thin-provisioning-tools/transaction_manager.tcc
2011-07-14 15:31:00 +01:00

168 lines
3.8 KiB
C++

#include "transaction_manager.h"
#include <string.h>
using namespace boost;
using namespace persistent_data;
using namespace std;
//----------------------------------------------------------------
template <uint32_t BlockSize>
transaction_manager<BlockSize>::transaction_manager(typename block_manager<BlockSize>::ptr bm,
space_map::ptr sm)
: bm_(bm),
sm_(sm)
{
}
template <uint32_t BlockSize>
transaction_manager<BlockSize>::~transaction_manager()
{
}
template <uint32_t BlockSize>
typename transaction_manager<BlockSize>::write_ref
transaction_manager<BlockSize>::begin(block_address superblock)
{
auto wr = bm_->superblock(superblock);
wipe_shadow_table();
return wr;
}
template <uint32_t BlockSize>
typename transaction_manager<BlockSize>::write_ref
transaction_manager<BlockSize>::begin(block_address superblock,
validator v)
{
auto wr = bm_->superblock(superblock, v);
wipe_shadow_table();
return wr;
}
// FIXME: these explicit try/catches are gross
template <uint32_t BlockSize>
typename transaction_manager<BlockSize>::write_ref
transaction_manager<BlockSize>::new_block()
{
block_address b = sm_->new_block();
try {
add_shadow(b);
try {
return bm_->write_lock_zero(b);
} catch (...) {
remove_shadow(b);
throw;
}
} catch (...) {
sm_->dec(b);
throw;
}
}
template <uint32_t BlockSize>
typename transaction_manager<BlockSize>::write_ref
transaction_manager<BlockSize>::new_block(validator v)
{
block_address b = sm_->new_block();
try {
add_shadow(b);
try {
return bm_->write_lock_zero(b, v);
} catch (...) {
remove_shadow(b);
throw;
}
} catch (...) {
sm_->dec(b);
throw;
}
}
// FIXME: make exception safe
template <uint32_t BlockSize>
pair<typename transaction_manager<BlockSize>::write_ref, bool>
transaction_manager<BlockSize>::shadow(block_address orig)
{
if (is_shadow(orig) &&
!sm_->count_possibly_greater_than_one(orig))
return make_pair(bm_->write_lock(orig), false);
auto src = bm_->read_lock(orig);
auto dest = bm_->write_lock_zero(sm_->new_block());
::memcpy(dest.data(), src.data(), BlockSize);
ref_t count = sm_->get_count(orig);
if (count == 0)
throw runtime_error("shadowing free block");
sm_->dec(orig);
add_shadow(dest.get_location());
return make_pair(dest, count > 1);
}
// FIXME: duplicate code
template <uint32_t BlockSize>
pair<typename transaction_manager<BlockSize>::write_ref, bool>
transaction_manager<BlockSize>::shadow(block_address orig, validator v)
{
if (is_shadow(orig) &&
sm_->count_possibly_greater_than_one(orig))
return make_pair(bm_->write_lock(orig), false);
auto src = bm_->read_lock(orig, v);
auto dest = bm_->write_lock_zero(sm_->new_block(), v);
::memcpy(dest->data_, src->data_, BlockSize);
ref_t count = sm_->get_count(orig);
if (count == 0)
throw runtime_error("shadowing free block");
sm_->dec(orig);
add_shadow(dest->location_);
return make_pair(dest, count > 1);
}
template <uint32_t BlockSize>
typename transaction_manager<BlockSize>::read_ref
transaction_manager<BlockSize>::read_lock(block_address b)
{
return bm_->read_lock(b);
}
template <uint32_t BlockSize>
typename transaction_manager<BlockSize>::read_ref
transaction_manager<BlockSize>::read_lock(block_address b, validator v)
{
return bm_->read_lock(b, v);
}
template <uint32_t BlockSize>
void
transaction_manager<BlockSize>::add_shadow(block_address b)
{
shadows_.insert(b);
}
template <uint32_t BlockSize>
void
transaction_manager<BlockSize>::remove_shadow(block_address b)
{
shadows_.erase(b);
}
template <uint32_t BlockSize>
bool
transaction_manager<BlockSize>::is_shadow(block_address b) const
{
return shadows_.count(b) > 0;
}
template <uint32_t BlockSize>
void
transaction_manager<BlockSize>::wipe_shadow_table()
{
shadows_.clear();
}
//----------------------------------------------------------------