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https://github.com/scylladb/scylladb.git
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8ba6366610
Currently every time cache needs to create reader for missing data it obtains a reader which is most up to date. That reader includes writes from later populate phases, for which update() was not yet called. This will be problematic once we allow partitions to be partially populated, because different parts of the partition could be partially populated using readers using different sets of writes, and break write atomicity. The solution will be to always populate given partition using the same set of writes, using reader created from the current snapshot. The snapshot changes only on update(), with update() gradually converting each partition to the new snapshot.
902 lines
34 KiB
C++
902 lines
34 KiB
C++
/*
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* Copyright (C) 2015 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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#include "row_cache.hh"
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#include "core/memory.hh"
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#include "core/do_with.hh"
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#include "core/future-util.hh"
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#include <seastar/core/metrics.hh>
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#include <seastar/util/defer.hh>
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#include "memtable.hh"
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#include "partition_snapshot_reader.hh"
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#include <chrono>
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#include "utils/move.hh"
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#include <boost/version.hpp>
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#include <sys/sdt.h>
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#include "stdx.hh"
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#include "read_context.hh"
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using namespace std::chrono_literals;
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using namespace cache;
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static logging::logger clogger("cache");
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thread_local seastar::thread_scheduling_group row_cache::_update_thread_scheduling_group(1ms, 0.2);
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mutation_reader
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row_cache::create_underlying_reader(read_context& ctx, const dht::partition_range& pr) {
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return _underlying(_schema, pr, query::full_slice, ctx.pc(), ctx.trace_state(), streamed_mutation::forwarding::no);
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}
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cache_tracker& global_cache_tracker() {
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static thread_local cache_tracker instance;
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return instance;
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}
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cache_tracker::cache_tracker() {
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setup_metrics();
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_region.make_evictable([this] {
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return with_allocator(_region.allocator(), [this] {
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// Removing a partition may require reading large keys when we rebalance
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// the rbtree, so linearize anything we read
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return with_linearized_managed_bytes([&] {
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try {
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auto evict_last = [this](lru_type& lru) {
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cache_entry& ce = lru.back();
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auto it = row_cache::partitions_type::s_iterator_to(ce);
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clear_continuity(*std::next(it));
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lru.pop_back_and_dispose(current_deleter<cache_entry>());
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};
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if (_lru.empty()) {
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return memory::reclaiming_result::reclaimed_nothing;
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}
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evict_last(_lru);
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--_stats.partitions;
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++_stats.evictions;
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++_stats.modification_count;
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return memory::reclaiming_result::reclaimed_something;
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} catch (std::bad_alloc&) {
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// Bad luck, linearization during partition removal caused us to
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// fail. Drop the entire cache so we can make forward progress.
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clear();
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return memory::reclaiming_result::reclaimed_something;
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}
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});
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});
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});
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}
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cache_tracker::~cache_tracker() {
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clear();
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}
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void
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cache_tracker::setup_metrics() {
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namespace sm = seastar::metrics;
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_metrics.add_group("cache", {
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sm::make_gauge("bytes_used", sm::description("current bytes used by the cache out of the total size of memory"), [this] { return _region.occupancy().used_space(); }),
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sm::make_gauge("bytes_total", sm::description("total size of memory for the cache"), [this] { return _region.occupancy().total_space(); }),
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sm::make_derive("total_operations_hits", sm::description("total number of operation hits"), _stats.hits),
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sm::make_derive("total_operations_misses", sm::description("total number of operation misses"), _stats.misses),
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sm::make_derive("total_operations_insertions", sm::description("total number of operation insert"), _stats.insertions),
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sm::make_derive("total_operations_concurrent_misses_same_key", sm::description("total number of operation with misses same key"), _stats.concurrent_misses_same_key),
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sm::make_derive("total_operations_merges", sm::description("total number of operation merged"), _stats.merges),
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sm::make_derive("total_operations_evictions", sm::description("total number of operation eviction"), _stats.evictions),
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sm::make_derive("total_operations_removals", sm::description("total number of operation removals"), _stats.removals),
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sm::make_gauge("objects_partitions", sm::description("total number of partition objects"), _stats.partitions)
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});
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}
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void cache_tracker::clear() {
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with_allocator(_region.allocator(), [this] {
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auto clear = [this] (lru_type& lru) {
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while (!lru.empty()) {
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cache_entry& ce = lru.back();
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auto it = row_cache::partitions_type::s_iterator_to(ce);
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while (it->is_evictable()) {
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cache_entry& to_remove = *it;
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++it;
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to_remove._lru_link.unlink();
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current_deleter<cache_entry>()(&to_remove);
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}
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clear_continuity(*it);
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}
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};
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clear(_lru);
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});
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_stats.removals += _stats.partitions;
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_stats.partitions = 0;
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++_stats.modification_count;
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}
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void cache_tracker::touch(cache_entry& e) {
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auto move_to_front = [this] (lru_type& lru, cache_entry& e) {
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lru.erase(lru.iterator_to(e));
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lru.push_front(e);
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};
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move_to_front(_lru, e);
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}
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void cache_tracker::insert(cache_entry& entry) {
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++_stats.insertions;
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++_stats.partitions;
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++_stats.modification_count;
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_lru.push_front(entry);
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}
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void cache_tracker::on_erase() {
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--_stats.partitions;
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++_stats.removals;
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++_stats.modification_count;
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}
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void cache_tracker::on_merge() {
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++_stats.merges;
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}
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void cache_tracker::on_hit() {
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++_stats.hits;
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}
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void cache_tracker::on_miss() {
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++_stats.misses;
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}
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void cache_tracker::on_miss_already_populated() {
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++_stats.concurrent_misses_same_key;
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}
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allocation_strategy& cache_tracker::allocator() {
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return _region.allocator();
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}
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logalloc::region& cache_tracker::region() {
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return _region;
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}
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const logalloc::region& cache_tracker::region() const {
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return _region;
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}
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/*
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* Represent a reader to the underlying source.
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* This reader automatically makes sure that it's up to date with all cache updates
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*/
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class autoupdating_underlying_reader final {
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row_cache& _cache;
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read_context& _read_context;
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stdx::optional<mutation_reader> _reader;
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utils::phased_barrier::phase_type _reader_creation_phase;
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dht::partition_range _range = { };
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stdx::optional<dht::decorated_key> _last_key;
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public:
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autoupdating_underlying_reader(row_cache& cache, read_context& context)
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: _cache(cache)
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, _read_context(context)
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{ }
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future<streamed_mutation_opt> operator()() {
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auto phase = _cache._populate_phaser.phase();
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if (!_reader || _reader_creation_phase != phase) {
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if (_last_key) {
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auto cmp = dht::ring_position_comparator(*_cache._schema);
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auto&& new_range = _range.split_after(*_last_key, cmp);
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if (!new_range) {
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return make_ready_future<streamed_mutation_opt>(streamed_mutation_opt());
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}
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_range = std::move(*new_range);
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_last_key = { };
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}
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_reader = _cache.create_underlying_reader(_read_context, _range);
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_reader_creation_phase = phase;
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}
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return (*_reader)().then([this] (auto&& smopt) {
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if (smopt) {
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_last_key = smopt->decorated_key();
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}
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return std::move(smopt);
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});
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}
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future<> fast_forward_to(dht::partition_range&& range) {
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_range = std::move(range);
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_last_key = { };
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auto phase = _cache._populate_phaser.phase();
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if (_reader && _reader_creation_phase == phase) {
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return _reader->fast_forward_to(_range);
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}
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_reader = _cache.create_underlying_reader(_read_context, _range);
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_reader_creation_phase = phase;
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return make_ready_future<>();
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}
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utils::phased_barrier::phase_type creation_phase() const {
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assert(_reader);
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return _reader_creation_phase;
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}
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const dht::partition_range& range() const {
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return _range;
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}
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};
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// Reader which populates the cache using data from the delegate.
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class single_partition_populating_reader final : public mutation_reader::impl {
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row_cache& _cache;
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mutation_source& _underlying;
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mutation_reader _delegate;
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lw_shared_ptr<read_context> _read_context;
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public:
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single_partition_populating_reader(row_cache& cache,
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mutation_source& underlying,
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mutation_reader delegate,
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lw_shared_ptr<read_context> context)
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: _cache(cache)
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, _underlying(underlying)
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, _delegate(std::move(delegate))
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, _read_context(std::move(context))
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{ }
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virtual future<streamed_mutation_opt> operator()() override {
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auto op = _cache._populate_phaser.start();
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return _delegate().then([this, op = std::move(op)] (auto sm) mutable {
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if (!sm) {
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return make_ready_future<streamed_mutation_opt>(streamed_mutation_opt());
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}
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return mutation_from_streamed_mutation(std::move(sm)).then([this, op = std::move(op)] (mutation_opt&& mo) {
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if (mo) {
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_cache.populate(*mo);
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mo->upgrade(_read_context->schema());
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auto ck_ranges = query::clustering_key_filter_ranges::get_ranges(*_read_context->schema(), _read_context->slice(), mo->key());
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auto filtered_partition = mutation_partition(std::move(mo->partition()), *(mo->schema()), std::move(ck_ranges));
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mo->partition() = std::move(filtered_partition);
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return make_ready_future<streamed_mutation_opt>(streamed_mutation_from_mutation(std::move(*mo), _read_context->fwd()));
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}
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return make_ready_future<streamed_mutation_opt>(streamed_mutation_opt());
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});
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});
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}
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};
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void cache_tracker::clear_continuity(cache_entry& ce) {
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ce.set_continuous(false);
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}
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void row_cache::on_hit() {
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_stats.hits.mark();
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_tracker.on_hit();
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}
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void row_cache::on_miss() {
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_stats.misses.mark();
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_tracker.on_miss();
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}
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class just_cache_scanning_reader final {
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row_cache& _cache;
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row_cache::partitions_type::iterator _it;
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row_cache::partitions_type::iterator _end;
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const dht::partition_range* _range;
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stdx::optional<dht::decorated_key> _last;
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uint64_t _last_reclaim_count;
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size_t _last_modification_count;
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read_context& _read_context;
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private:
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void update_iterators() {
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auto cmp = cache_entry::compare(_cache._schema);
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auto update_end = [&] {
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if (_range->end()) {
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if (_range->end()->is_inclusive()) {
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_end = _cache._partitions.upper_bound(_range->end()->value(), cmp);
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} else {
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_end = _cache._partitions.lower_bound(_range->end()->value(), cmp);
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}
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} else {
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_end = _cache.partitions_end();
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}
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};
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auto reclaim_count = _cache.get_cache_tracker().region().reclaim_counter();
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auto modification_count = _cache.get_cache_tracker().modification_count();
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if (!_last) {
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if (_range->start()) {
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if (_range->start()->is_inclusive()) {
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_it = _cache._partitions.lower_bound(_range->start()->value(), cmp);
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} else {
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_it = _cache._partitions.upper_bound(_range->start()->value(), cmp);
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}
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} else {
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_it = _cache._partitions.begin();
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}
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update_end();
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} else if (reclaim_count != _last_reclaim_count || modification_count != _last_modification_count) {
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_it = _cache._partitions.upper_bound(*_last, cmp);
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update_end();
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}
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_last_reclaim_count = reclaim_count;
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_last_modification_count = modification_count;
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}
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public:
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struct cache_data {
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streamed_mutation_opt mut;
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bool continuous;
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};
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just_cache_scanning_reader(row_cache& cache,
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const dht::partition_range& range,
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read_context& ctx)
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: _cache(cache)
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, _range(&range)
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, _read_context(ctx)
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{ }
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future<cache_data> operator()() {
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return _cache._read_section(_cache._tracker.region(), [this] {
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return with_linearized_managed_bytes([&] {
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update_iterators();
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if (_it == _end) {
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return make_ready_future<cache_data>(cache_data { {}, _it->continuous() });
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}
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cache_entry& ce = *_it;
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++_it;
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_last = ce.key();
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_cache.upgrade_entry(ce);
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_cache._tracker.touch(ce);
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_cache.on_hit();
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cache_data cd { { }, ce.continuous() };
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cd.mut = ce.read(_cache, _read_context);
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return make_ready_future<cache_data>(std::move(cd));
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});
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});
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}
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future<> fast_forward_to(const dht::partition_range& pr) {
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_last = {};
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_range = ≺
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return make_ready_future<>();
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}
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};
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class range_populating_reader {
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row_cache& _cache;
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autoupdating_underlying_reader _reader;
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row_cache::previous_entry_pointer _last_key;
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read_context& _read_context;
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private:
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void handle_end_of_stream() {
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if (_last_key._populate_phase != _reader.creation_phase()) {
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return;
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}
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if (!_reader.range().end() || !_reader.range().end()->is_inclusive()) {
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cache_entry::compare cmp(_cache._schema);
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auto it = _reader.range().end() ? _cache._partitions.find(_reader.range().end()->value(), cmp)
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: std::prev(_cache._partitions.end());
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if (it != _cache._partitions.end()) {
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if (it == _cache._partitions.begin()) {
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if (!_last_key._key) {
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it->set_continuous(true);
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}
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} else {
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auto prev = std::prev(it);
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if (prev->key().equal(*_cache._schema, *_last_key._key)) {
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it->set_continuous(true);
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}
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}
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}
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}
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}
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public:
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range_populating_reader(row_cache& cache, read_context& ctx)
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: _cache(cache)
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, _reader(cache, ctx)
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, _read_context(ctx)
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{}
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future<streamed_mutation_opt> operator()() {
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return _reader().then([this, op = _cache._populate_phaser.start()] (streamed_mutation_opt smopt) mutable {
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return mutation_from_streamed_mutation(std::move(smopt)).then(
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[this, op = std::move(op)] (mutation_opt&& mo) mutable {
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if (!mo) {
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handle_end_of_stream();
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return make_ready_future<streamed_mutation_opt>();
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}
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_cache.on_miss();
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_cache.populate(*mo, &_last_key);
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_last_key.reset(mo->decorated_key(), _reader.creation_phase());
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mo->upgrade(_read_context.schema());
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auto ck_ranges = query::clustering_key_filter_ranges::get_ranges(*_read_context.schema(), _read_context.slice(), mo->key());
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auto filtered_partition = mutation_partition(std::move(mo->partition()), *mo->schema(), std::move(ck_ranges));
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mo->partition() = std::move(filtered_partition);
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return make_ready_future<streamed_mutation_opt>(streamed_mutation_from_mutation(std::move(*mo), _read_context.fwd()));
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});
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});
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}
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future<> fast_forward_to(dht::partition_range&& pr) {
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auto phase = _cache._populate_phaser.phase();
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if (!pr.start()) {
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_last_key.reset({ }, phase);
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} else if (!pr.start()->is_inclusive() && pr.start()->value().has_key()) {
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_last_key.reset(pr.start()->value().as_decorated_key(), phase);
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} else {
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// Inclusive start bound, cannot set continuity flag.
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_last_key.reset(stdx::nullopt, phase - 1);
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}
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return _reader.fast_forward_to(std::move(pr));
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}
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};
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class scanning_and_populating_reader final : public mutation_reader::impl {
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const dht::partition_range* _pr;
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lw_shared_ptr<read_context> _read_context;
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just_cache_scanning_reader _primary_reader;
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range_populating_reader _secondary_reader;
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streamed_mutation_opt _next_primary;
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bool _secondary_in_progress = false;
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bool _first_element = true;
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stdx::optional<dht::decorated_key> _last_key;
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private:
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void update_last_key(const streamed_mutation_opt& smopt) {
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if (smopt) {
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_last_key = smopt->decorated_key();
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}
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}
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bool is_inclusive_start_bound(const dht::decorated_key& dk) {
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if (!_first_element) {
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return false;
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}
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return _pr->start() && _pr->start()->is_inclusive() && _pr->start()->value().equal(*_read_context->schema(), dk);
|
|
}
|
|
|
|
future<streamed_mutation_opt> read_from_primary() {
|
|
return _primary_reader().then([this] (just_cache_scanning_reader::cache_data cd) {
|
|
auto& smopt = cd.mut;
|
|
if (cd.continuous || (smopt && is_inclusive_start_bound(smopt->decorated_key()))) {
|
|
_first_element = false;
|
|
update_last_key(smopt);
|
|
return make_ready_future<streamed_mutation_opt>(std::move(smopt));
|
|
} else {
|
|
_next_primary = std::move(smopt);
|
|
|
|
dht::partition_range secondary_range = { };
|
|
if (!_next_primary) {
|
|
if (!_last_key) {
|
|
secondary_range = *_pr;
|
|
} else {
|
|
dht::ring_position_comparator cmp(*_read_context->schema());
|
|
auto&& new_range = _pr->split_after(*_last_key, cmp);
|
|
if (!new_range) {
|
|
return make_ready_future<streamed_mutation_opt>();
|
|
}
|
|
secondary_range = std::move(*new_range);
|
|
}
|
|
} else {
|
|
if (_last_key) {
|
|
secondary_range = dht::partition_range::make({ *_last_key, false }, { _next_primary->decorated_key(), false });
|
|
} else {
|
|
if (!_pr->start()) {
|
|
secondary_range = dht::partition_range::make_ending_with({ _next_primary->decorated_key(), false });
|
|
} else {
|
|
secondary_range = dht::partition_range::make(*_pr->start(), { _next_primary->decorated_key(), false });
|
|
}
|
|
}
|
|
}
|
|
|
|
_secondary_in_progress = true;
|
|
return _secondary_reader.fast_forward_to(std::move(secondary_range)).then([this] {
|
|
return read_from_secondary();
|
|
});
|
|
}
|
|
});
|
|
}
|
|
|
|
future<streamed_mutation_opt> read_from_secondary() {
|
|
return _secondary_reader().then([this] (streamed_mutation_opt smopt) {
|
|
if (smopt) {
|
|
return smopt;
|
|
} else {
|
|
_secondary_in_progress = false;
|
|
update_last_key(_next_primary);
|
|
return std::move(_next_primary);
|
|
}
|
|
});
|
|
}
|
|
public:
|
|
scanning_and_populating_reader(row_cache& cache,
|
|
const dht::partition_range& range,
|
|
lw_shared_ptr<read_context> context)
|
|
: _pr(&range)
|
|
, _read_context(std::move(context))
|
|
, _primary_reader(cache, range, *_read_context)
|
|
, _secondary_reader(cache, *_read_context)
|
|
{ }
|
|
|
|
future<streamed_mutation_opt> operator()() {
|
|
if (_secondary_in_progress) {
|
|
return read_from_secondary();
|
|
} else {
|
|
return read_from_primary();
|
|
}
|
|
}
|
|
|
|
future<> fast_forward_to(const dht::partition_range& pr) {
|
|
_secondary_in_progress = false;
|
|
_first_element = true;
|
|
_pr = ≺
|
|
return _primary_reader.fast_forward_to(pr);
|
|
}
|
|
};
|
|
|
|
mutation_reader
|
|
row_cache::make_scanning_reader(const dht::partition_range& range, lw_shared_ptr<read_context> context) {
|
|
return make_mutation_reader<scanning_and_populating_reader>(*this, range, std::move(context));
|
|
}
|
|
|
|
mutation_reader
|
|
row_cache::make_reader(schema_ptr s,
|
|
const dht::partition_range& range,
|
|
const query::partition_slice& slice,
|
|
const io_priority_class& pc,
|
|
tracing::trace_state_ptr trace_state,
|
|
streamed_mutation::forwarding fwd,
|
|
mutation_reader::forwarding fwd_mr)
|
|
{
|
|
auto ctx = make_lw_shared<read_context>(*this, std::move(s), range, slice, pc, trace_state, fwd, fwd_mr);
|
|
|
|
if (range.is_singular()) {
|
|
const query::ring_position& pos = range.start()->value();
|
|
|
|
if (!pos.has_key()) {
|
|
return make_scanning_reader(range, std::move(ctx));
|
|
}
|
|
|
|
return _read_section(_tracker.region(), [&] {
|
|
return with_linearized_managed_bytes([&] {
|
|
const dht::decorated_key& dk = pos.as_decorated_key();
|
|
auto i = _partitions.find(dk, cache_entry::compare(_schema));
|
|
if (i != _partitions.end()) {
|
|
cache_entry& e = *i;
|
|
_tracker.touch(e);
|
|
upgrade_entry(e);
|
|
mutation_reader reader;
|
|
reader = make_reader_returning(e.read(*this, *ctx));
|
|
on_hit();
|
|
return reader;
|
|
} else {
|
|
auto reader = make_mutation_reader<single_partition_populating_reader>(*this, _underlying,
|
|
_underlying(_schema, range, query::full_slice, pc, trace_state), std::move(ctx));
|
|
on_miss();
|
|
return reader;
|
|
}
|
|
});
|
|
});
|
|
}
|
|
|
|
return make_scanning_reader(range, std::move(ctx));
|
|
}
|
|
|
|
row_cache::~row_cache() {
|
|
with_allocator(_tracker.allocator(), [this] {
|
|
_partitions.clear_and_dispose([this, deleter = current_deleter<cache_entry>()] (auto&& p) mutable {
|
|
if (!p->is_dummy_entry()) {
|
|
_tracker.on_erase();
|
|
}
|
|
deleter(p);
|
|
});
|
|
});
|
|
}
|
|
|
|
void row_cache::clear_now() noexcept {
|
|
with_allocator(_tracker.allocator(), [this] {
|
|
auto it = _partitions.erase_and_dispose(_partitions.begin(), partitions_end(), [this, deleter = current_deleter<cache_entry>()] (auto&& p) mutable {
|
|
_tracker.on_erase();
|
|
deleter(p);
|
|
});
|
|
_tracker.clear_continuity(*it);
|
|
});
|
|
}
|
|
|
|
template<typename CreateEntry, typename VisitEntry>
|
|
//requires requires(CreateEntry create, VisitEntry visit, row_cache::partitions_type::iterator it) {
|
|
// { create(it) } -> row_cache::partitions_type::iterator;
|
|
// { visit(it) } -> void;
|
|
// }
|
|
void row_cache::do_find_or_create_entry(const dht::decorated_key& key,
|
|
const previous_entry_pointer* previous, CreateEntry&& create_entry, VisitEntry&& visit_entry)
|
|
{
|
|
with_allocator(_tracker.allocator(), [&] {
|
|
_populate_section(_tracker.region(), [&] {
|
|
with_linearized_managed_bytes([&] {
|
|
auto i = _partitions.lower_bound(key, cache_entry::compare(_schema));
|
|
if (i == _partitions.end() || !i->key().equal(*_schema, key)) {
|
|
i = create_entry(i);
|
|
} else {
|
|
visit_entry(i);
|
|
}
|
|
|
|
if (!previous || previous->_populate_phase != _populate_phaser.phase()) {
|
|
return;
|
|
}
|
|
|
|
if ((!previous->_key && i == _partitions.begin())
|
|
|| (previous->_key && i != _partitions.begin()
|
|
&& std::prev(i)->key().equal(*_schema, *previous->_key))) {
|
|
i->set_continuous(true);
|
|
}
|
|
});
|
|
});
|
|
});
|
|
}
|
|
|
|
void row_cache::populate(const mutation& m, const previous_entry_pointer* previous) {
|
|
do_find_or_create_entry(m.decorated_key(), previous, [&] (auto i) {
|
|
cache_entry* entry = current_allocator().construct<cache_entry>(
|
|
m.schema(), m.decorated_key(), m.partition());
|
|
upgrade_entry(*entry);
|
|
_tracker.insert(*entry);
|
|
return _partitions.insert(i, *entry);
|
|
}, [&] (auto i) {
|
|
_tracker.touch(*i);
|
|
// We cache whole partitions right now, so if cache already has this partition,
|
|
// it must be complete, so do nothing.
|
|
_tracker.on_miss_already_populated(); // #1534
|
|
});
|
|
}
|
|
|
|
future<> row_cache::update(memtable& m, partition_presence_checker presence_checker) {
|
|
m.on_detach_from_region_group();
|
|
_tracker.region().merge(m); // Now all data in memtable belongs to cache
|
|
auto attr = seastar::thread_attributes();
|
|
attr.scheduling_group = &_update_thread_scheduling_group;
|
|
STAP_PROBE(scylla, row_cache_update_start);
|
|
auto t = seastar::thread(attr, [this, &m, presence_checker = std::move(presence_checker)] {
|
|
auto cleanup = defer([&] {
|
|
with_allocator(_tracker.allocator(), [&m, this] () {
|
|
logalloc::reclaim_lock _(_tracker.region());
|
|
bool blow_cache = false;
|
|
// Note: clear_and_dispose() ought not to look up any keys, so it doesn't require
|
|
// with_linearized_managed_bytes(), but invalidate() does.
|
|
m.partitions.clear_and_dispose([this, deleter = current_deleter<memtable_entry>(), &blow_cache] (memtable_entry* entry) {
|
|
with_linearized_managed_bytes([&] {
|
|
try {
|
|
invalidate_locked(entry->key());
|
|
} catch (...) {
|
|
blow_cache = true;
|
|
}
|
|
deleter(entry);
|
|
});
|
|
});
|
|
if (blow_cache) {
|
|
// We failed to invalidate the key, presumably due to with_linearized_managed_bytes()
|
|
// running out of memory. Recover using clear_now(), which doesn't throw.
|
|
clear_now();
|
|
}
|
|
});
|
|
});
|
|
_underlying = _snapshot_source();
|
|
_populate_phaser.advance_and_await().get();
|
|
while (!m.partitions.empty()) {
|
|
with_allocator(_tracker.allocator(), [this, &m, &presence_checker] () {
|
|
unsigned quota = 30;
|
|
auto cmp = cache_entry::compare(_schema);
|
|
{
|
|
_update_section(_tracker.region(), [&] {
|
|
STAP_PROBE(scylla, row_cache_update_one_batch_start);
|
|
unsigned quota_before = quota;
|
|
// FIXME: we should really be checking should_yield() here instead of
|
|
// need_preempt() + quota. However, should_yield() is currently quite
|
|
// expensive and we need to amortize it somehow.
|
|
do {
|
|
auto i = m.partitions.begin();
|
|
STAP_PROBE(scylla, row_cache_update_partition_start);
|
|
with_linearized_managed_bytes([&] {
|
|
{
|
|
memtable_entry& mem_e = *i;
|
|
// FIXME: Optimize knowing we lookup in-order.
|
|
auto cache_i = _partitions.lower_bound(mem_e.key(), cmp);
|
|
// If cache doesn't contain the entry we cannot insert it because the mutation may be incomplete.
|
|
// FIXME: keep a bitmap indicating which sstables we do cover, so we don't have to
|
|
// search it.
|
|
if (cache_i != partitions_end() && cache_i->key().equal(*_schema, mem_e.key())) {
|
|
cache_entry& entry = *cache_i;
|
|
upgrade_entry(entry);
|
|
entry.partition().apply(*_schema, std::move(mem_e.partition()), *mem_e.schema());
|
|
_tracker.touch(entry);
|
|
_tracker.on_merge();
|
|
} else if (presence_checker(mem_e.key()) ==
|
|
partition_presence_checker_result::definitely_doesnt_exist) {
|
|
cache_entry* entry = current_allocator().construct<cache_entry>(
|
|
mem_e.schema(), std::move(mem_e.key()), std::move(mem_e.partition()));
|
|
_tracker.insert(*entry);
|
|
_partitions.insert(cache_i, *entry);
|
|
} else {
|
|
_tracker.clear_continuity(*cache_i);
|
|
}
|
|
i = m.partitions.erase(i);
|
|
current_allocator().destroy(&mem_e);
|
|
--quota;
|
|
}
|
|
});
|
|
STAP_PROBE(scylla, row_cache_update_partition_end);
|
|
} while (!m.partitions.empty() && quota && !need_preempt());
|
|
STAP_PROBE1(scylla, row_cache_update_one_batch_end, quota_before - quota);
|
|
});
|
|
if (quota == 0 && seastar::thread::should_yield()) {
|
|
return;
|
|
}
|
|
}
|
|
});
|
|
seastar::thread::yield();
|
|
}
|
|
});
|
|
STAP_PROBE(scylla, row_cache_update_end);
|
|
return do_with(std::move(t), [] (seastar::thread& t) {
|
|
return t.join();
|
|
});
|
|
}
|
|
|
|
void row_cache::touch(const dht::decorated_key& dk) {
|
|
_read_section(_tracker.region(), [&] {
|
|
with_linearized_managed_bytes([&] {
|
|
auto i = _partitions.find(dk, cache_entry::compare(_schema));
|
|
if (i != _partitions.end()) {
|
|
_tracker.touch(*i);
|
|
}
|
|
});
|
|
});
|
|
}
|
|
|
|
void row_cache::invalidate_locked(const dht::decorated_key& dk) {
|
|
auto pos = _partitions.lower_bound(dk, cache_entry::compare(_schema));
|
|
if (pos == partitions_end() || !pos->key().equal(*_schema, dk)) {
|
|
_tracker.clear_continuity(*pos);
|
|
} else {
|
|
auto it = _partitions.erase_and_dispose(pos,
|
|
[this, &dk, deleter = current_deleter<cache_entry>()](auto&& p) mutable {
|
|
_tracker.on_erase();
|
|
deleter(p);
|
|
});
|
|
_tracker.clear_continuity(*it);
|
|
}
|
|
}
|
|
|
|
future<> row_cache::invalidate(const dht::decorated_key& dk) {
|
|
return invalidate(dht::partition_range::make_singular(dk));
|
|
}
|
|
|
|
future<> row_cache::invalidate(const dht::partition_range& range) {
|
|
return invalidate(dht::partition_range_vector({range}));
|
|
}
|
|
|
|
future<> row_cache::invalidate(dht::partition_range_vector&& ranges) {
|
|
auto f = _populate_phaser.advance_and_await();
|
|
_underlying = _snapshot_source();
|
|
return f.then([this, ranges = std::move(ranges)] () mutable {
|
|
auto on_failure = defer([this] { this->clear_now(); });
|
|
with_linearized_managed_bytes([&] {
|
|
for (auto&& range : ranges) {
|
|
this->invalidate_unwrapped(range);
|
|
}
|
|
});
|
|
on_failure.cancel();
|
|
});
|
|
}
|
|
|
|
void row_cache::invalidate_unwrapped(const dht::partition_range& range) {
|
|
logalloc::reclaim_lock _(_tracker.region());
|
|
|
|
auto cmp = cache_entry::compare(_schema);
|
|
auto begin = _partitions.begin();
|
|
if (range.start()) {
|
|
if (range.start()->is_inclusive()) {
|
|
begin = _partitions.lower_bound(range.start()->value(), cmp);
|
|
} else {
|
|
begin = _partitions.upper_bound(range.start()->value(), cmp);
|
|
}
|
|
}
|
|
auto end = partitions_end();
|
|
if (range.end()) {
|
|
if (range.end()->is_inclusive()) {
|
|
end = _partitions.upper_bound(range.end()->value(), cmp);
|
|
} else {
|
|
end = _partitions.lower_bound(range.end()->value(), cmp);
|
|
}
|
|
}
|
|
with_allocator(_tracker.allocator(), [this, begin, end] {
|
|
auto it = _partitions.erase_and_dispose(begin, end, [this, deleter = current_deleter<cache_entry>()] (auto&& p) mutable {
|
|
_tracker.on_erase();
|
|
deleter(p);
|
|
});
|
|
assert(it != _partitions.end());
|
|
_tracker.clear_continuity(*it);
|
|
});
|
|
}
|
|
|
|
row_cache::row_cache(schema_ptr s, snapshot_source src, cache_tracker& tracker)
|
|
: _tracker(tracker)
|
|
, _schema(std::move(s))
|
|
, _partitions(cache_entry::compare(_schema))
|
|
, _underlying(src())
|
|
, _snapshot_source(std::move(src))
|
|
{
|
|
with_allocator(_tracker.allocator(), [this] {
|
|
cache_entry* entry = current_allocator().construct<cache_entry>(cache_entry::dummy_entry_tag());
|
|
_partitions.insert(*entry);
|
|
});
|
|
}
|
|
|
|
cache_entry::cache_entry(cache_entry&& o) noexcept
|
|
: _schema(std::move(o._schema))
|
|
, _key(std::move(o._key))
|
|
, _pe(std::move(o._pe))
|
|
, _flags(o._flags)
|
|
, _lru_link()
|
|
, _cache_link()
|
|
{
|
|
if (o._lru_link.is_linked()) {
|
|
auto prev = o._lru_link.prev_;
|
|
o._lru_link.unlink();
|
|
cache_tracker::lru_type::node_algorithms::link_after(prev, _lru_link.this_ptr());
|
|
}
|
|
|
|
{
|
|
using container_type = row_cache::partitions_type;
|
|
container_type::node_algorithms::replace_node(o._cache_link.this_ptr(), _cache_link.this_ptr());
|
|
container_type::node_algorithms::init(o._cache_link.this_ptr());
|
|
}
|
|
}
|
|
|
|
void row_cache::set_schema(schema_ptr new_schema) noexcept {
|
|
_schema = std::move(new_schema);
|
|
}
|
|
|
|
streamed_mutation cache_entry::read(row_cache& rc, read_context& ctx) {
|
|
auto s = ctx.schema();
|
|
auto& slice = ctx.slice();
|
|
auto fwd = ctx.fwd();
|
|
if (_schema->version() != s->version()) {
|
|
auto ck_ranges = query::clustering_key_filter_ranges::get_ranges(*s, slice, _key.key());
|
|
auto mp = mutation_partition(_pe.squashed(_schema, s), *s, std::move(ck_ranges));
|
|
auto m = mutation(s, _key, std::move(mp));
|
|
return streamed_mutation_from_mutation(std::move(m), fwd);
|
|
}
|
|
auto ckr = query::clustering_key_filter_ranges::get_ranges(*s, slice, _key.key());
|
|
auto snp = _pe.read(_schema);
|
|
return make_partition_snapshot_reader(_schema, _key, std::move(ckr), snp, rc._tracker.region(), rc._read_section, { }, fwd);
|
|
}
|
|
|
|
const schema_ptr& row_cache::schema() const {
|
|
return _schema;
|
|
}
|
|
|
|
void row_cache::upgrade_entry(cache_entry& e) {
|
|
if (e._schema != _schema) {
|
|
auto& r = _tracker.region();
|
|
assert(!r.reclaiming_enabled());
|
|
with_allocator(r.allocator(), [this, &e] {
|
|
with_linearized_managed_bytes([&] {
|
|
e.partition().upgrade(e._schema, _schema);
|
|
e._schema = _schema;
|
|
});
|
|
});
|
|
}
|
|
}
|