Frame Sets

Typedefs
typedef struct _cpl_frameset_	cpl_frameset
	The frame set data type.

Functions
int	cpl_frameset_count_tags (const cpl_frameset *self, const char *tag)
	Counts the frames stored in a frame set having the given tag.
void	cpl_frameset_delete (cpl_frameset *self)
	Destroy a frame set.
void	cpl_frameset_dump (const cpl_frameset *self, FILE *stream)
	Dump the frameset debugging information to the given stream.
cpl_frameset *	cpl_frameset_duplicate (const cpl_frameset *other)
	Create a copy of the given frame set.
cpl_size	cpl_frameset_erase (cpl_frameset *self, const char *tag)
	Erase all frames with the given tag from a frame set.
cpl_error_code	cpl_frameset_erase_frame (cpl_frameset *self, cpl_frame *frame)
	Erase the given frame from a frame set.
cpl_frameset *	cpl_frameset_extract (const cpl_frameset *self, const cpl_size *labels, cpl_size desired_label)
	Extract a subset of frames from a set of frames.
cpl_frame *	cpl_frameset_find (cpl_frameset *self, const char *tag)
	Find a frame with the given tag in a frame set.
const cpl_frame *	cpl_frameset_find_const (const cpl_frameset *self, const char *tag)
	Find a frame with the given tag in a frame set.
cpl_frame *	cpl_frameset_get_first (cpl_frameset *self)
	Get the first frame in the given set.
const cpl_frame *	cpl_frameset_get_first_const (const cpl_frameset *self)
	Get the first frame in the given set.
cpl_frame *	cpl_frameset_get_frame (cpl_frameset *set, cpl_size position)
	Get a frame from a frame set.
const cpl_frame *	cpl_frameset_get_frame_const (const cpl_frameset *set, cpl_size position)
	Get a frame from a frame set.
cpl_frame *	cpl_frameset_get_next (cpl_frameset *self)
	Get the next frame in the given set.
const cpl_frame *	cpl_frameset_get_next_const (const cpl_frameset *self)
	Get the next frame in the given set.
cpl_frame *	cpl_frameset_get_position (cpl_frameset *self, cpl_size position)
	Get the frame at a given position in the frame set.
const cpl_frame *	cpl_frameset_get_position_const (const cpl_frameset *self, cpl_size position)
	Get the frame at a given iterator position.
cpl_size	cpl_frameset_get_size (const cpl_frameset *self)
	Get the current size of a frame set.
cpl_error_code	cpl_frameset_insert (cpl_frameset *self, cpl_frame *frame)
	Insert a frame into the given frame set.
int	cpl_frameset_is_empty (const cpl_frameset *self)
	Check whether a frame set is empty.
cpl_error_code	cpl_frameset_join (cpl_frameset *self, const cpl_frameset *other)
	Join two frame sets.
cpl_size *	cpl_frameset_labelise (const cpl_frameset *self, int(*compare)(const cpl_frame *, const cpl_frame *), cpl_size *nb_labels)
	Separate a list of frames into groups, using a comparison function.
cpl_frameset *	cpl_frameset_new (void)
	Create a new, empty frame set.
cpl_error_code	cpl_frameset_sort (cpl_frameset *self, cpl_frame_compare_func compare)
	Sort a frame set.

Detailed Description

The module implements a container type for frames. Frames can be stored in a frame set and retrieved, either by searching for a particular frame tag or by sequential access. Frame sets can be created, filled and saved to a so called `set of frames' file or loaded from such a file.

Synopsis:

#include <cpl_frameset.h>

Typedef Documentation

typedef struct _cpl_frameset_ cpl_frameset

The frame set data type.

This data type is opaque.

Function Documentation

int cpl_frameset_count_tags	(	const cpl_frameset *	self,
		const char *	tag
	)

Counts the frames stored in a frame set having the given tag.

Parameters

self	A frame set.
tag	The frame tag.

Returns

The number of frames with tag tag. The function returns 0 if an error occurs and sets an appropriate error code.

Errors

CPL_ERROR_NULL_INPUT

The parameter self or tag is a NULL pointer.

The function scans the frame set self for frames with the tag tag and returns the number of frames found.

void cpl_frameset_delete

(

cpl_frameset *

self

)

Destroy a frame set.

Parameters

self	The frame set to destroy.

Returns

Nothing.

The function destroys the frame set self and its whole contents. If self is NULL, nothing is done and no error is set.

void cpl_frameset_dump	(	const cpl_frameset *	self,
		FILE *	stream
	)

Dump the frameset debugging information to the given stream.

Parameters

self	The frameset.
stream	The output stream to use.

Returns

Nothing.

The function dumps the contents of the frameset self to the output stream stream. If stream is NULL the function writes to the standard output. If self is NULL or the frameset is empty, the function does nothing.

cpl_frameset* cpl_frameset_duplicate

(

const cpl_frameset *

other

)

Create a copy of the given frame set.

Parameters

other

The frame set to be copied.

Returns

A handle for the created clone. The function returns NULL if an error occurs and sets an appropriate error code.

Errors

CPL_ERROR_NULL_INPUT

The parameter other is a NULL pointer.

The function creates a deep copy, i.e. the frame set object and its contents, of the frame set other. The created copy and the original set do not share any resources.

cpl_size cpl_frameset_erase	(	cpl_frameset *	self,
		const char *	tag
	)

Erase all frames with the given tag from a frame set.

Parameters

self	A frame set.
tag	The tag used to locate the frames to remove.

Returns

The function returns the number of frames removed. If an error occurs 0 is returned and an appropriate error code is set.

Errors

CPL_ERROR_NULL_INPUT

The parameter self or tag is a NULL pointer.

The function searches the frame set self for frames having the tag tag and removes them from the set. The removed frames are destroyed. If no frame with the tag tag is found the function has no effect.

cpl_error_code cpl_frameset_erase_frame	(	cpl_frameset *	self,
		cpl_frame *	frame
	)

Erase the given frame from a frame set.

Parameters

self	A frame set.
frame	The frame to remove.

Returns

The function returns CPL_ERROR_NONE on success or a CPL error code otherwise.

Errors

CPL_ERROR_NULL_INPUT

The parameter self or frame is a NULL pointer.

The function searches the frame set self for the first occurrance of frame. If it is present, the frame is removed from the set and destroyed. If frame is not present in self the function has no effect.

cpl_frameset* cpl_frameset_extract	(	const cpl_frameset *	self,
		const cpl_size *	labels,
		cpl_size	desired_label
	)

Extract a subset of frames from a set of frames.

Parameters

self	Input frame set
labels	The array of labels associated to each input frame
desired_label	The label identifying the requested frames

Note

The array of labels must have (at least) the length of the frame set

Returns

A pointer to a newly allocated frame set or NULL on error

Errors

CPL_ERROR_NULL_INPUT

The parameter self or labels is a NULL pointer.

The returned object must be deallocated with cpl_frameset_delete()

cpl_frame* cpl_frameset_find	(	cpl_frameset *	self,
		const char *	tag
	)

Find a frame with the given tag in a frame set.

Parameters

self	A frame set.
tag	The frame tag to search for.

Returns

The handle for a frame with tag tag, or NULL if no such frame was found. The function returns NULL if an error occurs and sets an appropriate error code.

Errors

CPL_ERROR_NULL_INPUT

The parameter self or tag is a NULL pointer.

The function searches the frame set self for the frames with the tag tag. If such a frame is present, a handle for it is returned. If the set contains several frames with the tag tag the first one is returned. The remaining frames with this tag can be accessed sequentially by using NULL as tag when calling this function repeatedly, since the most recent frame accessed is cached. This cache is reset whenever the provided tag is not NULL. If no frame with the tag tag is present in self or no more frames with this tag are found the function returns NULL.

const cpl_frame* cpl_frameset_find_const	(	const cpl_frameset *	self,
		const char *	tag
	)

Find a frame with the given tag in a frame set.

Parameters

self	A frame set.
tag	The frame tag to search for.

Returns

The handle for a frame with tag tag, or NULL if no such frame was found. The function returns NULL if an error occurs and sets an appropriate error code.

Errors

CPL_ERROR_NULL_INPUT

The parameter self or tag is a NULL pointer.

The function searches the frame set self for the frames with the tag tag. If such a frame is present, a handle for it is returned. If the set contains several frames with the tag tag the first one is returned. The remaining frames with this tag can be accessed sequentially by using NULL as tag when calling this function repeatedly, since the most recent frame accessed is cached. This cache is reset whenever the provided tag is not NULL. If no frame with the tag tag is present in self or no more frames with this tag are found the function returns NULL.

cpl_frame* cpl_frameset_get_first

(

cpl_frameset *

self

)

Get the first frame in the given set.

Parameters

self	A frame set.

Returns

A handle for the first frame in the set, or NULL if the set is empty. The function returns NULL if an error occurs and sets an appropriate error code.

Errors

CPL_ERROR_NULL_INPUT

The parameter self is a NULL pointer.

The function returns the first frame in the frame set self if it exists. If a first frame does not exist, i.e. the frame set is empty, NULL is returned. The function also updates the internal cache.

See Also

cpl_frameset_get_next()

Deprecated:

This function will be removed from CPL version 7. Code using these functions should be ported to make use of frame set iterators instead!

const cpl_frame* cpl_frameset_get_first_const

(

const cpl_frameset *

self

)

Get the first frame in the given set.

Parameters

self	A frame set.

Returns

A handle for the first frame in the set, or NULL if the set is empty. The function returns NULL if an error occurs and sets an appropriate error code.

Errors

CPL_ERROR_NULL_INPUT

The parameter self is a NULL pointer.

The function returns the first frame in the frame set self if it exists. If a first frame does not exist, i.e. the frame set is empty, NULL is returned. The function also updates the internal cache.

See Also

cpl_frameset_get_next_const()

Deprecated:

This function will be removed from CPL version 7. Code using these functions should be ported to make use of frame set iterators instead!

cpl_frame* cpl_frameset_get_frame	(	cpl_frameset *	set,
		cpl_size	position
	)

Get a frame from a frame set.

Parameters

set	Input frame set.
position	The requested frame.

Returns

The function returns a handle to the frame at position position in the set, or NULL in case an error occurs.

Errors

CPL_ERROR_NULL_INPUT	The parameter self is a NULL pointer.
CPL_ERROR_ILLEGAL_INPUT	The parameter position is out of range.

The function returns a handle to the frame at the index position in the set. The frame position ranges from 0 to one less than the size of the frame set.

The returned frame is still owned by the frame set set, i.e. the obtained frame must not be deleted through the returned handle and also its tag must not be modified.

As an alternative to using this function, the functions cpl_frameset_get_first() and cpl_frameset_get_next() should be considered, if performance is an issue.

See Also

cpl_frameset_get_size(), cpl_frameset_get_first(), cpl_frameset_get_next()

Deprecated:

This function will be removed from CPL version 7. Code using these functions should use cpl_frameset_get_position() instead!

const cpl_frame* cpl_frameset_get_frame_const	(	const cpl_frameset *	set,
		cpl_size	position
	)

Get a frame from a frame set.

Parameters

set	Input frame set.
position	The requested frame.

Returns

The function returns a handle to the frame at position position in the set, or NULL in case an error occurs.

Errors

CPL_ERROR_NULL_INPUT	The parameter self is a NULL pointer.
CPL_ERROR_ILLEGAL_INPUT	The parameter position is out of range.

The function returns a handle to the frame at the index position in the set. The frame position ranges from 0 to one less than the size of the frame set.

The returned frame is still owned by the frame set set, i.e. the obtained frame must not be deleted through the returned handle and also its tag must not be modified.

As an alternative to using this function, the functions cpl_frameset_get_first_const() and cpl_frameset_get_next_const() should be considered, if performance is an issue.

See Also

cpl_frameset_get_size(), cpl_frameset_get_first_const(), cpl_frameset_get_next_const()

Deprecated:

This function will be removed from CPL version 7. Code using these functions should use cpl_frameset_get_position_const() instead!

cpl_frame* cpl_frameset_get_next

(

cpl_frameset *

self

)

Get the next frame in the given set.

Parameters

self	A frame set.

Returns

A handle for the next frame in a set. If there are no more frames in the set the function returns NULL. The function returns NULL if an error occurs and sets an appropriate error code.

Errors

CPL_ERROR_NULL_INPUT

The parameter self is a NULL pointer.

The function returns the next frame in the frame set self if it exists and otherwise NULL. The function uses the internal cache to determine the most recently accessed frame. This means that the function only works as expected if self has been initialised by a call to cpl_frameset_get_first(), and if no function updating the internal cache was called between two subsequent calls to this function.

See Also

cpl_frameset_get_first()

Deprecated:

This function will be removed from CPL version 7. Code using these functions should be ported to make use of frame set iterators instead!

const cpl_frame* cpl_frameset_get_next_const

(

const cpl_frameset *

self

)

Get the next frame in the given set.

Parameters

self	A frame set.

Returns

A handle for the next frame in a set. If there are no more frames in the set the function returns NULL. The function returns NULL if an error occurs and sets an appropriate error code.

Errors

CPL_ERROR_NULL_INPUT

The parameter self is a NULL pointer.

The function returns the next frame in the frame set self if it exists and otherwise NULL. The function uses the internal cache to determine the most recently accessed frame. This means that the function only works as expected if self has been initialised by a call to cpl_frameset_get_first_const(), and if no function updating the internal cache was called between two subsequent calls to this function.

See Also

cpl_frameset_get_first_const()

Deprecated:

This function will be removed from CPL version 7. Code using these functions should be ported to make use of frame set iterators instead!

cpl_frame* cpl_frameset_get_position	(	cpl_frameset *	self,
		cpl_size	position
	)

Get the frame at a given position in the frame set.

Parameters

self	The frame set
position	Frame position.

Returns

The function returns the frame at the given position, or NULL if an error occurs.

Errors

CPL_ERROR_NULL_INPUT	The parameter self is a NULL pointer.
CPL_ERROR_ILLEGAL_INPUT	The parameter position is invalid, i.e. the given value is outside of its domain.

The function retrieves the frame stored in the frame set self at the index position position. The index positions are counted from zero, and reach up to one less than the number of frames in the frame set.

const cpl_frame* cpl_frameset_get_position_const	(	const cpl_frameset *	self,
		cpl_size	position
	)

Get the frame at a given iterator position.

Parameters

self	The iterator to dereference
position	Iterator offset from the beginning of the frame set.

Returns

The function returns the frame at the iterator position, or NULL if an error occurs.

Errors

CPL_ERROR_NULL_INPUT	The parameter self is a NULL pointer.
CPL_ERROR_ILLEGAL_INPUT	The parameter position is invalid, i.e. the given value is outside of its domain.

The function retrieves the frame stored in the frame set self at the index position position. The index positions are counted from zero, and reach up to one less than the number of frames in the frame set.

cpl_size cpl_frameset_get_size

(

const cpl_frameset *

self

)

Get the current size of a frame set.

Parameters

self	A frame set.

Returns

The frame set's current size, or 0 if it is empty. The function returns 0 if an error occurs and sets an appropriate error code.

Errors

CPL_ERROR_NULL_INPUT

The parameter self is a NULL pointer.

The reports the current number of frames stored in the frame set self.

cpl_error_code cpl_frameset_insert	(	cpl_frameset *	self,
		cpl_frame *	frame
	)

Insert a frame into the given frame set.

Parameters

self	A frame set.
frame	The frame to insert.

Returns

The function returns CPL_ERROR_NONE on success or a CPL error code otherwise.

Errors

CPL_ERROR_NULL_INPUT	The parameter self or frame is a NULL pointer.
CPL_ERROR_ILLEGAL_INPUT	The parameter frame has an invalid tag.

The function adds the frame frame to the frame set self using the frame's tag as key.

The insertion of a frame into a frameset transfers the ownership of the frame frame to the frameset self. This means that the frame must not be deallocated through the pointer frame.

In addition, the frame pointer returned by any member function call returning a handle to a frameset's member frame, must not be used to insert the returned frame into another framset without prior duplication of this frame, and, it must not be used to modify the frames tag without removing it from the frameset first and re-inserting it with the new tag afterwards.

int cpl_frameset_is_empty

(

const cpl_frameset *

self

)

Check whether a frame set is empty.

Parameters

self	A frame set.

Returns

The function returns 1 if the set is empty, and 0 otherwise. If an error occurs 0 is returned and an appropriate error code is set.

Errors

CPL_ERROR_NULL_INPUT

The parameter self is a NULL pointer.

The function checks if self contains any frames.

cpl_error_code cpl_frameset_join	(	cpl_frameset *	self,
		const cpl_frameset *	other
	)

Join two frame sets.

Parameters

self	The target frame set
other	The source frame set

Returns

The function returns CPL_ERROR_NONE on success or a CPL error code otherwise.

Errors

CPL_ERROR_NULL_INPUT

The parameter self or frame is a NULL pointer.

The function adds the contents of the frame set other to self by inserting copies of the elements of the frame set other. If the source frame set other is NULL, or if it is empty, the function has no effect.

cpl_size* cpl_frameset_labelise	(	const cpl_frameset *	self,
		int(*)(const cpl_frame *, const cpl_frame *)	compare,
		cpl_size *	nb_labels
	)

Separate a list of frames into groups, using a comparison function.

Parameters

self	Input frame set
compare	Pointer to comparison function to use.
nb_labels	Number of different sets or undefined on error

Returns

array of labels defining the selection or NULL on error

Errors

CPL_ERROR_NULL_INPUT

The parameter self, compare or nb_labels is a NULL pointer.

This function takes a set of frames and groups the frames that are 'identical' together. The user provided comparison function defines what being identical means for two frames. A label (non-negative int) is associated to each group of identical frames, these labels are returned in an array of length equal to the size of the frameset.

The comparison function should be commutative, must take two frames and return 1 if they are identical, 0 if they are different, and -1 on error.

The number of calls to the comparison functions is O(n*m), where n is the number of frames in the set, and m is the number of different labels found in the set. In the worst case m equals n, and the call requires n(n-1)/2 calls to the comparison function. If all identical frames appear together in the list, the number of required calls is only n + O(m^2).

The returned array must be deallocated with cpl_free().

cpl_frameset* cpl_frameset_new

(

void

)

Create a new, empty frame set.

Returns

The handle for the newly created frame set.

The function allocates the memory for the new frame set, initialises the set to be empty and returns a handle for it.

cpl_error_code cpl_frameset_sort	(	cpl_frameset *	self,
		cpl_frame_compare_func	compare
	)

Sort a frame set.

Parameters

self	The frame set to sort.
compare	Comparison function for frames.

Returns

The function returns CPL_ERROR_NONE on success, or an appropriate CPL error code otherwise.

Errors

• CPL_ERROR_NULL_INPUT

  The parameter self or compare is a NULL pointer.

The function replaces the existing order of the frame set self by sorting its contents according to the comparison function compare.

By default, the order of a frame set, i.e. the order of any newly created frame set object, is defined by the order in which frames are inserted into the frame set. By calling this function, this order will be lost. If this order has to be preserved, sorting has to be done on a copy of self.

The function compare compares two frames and must return -1, 0, or 1 if the first frame is considered to be less than, equal or larger than the second frame, respectively.

See Also

cpl_frame_compare_func