AA_API void aa_mem_region_pop( aa_mem_region_t *reg, void *ptr ) {
uint8_t *ptr8 = (uint8_t*)ptr;
if( aa_mem_region_pop_in_node( ptr8, reg->node ) ){
// fast path, in the top node
aa_mem_region_align( reg, ptr8 );
} else {
// ugly case, iterate through nodes
ptrdiff_t n = reg->node->end - reg->node->d;
struct aa_mem_region_node *p = aa_mem_region_node_free( reg->node );
// free old nodes
while( p && !aa_mem_region_pop_in_node(ptr8, p) ) {
n += (p->end - p->d);
p = aa_mem_region_node_free( p );
}
assert( !p || (ptr8 >= p->d && ptr8 <= p->end));
// now realloc a replacement node
// how much of the last chunk is now unused
ptrdiff_t popsize = p ? (p->end - ptr8) : 0;
assert( ( !p || ptr8 > p->d ) ?
// popped in middle of chunk, keep it
(!p || popsize < p->end - p->d ) :
// poppsed start of chunk, realloc it
( (ptr8 == p->d) &&
(popsize == p->end - p->d) ) );
reg->node =
aa_mem_region_node_alloc( (size_t)(n+popsize),
(p && aa_mem_region_alignptr(p->d) == ptr8) ?
aa_mem_region_node_free(p) : p );
reg->head = aa_mem_region_alignptr(reg->node->d);
}
}
void aa_mem_region_release( aa_mem_region_t *region ) {
if( region->node->next ) {
// compress buffers
struct aa_mem_region_node *p = region->node;
size_t n = 0;
while (p) { n+= (size_t)(p->end - p->d); p = aa_mem_region_node_free(p); }
region->node = aa_mem_region_node_alloc( n, NULL);
}
region->head = region->node->d;
}
void aa_mem_region_destroy( aa_mem_region_t *region )
{
struct aa_mem_region_node *p = region->node;
while (p) { p = aa_mem_region_node_free(p); }
if( region->free_on_destroy ) {
free(region);
} else {
region->node = NULL;
}
}
static void aa_mem_region_grow( aa_mem_region_t *reg, size_t size ) {
size_t nsize = AA_MAX(2*(size_t)(reg->node->end - reg->node->d),
size + AA_MEMREG_ALIGN);
// this growth strategy creates worst-case O(n) memory waste
reg->node =
aa_mem_region_node_alloc( nsize,
/* free unused chunk */
(aa_mem_region_alignptr(reg->node->d) == reg->head) ?
aa_mem_region_node_free(reg->node) : reg->node );
aa_mem_region_align(reg, reg->node->d);
assert( aa_mem_region_freesize(reg) >= size );
assert( ! ((uintptr_t)reg->head%16) );
}
void aa_mem_region_destroy( aa_mem_region_t *region ) {
struct aa_mem_region_node *p = region->node;
while (p) { p = aa_mem_region_node_free(p); }
region->node = NULL;
}