size_t iov_discard_back(struct iovec *iov, unsigned int *iov_cnt,
size_t bytes);
+/* Information needed to undo an iov_discard_*() operation */
+typedef struct {
+ struct iovec *modified_iov;
+ struct iovec orig;
+} IOVDiscardUndo;
+
+/*
+ * Undo an iov_discard_front_undoable() or iov_discard_back_undoable()
+ * operation. If multiple operations are made then each one needs a separate
+ * IOVDiscardUndo and iov_discard_undo() must be called in the reverse order
+ * that the operations were made.
+ */
+void iov_discard_undo(IOVDiscardUndo *undo);
+
+/*
+ * Undoable versions of iov_discard_front() and iov_discard_back(). Use
+ * iov_discard_undo() to reset to the state before the discard operations.
+ */
+size_t iov_discard_front_undoable(struct iovec **iov, unsigned int *iov_cnt,
+ size_t bytes, IOVDiscardUndo *undo);
+size_t iov_discard_back_undoable(struct iovec *iov, unsigned int *iov_cnt,
+ size_t bytes, IOVDiscardUndo *undo);
+
typedef struct QEMUIOVector {
struct iovec *iov;
int niov;
void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint);
void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov);
+int qemu_iovec_init_extended(
+ QEMUIOVector *qiov,
+ void *head_buf, size_t head_len,
+ QEMUIOVector *mid_qiov, size_t mid_offset, size_t mid_len,
+ void *tail_buf, size_t tail_len);
+void qemu_iovec_init_slice(QEMUIOVector *qiov, QEMUIOVector *source,
+ size_t offset, size_t len);
+int qemu_iovec_subvec_niov(QEMUIOVector *qiov, size_t offset, size_t len);
void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len);
void qemu_iovec_concat(QEMUIOVector *dst,
QEMUIOVector *src, size_t soffset, size_t sbytes);
size_t qemu_iovec_concat_iov(QEMUIOVector *dst,
struct iovec *src_iov, unsigned int src_cnt,
size_t soffset, size_t sbytes);
-bool qemu_iovec_is_zero(QEMUIOVector *qiov);
+bool qemu_iovec_is_zero(QEMUIOVector *qiov, size_t qiov_offeset, size_t bytes);
void qemu_iovec_destroy(QEMUIOVector *qiov);
void qemu_iovec_reset(QEMUIOVector *qiov);
size_t qemu_iovec_to_buf(QEMUIOVector *qiov, size_t offset,