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ircd::db: Remove the handles vector optimization.

This commit is contained in:
Jason Volk 2019-01-17 15:36:41 -08:00
parent bb354c5c05
commit 36bcb9a300

View file

@ -9351,16 +9351,8 @@ ircd::db::row::row(database &d,
std::vector<Iterator *> iterators;
if(key)
{
// The goal here is to optimize away the heap allocation incurred by
// having to pass RocksDB the specific std::vector type which doesn't
// have room for an allocator. We use a single thread_local vector
// and reserve() it with one worst-case size of all possible columns.
// Then we resize it to this specific call's requirements and copy the
// column pointers. On sane platforms only one allocation ever occurs.
thread_local std::vector<ColumnFamilyHandle *> handles;
assert(column_count <= d.columns.size());
handles.reserve(d.columns.size());
handles.resize(column_count);
std::vector<ColumnFamilyHandle *> handles(column_count);
std::transform(colptr, colptr + column_count, begin(handles), []
(database::column *const &ptr)
{
@ -9370,6 +9362,7 @@ ircd::db::row::row(database &d,
// This has been seen to lead to IO and block the ircd::ctx;
// specifically when background options are aggressive and shortly
// after db opens.
//const ctx::critical_assertion ca;
throw_on_error
{
d.d->NewIterators(options, handles, &iterators)