InfAdoptedAlgorithm

typedef struct _InfAdoptedAlgorithm InfAdoptedAlgorithm;

InfAdoptedAlgorithm is an opaque data type. You should only access it via the public API functions.

struct InfAdoptedAlgorithmClass

struct InfAdoptedAlgorithmClass {
  void(*can_undo_changed)(InfAdoptedAlgorithm* algorithm,
                          InfAdoptedUser* user,
                          gboolean can_undo);

  void(*can_redo_changed)(InfAdoptedAlgorithm* algorithm,
                          InfAdoptedUser* user,
                          gboolean can_redo);

  void(*execute_request)(InfAdoptedAlgorithm* algorithm,
                         InfAdoptedUser* user,
                         InfAdoptedRequest* request,
                         gboolean apply);

  void(*apply_request)(InfAdoptedAlgorithm* algorithm,
                       InfAdoptedUser* user,
                       InfAdoptedRequest* request);
};

Signals for the InfAdoptedAlgorithm class.

inf_adopted_algorithm_new ()

InfAdoptedAlgorithm * inf_adopted_algorithm_new         (InfUserTable *user_table,
                                                         InfBuffer *buffer);

Creates a InfAdoptedAlgorithm.

inf_adopted_algorithm_new_full ()

InfAdoptedAlgorithm * inf_adopted_algorithm_new_full    (InfUserTable *user_table,
                                                         InfBuffer *buffer,
                                                         guint max_total_log_size);

Note that it is possible that request logs need to grow a bit larger than max_total_log_size in high-latency situations or when a user does not send status updates frequently. However, when all requests have been processed by all users, the sum of all requests in the logs is guaranteed to be lower or equal to this value.

Set to G_MAXUINT to disable limitation. In theory, this would allow everyone to undo every operation up to the first one ever made. In practise, this issues a huge amount of data that needs to be synchronized on user join and is too expensive to compute anyway.

The default value is 2048.

inf_adopted_algorithm_get_current ()

InfAdoptedStateVector * inf_adopted_algorithm_get_current
                                                        (InfAdoptedAlgorithm *algorithm);

Returns the current vector time of algorithm.

inf_adopted_algorithm_generate_request_noexec ()

InfAdoptedRequest * inf_adopted_algorithm_generate_request_noexec
                                                        (InfAdoptedAlgorithm *algorithm,
                                                         InfAdoptedUser *user,
                                                         InfAdoptedOperation *operation);

Creates a InfAdoptedRequest for the given operation, executed by user. The user needs to have the INF_USER_LOCAL flag set.

The operation is not applied to the buffer, so you are responsible that the operation is applied before the next request is processed or generated. This may be useful if you are applying multiple operations, but want to only make a single request out of them to save bandwidth.

inf_adopted_algorithm_generate_request ()

InfAdoptedRequest * inf_adopted_algorithm_generate_request
                                                        (InfAdoptedAlgorithm *algorithm,
                                                         InfAdoptedUser *user,
                                                         InfAdoptedOperation *operation);

Creates a InfAdoptedRequest for the given operation, executed by user. The user needs to have the INF_USER_LOCAL flag set. operation is applied to the buffer (by user).

inf_adopted_algorithm_generate_undo ()

InfAdoptedRequest * inf_adopted_algorithm_generate_undo (InfAdoptedAlgorithm *algorithm,
                                                         InfAdoptedUser *user);

Creates a request of type INF_ADOPTED_REQUEST_UNDO for the given user and with the current vector time. The user needs to have the INF_USER_LOCAL flag set. It also applies the effect of the operation to the buffer.

inf_adopted_algorithm_generate_redo ()

InfAdoptedRequest * inf_adopted_algorithm_generate_redo (InfAdoptedAlgorithm *algorithm,
                                                         InfAdoptedUser *user);

Creates a request of type INF_ADOPTED_REQUEST_REDO for the given user and with the current vector time. The user needs to have the INF_USER_LOCAL flag set. It also applies the effect of the operation to the buffer.

inf_adopted_algorithm_translate_request ()

InfAdoptedRequest * inf_adopted_algorithm_translate_request
                                                        (InfAdoptedAlgorithm *algorithm,
                                                         InfAdoptedRequest *request,
                                                         InfAdoptedStateVector *to);

Translates request so that it can be applied to the document at state to. request will not be modified but a new, translated request is returned instead.

There are several preconditions for this function to be called. to must be a reachable point in the state space. Also, requests can only be translated in forward direction, so request's vector time must be causally before (see inf_adopted_state_vector_causally_before()) to.

inf_adopted_algorithm_receive_request ()

void                inf_adopted_algorithm_receive_request
                                                        (InfAdoptedAlgorithm *algorithm,
                                                         InfAdoptedRequest *request);

This function processes a request received from a non-local user and applies its operation to the buffer.

inf_adopted_algorithm_can_undo ()

gboolean            inf_adopted_algorithm_can_undo      (InfAdoptedAlgorithm *algorithm,
                                                         InfAdoptedUser *user);

Returns whether user can issue an undo request in the current state. Note that if user is non-local, then the result of this function does not depend on the current state but on the state that we know user is guaranteed to have reached. This is because user might still issue an Undo request even if the max-total-log-size is already exceeded if user does not know yet that it is exceeded.

inf_adopted_algorithm_can_redo ()

gboolean            inf_adopted_algorithm_can_redo      (InfAdoptedAlgorithm *algorithm,
                                                         InfAdoptedUser *user);

Returns whether user can issue a redo request in the current state. Note that if user is non-local, then the result of this function does not depend on the current state but on the state that we know user is guaranteed to have reached. This is because user might still issue a Redo request even if the max-total-log-size is already exceeded if user does not know yet that it is exceeded.

The "buffer" property

  "buffer"                   InfBuffer*            : Read / Write / Construct Only

The buffer to apply operations to.

The "buffer-modified-state" property

  "buffer-modified-state"    InfAdoptedStateVector*  : Read

The state in which the buffer is considered not being modified.

The "current-state" property

  "current-state"            InfAdoptedStateVector*  : Read

The state vector describing the current document state.

The "max-total-log-size" property

  "max-total-log-size"       guint                 : Read / Write / Construct Only

The maximum number of requests to keep in all user's logs.

Default value: 2048

The "user-table" property

  "user-table"               InfUserTable*         : Read / Write / Construct Only

The user table.

The "apply-request" signal

void                user_function                      (InfAdoptedAlgorithm *algorithm,
                                                        InfAdoptedUser      *user,
                                                        InfAdoptedRequest   *request,
                                                        gpointer             user_data)      : Run Last

This signal is emitted every time the algorithm applies a request.

Note a call to inf_adopted_algorithm_generate_request(), inf_adopted_algorithm_generate_undo() or inf_adopted_algorithm_generate_redo() always applies the generated request. In contrast, inf_adopted_algorithm_receive_request() might not apply the given request (if requests it depends upon have not yet received) or might apply multiple request (if the provided request fulfills the dependencies of queued requests).

Note also that the signal is not emitted for every request processed by InfAdoptedAlgorithm since inf_adopted_algorithm_generate_request_noexec() generates a request but does not apply it.

The "can-redo-changed" signal

void                user_function                      (InfAdoptedAlgorithm *algorithm,
                                                        InfAdoptedUser      *user,
                                                        gboolean             can_undo,
                                                        gpointer             user_data)      : Run Last

This signal is emitted every time the can-redo state of a local user in algorithm's user table changed. The can-redo state defines whether user can generate a redo request (via inf_adopted_algorithm_generate_redo()) in the current situation, see also inf_adopted_algorithm_can_redo().

The "can-undo-changed" signal

void                user_function                      (InfAdoptedAlgorithm *algorithm,
                                                        InfAdoptedUser      *user,
                                                        gboolean             can_undo,
                                                        gpointer             user_data)      : Run Last

This signal is emitted every time the can-undo state of a local user in algorithm's user table changed. The can-undo state defines whether user can generate an undo request (via inf_adopted_algorithm_generate_undo()) in the current situation, see also inf_adopted_algorithm_can_undo().

The "execute-request" signal

void                user_function                      (InfAdoptedAlgorithm *algorithm,
                                                        InfAdoptedUser      *user,
                                                        InfAdoptedRequest   *request,
                                                        gboolean             apply,
                                                        gpointer             user_data)      : Run Last

This signal is emitted every time the algorithm executes a request. request is the request that algorithm will execute. request can generally not be applied to the current state, and it might also be an undo or redo request. The default handler of this signal computes the operation that can be applied to the buffer, and applies it when apply is TRUE by emitting "apply-request".