Avoid disk I/O when data 'moves' in a SHAMap

This commit is contained in:
David Schwartz
2014-03-05 11:41:32 -08:00
committed by Nik Bougalis
parent 2505a908c5
commit 16d2bbd6e5
3 changed files with 24 additions and 6 deletions

View File

@@ -61,7 +61,7 @@ SHAMap::SHAMap (SHAMapType t, uint256 const& hash, FullBelowCache& fullBelowCach
mTNByID.replace(*root, root);
}
TaggedCache< SHAMap::TNIndex, SHAMapTreeNode>
TaggedCache <uint256, SHAMapTreeNode>
SHAMap::treeNodeCache ("TreeNodeCache", 65536, 60,
get_seconds_clock (),
LogPartition::getJournal <TaggedCacheLog> ());
@@ -1263,15 +1263,29 @@ void SHAMap::dump (bool hash)
SHAMapTreeNode::pointer SHAMap::getCache (uint256 const& hash, SHAMapNode const& id)
{
SHAMapTreeNode::pointer ret = treeNodeCache.fetch (TNIndex (hash, id));
SHAMapTreeNode::pointer ret = treeNodeCache.fetch (hash);
assert (!ret || !ret->getSeq());
if (ret && (*ret != id))
{
// We have the data, but with a different node ID
WriteLog (lsTRACE, SHAMap) << "ID mismatch: " << id << " != " << *ret;
ret = boost::make_shared <SHAMapTreeNode> (*ret, 0);
ret->set(id);
// Future fetches are likely to use the "new" ID
treeNodeCache.canonicalize (hash, ret, true);
assert (*ret == id);
assert (ret->getNodeHash() == hash);
}
return ret;
}
void SHAMap::canonicalize (uint256 const& hash, SHAMapTreeNode::pointer& node)
{
assert (node->getSeq() == 0);
treeNodeCache.canonicalize (TNIndex (hash, *node), node);
treeNodeCache.canonicalize (hash, node);
}
//------------------------------------------------------------------------------