/*
* IMFS_memfile_destroy
*
* This routine frees all memory associated with an in memory file.
*
* NOTE: This is an exceptionally conservative implementation.
* It will check EVERY pointer which is non-NULL and insure
* any child non-NULL pointers are freed. Optimistically, all that
* is necessary is to scan until a NULL pointer is found. There
* should be no allocated data past that point.
*
* In experimentation on the powerpc simulator, it was noted
* that using blocks which held 128 slots versus 16 slots made
* a significant difference in the performance of this routine.
*
* Regardless until the IMFS implementation is proven, it
* is better to stick to simple, easy to understand algorithms.
*/
static void IMFS_memfile_destroy(
IMFS_jnode_t *the_jnode
)
{
IMFS_memfile_t *memfile;
int i;
int j;
unsigned int to_free;
block_p *p;
memfile = (IMFS_memfile_t *) the_jnode;
/*
* Perform internal consistency checks
*/
IMFS_assert( memfile );
/*
* Eventually this could be set smarter at each call to
* memfile_free_blocks_in_table to greatly speed this up.
*/
to_free = IMFS_MEMFILE_BLOCK_SLOTS;
/*
* Now start freeing blocks in this order:
* + indirect
* + doubly indirect
* + triply indirect
*/
if ( memfile->indirect ) {
memfile_free_blocks_in_table( &memfile->indirect, to_free );
}
if ( memfile->doubly_indirect ) {
for ( i=0 ; i<IMFS_MEMFILE_BLOCK_SLOTS ; i++ ) {
if ( memfile->doubly_indirect[i] ) {
memfile_free_blocks_in_table(
(block_p **)&memfile->doubly_indirect[i], to_free );
}
}
memfile_free_blocks_in_table( &memfile->doubly_indirect, to_free );
}
if ( memfile->triply_indirect ) {
for ( i=0 ; i<IMFS_MEMFILE_BLOCK_SLOTS ; i++ ) {
p = (block_p *) memfile->triply_indirect[i];
if ( !p ) /* ensure we have a valid pointer */
break;
for ( j=0 ; j<IMFS_MEMFILE_BLOCK_SLOTS ; j++ ) {
if ( p[j] ) {
memfile_free_blocks_in_table( (block_p **)&p[j], to_free);
}
}
memfile_free_blocks_in_table(
(block_p **)&memfile->triply_indirect[i], to_free );
}
memfile_free_blocks_in_table(
(block_p **)&memfile->triply_indirect, to_free );
}
IMFS_node_destroy_default( the_jnode );
}
/*
* IMFS_memfile_remove
*
* This routine frees all memory associated with an in memory file.
*
* NOTE: This is an exceptionally conservative implementation.
* It will check EVERY pointer which is non-NULL and insure
* any child non-NULL pointers are freed. Optimistically, all that
* is necessary is to scan until a NULL pointer is found. There
* should be no allocated data past that point.
*
* In experimentation on the powerpc simulator, it was noted
* that using blocks which held 128 slots versus 16 slots made
* a significant difference in the performance of this routine.
*
* Regardless until the IMFS implementation is proven, it
* is better to stick to simple, easy to understand algorithms.
*/
IMFS_jnode_t *IMFS_memfile_remove(
IMFS_jnode_t *the_jnode
)
{
IMFS_memfile_t *info;
int i;
int j;
unsigned int to_free;
block_p *p;
/*
* Perform internal consistency checks
*/
IMFS_assert( the_jnode );
IMFS_assert( IMFS_type( the_jnode ) == IMFS_MEMORY_FILE );
/*
* Eventually this could be set smarter at each call to
* memfile_free_blocks_in_table to greatly speed this up.
*/
to_free = IMFS_MEMFILE_BLOCK_SLOTS;
/*
* Now start freeing blocks in this order:
* + indirect
* + doubly indirect
* + triply indirect
*/
info = &the_jnode->info.file;
if ( info->indirect ) {
memfile_free_blocks_in_table( &info->indirect, to_free );
}
if ( info->doubly_indirect ) {
for ( i=0 ; i<IMFS_MEMFILE_BLOCK_SLOTS ; i++ ) {
if ( info->doubly_indirect[i] ) {
memfile_free_blocks_in_table(
(block_p **)&info->doubly_indirect[i], to_free );
}
}
memfile_free_blocks_in_table( &info->doubly_indirect, to_free );
}
if ( info->triply_indirect ) {
for ( i=0 ; i<IMFS_MEMFILE_BLOCK_SLOTS ; i++ ) {
p = (block_p *) info->triply_indirect[i];
if ( !p ) /* ensure we have a valid pointer */
break;
for ( j=0 ; j<IMFS_MEMFILE_BLOCK_SLOTS ; j++ ) {
if ( p[j] ) {
memfile_free_blocks_in_table( (block_p **)&p[j], to_free);
}
}
memfile_free_blocks_in_table(
(block_p **)&info->triply_indirect[i], to_free );
}
memfile_free_blocks_in_table(
(block_p **)&info->triply_indirect, to_free );
}
return the_jnode;
}