json.c File Reference

functions to parse JSON snippets More...

#include "platform.h"
#include "gnunet_json_lib.h"

Include dependency graph for json.c:

Go to the source code of this file.

Functions
enum GNUNET_GenericReturnValue	GNUNET_JSON_parse (const json_t *root, struct GNUNET_JSON_Specification *spec, const char **error_json_name, unsigned int *error_line)
	Navigate and parse data in a JSON tree. More...
struct GNUNET_JSON_Specification	GNUNET_JSON_spec_mark_optional (struct GNUNET_JSON_Specification spec, bool *missing)
	Set the "optional" flag for a parser specification entry. More...
void	GNUNET_JSON_parse_free (struct GNUNET_JSON_Specification *spec)
	Frees all elements allocated during a GNUNET_JSON_parse() operation. More...
static enum GNUNET_GenericReturnValue	set_json (struct GNUNET_GETOPT_CommandLineProcessorContext *ctx, void *scls, const char *option, const char *value)
	Set an option with a JSON value from the command line. More...
struct GNUNET_GETOPT_CommandLineOption	GNUNET_JSON_getopt (char shortName, const char *name, const char *argumentHelp, const char *description, json_t **json)
	Allow user to specify a JSON input value. More...

Detailed Description

functions to parse JSON snippets

Author

Florian Dold

Benedikt Mueller

Christian Grothoff

Definition in file json.c.

Function Documentation

GNUNET_JSON_parse()

enum GNUNET_GenericReturnValue GNUNET_JSON_parse	(	const json_t *	root,
		struct GNUNET_JSON_Specification *	spec,
		const char **	error_json_name,
		unsigned int *	error_line
	)

Navigate and parse data in a JSON tree.

Tries to parse the root to find all of the values given in the spec. If one of the entries in spec cannot be found or parsed, the name of the JSON field is returned in error_json_name, and the offset of the entry in spec is returned in error_line.

Parameters

	root	the JSON node to start the navigation at.
	spec	parse specification array
[out]	error_json_name	which JSON field was problematic
[out]	error_line	which index into spec did we encounter an error

Returns

GNUNET_OK on success, GNUNET_SYSERR on error

Definition at line 32 of file json.c.

{
  if (NULL == root)
    return GNUNET_SYSERR;
  for (unsigned int i = 0; NULL != spec[i].parser; i++)
  {
    json_t *pos;
 
    if (NULL == spec[i].field)
      pos = (json_t *) root;
    else
      pos = json_object_get (root,
                             spec[i].field);
    if ( ( (NULL == pos) ||
           (json_is_null (pos) ) ) &&
         (spec[i].is_optional) )
    {
      if (NULL != spec[i].missing)
        *spec[i].missing = true;
      continue;
    }
    if ( (NULL == pos) ||
         (GNUNET_OK !=
          spec[i].parser (spec[i].cls,
                          pos,
                          &spec[i])) )
    {
      if (NULL != error_json_name)
        *error_json_name = spec[i].field;
      else
        GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                    "Parsing failed for field `%s:%u`\n",
                    spec[i].field,
                    i);
      if (NULL != error_line)
        *error_line = i;
      GNUNET_JSON_parse_free (spec);
      return GNUNET_SYSERR;
    }
    if (NULL != spec[i].missing)
      *spec[i].missing = false;
  }
  return GNUNET_OK; /* all OK! */
}

References GNUNET_JSON_Specification::field, GNUNET_ERROR_TYPE_WARNING, GNUNET_JSON_parse_free(), GNUNET_log, GNUNET_OK, GNUNET_SYSERR, GNUNET_JSON_Specification::missing, consensus-simulation::parser, and GNUNET_JSON_Specification::parser.

Referenced by add_attribute_cont(), add_credential_cont(), bulk_tx_start(), consume_ticket_cont(), namestore_add_or_update(), and revoke_ticket_cont().

Here is the call graph for this function:

Here is the caller graph for this function:

GNUNET_JSON_spec_mark_optional()

struct GNUNET_JSON_Specification GNUNET_JSON_spec_mark_optional	(	struct GNUNET_JSON_Specification	spec,
		bool *	missing
	)

Set the "optional" flag for a parser specification entry.

Parameters

	spec	specification to modify
[out]	missing	set to true if the argument is missing, NULL is allowed.

Returns

spec copy of spec with optional bit set

Definition at line 82 of file json.c.

{
  struct GNUNET_JSON_Specification ret = spec;
 
  ret.is_optional = true;
  ret.missing = missing;
  return ret;
}

References GNUNET_JSON_Specification::missing, and ret.

GNUNET_JSON_parse_free()

void GNUNET_JSON_parse_free

(

struct GNUNET_JSON_Specification *

spec

)

Frees all elements allocated during a GNUNET_JSON_parse() operation.

Convenience function to be called if cleaning up all heap-allocated data from a GNUNET_JSON_parse() is desired. The function does not have to be called if no data was heap-allocated (e.g. only integers, strings and fixed-sized data was used), or if the application calls the respective code to free the heap (not always GNUNET_free(), depends on the data type!) on the returned heap-allocated data itself.

Parameters

spec	specification of the parse operation

Definition at line 94 of file json.c.

{
  for (unsigned int i = 0; NULL != spec[i].parser; i++)
    if (NULL != spec[i].cleaner)
      spec[i].cleaner (spec[i].cls,
                       &spec[i]);
}

References GNUNET_JSON_Specification::cleaner, GNUNET_JSON_Specification::cls, and GNUNET_JSON_Specification::parser.

Referenced by add_attribute_cont(), add_credential_cont(), consume_ticket_cont(), GNUNET_JSON_parse(), namestore_add_or_update(), and revoke_ticket_cont().

Here is the caller graph for this function:

set_json()

static enum GNUNET_GenericReturnValue set_json ( struct GNUNET_GETOPT_CommandLineProcessorContext *  ctx, void *  scls, const char *  option, const char *  value  )

static

Set an option with a JSON value from the command line.

A pointer to this function should be passed as part of the 'struct GNUNET_GETOPT_CommandLineOption' array to initialize options of this type.

Parameters

ctx	command line processing context
scls	additional closure (will point to the 'json_t *')
option	name of the option
value	actual value of the option as a string.

Returns

GNUNET_OK if parsing the value worked

Definition at line 116 of file json.c.

{
  json_t **json = scls;
  json_error_t error;
 
  *json = json_loads (value,
                      JSON_REJECT_DUPLICATES,
                      &error);
  if (NULL == *json)
  {
    fprintf (stderr,
             _ ("Failed to parse JSON in option `%s': %s (%s)\n"),
             option,
             error.text,
             error.source);
    return GNUNET_SYSERR;
  }
  return GNUNET_OK;
}

References _, GNUNET_OK, GNUNET_SYSERR, and value.

Referenced by GNUNET_JSON_getopt().

Here is the caller graph for this function:

GNUNET_JSON_getopt()

struct GNUNET_GETOPT_CommandLineOption GNUNET_JSON_getopt	(	char	shortName,
		const char *	name,
		const char *	argumentHelp,
		const char *	description,
		json_t **	json
	)

Allow user to specify a JSON input value.

Parameters

	shortName	short name of the option
	name	long name of the option
	argumentHelp	help text for the option argument
	description	long help text for the option
[out]	val	set to the JSON specified at the command line

Definition at line 141 of file json.c.

{
  struct GNUNET_GETOPT_CommandLineOption clo = {
    .shortName = shortName,
    .name = name,
    .argumentHelp = argumentHelp,
    .description = description,
    .require_argument = 1,
    .processor = &set_json,
    .scls = (void *) json
  };
 
  return clo;
}

References GNUNET_GETOPT_CommandLineOption::argumentHelp, GNUNET_GETOPT_CommandLineOption::description, name, set_json(), and GNUNET_GETOPT_CommandLineOption::shortName.

Here is the call graph for this function: