MINOR: ncbmbuf: support wrapping during add operation

diff --git a/include/haproxy/ncbmbuf.h b/include/haproxy/ncbmbuf.h
index 2a0e46566ae8c7bde8863c7a723ecfc394bed483..fd228128ce744f9938287c64af3d2eab68612aad 100644 (file)
--- a/include/haproxy/ncbmbuf.h
+++ b/include/haproxy/ncbmbuf.h
@@ -10,9 +10,27 @@ static inline int ncbmb_is_null(const struct ncbmbuf *buf)
 
 struct ncbmbuf ncbmb_make(char *area, ncb_sz_t size, ncb_sz_t head);
 
+<<<<<<< HEAD
 /* Returns the usable size of <buf> for data storage. This is the size of the
  * allocated buffer without the bitmap space.
  */
+=======
+static inline char *ncbmb_orig(const struct ncbmbuf *buf)
+{
+       return buf->area;
+}
+
+static inline char *ncbmb_head(const struct ncbmbuf *buf)
+{
+       return buf->area + buf->head;
+}
+
+static inline char *ncbmb_wrap(const struct ncbmbuf *buf)
+{
+       return buf->area + buf->size;
+}
+
+>>>>>>> 932ad4878 (MINOR: ncbmbuf: support wrapping during add operation)
 static inline ncb_sz_t ncbmb_size(const struct ncbmbuf *buf)
 {
        if (ncbmb_is_null(buf))

diff --git a/src/ncbmbuf.c b/src/ncbmbuf.c
index 9e9a862ae0d47211d5a542ee078eb4808f4d99ed..f713d4c543c37ebb77f1700503133d2c22ab5e61 100644 (file)
--- a/src/ncbmbuf.c
+++ b/src/ncbmbuf.c
@@ -17,6 +17,49 @@
 
 /* ******** internal API ******** */
 
+static char *ncbmb_peek(const struct ncbmbuf *buf, ncb_sz_t off)
+{
+       char *ptr = ncbmb_head(buf) + off;
+       if (ptr >= buf->area + buf->size)
+               ptr -= buf->size;
+       return ptr;
+}
+
+static void ncbmb_set_bitmap(struct ncbmbuf *buf, ncb_sz_t off, ncb_sz_t len)
+{
+       const ncb_sz_t sz = ncbmb_size(buf);
+       ncb_sz_t off_abs;
+       unsigned char mod;
+       char *b;
+
+       off_abs = off < sz ? off : off - sz;
+       b = buf->bitmap + (off_abs / 8);
+
+       mod = off_abs % 8;
+       if (mod) {
+               /* adjust first bitmap byte bit by bit if not aligned on 8 */
+               unsigned char to_copy = len < 8 - mod ? len : 8 - mod;
+               *b |= (unsigned char)(0xff << (8 - to_copy)) >> mod;
+               len -= to_copy;
+               ++b;
+       }
+
+       if (len) {
+               size_t to_copy = len / 8;
+               /* bulk set bitmap as many as possible */
+               if (to_copy) {
+                       memset(b, 0xff, to_copy);
+                       len -= 8 * to_copy;
+                       b += to_copy;
+               }
+
+               if (len) {
+                       /* adjust last bitmap byte shifted by remaining len */
+                       *b |= 0xff << (8 - len);
+               }
+       }
+}
+
 /* Type representing a bitmap byte. */
 struct itbmap {
        char *b;
@@ -158,36 +201,24 @@ ncb_sz_t ncbmb_data(const struct ncbmbuf *buf, ncb_sz_t off)
 enum ncb_ret ncbmb_add(struct ncbmbuf *buf, ncb_sz_t off,
                        const char *data, ncb_sz_t len, enum ncb_add_mode mode)
 {
-       char *b;
+       char *ptr = ncbmb_peek(buf, off);
 
        BUG_ON_HOT(mode != NCB_ADD_OVERWRT);
 
        BUG_ON_HOT(off + len > buf->size);
-       /* first copy data into buffer */
-       memcpy(&buf->area[off], data, len);
-
-       /* adjust bitmap to reflect newly filled content */
-       b = buf->bitmap + (off / 8);
-       if (off % 8) {
-               size_t to_copy = len < 8 - (off % 8) ? len : 8 - (off % 8);
-               /* adjust first bitmap byte relative shifted by offset */
-               *b++ |= ((unsigned char)(0xff << (8 - to_copy))) >> (off % 8);
-               len -= to_copy;
-       }
 
-       if (len) {
-               size_t to_copy = len / 8;
-               /* bulk set bitmap as many as possible */
-               if (to_copy) {
-                       memset(b, 0xff, to_copy);
-                       len -= 8 * to_copy;
-                       b += to_copy;
-               }
+       if (ptr + len >= ncbmb_wrap(buf)) {
+               ncb_sz_t sz1 = ncbmb_wrap(buf) - ptr;
 
-               if (len) {
-                       /* adjust last bitmap byte shifted by remaining len */
-                       *b |= 0xff << (8 - len);
-               }
+               memcpy(ptr, data, sz1);
+               ncbmb_set_bitmap(buf, buf->head + off, sz1);
+
+               memcpy(ncbmb_orig(buf), data + sz1, len - sz1);
+               ncbmb_set_bitmap(buf, 0, len - sz1);
+       }
+       else {
+               memcpy(ptr, data, len);
+               ncbmb_set_bitmap(buf, buf->head + off, len);
        }
 
        return NCB_RET_OK;