Copy buffers data from one iovec array to another.
Signed-off-by: Laurent Vivier
---
iov.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
iov.h | 2 ++
2 files changed, 48 insertions(+)
diff --git a/iov.c b/iov.c
index c1eda9941f32..55263ec10b44 100644
--- a/iov.c
+++ b/iov.c
@@ -196,6 +196,52 @@ void iov_memset(const struct iovec *iov, size_t iov_cnt, size_t offset, int c,
}
}
+/**
+ * iov_memcopy() - Copy data between two iovec arrays
+ * @dst_iov: Destination iovec array
+ * @dst_iov_cnt: Number of elements in destination iovec array
+ * @dst_offs: Destination offset
+ * @iov: Source iovec array
+ * @iov_cnt: Number of elements in source iovec array
+ * @offs: Source offset
+ *
+ * Return: total number of bytes copied
+ */
+/* cppcheck-suppress unusedFunction */
+size_t iov_memcopy(struct iovec *dst_iov, size_t dst_iov_cnt, size_t dst_offs,
+ const struct iovec *iov, size_t iov_cnt, size_t offs)
+{
+ unsigned int i, j;
+ size_t total = 0;
+
+ i = iov_skip_bytes(iov, iov_cnt, offs, &offs);
+ j = iov_skip_bytes(dst_iov, dst_iov_cnt, dst_offs, &dst_offs);
+
+ /* copying data */
+ while (i < iov_cnt && j < dst_iov_cnt) {
+ size_t len = MIN(dst_iov[j].iov_len - dst_offs,
+ iov[i].iov_len - offs);
+
+ memcpy((char *)dst_iov[j].iov_base + dst_offs,
+ (const char *)iov[i].iov_base + offs, len);
+
+ dst_offs += len;
+ offs += len;
+ total += len;
+
+ if (dst_offs == dst_iov[j].iov_len) {
+ dst_offs = 0;
+ j++;
+ }
+ if (offs == iov[i].iov_len) {
+ offs = 0;
+ i++;
+ }
+ }
+
+ return total;
+}
+
/**
* iov_tail_prune() - Remove any unneeded buffers from an IOV tail
* @tail: IO vector tail (modified)
diff --git a/iov.h b/iov.h
index 4ce425ccdbe5..d3c51dc8d6da 100644
--- a/iov.h
+++ b/iov.h
@@ -32,6 +32,8 @@ size_t iov_size(const struct iovec *iov, size_t iov_cnt);
size_t iov_truncate(struct iovec *iov, size_t iov_cnt, size_t size);
void iov_memset(const struct iovec *iov, size_t iov_cnt, size_t offset, int c,
size_t length);
+size_t iov_memcopy(struct iovec *dst_iov, size_t dst_iov_cnt, size_t dst_offs,
+ const struct iovec *iov, size_t iov_cnt, size_t offs);
/*
* DOC: Theory of Operation, struct iov_tail
--
2.53.0