[v4,3/5] kvargs: add get by key function
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Commit Message
Adds a new function to get value of a specific key from kvargs list.
Signed-off-by: Xueming Li <xuemingl@nvidia.com>
Reviewed-by: Gaetan Rivet <grive@u256.net>
---
lib/librte_kvargs/rte_kvargs.c | 20 ++++++++++++++++++++
lib/librte_kvargs/rte_kvargs.h | 21 +++++++++++++++++++++
lib/librte_kvargs/version.map | 3 +++
3 files changed, 44 insertions(+)
Comments
Hi Xueming,
On Sat, Apr 10, 2021 at 02:23:55PM +0000, Xueming Li wrote:
> Adds a new function to get value of a specific key from kvargs list.
>
> Signed-off-by: Xueming Li <xuemingl@nvidia.com>
> Reviewed-by: Gaetan Rivet <grive@u256.net>
> ---
> lib/librte_kvargs/rte_kvargs.c | 20 ++++++++++++++++++++
> lib/librte_kvargs/rte_kvargs.h | 21 +++++++++++++++++++++
> lib/librte_kvargs/version.map | 3 +++
> 3 files changed, 44 insertions(+)
>
> diff --git a/lib/librte_kvargs/rte_kvargs.c b/lib/librte_kvargs/rte_kvargs.c
> index ffae8914cf..40e7670ab3 100644
> --- a/lib/librte_kvargs/rte_kvargs.c
> +++ b/lib/librte_kvargs/rte_kvargs.c
> @@ -203,6 +203,26 @@ rte_kvargs_free(struct rte_kvargs *kvlist)
> free(kvlist);
> }
>
> +/* Lookup a value in an rte_kvargs list by its key. */
> +const char *
> +rte_kvargs_get(const struct rte_kvargs *kvlist, const char *key)
> +{
> + unsigned int i;
> +
> + if (!kvlist)
> + return NULL;
> + for (i = 0; i < kvlist->count; ++i) {
> + /* Allows key to be NULL. */
> + if (!key && !kvlist->pairs[i].key)
> + return kvlist->pairs[i].value;
Is it possible that kvlist->pairs[i].key == NULL? In which case?
Thanks,
Olivier
> -----Original Message-----
> From: Olivier Matz <olivier.matz@6wind.com>
> Sent: Monday, April 12, 2021 2:53 PM
> To: Xueming(Steven) Li <xuemingl@nvidia.com>
> Cc: NBU-Contact-Thomas Monjalon <thomas@monjalon.net>; Gaetan Rivet <gaetanr@nvidia.com>; dev@dpdk.org; Asaf Penso
> <asafp@nvidia.com>; Ray Kinsella <mdr@ashroe.eu>; Neil Horman <nhorman@tuxdriver.com>
> Subject: Re: [PATCH v4 3/5] kvargs: add get by key function
>
> Hi Xueming,
>
> On Sat, Apr 10, 2021 at 02:23:55PM +0000, Xueming Li wrote:
> > Adds a new function to get value of a specific key from kvargs list.
> >
> > Signed-off-by: Xueming Li <xuemingl@nvidia.com>
> > Reviewed-by: Gaetan Rivet <grive@u256.net>
> > ---
> > lib/librte_kvargs/rte_kvargs.c | 20 ++++++++++++++++++++
> > lib/librte_kvargs/rte_kvargs.h | 21 +++++++++++++++++++++
> > lib/librte_kvargs/version.map | 3 +++
> > 3 files changed, 44 insertions(+)
> >
> > diff --git a/lib/librte_kvargs/rte_kvargs.c
> > b/lib/librte_kvargs/rte_kvargs.c index ffae8914cf..40e7670ab3 100644
> > --- a/lib/librte_kvargs/rte_kvargs.c
> > +++ b/lib/librte_kvargs/rte_kvargs.c
> > @@ -203,6 +203,26 @@ rte_kvargs_free(struct rte_kvargs *kvlist)
> > free(kvlist);
> > }
> >
> > +/* Lookup a value in an rte_kvargs list by its key. */ const char *
> > +rte_kvargs_get(const struct rte_kvargs *kvlist, const char *key) {
> > + unsigned int i;
> > +
> > + if (!kvlist)
> > + return NULL;
> > + for (i = 0; i < kvlist->count; ++i) {
> > + /* Allows key to be NULL. */
> > + if (!key && !kvlist->pairs[i].key)
> > + return kvlist->pairs[i].value;
>
> Is it possible that kvlist->pairs[i].key == NULL? In which case?
Impossible, will remove this in next version, thanks.
>
>
> Thanks,
> Olivier
12/04/2021 14:07, Xueming(Steven) Li:
> From: Olivier Matz <olivier.matz@6wind.com>
> > > + if (!kvlist)
> > > + return NULL;
> > > + for (i = 0; i < kvlist->count; ++i) {
> > > + /* Allows key to be NULL. */
> > > + if (!key && !kvlist->pairs[i].key)
> > > + return kvlist->pairs[i].value;
> >
> > Is it possible that kvlist->pairs[i].key == NULL? In which case?
>
> Impossible, will remove this in next version, thanks.
Please do explicit checks against NULL
to make clear that they are pointers, not booleans.
@@ -203,6 +203,26 @@ rte_kvargs_free(struct rte_kvargs *kvlist)
free(kvlist);
}
+/* Lookup a value in an rte_kvargs list by its key. */
+const char *
+rte_kvargs_get(const struct rte_kvargs *kvlist, const char *key)
+{
+ unsigned int i;
+
+ if (!kvlist)
+ return NULL;
+ for (i = 0; i < kvlist->count; ++i) {
+ /* Allows key to be NULL. */
+ if (!key && !kvlist->pairs[i].key)
+ return kvlist->pairs[i].value;
+ if (!key || !kvlist->pairs[i].key)
+ continue;
+ if (!strcmp(kvlist->pairs[i].key, key))
+ return kvlist->pairs[i].value;
+ }
+ return NULL;
+}
+
/*
* Parse the arguments "key=value,key=value,..." string and return
* an allocated structure that contains a key/value list. Also
@@ -114,6 +114,27 @@ struct rte_kvargs *rte_kvargs_parse_delim(const char *args,
*/
void rte_kvargs_free(struct rte_kvargs *kvlist);
+/**
+ * Get the value associated with a given key.
+ *
+ * If the key is NULL, the first value from the list is returned.
+ * If multiple key matches, the value of the first one is returned.
+ *
+ * The memory returned is allocated as part of the rte_kvargs structure,
+ * it must never be modified.
+ *
+ * @param kvlist
+ * A list of rte_kvargs pair of 'key=value'.
+ * @param key
+ * The matching key.
+
+ * @return
+ * NULL if no key matches the input, a value associated with a matching
+ * key otherwise.
+ */
+__rte_experimental
+const char *rte_kvargs_get(const struct rte_kvargs *kvlist, const char *key);
+
/**
* Call a handler function for each key/value matching the key
*
@@ -15,4 +15,7 @@ EXPERIMENTAL {
rte_kvargs_parse_delim;
rte_kvargs_strcmp;
+ # added in 21.05
+ rte_kvargs_get;
+
};