69 lines
1.7 KiB
C++
69 lines
1.7 KiB
C++
#pragma once
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#include "mvcc/id.hpp"
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#include "utils/border.hpp"
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#include "utils/total_ordering.hpp"
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namespace tx
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{
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class Transaction;
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}
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class DbTransaction;
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// TG type group
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// K key on which record is ordered.
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template <class TG, class K>
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class IndexRecord : public TotalOrdering<IndexRecord<TG, K>>,
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public TotalOrdering<Border<K>, IndexRecord<TG, K>>
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{
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public:
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IndexRecord() = default;
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IndexRecord(K key, typename TG::record_t *record,
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typename TG::vlist_t *vlist);
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friend bool operator<(const IndexRecord &lhs, const IndexRecord &rhs)
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{
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return (lhs.key < rhs.key ||
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(lhs.key == rhs.key && lhs.vlist == rhs.vlist &&
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lhs.record < rhs.record)) ^
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lhs.descending;
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}
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friend bool operator==(const IndexRecord &lhs, const IndexRecord &rhs)
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{
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return lhs.key == rhs.key &&
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(lhs.vlist != rhs.vlist || lhs.record == rhs.record);
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}
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friend bool operator<(const Border<K> &lhs, const IndexRecord &rhs)
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{
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return lhs < rhs.key;
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}
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friend bool operator==(const Border<K> &lhs, const IndexRecord &rhs)
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{
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return lhs == rhs.key;
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}
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// Will change ordering of record to descending.
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void set_descending();
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bool empty() const;
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bool is_valid(tx::Transaction &t) const;
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// True if it can be removed.
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bool to_clean(const Id &oldest_active) const;
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// This method is valid only if is_valid is true.
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const auto access(DbTransaction &db) const;
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const K key;
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private:
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bool descending = false;
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typename TG::record_t *const record{nullptr};
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typename TG::vlist_t *const vlist{nullptr};
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};
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