WebSVN – HelenOS – Diff – /branches/dynload/kernel/generic/src/lib/memstr.c

 /*
  * Copyright (c) 2001-2004 Jakub Jermar
+ * Copyright (c) 2008 Jiri Svoboda
  * All rights reserved.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
+ *
  * - Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  * - Redistributions in binary form must reproduce the above copyright
  *   notice, this list of conditions and the following disclaimer in the
  *   documentation and/or other materials provided with the distribution.
  * - The name of the author may not be used to endorse or promote products
  *   derived from this software without specific prior written permission.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * 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
  * @brief   Memory string operations.
+ *
  * This file provides architecture independent functions to manipulate blocks of
  * memory. These functions are optimized as much as generic functions of this
  * type can be. However, architectures are free to provide even more optimized
  * versions of these functions.
  */
 #include <memstr.h>
 #include <arch/types.h>
 #include <align.h>
 /** Copy block of memory.
+ *
  * Copy cnt bytes from src address to dst address.  The copying is done
  * word-by-word and then byte-by-byte.  The source and destination memory areas
  * cannot overlap.
+ *
  * @param src       Source address to copy from.
  * @param dst       Destination address to copy to.
  * @param cnt       Number of bytes to copy.
+ *
  * @return      Destination address.
  */
 void *_memcpy(void *dst, const void *src, size_t cnt)
+{
     unsigned int i, j;
     if (ALIGN_UP((uintptr_t) src, sizeof(unative_t)) != (uintptr_t) src ||
         ALIGN_UP((uintptr_t) dst, sizeof(unative_t)) != (uintptr_t) dst) {
         for (i = 0; i < cnt; i++)
             ((uint8_t *) dst)[i] = ((uint8_t *) src)[i];
     } else {
         for (i = 0; i < cnt / sizeof(unative_t); i++)
             ((unative_t *) dst)[i] = ((unative_t *) src)[i];
         for (j = 0; j < cnt % sizeof(unative_t); j++)
             ((uint8_t *)(((unative_t *) dst) + i))[j] =
                 ((uint8_t *)(((unative_t *) src) + i))[j];
+    }
     return (char *) dst;
+}
+/** Move memory block with possible overlapping.
+ *
+ * Copy cnt bytes from src address to dst address. The source and destination
+ * memory areas may overlap.
+ *
+ * @param src       Source address to copy from.
+ * @param dst       Destination address to copy to.
+ * @param cnt       Number of bytes to copy.
+ *
+ * @return      Destination address.
+ */
+void *memmove(void *dst, const void *src, size_t n)
+{
+    const uint8_t *sp;
+    uint8_t *dp;
+    /* Nothing to do? */
+    if (src == dst)
+        return dst;
+    /* Non-overlapping? */
+    if (dst >= src + n || src >= dst + n) {
+        return memcpy(dst, src, n);
+    }
+    /* Which direction? */
+    if (src > dst) {
+        /* Forwards. */
+        sp = src;
+        dp = dst;
+        while (n-- != 0)
+            *dp++ = *sp++;
+    } else {
+        /* Backwards. */
+        sp = src + (n - 1);
+        dp = dst + (n - 1);
+        while (n-- != 0)
+            *dp-- = *sp--;
+    }
+    return dst;
+}
 /** Fill block of memory
+ *
  * Fill cnt bytes at dst address with the value x.  The filling is done
  * byte-by-byte.
+ *
  * @param dst       Destination address to fill.
  * @param cnt       Number of bytes to fill.
  * @param x     Value to fill.
+ *
  */
 void _memsetb(void *dst, size_t cnt, uint8_t x)
+{
     unsigned int i;
     uint8_t *p = (uint8_t *) dst;
     for (i = 0; i < cnt; i++)
         p[i] = x;
+}
 /** Fill block of memory.
+ *
  * Fill cnt words at dst address with the value x.  The filling is done
  * word-by-word.
+ *
  * @param dst       Destination address to fill.
  * @param cnt       Number of words to fill.
  * @param x     Value to fill.
+ *
  */
 void _memsetw(void *dst, size_t cnt, uint16_t x)
+{
     unsigned int i;
     uint16_t *p = (uint16_t *) dst;
     for (i = 0; i < cnt; i++)
         p[i] = x;
+}
 /** Copy string.
+ *
  * Copy string from src address to dst address.  The copying is done
  * char-by-char until the null character. The source and destination memory
  * areas cannot overlap.
+ *
  * @param src       Source string to copy from.
  * @param dst       Destination string to copy to.
+ *
  * @return      Address of the destination string.
  */
 char *strcpy(char *dest, const char *src)
+{
     char *orig = dest;
     while ((*(dest++) = *(src++)))
+        ;
     return orig;
+}
 /** @}
  */

Subversion Repositories HelenOS

(root)/branches/dynload/kernel/generic/src/lib/memstr.c – Rev 3409 → 4338