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) More...
#define	BITMAP_INDEX(bit)   ( (bit) / BITMAP_BLKSIZE )
	Block index within bitmap. More...
#define	BITMAP_MASK(bit)   ( 1UL << ( (bit) % BITMAP_BLKSIZE ) )
	Block mask within bitmap. More...

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

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

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 20 of file bitmap.h.

BITMAP_INDEX

#define BITMAP_INDEX

(

bit

)

( (bit) / BITMAP_BLKSIZE )

Block index within bitmap.

Parameters

bit

Bit index

Return values

index

Block index

Definition at line 28 of file bitmap.h.

BITMAP_MASK

#define BITMAP_MASK

(

bit

)

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

Block mask within bitmap.

Parameters

bit

Bit index

Return values

mask	Block mask

Definition at line 36 of file bitmap.h.

Typedef Documentation

bitmap_block_t

typedef unsigned long bitmap_block_t

A single block of bits within a bitmap.

Definition at line 17 of file bitmap.h.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

bitmap_resize()

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

Resize bitmap.

Parameters

bitmap	Bitmap
new_length	New length of bitmap, in bits

Return values

rc	Return status code

Definition at line 42 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_INDEX ( bitmap->length + BITMAP_BLKSIZE - 1 );
        new_num_blocks = BITMAP_INDEX ( new_length + BITMAP_BLKSIZE - 1 );

        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_BLKSIZE, BITMAP_INDEX, 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
	)

Test bit in bitmap.

Parameters

bitmap	Bitmap
bit	Bit index

Return values

is_set

Bit is set

Definition at line 78 of file bitmap.c.

                                                            {
        unsigned int index = BITMAP_INDEX ( bit );
        bitmap_block_t mask = BITMAP_MASK ( bit );

        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()

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

Set bit in bitmap.

Parameters

bitmap	Bitmap
bit	Bit index

Definition at line 93 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 );

        /* Update bitmap */
        bitmap->blocks[index] |= mask;

        /* Update first gap counter */
        while ( bitmap_test ( bitmap, bitmap->first_gap ) ) {
                bitmap->first_gap++;
        }
}

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

Referenced by slam_mc_socket_deliver(), and tftp_rx_data().

bitmap_free()

static void bitmap_free ( struct bitmap *  bitmap )

inlinestatic

Free bitmap resources.

Parameters

bitmap

Bitmap

Definition at line 57 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()

static 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 69 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()

static 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 81 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().