Segment

A segment holds information about a continuous part of a data object. More...

Typedefs
typedef struct segment	segment_t
	Opaque type for segment ADT.
typedef int(*	segment_data_usage_func )(void *data, int change)
	Function called to change the usage count of some data.
Functions
int	segment_new (segment_t *seg, void data, off_t start, off_t size, segment_data_usage_func data_usage_func)
	Creates a new segment_t.
int	segment_copy (segment_t seg, segment_t *seg_copy)
	Creates a copy of a segment_t.
int	segment_free (segment_t *seg)
	Frees a segment_t.
int	segment_clear (segment_t *seg)
	Clears a segment_t.
int	segment_split (segment_t seg, segment_t *seg1, off_t split_index)
	Splits a segment.
int	segment_merge (segment_t seg, segment_t seg1)
	Merges two segments.
int	segment_get_data (segment_t seg, void *data)
	Gets data object a segment_t is related to.
int	segment_get_start (segment_t seg, off_t start)
	Gets the start offset of a segment_t.
int	segment_get_size (segment_t seg, off_t size)
	Gets the size of a segment_t.
int	segment_set_data (segment_t seg, void data, segment_data_usage_func data_usage_func)
	Sets the data association of a segment_t.
int	segment_set_range (segment_t *seg, off_t start, off_t size)
	Sets the range of a segment_t.

Detailed Description

A segment holds information about a continuous part of a data object.

By default, when a segment becomes associated with a data object, the segment is not responsible for managing the data object's memory. This kind of memory management can be achieved be specifying the data_usage_func when creating the segment or changing its data association. The function is called whenever the segment is created or freed and updates the data object's usage count.

Typedef Documentation

typedef int(* segment_data_usage_func)(void *data, int change)

Function called to change the usage count of some data.

Parameters:

	data	the data whose usage count is being changed
	change	the change in the usage count or 0 to reset the count

Returns:: the operation error code

Definition at line 58 of file segment.h.

Function Documentation

int segment_clear ( segment_t * seg )

Clears a segment_t.

Parameters:

seg

the segment_t to clear

Returns:: the operation error code

Definition at line 127 of file segment.c.

Referenced by segment_split().

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int segment_copy	(	segment_t *	seg,
		segment_t **	seg_copy
	)

Creates a copy of a segment_t.

Parameters:

	seg	the segment_t to copy
`[out]`	seg_copy	the new copy of the segment

Returns:: the operation error code

Definition at line 88 of file segment.c.

References segment_new().

Referenced by overlap_graph_add_segment(), and segcol_add_copy().

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int segment_free ( segment_t * seg )

Frees a segment_t.

Parameters:

seg

the segment_t to free

Returns:: the operation error code

Definition at line 109 of file segment.c.

Referenced by bless_buffer_save(), overlap_graph_add_segment(), overlap_graph_free(), segcol_add_copy(), segcol_store_in_file(), segcol_store_in_memory(), and segment_split().

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int segment_get_data	(	segment_t *	seg,
		void **	data
	)

Gets data object a segment_t is related to.

Parameters:

	seg	the segment_t
`[out]`	data	the data object

Returns:: the operation error code

Definition at line 241 of file segment.c.

Referenced by break_edge(), create_overlap_graph(), read_foreach_func(), read_segment_func(), store_segment_func(), write_segcol_rest(), and write_segment().

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int segment_get_size	(	segment_t *	seg,
		off_t *	size
	)

Gets the size of a segment_t.

Parameters:

	seg	the segment_t
`[out]`	size	the size

Returns:: the operation error code

Definition at line 277 of file segment.c.

Referenced by get_data_from_iter(), overlap_graph_add_segment(), segcol_append(), segcol_insert(), and write_segment().

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int segment_get_start	(	segment_t *	seg,
		off_t *	start
	)

Gets the start offset of a segment_t.

Parameters:

	seg	the segment_t
`[out]`	start	the start offset

Returns:: the operation error code

Definition at line 259 of file segment.c.

Referenced by break_edge(), get_data_from_iter(), overlap_graph_add_segment(), and write_segment().

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int segment_merge	(	segment_t *	seg,
		segment_t *	seg1
	)

Merges two segments.

This function merges two related segments. Segment seg1 must be a continuation of the first segment for the merge to succeed. The first segment is changed in place.

Parameters:

	seg	the first segment
	seg1	the segment to merge with the first segment

Returns:

Definition at line 205 of file segment.c.

int segment_new	(	segment_t **	seg,
		void *	data,
		off_t	start,
		off_t	size,
		segment_data_usage_func	data_usage_func
	)

Creates a new segment_t.

Parameters:

`[out]`	seg	the created segment or NULL
	data	the data object this segment is associated with
	start	the start offset of the segment
	size	the size of the segment
	data_usage_func	the function to call to update the usage count of the data associated with this segment (may be NULL)

Returns:: the operation error code

Definition at line 50 of file segment.c.

References segment_set_data(), and segment_set_range().

Referenced by bless_buffer_save(), segcol_store_in_file(), segcol_store_in_memory(), segment_copy(), and segment_split().

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int segment_set_data	(	segment_t *	seg,
		void *	data,
		segment_data_usage_func	data_usage_func
	)

Sets the data association of a segment_t.

Parameters:

	seg	the segment_t
	data	the new data associated with the segment
	data_usage_func	the function to call to update the usage count of the data associated with this segment (may be NULL)

Returns:: the operation error code

Definition at line 297 of file segment.c.

Referenced by segment_new().

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int segment_set_range	(	segment_t *	seg,
		off_t	start,
		off_t	size
	)

Sets the range of a segment_t.

Parameters:

	seg	the segment_t
	start	the new start offset
	size	the size of the segment

Returns:: the operation error code

Definition at line 335 of file segment.c.

Referenced by segment_new(), and segment_split().

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int segment_split	(	segment_t *	seg,
		segment_t **	seg1,
		off_t	split_index
	)

Splits a segment.

This functions splits a segment into two. The original segment is changed in-place and a new one is created. The caller is responsible for managing the new segment (eg freeing it).

Parameters:

	seg	the segment_t to split
`[out]`	seg1	the created new segment
	split_index	the index in the original segment_t that will be the start of the new segment_t

Returns:: the operation error code

Definition at line 152 of file segment.c.

References segment_clear(), segment_free(), segment_new(), and segment_set_range().

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Segment

Typedefs

Functions

Detailed Description

Typedef Documentation

Function Documentation