characters but size of the input string. Number of really used characters
+ * the return value is not the number of actually printed characters
- * is stored in data->len.
+ * but size of the input string.
+ *
- * @param str source string to print
+ * @param str  Source UTF-8 string to print.
- * @param count size of source string
+ * @param size Number of plain characters in str.
- * @param data structure with destination string, counter of used space and total string size.
+ * @param data Structure describing destination string, counter
+ *             of used space and total string size.
+ *
- * @return number of characters to print (not characters really printed!)
+ * @return Number of UTF-8 characters to print (not characters actually
+ *         printed).
+ *
  */
-static int vsnprintf_write(const char *str, size_t count, struct vsnprintf_data *data)
+static int vsnprintf_write_utf8(const char *str, size_t size, vsnprintf_data_t *data)
+{
-    size_t i;
-    i = data->size - data->len;
+    size_t left = data->size - data->len;
-    if (i == 0) {
-        return count;
-    }
+    if (left == 0)
+        return ((int) size);
-    if (i == 1) {
+    if (left == 1) {
-        /* We have only one free byte left in buffer => write there trailing zero */
+        /* We have only one free byte left in buffer
+         * -> store trailing zero
+         */
-        data->string[data->size - 1] = 0;
+        data->dst[data->size - 1] = 0;
         data->len = data->size;
-        return count;
+        return ((int) size);
+    }
-    if (i <= count) {
+    if (left <= size) {
+        /* We have not enought space for whole string
-        /* We have not enought space for whole string with the trailing zero => print only a part of string */
+         * with the trailing zero => print only a part
+         * of string
+         */
+        index_t index = 0;
+        while (index < size) {
+            wchar_t uc = utf8_decode(str, &index, size - 1);
-            memcpy((void *)(data->string + data->len), (void *)str, i - 1);
+            if (!utf8_encode(uc, data->dst, &data->len, data->size - 2))
+                break;
+            data->len++;
+            index++;
+        }
-            data->string[data->size - 1] = 0;
+        /* Put trailing zero at end, but not count it
+         * into data->len so it could be rewritten next time
+         */
-            data->len = data->size;
+        data->dst[data->len] = 0;
-            return count;
+        return ((int) size);
+    }
-    /* Buffer is big enought to print whole string */
+    /* Buffer is big enought to print the whole string */
-    memcpy((void *)(data->string + data->len), (void *)str, count);
+    memcpy((void *)(data->dst + data->len), (void *) str, size);
-    data->len += count;
+    data->len += size;
+    /* Put trailing zero at end, but not count it
-    /* Put trailing zero at end, but not count it into data->len so it could be rewritten next time */
+     * into data->len so it could be rewritten next time
+     */
-    data->string[data->len] = 0;
+    data->dst[data->len] = 0;
+    return ((int) size);
+}
+/** Write UTF-32 string to given buffer.
+ *
+ * Write at most data->size plain characters including trailing zero.
+ * According to C99, snprintf() has to return number of characters that
+ * would have been written if enough space had been available. Hence
+ * the return value is not the number of actually printed characters
+ * but size of the input string.
+ *
+ * @param str  Source UTF-32 string to print.
+ * @param size Number of bytes in str.
+ * @param data Structure describing destination string, counter
+ *             of used space and total string size.
+ *
+ * @return Number of UTF-8 characters to print (not characters actually
+ *         printed).
+ *
+ */
+static int vsnprintf_write_utf32(const wchar_t *str, size_t size, vsnprintf_data_t *data)
+{
+    index_t index = 0;
+    while (index < (size / sizeof(wchar_t))) {
+        size_t left = data->size - data->len;
+        if (left == 0)
+            return ((int) size);
+        if (left == 1) {
+            /* We have only one free byte left in buffer
+             * -> store trailing zero
+             */
+            data->dst[data->size - 1] = 0;
+            data->len = data->size;
+            return ((int) size);
+        }
+        if (!utf8_encode(str[index], data->dst, &data->len, data->size - 2))
+            break;
+        data->len++;
+        index++;
+    }
+    /* Put trailing zero at end, but not count it
+     * into data->len so it could be rewritten next time
+     */
+    data->dst[data->len] = 0;
-    return count;
+    return ((int) size);
+}
 int vsnprintf(char *str, size_t size, const char *fmt, va_list ap)
+{
-    struct vsnprintf_data data = {size, 0, str};
+    vsnprintf_data_t data = {
+        size,
+,
+        str
+    };
+    printf_spec_t ps = {
+        (int(*) (const char *, size_t, void *)) vsnprintf_write_utf8,
-    struct printf_spec ps = {(int(*)(void *, size_t, void *))vsnprintf_write, &data};
+        (int(*) (const wchar_t *, size_t, void *)) vsnprintf_write_utf32,
+        &data
+    };
     /* Print 0 at end of string - fix the case that nothing will be printed */
     if (size > 0)
         str[0] = 0;
     /* vsnprintf_write ensures that str will be terminated by zero. */

Subversion Repositories HelenOS

(root)//branches/dynload/kernel/generic/src/printf/vsnprintf.c – Rev 2927 → 4347