int mdb_read_next_dpg(MdbTableDef *table)
{
MdbCatalogEntry *entry = table->entry;
MdbHandle *mdb = entry->mdb;
int next_pg;
#ifndef SLOW_READ
next_pg = mdb_map_find_next(mdb, table->usage_map,
table->map_sz, table->cur_phys_pg);
if (next_pg >= 0) {
if (mdb_read_pg(mdb, next_pg)) {
table->cur_phys_pg = next_pg;
return table->cur_phys_pg;
} else {
return 0;
}
}
fprintf(stderr, "Warning: defaulting to brute force read\n");
#endif
/* can't do a fast read, go back to the old way */
do {
if (!mdb_read_pg(mdb, table->cur_phys_pg++))
return 0;
} while (mdb->pg_buf[0]!=0x01 || mdb_get_int32(mdb->pg_buf, 4)!=entry->table_pg);
/* fprintf(stderr,"returning new page %ld\n", table->cur_phys_pg); */
return table->cur_phys_pg;
}
guint32
mdb_map_find_next_freepage(MdbTableDef *table, int row_size)
{
MdbCatalogEntry *entry = table->entry;
MdbHandle *mdb = entry->mdb;
guint32 pgnum;
guint32 cur_pg = 0;
int free_space;
do {
pgnum = mdb_map_find_next(mdb,
table->free_usage_map,
table->freemap_sz, cur_pg);
//printf("looking at page %d\n", pgnum);
if (!pgnum) {
/* allocate new page */
pgnum = mdb_alloc_page(table);
return pgnum;
} else if (pgnum==-1) {
mdb->fatal_error_handler("Error: mdb_map_find_next_freepage error while reading maps.\n");
exit(1);
}
cur_pg = pgnum;
mdb_read_pg(mdb, pgnum);
free_space = mdb_pg_get_freespace(mdb);
} while (free_space < row_size);
//printf("page %d has %d bytes left\n", pgnum, free_space);
return pgnum;
}
guint32
mdb_map_find_next_freepage(MdbTableDef *table, int row_size)
{
MdbCatalogEntry *entry = table->entry;
MdbHandle *mdb = entry->mdb;
guint32 pgnum;
guint32 cur_pg = 0;
int free_space;
do {
pgnum = mdb_map_find_next(mdb,
table->free_usage_map,
table->freemap_sz, cur_pg);
if (!pgnum) {
/* allocate new page */
pgnum = mdb_alloc_page(table);
return pgnum;
}
cur_pg = pgnum;
mdb_read_pg(mdb, pgnum);
free_space = mdb_pg_get_freespace(mdb);
} while (free_space < row_size);
return pgnum;
}
/* Read next data page into mdb->pg_buf */
int mdb_read_next_dpg(MdbTableDef *table)
{
MdbCatalogEntry *entry = table->entry;
MdbHandle *mdb = entry->mdb;
int next_pg;
#ifndef SLOW_READ
while (1) {
next_pg = mdb_map_find_next(mdb, table->usage_map,
table->map_sz, table->cur_phys_pg);
if (next_pg < 0)
break; /* unknow map type: goto fallback */
if (!next_pg)
return 0;
if (!mdb_read_pg(mdb, next_pg)) {
fprintf(stderr, "error: reading page %d failed.\n", next_pg);
return 0;
}
table->cur_phys_pg = next_pg;
if (mdb->pg_buf[0]==MDB_PAGE_DATA && mdb_get_int32(mdb->pg_buf, 4)==entry->table_pg)
return table->cur_phys_pg;
/* On rare occasion, mdb_map_find_next will return a wrong page */
/* Found in a big file, over 4,000,000 records */
fprintf(stderr,
"warning: page %d from map doesn't match: Type=%d, buf[4..7]=%ld Expected table_pg=%ld\n",
next_pg, mdb->pg_buf[0], mdb_get_int32(mdb->pg_buf, 4), entry->table_pg);
}
fprintf(stderr, "Warning: defaulting to brute force read\n");
#endif
/* can't do a fast read, go back to the old way */
do {
if (!mdb_read_pg(mdb, table->cur_phys_pg++))
return 0;
} while (mdb->pg_buf[0]!=MDB_PAGE_DATA || mdb_get_int32(mdb->pg_buf, 4)!=entry->table_pg);
/* fprintf(stderr,"returning new page %ld\n", table->cur_phys_pg); */
return table->cur_phys_pg;
}
