datapagemap.c File Reference

#include "postgres_fe.h"
#include "common/logging.h"
#include "datapagemap.h"

Include dependency graph for datapagemap.c:

Go to the source code of this file.

Data Structures
struct	datapagemap_iterator

Functions
void	datapagemap_add (datapagemap_t *map, BlockNumber blkno)
datapagemap_iterator_t *	datapagemap_iterate (datapagemap_t *map)
bool	datapagemap_next (datapagemap_iterator_t *iter, BlockNumber *blkno)
void	datapagemap_print (datapagemap_t *map)

Function Documentation

datapagemap_add()

void datapagemap_add	(	datapagemap_t *	map,
		BlockNumber	blkno
	)

Definition at line 32 of file datapagemap.c.

{
    int         offset;
    int         bitno;
 
    offset = blkno / 8;
    bitno = blkno % 8;
 
    /* enlarge or create bitmap if needed */
    if (map->bitmapsize <= offset)
    {
        int         oldsize = map->bitmapsize;
        int         newsize;
 
        /*
         * The minimum to hold the new bit is offset + 1. But add some
         * headroom, so that we don't need to repeatedly enlarge the bitmap in
         * the common case that blocks are modified in order, from beginning
         * of a relation to the end.
         */
        newsize = offset + 1;
        newsize += 10;
 
        map->bitmap = pg_realloc(map->bitmap, newsize);
 
        /* zero out the newly allocated region */
        memset(&map->bitmap[oldsize], 0, newsize - oldsize);
 
        map->bitmapsize = newsize;
    }
 
    /* Set the bit */
    map->bitmap[offset] |= (1 << bitno);
}

References datapagemap::bitmap, datapagemap::bitmapsize, and pg_realloc().

Referenced by process_target_wal_block_change().

datapagemap_iterate()

datapagemap_iterator_t* datapagemap_iterate

(

datapagemap_t *

map

)

Definition at line 75 of file datapagemap.c.

{
    datapagemap_iterator_t *iter;
 
    iter = pg_malloc(sizeof(datapagemap_iterator_t));
    iter->map = map;
    iter->nextblkno = 0;
 
    return iter;
}

References datapagemap_iterator::map, datapagemap_iterator::nextblkno, and pg_malloc().

Referenced by calculate_totals(), datapagemap_print(), and perform_rewind().

datapagemap_next()

bool datapagemap_next	(	datapagemap_iterator_t *	iter,
		BlockNumber *	blkno
	)

Definition at line 87 of file datapagemap.c.

{
    datapagemap_t *map = iter->map;
 
    for (;;)
    {
        BlockNumber blk = iter->nextblkno;
        int         nextoff = blk / 8;
        int         bitno = blk % 8;
 
        if (nextoff >= map->bitmapsize)
            break;
 
        iter->nextblkno++;
 
        if (map->bitmap[nextoff] & (1 << bitno))
        {
            *blkno = blk;
            return true;
        }
    }
 
    /* no more set bits in this bitmap. */
    return false;
}

References datapagemap::bitmap, datapagemap::bitmapsize, datapagemap_iterator::map, and datapagemap_iterator::nextblkno.

Referenced by calculate_totals(), datapagemap_print(), and perform_rewind().

datapagemap_print()

void datapagemap_print

(

datapagemap_t *

map

)

Definition at line 117 of file datapagemap.c.

{
    datapagemap_iterator_t *iter;
    BlockNumber blocknum;
 
    iter = datapagemap_iterate(map);
    while (datapagemap_next(iter, &blocknum))
        pg_log_debug("block %u", blocknum);
 
    pg_free(iter);
}

References datapagemap_iterate(), datapagemap_next(), pg_free(), and pg_log_debug.

Referenced by print_filemap().