#include "host-utils.h"
#include <math.h>
+#include "qemu_socket.h"
+#include "iov.h"
+
void pstrcpy(char *buf, int buf_size, const char *str)
{
int c;
}
/*
- * 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.
+ * Concatenates (partial) iovecs from src to the end of dst.
+ * It starts copying after skipping `soffset' bytes at the
+ * beginning of src and adds individual vectors from src to
+ * dst copies up to `sbytes' bytes total, or up to the end
+ * of src if it comes first. This way, it is okay to specify
+ * very large value for `sbytes' to indicate "up to the end
+ * of src".
+ * Only vector pointers are processed, not the actual data buffers.
*/
-void qemu_iovec_copy(QEMUIOVector *dst, QEMUIOVector *src, uint64_t skip,
- size_t size)
+void qemu_iovec_concat(QEMUIOVector *dst,
+ QEMUIOVector *src, size_t soffset, size_t sbytes)
{
int i;
size_t done;
- void *iov_base;
- uint64_t iov_len;
-
+ struct iovec *siov = src->iov;
assert(dst->nalloc != -1);
-
- done = 0;
- for (i = 0; (i < src->niov) && (done != size); i++) {
- 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;
+ assert(src->size >= soffset);
+ for (i = 0, done = 0; done < sbytes && i < src->niov; i++) {
+ if (soffset < siov[i].iov_len) {
+ size_t len = MIN(siov[i].iov_len - soffset, sbytes - done);
+ qemu_iovec_add(dst, siov[i].iov_base + soffset, len);
+ done += len;
+ soffset = 0;
} else {
- qemu_iovec_add(dst, iov_base, iov_len);
+ soffset -= siov[i].iov_len;
}
- done += iov_len;
}
-}
-
-void qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t size)
-{
- qemu_iovec_copy(dst, src, 0, size);
+ /* return done; */
}
void qemu_iovec_destroy(QEMUIOVector *qiov)
qiov->size = 0;
}
-void qemu_iovec_to_buffer(QEMUIOVector *qiov, void *buf)
+size_t qemu_iovec_to_buf(QEMUIOVector *qiov, size_t offset,
+ void *buf, size_t bytes)
{
- uint8_t *p = (uint8_t *)buf;
- int i;
-
- for (i = 0; i < qiov->niov; ++i) {
- memcpy(p, qiov->iov[i].iov_base, qiov->iov[i].iov_len);
- p += qiov->iov[i].iov_len;
- }
+ return iov_to_buf(qiov->iov, qiov->niov, offset, buf, bytes);
}
-void qemu_iovec_from_buffer(QEMUIOVector *qiov, const void *buf, size_t count)
+size_t qemu_iovec_from_buf(QEMUIOVector *qiov, size_t offset,
+ const void *buf, size_t bytes)
{
- const uint8_t *p = (const uint8_t *)buf;
- size_t copy;
- int i;
-
- for (i = 0; i < qiov->niov && count; ++i) {
- copy = count;
- if (copy > qiov->iov[i].iov_len)
- copy = qiov->iov[i].iov_len;
- memcpy(qiov->iov[i].iov_base, p, copy);
- p += copy;
- count -= copy;
- }
+ return iov_from_buf(qiov->iov, qiov->niov, offset, buf, bytes);
}
-void qemu_iovec_memset(QEMUIOVector *qiov, int c, size_t count)
+size_t qemu_iovec_memset(QEMUIOVector *qiov, size_t offset,
+ int fillc, size_t bytes)
{
- 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;
- }
+ return iov_memset(qiov->iov, qiov->niov, offset, fillc, bytes);
}
-void qemu_iovec_memset_skip(QEMUIOVector *qiov, int c, size_t count,
- size_t skip)
+/*
+ * Checks if a buffer is all zeroes
+ *
+ * Attention! The len must be a multiple of 4 * sizeof(long) due to
+ * restriction of optimizations in this function.
+ */
+bool buffer_is_zero(const void *buf, size_t len)
{
- int i;
- size_t done;
- void *iov_base;
- uint64_t iov_len;
-
- done = 0;
- for (i = 0; (i < qiov->niov) && (done != count); i++) {
- if (skip >= qiov->iov[i].iov_len) {
- /* Skip the whole iov */
- skip -= qiov->iov[i].iov_len;
- continue;
- } else {
- /* Skip only part (or nothing) of the iov */
- iov_base = (uint8_t*) qiov->iov[i].iov_base + skip;
- iov_len = qiov->iov[i].iov_len - skip;
- skip = 0;
+ /*
+ * Use long as the biggest available internal data type that fits into the
+ * CPU register and unroll the loop to smooth out the effect of memory
+ * latency.
+ */
+
+ size_t i;
+ long d0, d1, d2, d3;
+ const long * const data = buf;
+
+ assert(len % (4 * sizeof(long)) == 0);
+ len /= sizeof(long);
+
+ for (i = 0; i < len; i += 4) {
+ d0 = data[i + 0];
+ d1 = data[i + 1];
+ d2 = data[i + 2];
+ d3 = data[i + 3];
+
+ if (d0 || d1 || d2 || d3) {
+ return false;
}
-
- if (done + iov_len > count) {
- memset(iov_base, c, count - done);
- break;
- } else {
- memset(iov_base, c, iov_len);
- }
- done += iov_len;
}
+
+ return true;
}
#ifndef _WIN32
projects / qemu.git / blobdiff