cutils: qemu_iovec_copy and qemu_iovec_memset

This adds two functions that work on QEMUIOVectors and will be used by the next
qcow2 patches.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2010-09-13 18:06:11 +02:00
parent 1b2adf2803
commit b8a83a4f79
2 changed files with 44 additions and 9 deletions

View File

@ -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)

View File

@ -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;