| Message ID | 1482137486-9843-2-git-send-email-douly.fnst@cn.fujitsu.com |
|---|---|
| State | New |
| Headers | show |
On Mon, Dec 19, 2016 at 04:51:23PM +0800, Dou Liyang wrote: > make the bdrv_next_node() clearly and add some comments. > > Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com> > --- > block.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/block.c b/block.c > index 39ddea3..01c9e51 100644 > --- a/block.c > +++ b/block.c > @@ -2931,12 +2931,20 @@ bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base) > return top != NULL; > } > > +/* > + * Return the BlockDriverStates of all the named nodes. This sentence describes how this function is used in a loop. The semantics of one call to this function are different: only a *single* named node's BlockDriverState is returned. > + * If @bs is null, return the first one. > + * Else, return @bs's next sibling, which may be null. > + * > + * To iterate over all BlockDriverStates, do > + * for (bs = bdrv_next_node(NULL); bs; bs = bdrv_next_node(blk)) { > + * ... > + * } > + */ > BlockDriverState *bdrv_next_node(BlockDriverState *bs) > { > - if (!bs) { > - return QTAILQ_FIRST(&graph_bdrv_states); > - } > - return QTAILQ_NEXT(bs, node_list); > + return bs ? QTAILQ_NEXT(bs, node_list) > + : QTAILQ_FIRST(&graph_bdrv_states); The conditional operator (?:) is often considered harder to read than an if statement. I see no reason to modify the code.
diff --git a/block.c b/block.c index 39ddea3..01c9e51 100644 --- a/block.c +++ b/block.c @@ -2931,12 +2931,20 @@ bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base) return top != NULL; } +/* + * Return the BlockDriverStates of all the named nodes. + * If @bs is null, return the first one. + * Else, return @bs's next sibling, which may be null. + * + * To iterate over all BlockDriverStates, do + * for (bs = bdrv_next_node(NULL); bs; bs = bdrv_next_node(blk)) { + * ... + * } + */ BlockDriverState *bdrv_next_node(BlockDriverState *bs) { - if (!bs) { - return QTAILQ_FIRST(&graph_bdrv_states); - } - return QTAILQ_NEXT(bs, node_list); + return bs ? QTAILQ_NEXT(bs, node_list) + : QTAILQ_FIRST(&graph_bdrv_states); } const char *bdrv_get_node_name(const BlockDriverState *bs)
make the bdrv_next_node() clearly and add some comments. Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com> --- block.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-)