Files
scylladb/memtable.hh
Tomasz Grabiec 892d4a2165 db: Enable creating forwardable readers via mutation_source
Right now all mutation source implementations will use
make_forwardable() wrapper.
2017-02-23 18:50:44 +01:00

197 lines
6.7 KiB
C++

/*
* Copyright (C) 2015 ScyllaDB
*/
/*
* This file is part of Scylla.
*
* Scylla is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Scylla is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <map>
#include <memory>
#include "database_fwd.hh"
#include "dht/i_partitioner.hh"
#include "schema.hh"
#include "mutation_reader.hh"
#include "db/commitlog/replay_position.hh"
#include "utils/logalloc.hh"
#include "sstables/sstables.hh"
#include "partition_version.hh"
class frozen_mutation;
namespace bi = boost::intrusive;
class memtable_entry {
bi::set_member_hook<> _link;
schema_ptr _schema;
dht::decorated_key _key;
partition_entry _pe;
public:
friend class memtable;
memtable_entry(schema_ptr s, dht::decorated_key key, mutation_partition p)
: _schema(std::move(s))
, _key(std::move(key))
, _pe(std::move(p))
{ }
memtable_entry(memtable_entry&& o) noexcept;
const dht::decorated_key& key() const { return _key; }
dht::decorated_key& key() { return _key; }
const partition_entry& partition() const { return _pe; }
partition_entry& partition() { return _pe; }
const schema_ptr& schema() const { return _schema; }
schema_ptr& schema() { return _schema; }
streamed_mutation read(lw_shared_ptr<memtable> mtbl, const schema_ptr&, const query::partition_slice&, streamed_mutation::forwarding);
size_t external_memory_usage_without_rows() const {
return _key.key().external_memory_usage();
}
struct compare {
dht::decorated_key::less_comparator _c;
compare(schema_ptr s)
: _c(std::move(s))
{}
bool operator()(const dht::decorated_key& k1, const memtable_entry& k2) const {
return _c(k1, k2._key);
}
bool operator()(const memtable_entry& k1, const memtable_entry& k2) const {
return _c(k1._key, k2._key);
}
bool operator()(const memtable_entry& k1, const dht::decorated_key& k2) const {
return _c(k1._key, k2);
}
bool operator()(const memtable_entry& k1, const dht::ring_position& k2) const {
return _c(k1._key, k2);
}
bool operator()(const dht::ring_position& k1, const memtable_entry& k2) const {
return _c(k1, k2._key);
}
};
};
class dirty_memory_manager;
// Managed by lw_shared_ptr<>.
class memtable final : public enable_lw_shared_from_this<memtable>, private logalloc::region {
public:
using partitions_type = bi::set<memtable_entry,
bi::member_hook<memtable_entry, bi::set_member_hook<>, &memtable_entry::_link>,
bi::compare<memtable_entry::compare>>;
private:
dirty_memory_manager& _dirty_mgr;
memtable_list *_memtable_list;
schema_ptr _schema;
logalloc::allocating_section _read_section;
logalloc::allocating_section _allocating_section;
partitions_type partitions;
db::replay_position _replay_position;
lw_shared_ptr<sstables::sstable> _sstable;
uint64_t _flushed_memory = 0;
void update(const db::replay_position&);
friend class row_cache;
friend class memtable_entry;
friend class flush_reader;
friend class flush_memory_accounter;
private:
boost::iterator_range<partitions_type::const_iterator> slice(const dht::partition_range& r) const;
partition_entry& find_or_create_partition(const dht::decorated_key& key);
partition_entry& find_or_create_partition_slow(partition_key_view key);
void upgrade_entry(memtable_entry&);
void add_flushed_memory(uint64_t);
void remove_flushed_memory(uint64_t);
void clear() noexcept;
uint64_t dirty_size() const;
public:
explicit memtable(schema_ptr schema, dirty_memory_manager&, memtable_list *memtable_list = nullptr);
// Used for testing that want to control the flush process.
explicit memtable(schema_ptr schema);
~memtable();
// Clears this memtable gradually without consuming the whole CPU.
// Never resolves with a failed future.
future<> clear_gently() noexcept;
schema_ptr schema() const { return _schema; }
void set_schema(schema_ptr) noexcept;
future<> apply(memtable&);
// Applies mutation to this memtable.
// The mutation is upgraded to current schema.
void apply(const mutation& m, const db::replay_position& = db::replay_position());
// The mutation is upgraded to current schema.
void apply(const frozen_mutation& m, const schema_ptr& m_schema, const db::replay_position& = db::replay_position());
static memtable& from_region(logalloc::region& r) {
return static_cast<memtable&>(r);
}
const logalloc::region& region() const {
return *this;
}
logalloc::region_group* region_group() {
return group();
}
public:
memtable_list* get_memtable_list() {
return _memtable_list;
}
size_t partition_count() const;
logalloc::occupancy_stats occupancy() const;
// Creates a reader of data in this memtable for given partition range.
//
// Live readers share ownership of the memtable instance, so caller
// doesn't need to ensure that memtable remains live.
//
// The 'range' parameter must be live as long as the reader is being used
//
// Mutations returned by the reader will all have given schema.
mutation_reader make_reader(schema_ptr,
const dht::partition_range& range = query::full_partition_range,
const query::partition_slice& slice = query::full_slice,
const io_priority_class& pc = default_priority_class(),
tracing::trace_state_ptr trace_state_ptr = nullptr,
streamed_mutation::forwarding fwd = streamed_mutation::forwarding::no);
mutation_reader make_flush_reader(schema_ptr, const io_priority_class& pc);
mutation_source as_data_source();
bool empty() const { return partitions.empty(); }
void mark_flushed(lw_shared_ptr<sstables::sstable> sst);
bool is_flushed() const;
void on_detach_from_region_group() noexcept;
void revert_flushed_memory() noexcept;
const db::replay_position& replay_position() const {
return _replay_position;
}
friend class iterator_reader;
};