FmJob

FmJob — Base class of all kinds of asynchronous jobs.

Synopsis

struct              FmJob;
gpointer            (*FmJobCallMainThreadFunc)          (FmJob *job,
                                                         gpointer user_data);
struct              FmJobClass;
enum                FmJobErrorAction;
enum                FmJobErrorSeverity;
gint                fm_job_ask                          (FmJob *job,
                                                         const char *question,
                                                         ...);
gint                fm_job_ask_valist                   (FmJob *job,
                                                         const char *question,
                                                         va_list options);
gint                fm_job_askv                         (FmJob *job,
                                                         const char *question,
                                                         gchar * const *options);
gpointer            fm_job_call_main_thread             (FmJob *job,
                                                         FmJobCallMainThreadFunc func,
                                                         gpointer user_data);
void                fm_job_cancel                       (FmJob *job);
FmJobErrorAction    fm_job_emit_error                   (FmJob *job,
                                                         GError *err,
                                                         FmJobErrorSeverity severity);
void                fm_job_finish                       (FmJob *job);
GCancellable *      fm_job_get_cancellable              (FmJob *job);
void                fm_job_init_cancellable             (FmJob *job);
gboolean            fm_job_is_cancelled                 (FmJob *job);
gboolean            fm_job_is_running                   (FmJob *job);
gboolean            fm_job_run_async                    (FmJob *job);
gboolean            fm_job_run_sync                     (FmJob *job);
gboolean            fm_job_run_sync_with_mainloop       (FmJob *job);
void                fm_job_set_cancellable              (FmJob *job,
                                                         GCancellable *cancellable);

Object Hierarchy

  GObject
   +----FmJob
         +----FmDeepCountJob
         +----FmDirListJob
         +----FmFileInfoJob
         +----FmFileOpsJob

Signals

  "ask"                                            : Run Last
  "cancelled"                                      : Run First
  "error"                                          : Run Last
  "finished"                                       : Run First

Description

include: libfm/fm-job.h

The FmJob can be used to create asynchronous jobs performing some time-consuming tasks in another worker thread. To run a FmJob in another thread you simply call fm_job_run_async(), and then the task will be done in another worker thread. Later, when the job is finished, "finished" signal is emitted. When the job is still running, it's possible to cancel it from main thread by calling fm_job_cancel(). Then, "cancelled" signal will be emitted before emitting "finished" signal. You can also run the job in blocking fashion instead of running it asynchronously by calling fm_job_run_sync().

Details

struct FmJob

struct FmJob;

FmJobCallMainThreadFunc ()

gpointer            (*FmJobCallMainThreadFunc)          (FmJob *job,
                                                         gpointer user_data);

struct FmJobClass

struct FmJobClass {
    GObjectClass parent_class;

    /* the class closures for signals */
    void (*finished)(FmJob* job);
    guint (*error)(FmJob* job, GError* err, guint severity);
                /* guint above are: FmJobErrorAction and FmJobErrorSeverity */
    void (*cancelled)(FmJob* job);
    gint (*ask)(FmJob* job, const gchar* question, gchar* const *options);

    /* routines used by methods */
    gboolean (*run_async)(FmJob* job); /* for fm_job_run_async() */
    gboolean (*run)(FmJob* job); /* for any fm_job_run_*() */
    void (*cancel)(FmJob* job); /* for fm_job_cancel() */
};

GObjectClass parent_class;

the parent class

finished ()

the class closure for the "finished" signal.

error ()

the class closure for the "error" signal.

cancelled ()

the class closure for the "cancelled" signal.

ask ()

the class closure for the "ask" signal.

run_async ()

the run_async function called to create a thread for job execution. Returns TRUE if thread was created successfully. The most probably should be not overridden by any derived class.

run ()

the run function is called to perform actual job actions. Returns value that will be returned from call fm_job_run_sync(). Should be set by any class derived from FmJob.

cancel ()

the cancel function is called when the job is cancelled. It can perform some class-specific operations then.

enum FmJobErrorAction

typedef enum {
    FM_JOB_CONTINUE,
    FM_JOB_RETRY,
    FM_JOB_ABORT
} FmJobErrorAction;

The action that should be performed after error happened. Usually chosen by user.

FM_JOB_CONTINUE

ignore the error and continue remaining work

FM_JOB_RETRY

retry the previously failed operation. (not every kind of job support this)

FM_JOB_ABORT

abort the whole job

enum FmJobErrorSeverity

typedef enum {
    FM_JOB_ERROR_WARNING,
    FM_JOB_ERROR_MILD,
    FM_JOB_ERROR_MODERATE,
    FM_JOB_ERROR_SEVERE,
    FM_JOB_ERROR_CRITICAL
} FmJobErrorSeverity;

FM_JOB_ERROR_WARNING

not an error, just a warning

FM_JOB_ERROR_MILD

no big deal, can be ignored most of the time

FM_JOB_ERROR_MODERATE

moderate errors

FM_JOB_ERROR_SEVERE

severe errors, whether to abort operation depends on error handlers

FM_JOB_ERROR_CRITICAL

critical errors, the operation is aborted

fm_job_ask ()

gint                fm_job_ask                          (FmJob *job,
                                                         const char *question,
                                                         ...);

Asks the user for some interactions. The user will have a list of available options and should make a choice.

This APIs is private to FmJob and should only be used in the implementation of classes derived from FmJob.

This function should be called from working thread only.

job :

the job that calls main thread

question :

the text to ask the user

... :

list of choices to give the user

Returns :

user's choice.

Since 0.1.0


fm_job_ask_valist ()

gint                fm_job_ask_valist                   (FmJob *job,
                                                         const char *question,
                                                         va_list options);

Asks the user for some interactions. The user will have a list of available options and should make a choice.

This APIs is private to FmJob and should only be used in the implementation of classes derived from FmJob.

This function should be called from working thread only.

job :

the job that calls main thread

question :

the text to ask the user

options :

list of choices to give the user

Returns :

user's choice.

Since 0.1.0


fm_job_askv ()

gint                fm_job_askv                         (FmJob *job,
                                                         const char *question,
                                                         gchar * const *options);

Asks the user for some interactions. The user will have a list of available options and should make a choice.

This APIs is private to FmJob and should only be used in the implementation of classes derived from FmJob.

This function should be called from working thread only.

job :

the job that calls main thread

question :

the text to ask the user

options :

list of choices to give the user

Returns :

user's choice.

Since 0.1.0


fm_job_call_main_thread ()

gpointer            fm_job_call_main_thread             (FmJob *job,
                                                         FmJobCallMainThreadFunc func,
                                                         gpointer user_data);

Stops calling thread, waits main thread for idle, passes user_data to callback func in main thread, gathers result of callback, and returns it to caller.

This APIs is private to FmJob and should only be used in the implementation of classes derived from FmJob.

This function should be called from working thread only.

job :

the job that calls main thread

func :

callback to run from main thread

user_data :

user data for the callback

Returns :

return value from running func.

Since 0.1.0


fm_job_cancel ()

void                fm_job_cancel                       (FmJob *job);

Cancels the job.

job :

a job to cancel

Since 0.1.0


fm_job_emit_error ()

FmJobErrorAction    fm_job_emit_error                   (FmJob *job,
                                                         GError *err,
                                                         FmJobErrorSeverity severity);

Emits an "error" signal in the main thread to notify it when an error occurs. The return value of this function is the return value returned by the connected signal handlers. If severity is FM_JOB_ERROR_CRITICAL, the returned value is ignored and fm_job_cancel() is called to abort the job. Otherwise, the signal handler of this error can return FM_JOB_RETRY to ask for retrying the failed operation, return FM_JOB_CONTINUE to ignore the error and continue the remaining job, or return FM_JOB_ABORT to abort the job. If FM_JOB_ABORT is returned by the signal handler, fm_job_cancel() will be called in fm_job_emit_error().

This APIs is private to FmJob and should only be used in the implementation of classes derived from FmJob.

This function should be called from working thread only.

job :

a job that emitted the signal

err :

an error descriptor

severity :

severity of the error

Returns :

action that should be performed on that error.

Since 0.1.0


fm_job_finish ()

void                fm_job_finish                       (FmJob *job);

Schedules the finishing of job. Once this function is called the job becomes invalid for the caller and should be not used anymore.

This APIs is private to FmJob and should only be used in the implementation of classes derived from FmJob.

This function should be called from working thread only.

job :

the job that was finished

Since 0.1.0


fm_job_get_cancellable ()

GCancellable *      fm_job_get_cancellable              (FmJob *job);

Get an existing GCancellable object from job for use with gio in another job by calling fm_job_set_cancellable(). This can be used when you wish to share a cancellable object among different jobs.

This APIs is private to FmJob and should only be used in the implementation of classes derived from FmJob.

job :

the job to inspect

Returns :

a GCancellable object if it was initialized for job.

Since 0.1.9


fm_job_init_cancellable ()

void                fm_job_init_cancellable             (FmJob *job);

Used by derived classes to implement FmJobClass:run() using gio inside. This API tries to initialize a GCancellable object for use with gio and should only be called once in the constructor of derived classes which require the use of GCancellable.

This APIs is private to FmJob and should only be used in the implementation of classes derived from FmJob.

job :

the job to init

Since 0.1.0


fm_job_is_cancelled ()

gboolean            fm_job_is_cancelled                 (FmJob *job);

Checks if the job is already cancelled.

job :

the job to inspect

Returns :

TRUE if the job is already cancelled.

Since 0.1.9


fm_job_is_running ()

gboolean            fm_job_is_running                   (FmJob *job);

Checks if the job is still running.

job :

the job to inspect

Returns :

TRUE if the job is still running.

Since 0.1.9


fm_job_run_async ()

gboolean            fm_job_run_async                    (FmJob *job);

Starts the job asyncronously creating new thread. If job starts successfully then the "finished" signal will be emitted when job is either succeeded or was cancelled. If job could not be started then "cancelled" signal is emitted before return from this function.

job :

a job to run

Returns :

TRUE if job started successfully.

Since 0.1.0


fm_job_run_sync ()

gboolean            fm_job_run_sync                     (FmJob *job);

Runs the job in current thread in a blocking fashion. The job will emit either "cancelled" signal if job was cancelled or "finished" signal if it finished successfully.

job :

a job to run

Returns :

TRUE if job ran successfully.

Since 0.1.0


fm_job_run_sync_with_mainloop ()

gboolean            fm_job_run_sync_with_mainloop       (FmJob *job);

Runs the job in current thread in a blocking fashion and an additional mainloop being created to prevent blocking of user interface. If job started successfully then "finished" signal is emitted when job is either succeeded or was cancelled.

job :

a job to run

Returns :

TRUE if job started successfully.

Since 0.1.1


fm_job_set_cancellable ()

void                fm_job_set_cancellable              (FmJob *job,
                                                         GCancellable *cancellable);

Lets the job to use an existing cancellable object. This can be used when you wish to share a cancellable object among different jobs. This should only be called before the job is launched.

This APIs is private to FmJob and should only be used in the implementation of classes derived from FmJob.

job :

the job to set

cancellable :

a shared cancellable object. [allow-none]

Since 0.1.0

Signal Details

The "ask" signal

gint                user_function                      (FmJob   *job,
                                                        gpointer question,
                                                        gpointer options,
                                                        gpointer user_data)      : Run Last

The "ask" signal is emitted when the job asks for some user interactions. The user then will have a list of available options. If there is more than one handler connected to the signal then only one of them will receive it.

job :

a job that emitted the signal

question :

(const gchar *) a question to ask user

options :

(gchar* const *) list of choices to ask user

user_data :

user data set when the signal handler was connected.

Returns :

user's choice.

Since 0.1.0


The "cancelled" signal

void                user_function                      (FmJob   *job,
                                                        gpointer user_data)      : Run First

The "cancelled" signal is emitted when the job is cancelled or aborted due to critical errors.

job :

a job that emitted the signal

user_data :

user data set when the signal handler was connected.

Since 0.1.0


The "error" signal

guint               user_function                      (FmJob   *job,
                                                        GError  *error,
                                                        guint    severity,
                                                        gpointer user_data)      : Run Last

The "error" signal is emitted when errors happen. A case if more than one handler is connected to this signal is ambiguous.

job :

a job that emitted the signal

error :

an error descriptor

severity :

FmJobErrorSeverity of the error

user_data :

user data set when the signal handler was connected.

Returns :

FmJobErrorAction that should be performed on that error.

Since 0.1.0


The "finished" signal

void                user_function                      (FmJob   *job,
                                                        gpointer user_data)      : Run First

The "finished" signal is emitted after the job is finished. The signal is never emitted if the fm_job_run_XXX function returned FALSE, in that case the "cancelled" signal will be emitted instead.

job :

a job that emitted the signal

user_data :

user data set when the signal handler was connected.

Since 0.1.0