85 lines
2.1 KiB
C++
85 lines
2.1 KiB
C++
// Copyright 2021, Beeri 15. All rights reserved.
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// Author: Roman Gershman (romange@gmail.com)
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//
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#pragma once
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#include <absl/container/flat_hash_map.h>
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#include <absl/container/flat_hash_set.h>
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#include "server/op_status.h"
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namespace util {
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class ProactorBase;
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}
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namespace dfly {
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class EngineShard;
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class DbSlice {
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struct InternalDbStats {
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// Object memory usage besides hash-table capacity.
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size_t obj_memory_usage = 0;
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};
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public:
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using MainValue = std::string;
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using MainTable = absl::flat_hash_map<std::string, MainValue>;
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using MainIterator = MainTable::iterator;
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using ShardId = uint16_t;
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using DbIndex = uint16_t;
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DbSlice(uint32_t index, EngineShard* owner);
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~DbSlice();
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// Activates `db_ind` database if it does not exist (see ActivateDb below).
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void Reserve(DbIndex db_ind, size_t key_size);
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OpResult<MainIterator> Find(DbIndex db_index, std::string_view key) const;
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// Return .second=true if insertion ocurred, false if we return the existing key.
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std::pair<MainIterator, bool> AddOrFind(DbIndex db_ind, std::string_view key);
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// Adds a new entry. Requires: key does not exist in this slice.
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void AddNew(DbIndex db_ind, std::string_view key, MainValue obj, uint64_t expire_at_ms);
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// Adds a new entry if a key does not exists. Returns true if insertion took place,
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// false otherwise. expire_at_ms equal to 0 - means no expiry.
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bool AddIfNotExist(DbIndex db_ind, std::string_view key, MainValue obj, uint64_t expire_at_ms);
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// Creates a database with index `db_ind`. If such database exists does nothing.
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void ActivateDb(DbIndex db_ind);
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size_t db_array_size() const {
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return db_arr_.size();
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}
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bool IsDbValid(DbIndex id) const {
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return bool(db_arr_[id].main_table);
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}
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// Returns existing keys count in the db.
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size_t DbSize(DbIndex db_ind) const;
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ShardId shard_id() const { return shard_id_;}
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private:
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void CreateDbRedis(unsigned index);
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ShardId shard_id_;
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EngineShard* owner_;
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struct DbRedis {
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std::unique_ptr<MainTable> main_table;
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mutable InternalDbStats stats;
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};
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std::vector<DbRedis> db_arr_;
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};
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} // namespace dfly
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