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row_cache: Handle eviction in partition reader

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This commit is contained in:
Tomasz Grabiec
2017-09-12 19:03:51 +02:00
parent 99aa3d1964
commit fa2c26342c
1 changed files with 17 additions and 5 deletions
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22
cache_streamed_mutation.hh
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@@ -205,10 +205,15 @@ future<> cache_streamed_mutation::do_fill_buffer() {
return read_from_underlying();
}
return _lsa_manager.run_in_read_section([this] {
auto same_pos = _next_row.maybe_refresh();
// FIXME: If continuity changed anywhere between _lower_bound and _next_row.position()
// we need to redo the lookup with _lower_bound. There is no eviction yet, so not yet a problem.
assert(same_pos);
// We assume that if there was eviction, and thus the range may
// no longer be continuous, the cursor was invalidated.
if (!_next_row.up_to_date()) {
auto adjacent = _next_row.advance_to(_lower_bound);
_next_row_in_range = !after_current_range(_next_row.position());
if (!adjacent && !_next_row.continuous()) {
return start_reading_from_underlying();
}
}
while (!is_buffer_full() && !_end_of_stream && !_reading_underlying) {
future<> f = copy_from_cache_to_buffer();
if (!f.available() || need_preempt()) {
@@ -232,7 +237,14 @@ future<> cache_streamed_mutation::read_from_underlying() {
_reading_underlying = false;
return _lsa_manager.run_in_update_section([this] {
auto same_pos = _next_row.maybe_refresh();
assert(same_pos); // FIXME: handle eviction
if (!same_pos) {
_read_context->cache().on_mispopulate(); // FIXME: Insert dummy entry at _upper_bound.
_next_row_in_range = !after_current_range(_next_row.position());
if (!_next_row.continuous()) {
return start_reading_from_underlying();
}
return make_ready_future<>();
}
if (_next_row_in_range) {
maybe_update_continuity();
add_to_buffer(_next_row);