ee103636ac
The B-tree's insert_before() is throwing operation, its caller
must account for that. When the rows_entry's collection was
switched on B-tree all the risky places were fixed by ee9e1045,
but few places went under the radar.
In the cache_flat_mutation_reader there's a place where a C-pointer
is inserted into the tree, thus potentially leaking the entry.
In the partition_snapshot_row_cursor there are two places that not
only leak the entry, but also leave it in the LRU list. The latter
it quite nasty, because those entry can be evicted, eviction code
tries to get rows_entry iterator from "this", but the hook happens
to be unattached (because insertion threw) and fails the assert.
fixes: #9728
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
802 lines
35 KiB
C++
802 lines
35 KiB
C++
/*
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* Copyright (C) 2017-present ScyllaDB
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*/
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/*
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* This file is part of Scylla.
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*
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* Scylla is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* Scylla is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
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*/
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#pragma once
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#include <vector>
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#include "row_cache.hh"
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#include "mutation_reader.hh"
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#include "mutation_fragment.hh"
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#include "query-request.hh"
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#include "partition_snapshot_row_cursor.hh"
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#include "read_context.hh"
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#include "flat_mutation_reader.hh"
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#include "clustering_key_filter.hh"
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namespace cache {
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extern logging::logger clogger;
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class cache_flat_mutation_reader final : public flat_mutation_reader::impl {
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enum class state {
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before_static_row,
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// Invariants:
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// - position_range(_lower_bound, _upper_bound) covers all not yet emitted positions from current range
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// - if _next_row has valid iterators:
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// - _next_row points to the nearest row in cache >= _lower_bound
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// - _next_row_in_range = _next.position() < _upper_bound
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// - if _next_row doesn't have valid iterators, it has no meaning.
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reading_from_cache,
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// Starts reading from underlying reader.
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// The range to read is position_range(_lower_bound, min(_next_row.position(), _upper_bound)).
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// Invariants:
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// - _next_row_in_range = _next.position() < _upper_bound
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move_to_underlying,
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// Invariants:
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// - Upper bound of the read is min(_next_row.position(), _upper_bound)
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// - _next_row_in_range = _next.position() < _upper_bound
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// - _last_row points at a direct predecessor of the next row which is going to be read.
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// Used for populating continuity.
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// - _population_range_starts_before_all_rows is set accordingly
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// - _underlying is engaged and fast-forwarded
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reading_from_underlying,
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end_of_stream
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};
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partition_snapshot_ptr _snp;
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query::clustering_key_filter_ranges _ck_ranges;
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query::clustering_row_ranges::const_iterator _ck_ranges_curr;
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query::clustering_row_ranges::const_iterator _ck_ranges_end;
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lsa_manager _lsa_manager;
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partition_snapshot_row_weakref _last_row;
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// Holds the lower bound of a position range which hasn't been processed yet.
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// Only rows with positions < _lower_bound have been emitted, and only
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// range_tombstones with positions <= _lower_bound.
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position_in_partition _lower_bound;
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position_in_partition_view _upper_bound;
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// cache_flat_mutation_reader may be constructed either
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// with a read_context&, where it knows that the read_context
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// is owned externally, by the caller. In this case
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// _read_context_holder would be disengaged.
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// Or, it could be constructed with a std::unique_ptr<read_context>,
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// in which case it assumes ownership of the read_context
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// and it is now responsible for closing it.
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// In this case, _read_context_holder would be engaged
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// and _read_context will reference its content.
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std::unique_ptr<read_context> _read_context_holder;
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read_context& _read_context;
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partition_snapshot_row_cursor _next_row;
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state _state = state::before_static_row;
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bool _next_row_in_range = false;
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// True iff current population interval, since the previous clustering row, starts before all clustered rows.
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// We cannot just look at _lower_bound, because emission of range tombstones changes _lower_bound and
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// because we mark clustering intervals as continuous when consuming a clustering_row, it would prevent
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// us from marking the interval as continuous.
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// Valid when _state == reading_from_underlying.
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bool _population_range_starts_before_all_rows;
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// Whether _lower_bound was changed within current fill_buffer().
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// If it did not then we cannot break out of it (e.g. on preemption) because
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// forward progress is not guaranteed in case iterators are getting constantly invalidated.
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bool _lower_bound_changed = false;
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// Points to the underlying reader conforming to _schema,
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// either to *_underlying_holder or _read_context.underlying().underlying().
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flat_mutation_reader* _underlying = nullptr;
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flat_mutation_reader_opt _underlying_holder;
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future<> do_fill_buffer();
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future<> ensure_underlying();
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void copy_from_cache_to_buffer();
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future<> process_static_row();
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void move_to_end();
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void move_to_next_range();
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void move_to_range(query::clustering_row_ranges::const_iterator);
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void move_to_next_entry();
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void maybe_drop_last_entry() noexcept;
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void add_to_buffer(const partition_snapshot_row_cursor&);
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void add_clustering_row_to_buffer(mutation_fragment&&);
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void add_to_buffer(range_tombstone&&);
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void add_range_tombstone_to_buffer(range_tombstone&&);
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void add_to_buffer(mutation_fragment&&);
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future<> read_from_underlying();
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void start_reading_from_underlying();
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bool after_current_range(position_in_partition_view position);
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bool can_populate() const;
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// Marks the range between _last_row (exclusive) and _next_row (exclusive) as continuous,
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// provided that the underlying reader still matches the latest version of the partition.
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// Invalidates _last_row.
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void maybe_update_continuity();
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// Tries to ensure that the lower bound of the current population range exists.
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// Returns false if it failed and range cannot be populated.
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// Assumes can_populate().
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bool ensure_population_lower_bound();
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void maybe_add_to_cache(const mutation_fragment& mf);
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void maybe_add_to_cache(const clustering_row& cr);
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void maybe_add_to_cache(const range_tombstone& rt);
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void maybe_add_to_cache(const static_row& sr);
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void maybe_set_static_row_continuous();
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void finish_reader() {
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push_mutation_fragment(*_schema, _permit, partition_end());
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_end_of_stream = true;
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_state = state::end_of_stream;
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}
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void touch_partition();
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public:
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cache_flat_mutation_reader(schema_ptr s,
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dht::decorated_key dk,
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query::clustering_key_filter_ranges&& crr,
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read_context& ctx,
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partition_snapshot_ptr snp,
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row_cache& cache)
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: flat_mutation_reader::impl(std::move(s), ctx.permit())
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, _snp(std::move(snp))
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, _ck_ranges(std::move(crr))
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, _ck_ranges_curr(_ck_ranges.begin())
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, _ck_ranges_end(_ck_ranges.end())
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, _lsa_manager(cache)
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, _lower_bound(position_in_partition::before_all_clustered_rows())
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, _upper_bound(position_in_partition_view::before_all_clustered_rows())
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, _read_context_holder()
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, _read_context(ctx) // ctx is owned by the caller, who's responsible for closing it.
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, _next_row(*_schema, *_snp)
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{
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clogger.trace("csm {}: table={}.{}", fmt::ptr(this), _schema->ks_name(), _schema->cf_name());
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push_mutation_fragment(*_schema, _permit, partition_start(std::move(dk), _snp->partition_tombstone()));
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}
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cache_flat_mutation_reader(schema_ptr s,
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dht::decorated_key dk,
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query::clustering_key_filter_ranges&& crr,
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std::unique_ptr<read_context> unique_ctx,
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partition_snapshot_ptr snp,
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row_cache& cache)
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: cache_flat_mutation_reader(s, std::move(dk), std::move(crr), *unique_ctx, std::move(snp), cache)
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{
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// Assume ownership of the read_context.
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// It is our responsibility to close it now.
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_read_context_holder = std::move(unique_ctx);
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}
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cache_flat_mutation_reader(const cache_flat_mutation_reader&) = delete;
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cache_flat_mutation_reader(cache_flat_mutation_reader&&) = delete;
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virtual future<> fill_buffer() override;
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virtual future<> next_partition() override {
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clear_buffer_to_next_partition();
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if (is_buffer_empty()) {
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_end_of_stream = true;
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}
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return make_ready_future<>();
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}
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virtual future<> fast_forward_to(const dht::partition_range&) override {
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clear_buffer();
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_end_of_stream = true;
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return make_ready_future<>();
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}
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virtual future<> fast_forward_to(position_range pr) override {
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return make_exception_future<>(make_backtraced_exception_ptr<std::bad_function_call>());
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}
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virtual future<> close() noexcept override {
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auto close_read_context = _read_context_holder ? _read_context_holder->close() : make_ready_future<>();
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auto close_underlying = _underlying_holder ? _underlying_holder->close() : make_ready_future<>();
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return when_all_succeed(std::move(close_read_context), std::move(close_underlying)).discard_result();
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}
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};
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inline
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future<> cache_flat_mutation_reader::process_static_row() {
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if (_snp->static_row_continuous()) {
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_read_context.cache().on_row_hit();
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static_row sr = _lsa_manager.run_in_read_section([this] {
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return _snp->static_row(_read_context.digest_requested());
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});
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if (!sr.empty()) {
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push_mutation_fragment(mutation_fragment(*_schema, _permit, std::move(sr)));
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}
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return make_ready_future<>();
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} else {
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_read_context.cache().on_row_miss();
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return ensure_underlying().then([this] {
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return (*_underlying)().then([this] (mutation_fragment_opt&& sr) {
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if (sr) {
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assert(sr->is_static_row());
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maybe_add_to_cache(sr->as_static_row());
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push_mutation_fragment(std::move(*sr));
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}
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maybe_set_static_row_continuous();
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});
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});
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}
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}
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inline
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void cache_flat_mutation_reader::touch_partition() {
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_snp->touch();
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}
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inline
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future<> cache_flat_mutation_reader::fill_buffer() {
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if (_state == state::before_static_row) {
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touch_partition();
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auto after_static_row = [this] {
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if (_ck_ranges_curr == _ck_ranges_end) {
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finish_reader();
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return make_ready_future<>();
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}
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_state = state::reading_from_cache;
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_lsa_manager.run_in_read_section([this] {
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move_to_range(_ck_ranges_curr);
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});
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return fill_buffer();
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};
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if (_schema->has_static_columns()) {
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return process_static_row().then(std::move(after_static_row));
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} else {
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return after_static_row();
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}
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}
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clogger.trace("csm {}: fill_buffer(), range={}, lb={}", fmt::ptr(this), *_ck_ranges_curr, _lower_bound);
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return do_until([this] { return _end_of_stream || is_buffer_full(); }, [this] {
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return do_fill_buffer();
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});
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}
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inline
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future<> cache_flat_mutation_reader::ensure_underlying() {
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if (_underlying) {
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return make_ready_future<>();
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}
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return _read_context.ensure_underlying().then([this] {
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flat_mutation_reader& ctx_underlying = _read_context.underlying().underlying();
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if (ctx_underlying.schema() != _schema) {
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_underlying_holder = make_delegating_reader(ctx_underlying);
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_underlying_holder->upgrade_schema(_schema);
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_underlying = &*_underlying_holder;
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} else {
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_underlying = &ctx_underlying;
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}
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});
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}
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inline
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future<> cache_flat_mutation_reader::do_fill_buffer() {
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if (_state == state::move_to_underlying) {
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if (!_underlying) {
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return ensure_underlying().then([this] {
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return do_fill_buffer();
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});
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}
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_state = state::reading_from_underlying;
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_population_range_starts_before_all_rows = _lower_bound.is_before_all_clustered_rows(*_schema);
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if (!_read_context.partition_exists()) {
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return read_from_underlying();
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}
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auto end = _next_row_in_range ? position_in_partition(_next_row.position())
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: position_in_partition(_upper_bound);
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return _underlying->fast_forward_to(position_range{_lower_bound, std::move(end)}).then([this] {
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return read_from_underlying();
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});
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}
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if (_state == state::reading_from_underlying) {
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return read_from_underlying();
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}
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// assert(_state == state::reading_from_cache)
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return _lsa_manager.run_in_read_section([this] {
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auto next_valid = _next_row.iterators_valid();
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clogger.trace("csm {}: reading_from_cache, range=[{}, {}), next={}, valid={}", fmt::ptr(this), _lower_bound,
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_upper_bound, _next_row.position(), next_valid);
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// We assume that if there was eviction, and thus the range may
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// no longer be continuous, the cursor was invalidated.
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if (!next_valid) {
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auto adjacent = _next_row.advance_to(_lower_bound);
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_next_row_in_range = !after_current_range(_next_row.position());
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if (!adjacent && !_next_row.continuous()) {
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_last_row = nullptr; // We could insert a dummy here, but this path is unlikely.
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start_reading_from_underlying();
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return make_ready_future<>();
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}
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}
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_next_row.maybe_refresh();
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clogger.trace("csm {}: next={}, cont={}", fmt::ptr(this), _next_row.position(), _next_row.continuous());
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_lower_bound_changed = false;
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while (_state == state::reading_from_cache) {
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copy_from_cache_to_buffer();
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// We need to check _lower_bound_changed even if is_buffer_full() because
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// we may have emitted only a range tombstone which overlapped with _lower_bound
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// and thus didn't cause _lower_bound to change.
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if ((need_preempt() || is_buffer_full()) && _lower_bound_changed) {
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break;
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}
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}
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return make_ready_future<>();
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});
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}
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inline
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future<> cache_flat_mutation_reader::read_from_underlying() {
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return consume_mutation_fragments_until(*_underlying,
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[this] { return _state != state::reading_from_underlying || is_buffer_full(); },
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[this] (mutation_fragment mf) {
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_read_context.cache().on_row_miss();
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maybe_add_to_cache(mf);
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add_to_buffer(std::move(mf));
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},
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[this] {
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_state = state::reading_from_cache;
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_lsa_manager.run_in_update_section([this] {
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auto same_pos = _next_row.maybe_refresh();
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if (!same_pos) {
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_read_context.cache().on_mispopulate(); // FIXME: Insert dummy entry at _upper_bound.
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_next_row_in_range = !after_current_range(_next_row.position());
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if (!_next_row.continuous()) {
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start_reading_from_underlying();
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}
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return;
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}
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if (_next_row_in_range) {
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maybe_update_continuity();
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if (!_next_row.dummy()) {
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_lower_bound = position_in_partition::before_key(_next_row.key());
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} else {
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_lower_bound = _next_row.position();
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}
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} else {
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if (no_clustering_row_between(*_schema, _upper_bound, _next_row.position())) {
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this->maybe_update_continuity();
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} else if (can_populate()) {
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rows_entry::tri_compare cmp(*_schema);
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auto& rows = _snp->version()->partition().mutable_clustered_rows();
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if (query::is_single_row(*_schema, *_ck_ranges_curr)) {
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with_allocator(_snp->region().allocator(), [&] {
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auto e = alloc_strategy_unique_ptr<rows_entry>(
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current_allocator().construct<rows_entry>(_ck_ranges_curr->start()->value()));
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// Use _next_row iterator only as a hint, because there could be insertions after _upper_bound.
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auto insert_result = rows.insert_before_hint(_next_row.get_iterator_in_latest_version(), std::move(e), cmp);
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if (insert_result.second) {
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auto it = insert_result.first;
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_snp->tracker()->insert(*it);
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auto next = std::next(it);
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it->set_continuous(next->continuous());
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clogger.trace("csm {}: inserted empty row at {}, cont={}", fmt::ptr(this), it->position(), it->continuous());
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}
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});
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} else if (ensure_population_lower_bound()) {
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with_allocator(_snp->region().allocator(), [&] {
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auto e = alloc_strategy_unique_ptr<rows_entry>(
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current_allocator().construct<rows_entry>(*_schema, _upper_bound, is_dummy::yes, is_continuous::yes));
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// Use _next_row iterator only as a hint, because there could be insertions after _upper_bound.
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auto insert_result = rows.insert_before_hint(_next_row.get_iterator_in_latest_version(), std::move(e), cmp);
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if (insert_result.second) {
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clogger.trace("csm {}: inserted dummy at {}", fmt::ptr(this), _upper_bound);
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_snp->tracker()->insert(*insert_result.first);
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} else {
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clogger.trace("csm {}: mark {} as continuous", fmt::ptr(this), insert_result.first->position());
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insert_result.first->set_continuous(true);
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}
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maybe_drop_last_entry();
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});
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}
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} else {
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_read_context.cache().on_mispopulate();
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}
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try {
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move_to_next_range();
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} catch (const std::bad_alloc&) {
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// We cannot reenter the section, since we may have moved to the new range
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_snp->region().allocator().invalidate_references(); // Invalidates _next_row
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}
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}
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});
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return make_ready_future<>();
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});
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}
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inline
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bool cache_flat_mutation_reader::ensure_population_lower_bound() {
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if (_population_range_starts_before_all_rows) {
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return true;
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}
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if (!_last_row.refresh(*_snp)) {
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return false;
|
|
}
|
|
// Continuity flag we will later set for the upper bound extends to the previous row in the same version,
|
|
// so we need to ensure we have an entry in the latest version.
|
|
if (!_last_row.is_in_latest_version()) {
|
|
with_allocator(_snp->region().allocator(), [&] {
|
|
auto& rows = _snp->version()->partition().mutable_clustered_rows();
|
|
rows_entry::tri_compare cmp(*_schema);
|
|
// FIXME: Avoid the copy by inserting an incomplete clustering row
|
|
auto e = alloc_strategy_unique_ptr<rows_entry>(
|
|
current_allocator().construct<rows_entry>(*_schema, *_last_row));
|
|
e->set_continuous(false);
|
|
auto insert_result = rows.insert_before_hint(rows.end(), std::move(e), cmp);
|
|
if (insert_result.second) {
|
|
auto it = insert_result.first;
|
|
clogger.trace("csm {}: inserted lower bound dummy at {}", fmt::ptr(this), it->position());
|
|
_snp->tracker()->insert(*it);
|
|
}
|
|
});
|
|
}
|
|
return true;
|
|
}
|
|
|
|
inline
|
|
void cache_flat_mutation_reader::maybe_update_continuity() {
|
|
if (can_populate() && ensure_population_lower_bound()) {
|
|
with_allocator(_snp->region().allocator(), [&] {
|
|
rows_entry& e = _next_row.ensure_entry_in_latest().row;
|
|
e.set_continuous(true);
|
|
maybe_drop_last_entry();
|
|
});
|
|
} else {
|
|
_read_context.cache().on_mispopulate();
|
|
}
|
|
}
|
|
|
|
inline
|
|
void cache_flat_mutation_reader::maybe_add_to_cache(const mutation_fragment& mf) {
|
|
if (mf.is_range_tombstone()) {
|
|
maybe_add_to_cache(mf.as_range_tombstone());
|
|
} else {
|
|
assert(mf.is_clustering_row());
|
|
const clustering_row& cr = mf.as_clustering_row();
|
|
maybe_add_to_cache(cr);
|
|
}
|
|
}
|
|
|
|
inline
|
|
void cache_flat_mutation_reader::maybe_add_to_cache(const clustering_row& cr) {
|
|
if (!can_populate()) {
|
|
_last_row = nullptr;
|
|
_population_range_starts_before_all_rows = false;
|
|
_read_context.cache().on_mispopulate();
|
|
return;
|
|
}
|
|
clogger.trace("csm {}: populate({})", fmt::ptr(this), clustering_row::printer(*_schema, cr));
|
|
_lsa_manager.run_in_update_section_with_allocator([this, &cr] {
|
|
mutation_partition& mp = _snp->version()->partition();
|
|
rows_entry::tri_compare cmp(*_schema);
|
|
|
|
if (_read_context.digest_requested()) {
|
|
cr.cells().prepare_hash(*_schema, column_kind::regular_column);
|
|
}
|
|
auto new_entry = alloc_strategy_unique_ptr<rows_entry>(
|
|
current_allocator().construct<rows_entry>(*_schema, cr.key(), cr.as_deletable_row()));
|
|
new_entry->set_continuous(false);
|
|
auto it = _next_row.iterators_valid() ? _next_row.get_iterator_in_latest_version()
|
|
: mp.clustered_rows().lower_bound(cr.key(), cmp);
|
|
auto insert_result = mp.mutable_clustered_rows().insert_before_hint(it, std::move(new_entry), cmp);
|
|
it = insert_result.first;
|
|
if (insert_result.second) {
|
|
_snp->tracker()->insert(*it);
|
|
}
|
|
|
|
rows_entry& e = *it;
|
|
if (ensure_population_lower_bound()) {
|
|
clogger.trace("csm {}: set_continuous({})", fmt::ptr(this), e.position());
|
|
e.set_continuous(true);
|
|
} else {
|
|
_read_context.cache().on_mispopulate();
|
|
}
|
|
with_allocator(standard_allocator(), [&] {
|
|
_last_row = partition_snapshot_row_weakref(*_snp, it, true);
|
|
});
|
|
_population_range_starts_before_all_rows = false;
|
|
});
|
|
}
|
|
|
|
inline
|
|
bool cache_flat_mutation_reader::after_current_range(position_in_partition_view p) {
|
|
position_in_partition::tri_compare cmp(*_schema);
|
|
return cmp(p, _upper_bound) >= 0;
|
|
}
|
|
|
|
inline
|
|
void cache_flat_mutation_reader::start_reading_from_underlying() {
|
|
clogger.trace("csm {}: start_reading_from_underlying(), range=[{}, {})", fmt::ptr(this), _lower_bound, _next_row_in_range ? _next_row.position() : _upper_bound);
|
|
_state = state::move_to_underlying;
|
|
_next_row.touch();
|
|
}
|
|
|
|
inline
|
|
void cache_flat_mutation_reader::copy_from_cache_to_buffer() {
|
|
clogger.trace("csm {}: copy_from_cache, next={}, next_row_in_range={}", fmt::ptr(this), _next_row.position(), _next_row_in_range);
|
|
_next_row.touch();
|
|
position_in_partition_view next_lower_bound = _next_row.dummy() ? _next_row.position() : position_in_partition_view::after_key(_next_row.key());
|
|
auto upper_bound = _next_row_in_range ? next_lower_bound : _upper_bound;
|
|
if (_snp->range_tombstones(_lower_bound, upper_bound, [&] (range_tombstone rts) {
|
|
position_in_partition::less_compare less(*_schema);
|
|
// Avoid emitting overlapping range tombstones for performance reasons.
|
|
if (less(upper_bound, rts.end_position())) {
|
|
rts.set_end(*_schema, upper_bound);
|
|
}
|
|
add_range_tombstone_to_buffer(std::move(rts));
|
|
return stop_iteration(_lower_bound_changed && is_buffer_full());
|
|
}) == stop_iteration::no) {
|
|
return;
|
|
}
|
|
// We add the row to the buffer even when it's full.
|
|
// This simplifies the code. For more info see #3139.
|
|
if (_next_row_in_range) {
|
|
add_to_buffer(_next_row);
|
|
move_to_next_entry();
|
|
} else {
|
|
move_to_next_range();
|
|
}
|
|
}
|
|
|
|
inline
|
|
void cache_flat_mutation_reader::move_to_end() {
|
|
finish_reader();
|
|
clogger.trace("csm {}: eos", fmt::ptr(this));
|
|
}
|
|
|
|
inline
|
|
void cache_flat_mutation_reader::move_to_next_range() {
|
|
auto next_it = std::next(_ck_ranges_curr);
|
|
if (next_it == _ck_ranges_end) {
|
|
move_to_end();
|
|
_ck_ranges_curr = next_it;
|
|
} else {
|
|
move_to_range(next_it);
|
|
}
|
|
}
|
|
|
|
inline
|
|
void cache_flat_mutation_reader::move_to_range(query::clustering_row_ranges::const_iterator next_it) {
|
|
auto lb = position_in_partition::for_range_start(*next_it);
|
|
auto ub = position_in_partition_view::for_range_end(*next_it);
|
|
_last_row = nullptr;
|
|
_lower_bound = std::move(lb);
|
|
_upper_bound = std::move(ub);
|
|
_lower_bound_changed = true;
|
|
_ck_ranges_curr = next_it;
|
|
auto adjacent = _next_row.advance_to(_lower_bound);
|
|
_next_row_in_range = !after_current_range(_next_row.position());
|
|
clogger.trace("csm {}: move_to_range(), range={}, lb={}, ub={}, next={}", fmt::ptr(this), *_ck_ranges_curr, _lower_bound, _upper_bound, _next_row.position());
|
|
if (!adjacent && !_next_row.continuous()) {
|
|
// FIXME: We don't insert a dummy for singular range to avoid allocating 3 entries
|
|
// for a hit (before, at and after). If we supported the concept of an incomplete row,
|
|
// we could insert such a row for the lower bound if it's full instead, for both singular and
|
|
// non-singular ranges.
|
|
if (_ck_ranges_curr->start() && !query::is_single_row(*_schema, *_ck_ranges_curr)) {
|
|
// Insert dummy for lower bound
|
|
if (can_populate()) {
|
|
// FIXME: _lower_bound could be adjacent to the previous row, in which case we could skip this
|
|
clogger.trace("csm {}: insert dummy at {}", fmt::ptr(this), _lower_bound);
|
|
auto it = with_allocator(_lsa_manager.region().allocator(), [&] {
|
|
auto& rows = _snp->version()->partition().mutable_clustered_rows();
|
|
auto new_entry = alloc_strategy_unique_ptr<rows_entry>(current_allocator().construct<rows_entry>(*_schema, _lower_bound, is_dummy::yes, is_continuous::no));
|
|
return rows.insert_before(_next_row.get_iterator_in_latest_version(), std::move(new_entry));
|
|
});
|
|
_snp->tracker()->insert(*it);
|
|
_last_row = partition_snapshot_row_weakref(*_snp, it, true);
|
|
} else {
|
|
_read_context.cache().on_mispopulate();
|
|
}
|
|
}
|
|
start_reading_from_underlying();
|
|
}
|
|
}
|
|
|
|
// Drops _last_row entry when possible without changing logical contents of the partition.
|
|
// Call only when _last_row and _next_row are valid.
|
|
// Calling after ensure_population_lower_bound() is ok.
|
|
// _next_row must have a greater position than _last_row.
|
|
// Invalidates references but keeps the _next_row valid.
|
|
inline
|
|
void cache_flat_mutation_reader::maybe_drop_last_entry() noexcept {
|
|
// Drop dummy entry if it falls inside a continuous range.
|
|
// This prevents unnecessary dummy entries from accumulating in cache and slowing down scans.
|
|
//
|
|
// Eviction can happen only from oldest versions to preserve the continuity non-overlapping rule
|
|
// (See docs/design-notes/row_cache.md)
|
|
//
|
|
if (_last_row
|
|
&& _last_row->dummy()
|
|
&& _last_row->continuous()
|
|
&& _snp->at_latest_version()
|
|
&& _snp->at_oldest_version()) {
|
|
|
|
with_allocator(_snp->region().allocator(), [&] {
|
|
_last_row->on_evicted(_read_context.cache()._tracker);
|
|
});
|
|
_last_row = nullptr;
|
|
|
|
// There could be iterators pointing to _last_row, invalidate them
|
|
_snp->region().allocator().invalidate_references();
|
|
|
|
// Don't invalidate _next_row, move_to_next_entry() expects it to be still valid.
|
|
_next_row.force_valid();
|
|
}
|
|
}
|
|
|
|
// _next_row must be inside the range.
|
|
inline
|
|
void cache_flat_mutation_reader::move_to_next_entry() {
|
|
clogger.trace("csm {}: move_to_next_entry(), curr={}", fmt::ptr(this), _next_row.position());
|
|
if (no_clustering_row_between(*_schema, _next_row.position(), _upper_bound)) {
|
|
move_to_next_range();
|
|
} else {
|
|
auto new_last_row = partition_snapshot_row_weakref(_next_row);
|
|
if (!_next_row.next()) {
|
|
move_to_end();
|
|
return;
|
|
}
|
|
_last_row = std::move(new_last_row);
|
|
_next_row_in_range = !after_current_range(_next_row.position());
|
|
clogger.trace("csm {}: next={}, cont={}, in_range={}", fmt::ptr(this), _next_row.position(), _next_row.continuous(), _next_row_in_range);
|
|
if (!_next_row.continuous()) {
|
|
start_reading_from_underlying();
|
|
} else {
|
|
maybe_drop_last_entry();
|
|
}
|
|
}
|
|
}
|
|
|
|
inline
|
|
void cache_flat_mutation_reader::add_to_buffer(mutation_fragment&& mf) {
|
|
clogger.trace("csm {}: add_to_buffer({})", fmt::ptr(this), mutation_fragment::printer(*_schema, mf));
|
|
if (mf.is_clustering_row()) {
|
|
add_clustering_row_to_buffer(std::move(mf));
|
|
} else {
|
|
assert(mf.is_range_tombstone());
|
|
add_to_buffer(std::move(mf).as_range_tombstone());
|
|
}
|
|
}
|
|
|
|
inline
|
|
void cache_flat_mutation_reader::add_to_buffer(const partition_snapshot_row_cursor& row) {
|
|
if (!row.dummy()) {
|
|
_read_context.cache().on_row_hit();
|
|
if (_read_context.digest_requested()) {
|
|
row.latest_row().cells().prepare_hash(*_schema, column_kind::regular_column);
|
|
}
|
|
add_clustering_row_to_buffer(mutation_fragment(*_schema, _permit, row.row()));
|
|
} else {
|
|
position_in_partition::less_compare less(*_schema);
|
|
if (less(_lower_bound, row.position())) {
|
|
_lower_bound = row.position();
|
|
_lower_bound_changed = true;
|
|
}
|
|
_read_context.cache()._tracker.on_dummy_row_hit();
|
|
}
|
|
}
|
|
|
|
// Maintains the following invariants, also in case of exception:
|
|
// (1) no fragment with position >= _lower_bound was pushed yet
|
|
// (2) If _lower_bound > mf.position(), mf was emitted
|
|
inline
|
|
void cache_flat_mutation_reader::add_clustering_row_to_buffer(mutation_fragment&& mf) {
|
|
clogger.trace("csm {}: add_clustering_row_to_buffer({})", fmt::ptr(this), mutation_fragment::printer(*_schema, mf));
|
|
auto& row = mf.as_clustering_row();
|
|
auto new_lower_bound = position_in_partition::after_key(row.key());
|
|
push_mutation_fragment(std::move(mf));
|
|
_lower_bound = std::move(new_lower_bound);
|
|
_lower_bound_changed = true;
|
|
if (row.tomb()) {
|
|
_read_context.cache()._tracker.on_row_tombstone_read();
|
|
}
|
|
}
|
|
|
|
inline
|
|
void cache_flat_mutation_reader::add_to_buffer(range_tombstone&& rt) {
|
|
clogger.trace("csm {}: add_to_buffer({})", fmt::ptr(this), rt);
|
|
// This guarantees that rt starts after any emitted clustering_row
|
|
// and not before any emitted range tombstone.
|
|
position_in_partition::less_compare less(*_schema);
|
|
if (less(_lower_bound, rt.end_position())) {
|
|
add_range_tombstone_to_buffer(std::move(rt));
|
|
}
|
|
}
|
|
|
|
inline
|
|
void cache_flat_mutation_reader::add_range_tombstone_to_buffer(range_tombstone&& rt) {
|
|
position_in_partition::less_compare less(*_schema);
|
|
if (!less(_lower_bound, rt.position())) {
|
|
rt.set_start(_lower_bound);
|
|
} else {
|
|
_lower_bound = position_in_partition(rt.position());
|
|
_lower_bound_changed = true;
|
|
}
|
|
push_mutation_fragment(*_schema, _permit, std::move(rt));
|
|
_read_context.cache()._tracker.on_range_tombstone_read();
|
|
}
|
|
|
|
inline
|
|
void cache_flat_mutation_reader::maybe_add_to_cache(const range_tombstone& rt) {
|
|
if (can_populate()) {
|
|
clogger.trace("csm {}: maybe_add_to_cache({})", fmt::ptr(this), rt);
|
|
_lsa_manager.run_in_update_section_with_allocator([&] {
|
|
_snp->version()->partition().mutable_row_tombstones().apply_monotonically(*_schema, rt);
|
|
});
|
|
} else {
|
|
_read_context.cache().on_mispopulate();
|
|
}
|
|
}
|
|
|
|
inline
|
|
void cache_flat_mutation_reader::maybe_add_to_cache(const static_row& sr) {
|
|
if (can_populate()) {
|
|
clogger.trace("csm {}: populate({})", fmt::ptr(this), static_row::printer(*_schema, sr));
|
|
_read_context.cache().on_static_row_insert();
|
|
_lsa_manager.run_in_update_section_with_allocator([&] {
|
|
if (_read_context.digest_requested()) {
|
|
sr.cells().prepare_hash(*_schema, column_kind::static_column);
|
|
}
|
|
_snp->version()->partition().static_row().apply(*_schema, column_kind::static_column, sr.cells());
|
|
});
|
|
} else {
|
|
_read_context.cache().on_mispopulate();
|
|
}
|
|
}
|
|
|
|
inline
|
|
void cache_flat_mutation_reader::maybe_set_static_row_continuous() {
|
|
if (can_populate()) {
|
|
clogger.trace("csm {}: set static row continuous", fmt::ptr(this));
|
|
_snp->version()->partition().set_static_row_continuous(true);
|
|
} else {
|
|
_read_context.cache().on_mispopulate();
|
|
}
|
|
}
|
|
|
|
inline
|
|
bool cache_flat_mutation_reader::can_populate() const {
|
|
return _snp->at_latest_version() && _read_context.cache().phase_of(_read_context.key()) == _read_context.phase();
|
|
}
|
|
|
|
} // namespace cache
|
|
|
|
// pass a reference to ctx to cache_flat_mutation_reader
|
|
// keeping its ownership at caller's.
|
|
inline flat_mutation_reader make_cache_flat_mutation_reader(schema_ptr s,
|
|
dht::decorated_key dk,
|
|
query::clustering_key_filter_ranges crr,
|
|
row_cache& cache,
|
|
cache::read_context& ctx,
|
|
partition_snapshot_ptr snp)
|
|
{
|
|
return make_flat_mutation_reader<cache::cache_flat_mutation_reader>(
|
|
std::move(s), std::move(dk), std::move(crr), ctx, std::move(snp), cache);
|
|
}
|
|
|
|
// transfer ownership of ctx to cache_flat_mutation_reader
|
|
inline flat_mutation_reader make_cache_flat_mutation_reader(schema_ptr s,
|
|
dht::decorated_key dk,
|
|
query::clustering_key_filter_ranges crr,
|
|
row_cache& cache,
|
|
std::unique_ptr<cache::read_context> unique_ctx,
|
|
partition_snapshot_ptr snp)
|
|
{
|
|
return make_flat_mutation_reader<cache::cache_flat_mutation_reader>(
|
|
std::move(s), std::move(dk), std::move(crr), std::move(unique_ctx), std::move(snp), cache);
|
|
}
|