bitmap.h File Reference

Bitmaps for multicast downloads. More...

#include <stdint.h>
#include <stddef.h>
#include <stdlib.h>

Go to the source code of this file.

Data Structures
struct	bitmap
	A bitmap. More...

Macros
#define	BITMAP_BLKSIZE   ( sizeof ( bitmap_block_t ) * 8 )
	Size of a block of bits (in bits).
#define	BITMAP_INDEX(bit)
	Block index within bitmap.
#define	BITMAP_MASK(bit)
	Block mask within bitmap.
#define	BITMAP_BLOCKS(length)
	Number of blocks in the bitmap.

Typedefs
typedef unsigned long	bitmap_block_t
	A single block of bits within a bitmap.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
	FILE_SECBOOT (PERMITTED)
int	bitmap_resize (struct bitmap *bitmap, unsigned int new_length)
	Resize bitmap.
int	bitmap_test (struct bitmap *bitmap, unsigned int bit)
	Test bit in bitmap.
int	bitmap_set (struct bitmap *bitmap, unsigned int bit)
	Set bit in bitmap.
static void	bitmap_free (struct bitmap *bitmap)
	Free bitmap resources.
static unsigned int	bitmap_first_gap (struct bitmap *bitmap)
	Get first gap within bitmap.
static int	bitmap_full (struct bitmap *bitmap)
	Check to see if bitmap is full.

Detailed Description

Bitmaps for multicast downloads.

Definition in file bitmap.h.

Macro Definition Documentation

BITMAP_BLKSIZE

#define BITMAP_BLKSIZE   ( sizeof ( bitmap_block_t ) * 8 )

Size of a block of bits (in bits).

Definition at line 21 of file bitmap.h.

BITMAP_INDEX

#define BITMAP_INDEX

(

bit

)

Value:

( (bit) / BITMAP_BLKSIZE )

Block index within bitmap.

Parameters

bit

Bit index

Return values

index

Block index

Definition at line 29 of file bitmap.h.

Referenced by bitmap_set(), and bitmap_test().

BITMAP_MASK

#define BITMAP_MASK

(

bit

)

Value:

( 1UL << ( (bit) % BITMAP_BLKSIZE ) )

Block mask within bitmap.

Parameters

bit

Bit index

Return values

mask	Block mask

Definition at line 37 of file bitmap.h.

Referenced by bitmap_set(), and bitmap_test().

BITMAP_BLOCKS

#define BITMAP_BLOCKS

(

length

)

Value:

( ( (length) / BITMAP_BLKSIZE ) +     \
( !! ( (length) % BITMAP_BLKSIZE ) ) )

Number of blocks in the bitmap.

Parameters

length

Length of the bitmap, in bits

Return values

blocks

Number of blocks

Definition at line 45 of file bitmap.h.

#define BITMAP_BLOCKS( length ) ( ( (length) / BITMAP_BLKSIZE ) +       \
                                  ( !! ( (length) % BITMAP_BLKSIZE ) ) )

Referenced by bitmap_resize().

Typedef Documentation

bitmap_block_t

typedef unsigned long bitmap_block_t

A single block of bits within a bitmap.

Definition at line 18 of file bitmap.h.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

FILE_SECBOOT()

FILE_SECBOOT

(

PERMITTED

)

bitmap_resize()

int bitmap_resize ( struct bitmap * bitmap, unsigned int new_length )

extern

Resize bitmap.

Parameters

bitmap	Bitmap
new_length	New length of bitmap, in bits

Return values

rc	Return status code

Definition at line 43 of file bitmap.c.

                                                                     {
        unsigned int old_num_blocks;
        unsigned int new_num_blocks;
        size_t new_size;
        bitmap_block_t *new_blocks;
 
        old_num_blocks = BITMAP_BLOCKS ( bitmap->length );
        new_num_blocks = BITMAP_BLOCKS ( new_length );
 
        if ( old_num_blocks != new_num_blocks ) {
                new_size = ( new_num_blocks * sizeof ( bitmap->blocks[0] ) );
                new_blocks = realloc ( bitmap->blocks, new_size );
                if ( ! new_blocks ) {
                        DBGC ( bitmap, "Bitmap %p could not resize to %d "
                               "bits\n", bitmap, new_length );
                        return -ENOMEM;
                }
                bitmap->blocks = new_blocks;
        }
        bitmap->length = new_length;
 
        while ( old_num_blocks < new_num_blocks ) {
                bitmap->blocks[old_num_blocks++] = 0;
        }
 
        DBGC ( bitmap, "Bitmap %p resized to %d bits\n", bitmap, new_length );
        return 0;
}

References BITMAP_BLOCKS, bitmap::blocks, DBGC, ENOMEM, bitmap::length, and realloc().

Referenced by slam_open(), slam_pull_header(), and tftp_presize().

bitmap_test()

int bitmap_test ( struct bitmap * bitmap, unsigned int bit )

extern

Test bit in bitmap.

Parameters

bitmap	Bitmap
bit	Bit index

Return values

is_set

Bit is set

Definition at line 79 of file bitmap.c.

                                                            {
        unsigned int index = BITMAP_INDEX ( bit );
        bitmap_block_t mask = BITMAP_MASK ( bit );
 
        /* Treat out-of-range bits as implicitly being zero */
        if ( bit >= bitmap->length )
                return 0;
 
        return ( ( bitmap->blocks[index] & mask ) != 0 );
}

References bit, BITMAP_INDEX, BITMAP_MASK, bitmap::blocks, index, and bitmap::length.

Referenced by bitmap_set(), slam_mc_socket_deliver(), and slam_tx_nack().

bitmap_set()

int bitmap_set ( struct bitmap * bitmap, unsigned int bit )

extern

Set bit in bitmap.

Parameters

bitmap	Bitmap
bit	Bit index

Return values

rc	Return status code

Definition at line 97 of file bitmap.c.

                                                           {
        unsigned int index = BITMAP_INDEX ( bit );
        bitmap_block_t mask = BITMAP_MASK ( bit );
 
        DBGC ( bitmap, "Bitmap %p setting bit %d\n", bitmap, bit );
 
        /* Fail if we cannot set this bit */
        if ( bit >= bitmap->length ) {
                DBGC ( bitmap, "Bitmap %p bit %d is outside range [0,%d)\n",
                       bitmap, bit, bitmap->length );
                return -ERANGE;
        }
 
        /* Update bitmap */
        bitmap->blocks[index] |= mask;
 
        /* Update first gap counter */
        while ( bitmap_test ( bitmap, bitmap->first_gap ) ) {
                bitmap->first_gap++;
        }
 
        return 0;
}

References bit, BITMAP_INDEX, BITMAP_MASK, bitmap_test(), bitmap::blocks, DBGC, ERANGE, bitmap::first_gap, index, and bitmap::length.

Referenced by slam_mc_socket_deliver(), and tftp_rx_data().

bitmap_free()

void bitmap_free ( struct bitmap * bitmap )

inlinestatic

Free bitmap resources.

Parameters

bitmap

Bitmap

Definition at line 67 of file bitmap.h.

                                                         {
        free ( bitmap->blocks );
}

References bitmap::blocks, and free.

Referenced by slam_free(), slam_pull_header(), tftp_free(), and tftp_timer_expired().

bitmap_first_gap()

unsigned int bitmap_first_gap ( struct bitmap * bitmap )

inlinestatic

Get first gap within bitmap.

Parameters

bitmap

Bitmap

Return values

first_gap

First gap

The first gap is the first unset bit within the bitmap.

Definition at line 79 of file bitmap.h.

                                                                      {
        return bitmap->first_gap;
}

References bitmap::first_gap.

Referenced by slam_tx_nack(), tftp_rx_data(), and tftp_send_ack().

bitmap_full()

int bitmap_full ( struct bitmap * bitmap )

inlinestatic

Check to see if bitmap is full.

Parameters

bitmap

Bitmap

Return values

is_full

Bitmap is full

The bitmap is full if it has no gaps (i.e. no unset bits).

Definition at line 91 of file bitmap.h.

                                                        {
        return ( bitmap->first_gap == bitmap->length );
}

References bitmap::first_gap, and bitmap::length.

Referenced by slam_mc_socket_deliver(), and tftp_rx_data().