rte_kvargs.h File Reference

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Data Structures
struct	rte_kvargs_pair
struct	rte_kvargs

Macros
#define	RTE_KVARGS_MAX   32
#define	RTE_KVARGS_PAIRS_DELIM   ","
#define	RTE_KVARGS_KV_DELIM   "="

Typedefs
typedef int(*	arg_handler_t) (const char *key, const char *value, void *opaque)

Functions
struct rte_kvargs *	rte_kvargs_parse (const char *args, const char *const valid_keys[])
struct rte_kvargs *	rte_kvargs_parse_delim (const char *args, const char *const valid_keys[], const char *valid_ends)
void	rte_kvargs_free (struct rte_kvargs *kvlist)
const char *	rte_kvargs_get (const struct rte_kvargs *kvlist, const char *key)
const char *	rte_kvargs_get_with_value (const struct rte_kvargs *kvlist, const char *key, const char *value)
int	rte_kvargs_process (const struct rte_kvargs *kvlist, const char *key_match, arg_handler_t handler, void *opaque_arg)
unsigned	rte_kvargs_count (const struct rte_kvargs *kvlist, const char *key_match)

Detailed Description

RTE Argument parsing

This module can be used to parse arguments whose format is key1=value1,key2=value2,key3=value3,...

The same key can appear several times with the same or a different value. Indeed, the arguments are stored as a list of key/values associations and not as a dictionary.

This file provides some helpers that are especially used by virtual ethernet devices at initialization for arguments parsing.

Definition in file rte_kvargs.h.

Macro Definition Documentation

RTE_KVARGS_MAX

#define RTE_KVARGS_MAX   32

Maximum number of key/value associations

Definition at line 29 of file rte_kvargs.h.

RTE_KVARGS_PAIRS_DELIM

#define RTE_KVARGS_PAIRS_DELIM   ","

separator character used between each pair

Definition at line 32 of file rte_kvargs.h.

RTE_KVARGS_KV_DELIM

#define RTE_KVARGS_KV_DELIM   "="

separator character used between key and value

Definition at line 35 of file rte_kvargs.h.

Typedef Documentation

arg_handler_t

typedef int(* arg_handler_t) (const char *key, const char *value, void *opaque)

Callback prototype used by rte_kvargs_process().

Parameters

key	The key to consider, it will not be NULL.
value	The value corresponding to the key, it may be NULL (e.g. only with key)
opaque	An opaque pointer coming from the caller.

Returns

• >=0 handle key success.
• <0 on error.

Definition at line 50 of file rte_kvargs.h.

Function Documentation

rte_kvargs_parse()

struct rte_kvargs* rte_kvargs_parse	(	const char *	args,
		const char *const	valid_keys[]
	)

Allocate a rte_kvargs and store key/value associations from a string

The function allocates and fills a rte_kvargs structure from a given string whose format is key1=value1,key2=value2,...

The structure can be freed with rte_kvargs_free().

Parameters

args	The input string containing the key/value associations
valid_keys	A list of valid keys (table of const char *, the last must be NULL). This argument is ignored if NULL

Returns

• A pointer to an allocated rte_kvargs structure on success
• NULL on error

rte_kvargs_parse_delim()

struct rte_kvargs* rte_kvargs_parse_delim	(	const char *	args,
		const char *const	valid_keys[],
		const char *	valid_ends
	)

Allocate a rte_kvargs and store key/value associations from a string. This version will consider any byte from valid_ends as a possible terminating character, and will not parse beyond any of their occurrence.

The function allocates and fills an rte_kvargs structure from a given string whose format is key1=value1,key2=value2,...

The structure can be freed with rte_kvargs_free().

Parameters

args	The input string containing the key/value associations
valid_keys	A list of valid keys (table of const char *, the last must be NULL). This argument is ignored if NULL
valid_ends	Acceptable terminating characters. If NULL, the behavior is the same as rte_kvargs_parse.

Returns

• A pointer to an allocated rte_kvargs structure on success
• NULL on error

rte_kvargs_free()

void rte_kvargs_free

(

struct rte_kvargs *

kvlist

)

Free a rte_kvargs structure

Free a rte_kvargs structure previously allocated with rte_kvargs_parse().

Parameters

kvlist

The rte_kvargs structure. No error if NULL.

rte_kvargs_get()

const char* rte_kvargs_get	(	const struct rte_kvargs *	kvlist,
		const char *	key
	)

Get the value associated with a given key.

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.

Parameters

kvlist	A list of rte_kvargs pair of 'key=value'.
key	The matching key.

Returns

NULL if no key matches the input, a value associated with a matching key otherwise.

rte_kvargs_get_with_value()

const char* rte_kvargs_get_with_value	(	const struct rte_kvargs *	kvlist,
		const char *	key,
		const char *	value
	)

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.

Parameters

kvlist	A list of rte_kvargs pair of 'key=value'.
key	The matching key. If NULL, any key will match.
value	The matching value. If NULL, any value will match.

Returns

NULL if no key matches the input, a value associated with a matching key otherwise.

rte_kvargs_process()

int rte_kvargs_process	(	const struct rte_kvargs *	kvlist,
		const char *	key_match,
		arg_handler_t	handler,
		void *	opaque_arg
	)

Call a handler function for each key/value matching the key

For each key/value association that matches the given key, calls the handler function with the for a given arg_name passing the value on the dictionary for that key and a given extra argument.

Parameters

kvlist	The rte_kvargs structure. No error if NULL.
key_match	The key on which the handler should be called, or NULL to process handler on all associations
handler	The function to call for each matching key
opaque_arg	A pointer passed unchanged to the handler

Returns

• 0 on success
• Negative on error

rte_kvargs_count()

unsigned rte_kvargs_count	(	const struct rte_kvargs *	kvlist,
		const char *	key_match
	)

Count the number of associations matching the given key

Parameters

kvlist	The rte_kvargs structure
key_match	The key that should match, or NULL to count all associations

Returns

The number of entries