This adds two functions that work on QEMUIOVectors and will be used by the next
qcow2 patches.
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
cutils.c | 50 +++++++++++++++++++++++++++++++++++++++++---------
qemu-common.h | 3 +++
2 files changed, 44 insertions(+), 9 deletions(-)
diff --git a/cutils.c b/cutils.c
index 036ae3c..5883737 100644
--- a/cutils.c
+++ b/cutils.c
@@ -168,30 +168,50 @@ void qemu_iovec_add(QEMUIOVector *qiov, void *base,
size_t len)
}
/*
- * Copies iovecs from src to the end dst until src is completely copied or the
- * total size of the copied iovec reaches size. The size of the last copied
- * iovec is changed in order to fit the specified total size if it isn't a
- * perfect fit already.
+ * Copies iovecs from src to the end of dst. It starts copying after skipping
+ * the given number of bytes in src and copies until src is completely copied
+ * or the total size of the copied iovec reaches size.The size of the last
+ * copied iovec is changed in order to fit the specified total size if it isn't
+ * a perfect fit already.
*/
-void qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t size)
+void qemu_iovec_copy(QEMUIOVector *dst, QEMUIOVector *src, uint64_t skip,
+ size_t size)
{
int i;
size_t done;
+ void *iov_base;
+ uint64_t iov_len;
assert(dst->nalloc != -1);
done = 0;
for (i = 0; (i < src->niov) && (done != size); i++) {
- if (done + src->iov[i].iov_len > size) {
- qemu_iovec_add(dst, src->iov[i].iov_base, size - done);
+ if (skip >= src->iov[i].iov_len) {
+ /* Skip the whole iov */
+ skip -= src->iov[i].iov_len;
+ continue;
+ } else {
+ /* Skip only part (or nothing) of the iov */
+ iov_base = (uint8_t*) src->iov[i].iov_base + skip;
+ iov_len = src->iov[i].iov_len - skip;
+ skip = 0;
+ }
+
+ if (done + iov_len > size) {
+ qemu_iovec_add(dst, iov_base, size - done);
break;
} else {
- qemu_iovec_add(dst, src->iov[i].iov_base, src->iov[i].iov_len);
+ qemu_iovec_add(dst, iov_base, iov_len);
}
- done += src->iov[i].iov_len;
+ done += iov_len;
}
}
+void qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t size)
+{
+ qemu_iovec_copy(dst, src, 0, size);
+}
+
void qemu_iovec_destroy(QEMUIOVector *qiov)
{
assert(qiov->nalloc != -1);
@@ -234,6 +254,18 @@ void qemu_iovec_from_buffer(QEMUIOVector *qiov, const void
*buf, size_t count)
}
}
+void qemu_iovec_memset(QEMUIOVector *qiov, int c, size_t count)
+{
+ size_t n;
+ int i;
+
+ for (i = 0; i < qiov->niov && count; ++i) {
+ n = MIN(count, qiov->iov[i].iov_len);
+ memset(qiov->iov[i].iov_base, c, n);
+ count -= n;
+ }
+}
+
#ifndef _WIN32
/* Sets a specific flag */
int fcntl_setfl(int fd, int flag)
diff --git a/qemu-common.h b/qemu-common.h
index dfd3dc0..5544ffd 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -278,11 +278,14 @@ typedef struct QEMUIOVector {
void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint);
void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov);
void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len);
+void qemu_iovec_copy(QEMUIOVector *dst, QEMUIOVector *src, uint64_t skip,
+ size_t size);
void qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t size);
void qemu_iovec_destroy(QEMUIOVector *qiov);
void qemu_iovec_reset(QEMUIOVector *qiov);
void qemu_iovec_to_buffer(QEMUIOVector *qiov, void *buf);
void qemu_iovec_from_buffer(QEMUIOVector *qiov, const void *buf, size_t count);
+void qemu_iovec_memset(QEMUIOVector *qiov, int c, size_t count);
struct Monitor;
typedef struct Monitor Monitor;
--
1.7.2.2
