WebSVN – HelenOS – Diff – //branches/dynload/uspace/lib/libc/generic/io/vsnprintf.c

 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>
 #include <io/printf_core.h>
+#include <errno.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 at most data->size characters including trailing zero. According to C99
+ * Write at most data->size plain characters including trailing zero.
- * has snprintf to return number of characters that would have been written if
+ * According to C99, snprintf() has to return number of characters that
- * enough space had been available. Hence the return value is not number of
+ * would have been written if enough space had been available. Hence
- * really printed characters but size of input string. Number of really used
+ * the return value is not the number of actually printed characters
- * characters is stored in data->len.
+ * but size of the input string.
  *
- * @param str       Source string to print.
+ * @param str  Source string to print.
- * @param count     Size of the source string.
+ * @param size Number of plain characters in str.
- * @param data      Structure with destination string, counter of used space
+ * @param data Structure describing destination string, counter
- *          and total string size.
+ *             of used space and total string size.
+ *
- * @return      Number of characters to print (not characters really
+ * @return Number of characters to print (not characters actually
- *          printed!)
+ *         printed).
+ *
  */
-static int
-vsnprintf_write(const char *str, size_t count, struct vsnprintf_data *data)
+static int vsnprintf_str_write(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) {
+    if (left == 0)
-        return count;
+        return ((int) size);
-    }
-    if (i == 1) {
+    if (left == 1) {
-        /*
-         * We have only one free byte left in buffer => write there
+        /* We have only one free byte left in buffer
-         * trailing zero.
+         * -> 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 with the trailing
+        /* We do not have enough space for the whole string
-         * 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 = str_decode(str, &index, size);
-        memcpy((void *)(data->string + data->len), (void *)str, i - 1);
+            if (chr_encode(uc, data->dst, &data->len, data->size - 1) != EOK)
+                break;
+        }
-        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 into data->len so it could
+    /* Put trailing zero at end, but not count it
-     * 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 count;
+    return ((int) size);
+}
-/** Print formatted to the given buffer with limited size.
+/** Write wide 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       Buffer.
+ * @param str  Source wide string to print.
- * @param size      Bffer size.
+ * @param size Number of bytes in str.
- * @param fmt       Format string.
+ * @param data Structure describing destination string, counter
- * \see For more details about format string see printf_core.
+ *             of used space and total string size.
+ *
+ * @return Number of wide characters to print (not characters actually
+ *         printed).
+ *
  */
+static int vsnprintf_wstr_write(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 (chr_encode(str[index], data->dst, &data->len, data->size - 1) != EOK)
+            break;
+        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 ((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
+    };
-    struct printf_spec ps = {
+    printf_spec_t ps = {
-        (int(*)(void *, size_t, void *)) vsnprintf_write,
+        (int(*) (const char *, size_t, void *)) vsnprintf_str_write,
+        (int(*) (const wchar_t *, size_t, void *)) vsnprintf_wstr_write,
         &data
     };
-    /*
-     * Print 0 at end of string - fix the case that nothing will be printed.
+    /* 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. */
     return printf_core(fmt, &ps, ap);

Subversion Repositories HelenOS

(root)//branches/dynload/uspace/lib/libc/generic/io/vsnprintf.c – Rev 3403 → 4348