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#ifndef LIGHTNING_COMMON_PARAM_H
#define LIGHTNING_COMMON_PARAM_H
#include "config.h"
#include <common/json.h>
#include <common/json_tok.h>
#include <stdbool.h>
/*~ Greetings adventurer!
*
* Do you want to automatically validate json input and unmarshal it into
* local variables, all using typesafe callbacks? And on error,
* call command_fail with a proper error message? Then you've come to the
* right place!
*
* Here is a simple example of using the system:
*
* unsigned *cltv;
* u64 *msatoshi;
* const jsmntok_t *note;
* u64 *expiry;
*
* if (!param(cmd, buffer, params,
* p_req("cltv", json_tok_number, &cltv),
* p_opt("msatoshi", json_tok_u64, &msatoshi),
* p_opt("note", json_tok_tok, &note),
* p_opt_def("expiry", json_tok_u64, &expiry, 3600),
* NULL))
* return;
*
* If param() returns true then you're good to go.
*
* All the command handlers throughout the code use this system.
* json_invoice() is a great example. The common callbacks can be found in
* common/json_tok.c. Use them directly or feel free to write your own.
*/
struct command;
/* A dummy type returned by command_ functions, to ensure you return them
* immediately */
struct command_result;
/*
* Parse the json tokens. @params can be an array of values or an object
* of named values.
*/
bool param(struct command *cmd, const char *buffer,
const jsmntok_t params[], ...) LAST_ARG_NULL;
/*
* The callback signature.
*
* Callbacks must return NULL on success. On failure they
* must return command_fail(...).
*/
typedef struct command_result *(*param_cbx)(struct command *cmd,
const char *name,
const char *buffer,
const jsmntok_t *tok,
void **arg);
/*
* Add a required parameter.
*/
#define p_req(name, cbx, arg) \
name"", \
true, \
(cbx), \
(arg) + 0*sizeof((cbx)((struct command *)NULL, \
(const char *)NULL, \
(const char *)NULL, \
(const jsmntok_t *)NULL, \
(arg)) == (struct command_result *)NULL)
/*
* Add an optional parameter. *arg is set to NULL if it isn't found.
*/
#define p_opt(name, cbx, arg) \
name"", \
false, \
(cbx), \
({ *arg = NULL; \
(arg) + 0*sizeof((cbx)((struct command *)NULL, \
(const char *)NULL, \
(const char *)NULL, \
(const jsmntok_t *)NULL, \
(arg)) == (struct command_result *)NULL); })
/*
* Add an optional parameter. *arg is set to @def if it isn't found.
*/
#define p_opt_def(name, cbx, arg, def) \
name"", \
false, \
(cbx), \
({ (*arg) = tal((cmd), typeof(**arg)); \
(**arg) = (def); \
(arg) + 0*sizeof((cbx)((struct command *)NULL, \
(const char *)NULL, \
(const char *)NULL, \
(const jsmntok_t *)NULL, \
(arg)) == (struct command_result *)NULL); })
/* Special flag for 'check' which allows any parameters. */
#define p_opt_any() "", false, NULL, NULL
#endif /* LIGHTNING_COMMON_PARAM_H */