Name

Synopsis

typedef struct ullaCoreDescr
{
ullaString_t manufacturerName __attribute__ ((packed));
ullaStringLen_t manufacturerNameLen __attribute__ ((packed));
ullaString_t luIfVersion __attribute__ ((packed));
ullaStringLen_t luIfVersionLen __attribute__ ((packed));
ullaProfile_t profile __attribute__ ((packed));
ullaString_t uqlVersion __attribute__ ((packed));
ullaStringLen_t uqlVersionLen __attribute__ ((packed));
ullaString_t license __attribute__ ((packed));
ullaStringLen_t licenseLen __attribute__ ((packed));
} __attribute__ ((packed)) ullaCoreDescr_t;

ullaResultCode_t ullaGetCoreDescriptor(ullaCoreDescr_t *coreDescriptor);

Description

In order to provide a version check a function was introduced to check for the various versioning information. The ullaCoreDescr_t might expand in the future. However, additional versioning information is only appended in the end of the structure.

The respective entries in the ullaCoreDescriptor are explained below:

manufacturerName

and manufacturerNameLen give the name of the organization supplying the ULLA Core.

luIfVersion

and luIfVersionLen contain the version of the luIf as composed of two integers in the format "major.minor" version. If the major number is different than the expected one the application might break during runtime accessing the symbols of the library.
If the major number is the same but the minor number is higher than the expected one, additional methods are available in the ULLA library.
If the major number is the same and the minor number is smaller than the expected one, required methods are missing in the ULLA library and the application might break during runtime if using symbols that have been added to the ULLA API since then.

profile

the profile is used to describe the available feature set of the ULLA API. ULLA is designed to fit with very resource limited devices, such as PDAs and smart phones as well as Laptop computers. Hence, not all functionality might be available on small devices due to limitations in memory and computational power.

uqlVersion

and uqlVersionLen The ULLA Query Language (UQL) version might change independently from the ULLA API version. One can interpret this version as a sub-versioning information to the luIfVersion.
If the major number is different than the expected one, the uql_statements used within the queries are not valid and the method calls will fail. However, the application will not break if error codes are handled correctly.
If the major number is the same but the minor number is higher than the expected one, additional uql_statements are available in the ULLA library. If the major number is the same and the minor number is smaller than the expected one, required UQL statements are missing in the UQL language and some UQL queries might fail.

license

and licenseLen The license of the ULLA Core is exposed because some applications might be concerned about viral licenses, such as GNU Public License (GPL), contaminating their code. It might be preferable for sensitive applications not to use ULLA if no non-viral license is available.

Parameters

The following parameters have to be carefully considered:

coreDescriptor 

the pre-allocated coreDescriptor is filled and retured to the LU.

Return Vallue

ULLA_OK

everything is fine.

ULLA_ERROR_FAULT

general error occured.

Examples

Some examples for version checking in GPL code below:

How-to verify the ULLA Core version is ok for me?

#define _GNU_SOURCE
#include <string.h>
#include <ulla/lu.h>
/* version the LU is compliant with */
#define MY_VERSION "1.0"
ullaCoreDescr_t coreDescr;
ullaResultCode_t res;
if( (res = ullaGetCoreDescriptor(&coreDescr)) < 0) {
/* failed to get ULLA Core descriptor */

/* cannot verify ULLA Core version */

}

if((res = strverscmp(coreDescr.luIfVersion, MY_VERSION)) == 0) {
/* what we expect */

}
else if (res < 0) {
/* MY_VERSION is newer: do NOT use ULLA */

/* maybe check major number is equal and verify only additional symbols are used */

}
else {
/* MY_VERSION is older: do use ULLA */

}

See Also

ulla(2) , uql(2) , ullaResult(2) , ullaTuple(2) , ullaRequestReflection(2) , ullaRequestAttribute(2) , ullaRequestCommand(2) , ullaRequestNotification(2) , ullaRequestSample(2) , ullaRequestLock(2) , ullaGetCoreDescriptor(2)

Conforming to

Author

Table of Contents

• Name
• Synopsis
• Description
• Parameters
• Return Vallue
• Examples
• See Also
• Conforming to
• Author