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/*
* include/framework/scheduling/Version.h
*
* Copyright (C) 2023-2024 Douglas B. Rumbaugh <drumbaugh@psu.edu>
*
* Distributed under the Modified BSD License.
*
*/
#pragma once
#include <mutex>
#include "framework/structure/BufferView.h"
#include "framework/structure/ExtensionStructure.h"
#include "framework/structure/MutableBuffer.h"
namespace de {
template <ShardInterface ShardType, QueryInterface<ShardType> QueryType>
class Version {
private:
typedef typename ShardType::RECORD RecordType;
typedef MutableBuffer<RecordType> BufferType;
typedef ExtensionStructure<ShardType, QueryType> StructureType;
typedef BufferView<RecordType> BufferViewType;
public:
Version(size_t vid = 0)
: m_buffer(nullptr), m_structure(nullptr), m_id(vid), m_buffer_head(0),
m_pending_buffer_head(-1) {}
Version(size_t number, std::unique_ptr<StructureType> structure, BufferType *buff,
size_t head)
: m_buffer(buff), m_structure(std::move(structure)), m_id(number),
m_buffer_head(head), m_pending_buffer_head(-1) {}
~Version() = default;
/*
* Versions are *not* copyable or movable. Only one can exist, and all users
* of it work with pointers
*/
Version(const Version &) = delete;
Version(Version &&) = delete;
Version &operator=(const Version &) = delete;
Version &operator=(Version &&) = delete;
size_t get_id() const { return m_id; }
void set_id(size_t id) { m_id = id;}
const StructureType *get_structure() const { return m_structure.get(); }
StructureType *get_mutable_structure() { return m_structure.get(); }
bool set_structure(std::unique_ptr<StructureType> new_struct) {
if (m_structure) {
return false;
}
m_structure = std::move(new_struct);
return true;
}
BufferViewType get_buffer() const {
return m_buffer->get_buffer_view(m_buffer_head);
}
/*
* Returns a new Version object that is a copy of this one. The new object
* will also contain a copy of the m_structure, rather than a reference to
* the same one. The epoch number of the new epoch will be set to the
* provided argument.
*/
Version *clone(size_t number) {
auto version = new Version(number);
version->m_buffer = m_buffer;
version->m_buffer_head = m_buffer_head;
if (m_structure) {
version->m_structure = std::unique_ptr(m_structure->copy());
}
return version;
}
void set_next_buffer_head(size_t new_head) {
m_pending_buffer_head = new_head;
}
bool advance_buffer_head() {
m_buffer_head = m_pending_buffer_head;
return m_buffer->advance_head(m_buffer_head);
}
private:
BufferType *m_buffer;
std::unique_ptr<StructureType> m_structure;
/*
* The number of currently active jobs
* (queries/merges) operating on this
* epoch. An epoch can only be retired
* when this number is 0.
*/
size_t m_id;
size_t m_buffer_head;
ssize_t m_pending_buffer_head;
};
} // namespace de
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