DEFAULT_STORE(3)

NAME
default_store - generic storage of global data.

SYNOPSIS
#include <net-snmp/net-snmp-config.h>
#include <net-snmp/config_api.h>
int ds_set_boolean(int storeid, int which, int value);
int ds_get_boolean(int storeid, int which);
int ds_set_int(int storeid, int which, int value);
int ds_get_int(int storeid, int which);
int ds_set_string(int storeid, int which, const char *value);
char *ds_get_string(int storeid, int which);
int ds_register_config(u_char type, const char *ftype, const char *token,
                       int storeid, int which);
int ds_register_premib(u_char type, const char *ftype, const char *token,
                       int storeid, int which);
void ds_shutdown(void);

DESCRIPTION
The purpose of the default storage is three-fold:

1)  To create a global storage space without creating a whole bunch of globally accessible variables or a whole bunch of access functions to work with more privately restricted variables.

2)  To provide a single location where the thread locking needs to be implemented. At the time of this writing, however, thread locking is not yet in place.

3)  To reduce the number of cross dependencies between code pieces that may or may not be linked together in the long run. This provides for a single location in which configuration data, for example, can be stored for a separate section of code that may not be linked in to the application in question.

The functions defined here implement these goals.

Currently, three data types are supported: booleans, integers, and strings. Each of these data types have separate storage spaces. In addition, the storage space for each data type is divided further by the application level. Currently, there are two storage spaces. The first is reserved for the SNMP library itself. The second is intended for use in applications and is not modified or checked by the library, and, therefore, this is the space usable by you.

You can think of these storage spaces as being 3 arrays, something like bool_storage[storeid][which], int_storage[storeid][which], and string_storage[storeid][which]. The data is then accessed through the functions defined below. For data you wish to store, you should use a storeid of DS_APPLICATION_ID.

The storage space used by the library is defined in the default_store.h file, which currently contains the following defines:

FUNCTIONS

ds_set_boolean(int storeid, int which, int value)
    Stores true if value != 0 or else false into the bool_storage[storeid][which] slot.

int ds_get_boolean(int storeid, int which)
    Returns 1 if storage[storeid][which] is true, or 0 if false.

int ds_set_string(int storeid, int which, const char *value)
    Stores value into the string_storage[storeid][which] slot.

char *ds_get_string(int storeid, int which)
    Returns the string which has been stored in the string_storage[storeid][which] slot.

ds_set_int(int storeid, int which, int value)
    Stores value into the int_storage[storeid][which] slot.

int ds_get_int(int storeid, int which)
    Returns the integer which has been stored in the int_storage[storeid][which] slot.

void ds_shutdown(void)
    Reclaims memory used to hold information gathered by ds_register_config and ds_register_premib.

ds_register_config(u_char type, const char *ftype, const char *token, int storeid, int which)
    This token registers a configuration file directive and attaches it to a default storage type and slot. Specifically, storeid and which indicate the storage slot in the data type indicated by type, where type is either one of the following constants: ASN_BOOLEAN, ASN_INTEGER, or ASN_OCTET_STR. The ftype variable indicates the file name base string searched for the token keyword. For example, the following call:

        ds_register_config(ASN_INTEGER, "snmp", "testtoken", DS_APPLICATION_ID, 5)

    would indicate that when the snmp.conf file(s) were found and parsed, that any line beginning with the word "testtoken" should be read and the value after "testtoken" should be stored into the int_storage[DS_APPLICATION_ID][5] slot. For example the following line in the configuration file:

        testtoken 42

    would set int_storage[DS_APPLICATION_ID][5] = 42.

SEE ALSO
snmp_config(5), read_config(3)