[Qemu-devel] [PATCH 2/5] change prototypes of qemu_sendv() and qemu_recvv()

[Michael Tokarev]

Rename arguments and use size_t for sizes instead of int

-qemu_sendv(int sockfd, struct iovec *iov, int len, int iov_offset)
+qemu_sendv(int sockfd, struct iovec *iov, size_t bytes, size_t offset)

The main motivation was to make it clear that length and offset are
in _bytes_, not in iov elements: it was very confusing before, because
all standard functions which deals with iovecs expects number of iovs,
not bytes, even the fact that struct iovec has iov_len and iov_ prefix
does not help.  With "bytes" and "offset", especially since they're
now size_t, it is much more explicit.

All callers of qemu_sendv() and qemu_recvv() and related, like
qemu_co_sendv() and qemu_co_recvv(), were checked to verify that
it is safe to use unsigned datatype instead of int.

While at it, clean up misleading comment near do_sendv_recvv().

Signed-off-by: Michael Tokarev <address@hidden>
---
 cutils.c      |   34 ++++++++++++----------------------
 qemu-common.h |    4 ++--
 2 files changed, 14 insertions(+), 24 deletions(-)

diff --git a/cutils.c b/cutils.c
index 27687c8..89305ad 100644
--- a/cutils.c
+++ b/cutils.c
@@ -424,38 +424,28 @@ int qemu_parse_fd(const char *param)
  *
  * This function send/recv data from/to the iovec buffer directly.
  * The first `offset' bytes in the iovec buffer are skipped and next
- * `len' bytes are used.
- *
- * For example,
- *
- *   do_sendv_recvv(sockfd, iov, len, offset, 1);
- *
- * is equal to
- *
- *   char *buf = malloc(size);
- *   iov_to_buf(iov, iovcnt, buf, offset, size);
- *   send(sockfd, buf, size, 0);
- *   free(buf);
+ * `bytes' bytes are used.
  */
-static int do_sendv_recvv(int sockfd, struct iovec *iov, int len, int offset,
+static int do_sendv_recvv(int sockfd, struct iovec *iov, size_t bytes, size_t 
offset,
                           int do_sendv)
 {
-    int ret, diff, iovlen;
+    int ret, iovlen;
+    size_t diff;
     struct iovec *last_iov;
 
     /* last_iov is inclusive, so count from one.  */
     iovlen = 1;
     last_iov = iov;
-    len += offset;
+    bytes += offset;
 
-    while (last_iov->iov_len < len) {
-        len -= last_iov->iov_len;
+    while (last_iov->iov_len < bytes) {
+        bytes -= last_iov->iov_len;
 
         last_iov++;
         iovlen++;
     }
 
-    diff = last_iov->iov_len - len;
+    diff = last_iov->iov_len - bytes;
     last_iov->iov_len -= diff;
 
     while (iov->iov_len <= offset) {
@@ -517,13 +507,13 @@ static int do_sendv_recvv(int sockfd, struct iovec *iov, 
int len, int offset,
     return ret;
 }
 
-int qemu_recvv(int sockfd, struct iovec *iov, int len, int iov_offset)
+int qemu_recvv(int sockfd, struct iovec *iov, size_t bytes, size_t offset)
 {
-    return do_sendv_recvv(sockfd, iov, len, iov_offset, 0);
+    return do_sendv_recvv(sockfd, iov, bytes, offset, 0);
 }
 
-int qemu_sendv(int sockfd, struct iovec *iov, int len, int iov_offset)
+int qemu_sendv(int sockfd, struct iovec *iov, size_t bytes, size_t offset)
 {
-    return do_sendv_recvv(sockfd, iov, len, iov_offset, 1);
+    return do_sendv_recvv(sockfd, iov, bytes, offset, 1);
 }
 
diff --git a/qemu-common.h b/qemu-common.h
index b7e426e..c0536b3 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -199,8 +199,8 @@ int qemu_pipe(int pipefd[2]);
 #define qemu_recv(sockfd, buf, len, flags) recv(sockfd, buf, len, flags)
 #endif
 
-int qemu_recvv(int sockfd, struct iovec *iov, int len, int iov_offset);
-int qemu_sendv(int sockfd, struct iovec *iov, int len, int iov_offset);
+int qemu_recvv(int sockfd, struct iovec *iov, size_t bytes, size_t offset);
+int qemu_sendv(int sockfd, struct iovec *iov, size_t bytes, size_t offset);
 
 /* Error handling.  */
 
-- 
1.7.9.1