86 lines
1.8 KiB
C
86 lines
1.8 KiB
C
#ifndef _IPXE_BITMAP_H
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#define _IPXE_BITMAP_H
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/** @file
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*
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* Bitmaps for multicast downloads
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*
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*/
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FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
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#include <stdint.h>
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#include <stddef.h>
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#include <stdlib.h>
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/** A single block of bits within a bitmap */
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typedef unsigned long bitmap_block_t;
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/** Size of a block of bits (in bits) */
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#define BITMAP_BLKSIZE ( sizeof ( bitmap_block_t ) * 8 )
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/**
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* Block index within bitmap
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*
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* @v bit Bit index
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* @ret index Block index
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*/
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#define BITMAP_INDEX( bit ) ( (bit) / BITMAP_BLKSIZE )
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/**
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* Block mask within bitmap
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*
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* @v bit Bit index
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* @ret mask Block mask
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*/
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#define BITMAP_MASK( bit ) ( 1UL << ( (bit) % BITMAP_BLKSIZE ) )
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/** A bitmap */
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struct bitmap {
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/** Bitmap data */
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bitmap_block_t *blocks;
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/** Length of the bitmap, in bits */
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unsigned int length;
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/** Index of first gap in the bitmap */
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unsigned int first_gap;
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};
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extern int bitmap_resize ( struct bitmap *bitmap, unsigned int new_length );
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extern int bitmap_test ( struct bitmap *bitmap, unsigned int bit );
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extern void bitmap_set ( struct bitmap *bitmap, unsigned int bit );
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/**
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* Free bitmap resources
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*
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* @v bitmap Bitmap
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*/
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static inline void bitmap_free ( struct bitmap *bitmap ) {
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free ( bitmap->blocks );
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}
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/**
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* Get first gap within bitmap
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*
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* @v bitmap Bitmap
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* @ret first_gap First gap
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*
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* The first gap is the first unset bit within the bitmap.
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*/
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static inline unsigned int bitmap_first_gap ( struct bitmap *bitmap ) {
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return bitmap->first_gap;
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}
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/**
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* Check to see if bitmap is full
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*
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* @v bitmap Bitmap
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* @ret is_full Bitmap is full
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*
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* The bitmap is full if it has no gaps (i.e. no unset bits).
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*/
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static inline int bitmap_full ( struct bitmap *bitmap ) {
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return ( bitmap->first_gap == bitmap->length );
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}
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#endif /* _IPXE_BITMAP_H */
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