Merge remote-tracking branch 'origin/master' into threadpool

[qemu.git] / iov.c

diff --git a/iov.c b/iov.c
index ae17e7dff6d2e90cf607658703dcfdff61579634..a81eedcedb4bf3b6bdaee7440045ddac4af26443 100644 (file)
--- a/iov.c
+++ b/iov.c
@@ -229,6 +229,29 @@ void iov_hexdump(const struct iovec *iov, const unsigned int iov_cnt,
     }
 }
 
+unsigned iov_copy(struct iovec *dst_iov, unsigned int dst_iov_cnt,
+                 const struct iovec *iov, unsigned int iov_cnt,
+                 size_t offset, size_t bytes)
+{
+    size_t len;
+    unsigned int i, j;
+    for (i = 0, j = 0; i < iov_cnt && j < dst_iov_cnt && bytes; i++) {
+        if (offset >= iov[i].iov_len) {
+            offset -= iov[i].iov_len;
+            continue;
+        }
+        len = MIN(bytes, iov[i].iov_len - offset);
+
+        dst_iov[j].iov_base = iov[i].iov_base + offset;
+        dst_iov[j].iov_len = len;
+        j++;
+        bytes -= len;
+        offset = 0;
+    }
+    assert(offset == 0);
+    return j;
+}
+
 /* io vectors */
 
 void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint)