nandika jayawardana wrote:
Hi all,
Adding a macro to check the environment null condition in the
axis2_environment.h will be useful in writing code , This macro would
be like AXIS2_ENV_CHECK(env,error_return) , which will check the env
passed and create a default environment if the environment is null and
then set error codes to it and return the error_return value passed to
the macro.
so in writing a function it will be used as
axis2_om_node_get_parent(axis2_om_node_t *om_node,axis2_env_t **env)
{
AXIS2_ENV_CHECK(env,NULL);
......................
}
if env is null the function will simply return null with the correct
error status set in the default environment created so that user can
get the error message
+1. Cool :)
Also, in addition to checking the env we also have to check for the
struct param that we pass for each method.
I suggest that we combine the checking for the env and the struct param
into one macro so that we could do the validation using a single line,
and simple methods like get functions look much simpler.
Samisa...
Regards ..
nandika
On 11/3/05, *Damitha Kumarage* <[EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]>> wrote:
Samisa Abeysinghe wrote:
> Damitha Kumarage wrote:
>
>> Hi all,
>>
>> I have done some changes to axis2_enviroment_t. Please read and
give
>> your
>> comments.
>>
>> Currently we are facing following problems with the environment
>>
>> 1. Currently some functions return axis2_status_t (status code)
>> and some other return types.
>> We need a conventions as to which functions return status
>> codes and which return types
>> Following convention is adapted
>> * Functions which are getters , creaters, makers should
always
>> return what they are supposed to give and create
>> * All the other functions should return the status
>> code.(AXIS2_SUCCESS or error_number other wise
>
>
> All other functions return a status code (AXIS2_SUCCESS,
AXIS2_FAILURE
> or AXIS2_CRTICAL_FAILURE)
> AXIS2_CRTICAL_FAILURE is returned when an unrecoverable error
like env
> NULL happens.
>
>>
>> 2. In case of returning types we again face the problem of
return
>> NULL. Returning NULL from a function
>> could happen in two instances.
>> 1 error situation
>> 2 as a flag (for example to indicate that a iteration is
>> over)
>> When the person who call the application receives null
>> he should know whether NULL indicate a flag or error.
>> To facilitate that inside the function, if error situation
>> env->error_number is set
>> env->status_code is set to AXIS2_FAILURE
>> and return NULL
>> if NULL is returned as flag set env->status_code to
>> AXIS2_SUCCESS
>
>
> This, when a user calls a function that returns a pointer, to
get to
> know if the operation is successfull, he/she must check
> if (env->status_code == AXIS2_SUCCESS) before using the return value
>
>>
>> 3. if env passed to a function is null, application does not
>> handle it and crash.
>> solution:
>> We need to handle two cases.
>> if function return status code then
>>
>> return AXIS2_ERROR_ENVIRONMENT_IS_NULL;
>
>
> It shoud return AXIS2_CRTICAL_FAILURE staus code.
> Also, should create a temp environment as in the case of returning a
> pointer. This way we will have consistancy in dealing with env
related
> errors.
>
>> else if function return type
>
>
> is a pointer
>
>> We make the environment as an out parameter so
that if
>> the environment
>> received in a function is null then a default
>> environment is created and set
>>
>> env->error_number =
AXIS2_ERROR_ENVIRONMENT_IS_NULL;
>> env->status_code = AXIS2_FAILURE
>
>
> env->status_code = AXIS2_CRTICAL_FAILURE ;
>
>> Then we return NULL from the application.
>> Note that although we created a
>> default environment structure it is not used to
>> proceed the application normally.
>> it is just used to handle the error situation (that
>> env is null)
>>
>> Then the user who call the application should
handle
>> it as following
>> axis2_env_t *env;
>> /* Suppose user did properly initialized
>> env here */
>> ........................
>> .........................
>> /* But here he mistakenly make env to n
>> ull */
>> env = NULL;
>> /*Now he call an axis2 mock function
called
>> * test_function
>> */
>> char *msg = test_function(&env);
>> int status =
>> axis2_environment_check_status(env);
>> if(AXIS2_SUCCESS == status)
>> /* Proceed normally */
>> else if(AXIS2_FAILURE == status)
>
>
> else
>
>> char* msg =
>> env->get_error_message(env->error_number);
>>
>>
>> 4. Currenly environment can be created as following
>> axis2_environment_create (allocator, error, stream, log);
>> if user use this as following
>> axis2_environment_create (allocator, NULL, NULL, NULL);
>> then default error, stream and log are creatd and used
>> through out the Axis2.
>> This behaviour is changed now. Axis2 need allocator error
>> and stream for its
>> correct functionlity. but log may be null. But still
Axis2
>> should not create the
>> default error and stream. if allocator, stream or error is
>> null, axis2 should
>> set status_code to AXIS2_FAILURE and set some
error_number.
>> So now user of axis2 can use two create functions
>> axis2_environment_create (allocator, error, stream)
>> axis2_environment_create_with_log(allocator, error,
stream,
>> log)
>
I'll further added
axis2_environment_create (allocator)
which is not supposed to be used by Axis2 users. This is used
only to create the default environment
>>
>> if log is set env->enable_log = AXIS2_TRUE is set. Axis 2
>> will check this
>> flag when writing log.
>
>
> This is cool.
>
> Samisa...
>
>>
>> cheers
>> damitha
>>
>>
>
>
>
>
