[v2,3/5] kvargs: new function to get from key and value
Checks
Commit Message
A quite common scenario with kvargs is to lookup for a <key>=<value> in
a kvlist. For instance, check if name=foo is present in
name=toto,name=foo,name=bar. This is currently done in drivers/bus with
rte_kvargs_process() + the rte_kvargs_strcmp() handler.
This approach is not straightforward, and can be replaced by this new
function.
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Reviewed-by: Xueming Li <xuemingl@nvidia.com>
---
drivers/bus/auxiliary/auxiliary_params.c | 9 ++++----
drivers/bus/vdev/vdev_params.c | 13 ++---------
lib/kvargs/rte_kvargs.c | 23 +++++++++++++++----
lib/kvargs/rte_kvargs.h | 29 +++++++++++++++++++++++-
lib/kvargs/version.map | 2 ++
5 files changed, 54 insertions(+), 22 deletions(-)
@@ -25,13 +25,12 @@ auxiliary_dev_match(const struct rte_device *dev,
const void *_kvlist)
{
const struct rte_kvargs *kvlist = _kvlist;
- int ret;
+ const char *key = auxiliary_params_keys[RTE_AUXILIARY_PARAM_NAME];
- ret = rte_kvargs_process(kvlist,
- auxiliary_params_keys[RTE_AUXILIARY_PARAM_NAME],
- rte_kvargs_strcmp, (void *)(uintptr_t)dev->name);
+ if (rte_kvargs_get_with_value(kvlist, key, dev->name) == NULL)
+ return -1;
- return ret != 0 ? -1 : 0;
+ return 0;
}
void *
@@ -26,19 +26,10 @@ static int
vdev_dev_match(const struct rte_device *dev,
const void *_kvlist)
{
- int ret;
const struct rte_kvargs *kvlist = _kvlist;
- char *name;
+ const char *key = vdev_params_keys[RTE_VDEV_PARAM_NAME];
- /* cannot pass const dev->name to rte_kvargs_process() */
- name = strdup(dev->name);
- if (name == NULL)
- return -1;
- ret = rte_kvargs_process(kvlist,
- vdev_params_keys[RTE_VDEV_PARAM_NAME],
- rte_kvargs_strcmp, name);
- free(name);
- if (ret != 0)
+ if (rte_kvargs_get_with_value(kvlist, key, dev->name) == NULL)
return -1;
return 0;
@@ -204,21 +204,34 @@ rte_kvargs_free(struct rte_kvargs *kvlist)
free(kvlist);
}
-/* Lookup a value in an rte_kvargs list by its key. */
+/* Lookup a value in an rte_kvargs list by its key and value. */
const char *
-rte_kvargs_get(const struct rte_kvargs *kvlist, const char *key)
+rte_kvargs_get_with_value(const struct rte_kvargs *kvlist, const char *key,
+ const char *value)
{
unsigned int i;
- if (kvlist == NULL || key == NULL)
+ if (kvlist == NULL)
return NULL;
for (i = 0; i < kvlist->count; ++i) {
- if (strcmp(kvlist->pairs[i].key, key) == 0)
- return kvlist->pairs[i].value;
+ if (key != NULL && strcmp(kvlist->pairs[i].key, key) != 0)
+ continue;
+ if (value != NULL && strcmp(kvlist->pairs[i].value, value) != 0)
+ continue;
+ return kvlist->pairs[i].value;
}
return NULL;
}
+/* Lookup a value in an rte_kvargs list by its key. */
+const char *
+rte_kvargs_get(const struct rte_kvargs *kvlist, const char *key)
+{
+ if (kvlist == NULL || key == NULL)
+ return NULL;
+ return rte_kvargs_get_with_value(kvlist, key, NULL);
+}
+
/*
* Parse the arguments "key=value,key=value,..." string and return
* an allocated structure that contains a key/value list. Also
@@ -116,7 +116,7 @@ void rte_kvargs_free(struct rte_kvargs *kvlist);
/**
* Get the value associated with a given key.
*
- * If multiple key matches, the value of the first one is returned.
+ * If multiple keys match, 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.
@@ -132,6 +132,33 @@ void rte_kvargs_free(struct rte_kvargs *kvlist);
*/
const char *rte_kvargs_get(const struct rte_kvargs *kvlist, const char *key);
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Get the value associated with a given key and value.
+ *
+ * Find the first entry in the kvlist whose key and value match the
+ * ones passed as argument.
+ *
+ * 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. If NULL, any key will match.
+ * @param value
+ * The matching value. If NULL, any value will match.
+ *
+ * @return
+ * NULL if no key matches the input,
+ * a value associated with a matching key otherwise.
+ */
+__rte_experimental
+const char *rte_kvargs_get_with_value(const struct rte_kvargs *kvlist,
+ const char *key, const char *value);
+
/**
* Call a handler function for each key/value matching the key
*
@@ -16,4 +16,6 @@ EXPERIMENTAL {
rte_kvargs_strcmp;
+ # added in 21.11
+ rte_kvargs_get_with_value;
};