190 lines
5.8 KiB
C++
190 lines
5.8 KiB
C++
/*------------------------------------------------------------------------------*
|
|
* Architecture & Implementation of DBMS *
|
|
*------------------------------------------------------------------------------*
|
|
* Copyright 2022 Databases and Information Systems Group TU Dortmund *
|
|
* Visit us at *
|
|
* http://dbis.cs.tu-dortmund.de/cms/en/home/ *
|
|
* *
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
|
|
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR *
|
|
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, *
|
|
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR *
|
|
* OTHER DEALINGS IN THE SOFTWARE. *
|
|
* *
|
|
* Authors: *
|
|
* Maximilian Berens <maximilian.berens@tu-dortmund.de> *
|
|
* Roland Kühn <roland.kuehn@cs.tu-dortmund.de> *
|
|
* Jan Mühlig <jan.muehlig@tu-dortmund.de> *
|
|
*------------------------------------------------------------------------------*
|
|
*/
|
|
|
|
#pragma once
|
|
#include "schema.h"
|
|
#include "tuple.h"
|
|
#include <cstddef>
|
|
#include <cstdlib>
|
|
#include <cstring>
|
|
#include <string>
|
|
#include <vector>
|
|
|
|
namespace beedb::table
|
|
{
|
|
/**
|
|
* Stores data in memory.
|
|
* Some times, the data can not stay in the buffer from the BufferManager
|
|
* and has to be copied to "safe" memory that will not be replaced.
|
|
*/
|
|
class MemoryTable
|
|
{
|
|
public:
|
|
explicit MemoryTable(const Schema &schema)
|
|
: _schema(schema), _row_size(schema.row_size() + sizeof(concurrency::Metadata))
|
|
{
|
|
allocate(512u);
|
|
}
|
|
|
|
MemoryTable(MemoryTable &&other) noexcept
|
|
: _schema(std::move(other._schema)), _row_size(other._row_size), _capacity(other._capacity), _data(other._data)
|
|
{
|
|
other._data = nullptr;
|
|
|
|
_tuples.reserve(other._tuples.size());
|
|
for (auto &&tuple : other._tuples)
|
|
{
|
|
_tuples.emplace_back(Tuple{_schema, std::move(tuple)});
|
|
}
|
|
}
|
|
|
|
MemoryTable(const MemoryTable &) = delete;
|
|
|
|
~MemoryTable()
|
|
{
|
|
std::free(_data);
|
|
}
|
|
|
|
/**
|
|
* Copy data from disk (or page) to the memory.
|
|
*
|
|
* @param tuple Tuple to be copied to memory.
|
|
* @return Index within the memory table.
|
|
*/
|
|
std::size_t add(const Tuple &tuple)
|
|
{
|
|
// Reallocate if needed.
|
|
if (_tuples.size() == _capacity)
|
|
{
|
|
allocate(_capacity << 1);
|
|
}
|
|
|
|
// At this location, we will copy the tuples data.
|
|
auto *data = _data + _tuples.size() * _row_size;
|
|
std::memcpy(data, tuple.metadata(), sizeof(concurrency::Metadata));
|
|
std::memcpy(data + sizeof(concurrency::Metadata), tuple.data(), _schema.row_size());
|
|
|
|
_tuples.emplace_back(Tuple{_schema,
|
|
{storage::Page::MEMORY_TABLE_PAGE_ID, 0u},
|
|
reinterpret_cast<concurrency::Metadata *>(data),
|
|
data + sizeof(concurrency::Metadata)});
|
|
return _tuples.size() - 1;
|
|
}
|
|
|
|
/**
|
|
* @return Constant set of all tuples stored in the memory table.
|
|
*/
|
|
[[nodiscard]] const std::vector<Tuple> &tuples() const
|
|
{
|
|
return _tuples;
|
|
}
|
|
|
|
/**
|
|
* @return Set of all tuples stored in the memory table.
|
|
*/
|
|
std::vector<Tuple> &tuples()
|
|
{
|
|
return _tuples;
|
|
}
|
|
|
|
/**
|
|
* @return Schema of this table.
|
|
*/
|
|
[[nodiscard]] const Schema &schema() const
|
|
{
|
|
return _schema;
|
|
}
|
|
|
|
/**
|
|
* @return True, when the table has no tuples stored.
|
|
*/
|
|
[[nodiscard]] bool empty() const
|
|
{
|
|
return _tuples.empty();
|
|
}
|
|
|
|
/**
|
|
* @return Number of stored tuples.
|
|
*/
|
|
[[nodiscard]] std::size_t size() const
|
|
{
|
|
return _tuples.size();
|
|
}
|
|
|
|
/**
|
|
* Grants access to a specific tuple.
|
|
* @param index Index of the tuple.
|
|
* @return Tuple.
|
|
*/
|
|
[[nodiscard]] const Tuple &at(const std::size_t index) const
|
|
{
|
|
return _tuples[index];
|
|
}
|
|
|
|
const Tuple &operator[](const std::size_t index) const
|
|
{
|
|
return _tuples[index];
|
|
}
|
|
|
|
[[nodiscard]] auto begin() const
|
|
{
|
|
return _tuples.begin();
|
|
}
|
|
[[nodiscard]] auto end() const
|
|
{
|
|
return _tuples.end();
|
|
}
|
|
|
|
private:
|
|
Schema _schema;
|
|
const std::uint32_t _row_size;
|
|
std::uint64_t _capacity = 0u;
|
|
std::byte *_data = nullptr;
|
|
std::vector<Tuple> _tuples;
|
|
|
|
void allocate(const std::uint64_t capacity)
|
|
{
|
|
// Resize capacity.
|
|
const auto old_capacity = _capacity;
|
|
_capacity = capacity;
|
|
|
|
// Resize "real" data.
|
|
auto *old_data = _data;
|
|
_data = static_cast<std::byte *>(std::aligned_alloc(64u, capacity * _row_size));
|
|
|
|
// Copy old data to new location.
|
|
if (old_data != nullptr)
|
|
{
|
|
std::memmove(_data, old_data, old_capacity * _row_size);
|
|
std::free(old_data);
|
|
}
|
|
|
|
// Tell tuples their new location.
|
|
for (auto i = 0u; i < _tuples.size(); ++i)
|
|
{
|
|
_tuples[i].metadata(reinterpret_cast<concurrency::Metadata *>(_data + i * _row_size));
|
|
_tuples[i].data(_data + i * _row_size + sizeof(concurrency::Metadata));
|
|
}
|
|
}
|
|
};
|
|
} // namespace beedb::table
|