thin-provisioning-tools/space_map_transactional.cc
2011-11-21 12:17:38 +00:00

114 lines
2.5 KiB
C++

#include "space_map_transactional.h"
//----------------------------------------------------------------
namespace {
class sm_transactional : public checked_space_map {
public:
typedef shared_ptr<sm_transactional> ptr;
sm_transactional(checked_space_map::ptr sm)
: sm_(sm),
committed_(sm_->clone()),
allocated_(0),
search_start_(0) {
}
virtual block_address get_nr_blocks() const {
return committed_->get_nr_blocks();
}
virtual block_address get_nr_free() const {
return committed_->get_nr_free() - allocated_;
}
virtual ref_t get_count(block_address b) const {
return sm_->get_count(b);
}
virtual void set_count(block_address b, ref_t c) {
sm_->set_count(b, c);
}
virtual void commit() {
sm_->commit();
committed_ = sm_->clone();
allocated_ = 0;
search_start_ = 0;
}
virtual void inc(block_address b) {
// FIXME: this may do an implicit allocation, so
// search_start_ and allocated_ will be wrong.
sm_->inc(b);
}
virtual void dec(block_address b) {
sm_->dec(b);
}
virtual maybe_block new_block() {
return new_block(0, sm_->get_nr_blocks());
}
virtual maybe_block new_block(block_address begin, block_address end) {
if (end <= search_start_)
return maybe_block();
maybe_block mb = committed_->new_block(max(search_start_, begin), end);
if (mb) {
allocated_++;
search_start_ = *mb + 1;
} else
search_start_ = end;
return mb;
}
virtual bool count_possibly_greater_than_one(block_address b) const {
return sm_->count_possibly_greater_than_one(b);
}
virtual void extend(block_address extra_blocks) {
return sm_->extend(extra_blocks);
}
virtual void iterate(iterator &it) const {
sm_->iterate(it);
}
virtual size_t root_size() const {
return sm_->root_size();
}
virtual void copy_root(void *dest, size_t len) const {
return sm_->copy_root(dest, len);
}
virtual void check(block_counter &counter) const {
return sm_->check(counter);
}
virtual checked_space_map::ptr clone() const {
return checked_space_map::ptr(new sm_transactional(sm_));
}
private:
checked_space_map::ptr sm_;
checked_space_map::ptr committed_;
block_address allocated_;
block_address search_start_;
};
}
//----------------------------------------------------------------
checked_space_map::ptr
persistent_data::create_transactional_sm(checked_space_map::ptr sm)
{
return checked_space_map::ptr(new sm_transactional(sm));
}
//----------------------------------------------------------------