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arangodb/arangod/MMFiles/MMFilesHashIndex.h

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10 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGOD_MMFILES_HASH_INDEX_H
#define ARANGOD_MMFILES_HASH_INDEX_H 1
#include "Basics/AssocMulti.h"
#include "Basics/AssocUnique.h"
#include "Basics/Common.h"
#include "Basics/VelocyPackHelper.h"
#include "Basics/fasthash.h"
#include "Indexes/IndexIterator.h"
#include "MMFiles/MMFilesIndexElement.h"
#include "MMFiles/MMFilesPathBasedIndex.h"
#include "Transaction/Helpers.h"
#include "Transaction/Methods.h"
#include "VocBase/voc-types.h"
#include "VocBase/vocbase.h"
#include <velocypack/Iterator.h>
#include <velocypack/Slice.h>
#include <velocypack/velocypack-aliases.h>
/// @brief hash index query parameter
namespace arangodb {
namespace basics {
class LocalTaskQueue;
}
class MMFilesHashIndex;
/// @brief Class to build Slice lookups out of AST Conditions
class MMFilesHashIndexLookupBuilder {
private:
transaction::BuilderLeaser _builder;
bool _usesIn;
bool _isEmpty;
size_t _coveredFields;
std::unordered_map<size_t, arangodb::aql::AstNode const*>
_mappingFieldCondition;
std::unordered_map<
size_t, std::pair<size_t, std::vector<arangodb::velocypack::Slice>>>
_inPosition;
transaction::BuilderLeaser _inStorage;
public:
MMFilesHashIndexLookupBuilder(
transaction::Methods*, arangodb::aql::AstNode const*,
arangodb::aql::Variable const*,
std::vector<std::vector<arangodb::basics::AttributeName>> const&);
arangodb::velocypack::Slice lookup();
bool hasAndGetNext();
void reset();
private:
bool incrementInPosition();
void buildNextSearchValue();
};
class MMFilesHashIndexIterator final : public IndexIterator {
public:
/// @brief Construct an MMFilesHashIndexIterator based on Ast Conditions
MMFilesHashIndexIterator(LogicalCollection* collection,
transaction::Methods* trx,
ManagedDocumentResult* mmdr,
MMFilesHashIndex const* index,
arangodb::aql::AstNode const*,
arangodb::aql::Variable const*);
~MMFilesHashIndexIterator() = default;
char const* typeName() const override { return "hash-index-iterator"; }
bool next(TokenCallback const& cb, size_t limit) override;
void reset() override;
private:
MMFilesHashIndex const* _index;
MMFilesHashIndexLookupBuilder _lookups;
std::vector<MMFilesHashIndexElement*> _buffer;
size_t _posInBuffer;
};
class MMFilesHashIndexIteratorVPack final : public IndexIterator {
public:
/// @brief Construct an MMFilesHashIndexIterator based on VelocyPack
MMFilesHashIndexIteratorVPack(
LogicalCollection* collection, transaction::Methods* trx,
ManagedDocumentResult* mmdr, MMFilesHashIndex const* index,
std::unique_ptr<arangodb::velocypack::Builder>& searchValues);
~MMFilesHashIndexIteratorVPack();
char const* typeName() const override { return "hash-index-iterator-vpack"; }
bool next(TokenCallback const& cb, size_t limit) override;
void reset() override;
private:
MMFilesHashIndex const* _index;
std::unique_ptr<arangodb::velocypack::Builder> _searchValues;
arangodb::velocypack::ArrayIterator _iterator;
std::vector<MMFilesHashIndexElement*> _buffer;
size_t _posInBuffer;
};
class MMFilesHashIndex final : public MMFilesPathBasedIndex {
friend class MMFilesHashIndexIterator;
friend class MMFilesHashIndexIteratorVPack;
public:
MMFilesHashIndex() = delete;
MMFilesHashIndex(TRI_idx_iid_t, LogicalCollection*,
arangodb::velocypack::Slice const&);
~MMFilesHashIndex();
public:
IndexType type() const override { return Index::TRI_IDX_TYPE_HASH_INDEX; }
char const* typeName() const override { return "hash"; }
bool allowExpansion() const override { return true; }
bool canBeDropped() const override { return true; }
bool isSorted() const override { return false; }
bool hasSelectivityEstimate() const override { return true; }
double selectivityEstimate(
arangodb::StringRef const* = nullptr) const override;
size_t memory() const override;
void toVelocyPack(VPackBuilder&, bool, bool) const override;
void toVelocyPackFigures(VPackBuilder&) const override;
bool matchesDefinition(VPackSlice const& info) const override;
Result insert(transaction::Methods*, TRI_voc_rid_t,
arangodb::velocypack::Slice const&, bool isRollback) override;
Result remove(transaction::Methods*, TRI_voc_rid_t,
arangodb::velocypack::Slice const&, bool isRollback) override;
void batchInsert(
transaction::Methods*,
std::vector<std::pair<TRI_voc_rid_t, arangodb::velocypack::Slice>> const&,
std::shared_ptr<arangodb::basics::LocalTaskQueue> queue) override;
int unload() override;
int sizeHint(transaction::Methods*, size_t) override;
bool hasBatchInsert() const override { return true; }
bool supportsFilterCondition(arangodb::aql::AstNode const*,
arangodb::aql::Variable const*, size_t, size_t&,
double&) const override;
IndexIterator* iteratorForCondition(transaction::Methods*,
ManagedDocumentResult*,
arangodb::aql::AstNode const*,
arangodb::aql::Variable const*,
bool) override;
arangodb::aql::AstNode* specializeCondition(
arangodb::aql::AstNode*, arangodb::aql::Variable const*) const override;
private:
/// @brief locates entries in the hash index given a velocypack slice
int lookup(transaction::Methods*, arangodb::velocypack::Slice,
std::vector<MMFilesHashIndexElement*>&) const;
int insertUnique(transaction::Methods*, TRI_voc_rid_t,
arangodb::velocypack::Slice const&, bool isRollback);
void batchInsertUnique(
transaction::Methods*,
std::vector<std::pair<TRI_voc_rid_t, arangodb::velocypack::Slice>> const&,
std::shared_ptr<arangodb::basics::LocalTaskQueue> queue);
int insertMulti(transaction::Methods*, TRI_voc_rid_t,
arangodb::velocypack::Slice const&, bool isRollback);
void batchInsertMulti(
transaction::Methods*,
std::vector<std::pair<TRI_voc_rid_t, arangodb::velocypack::Slice>> const&,
std::shared_ptr<arangodb::basics::LocalTaskQueue> queue);
int removeUniqueElement(transaction::Methods*, MMFilesHashIndexElement*,
bool);
int removeMultiElement(transaction::Methods*, MMFilesHashIndexElement*, bool);
bool accessFitsIndex(arangodb::aql::AstNode const* access,
arangodb::aql::AstNode const* other,
arangodb::aql::Variable const* reference,
std::unordered_set<size_t>& found) const;
/// @brief given an element generates a hash integer
private:
class HashElementFunc {
public:
HashElementFunc() {}
uint64_t operator()(void* userData, MMFilesHashIndexElement const* element,
bool byKey = true) {
uint64_t hash = element->hash();
if (byKey) {
return hash;
}
TRI_voc_rid_t revisionId = element->revisionId();
return fasthash64_uint64(revisionId, hash);
}
};
/// @brief determines if a key corresponds to an element
class IsEqualElementElementByKey {
size_t _numFields;
bool _allowExpansion;
public:
IsEqualElementElementByKey(size_t n, bool allowExpansion)
: _numFields(n), _allowExpansion(allowExpansion) {}
bool operator()(void* userData, MMFilesHashIndexElement const* left,
MMFilesHashIndexElement const* right) {
TRI_ASSERT(left->revisionId() != 0);
TRI_ASSERT(right->revisionId() != 0);
if (!_allowExpansion && left->revisionId() == right->revisionId()) {
return true;
}
IndexLookupContext* context = static_cast<IndexLookupContext*>(userData);
for (size_t i = 0; i < _numFields; ++i) {
VPackSlice leftData = left->slice(context, i);
VPackSlice rightData = right->slice(context, i);
int res = arangodb::basics::VelocyPackHelper::compare(leftData,
rightData, false);
if (res != 0) {
return false;
}
}
return true;
}
};
private:
/// @brief the actual hash index (unique type)
typedef arangodb::basics::AssocUnique<arangodb::velocypack::Slice,
MMFilesHashIndexElement*>
TRI_HashArray_t;
struct UniqueArray {
UniqueArray() = delete;
UniqueArray(size_t numPaths, TRI_HashArray_t*, HashElementFunc*,
IsEqualElementElementByKey*);
~UniqueArray();
TRI_HashArray_t* _hashArray; // the hash array itself, unique values
HashElementFunc* _hashElement; // hash function for elements
IsEqualElementElementByKey* _isEqualElElByKey; // comparison func
size_t _numPaths;
};
/// @brief the actual hash index (multi type)
typedef arangodb::basics::AssocMulti<
arangodb::velocypack::Slice, MMFilesHashIndexElement*, uint32_t, false>
TRI_HashArrayMulti_t;
struct MultiArray {
MultiArray() = delete;
MultiArray(size_t numPaths, TRI_HashArrayMulti_t*, HashElementFunc*,
IsEqualElementElementByKey*);
~MultiArray();
TRI_HashArrayMulti_t*
_hashArray; // the hash array itself, non-unique values
HashElementFunc* _hashElement; // hash function for elements
IsEqualElementElementByKey* _isEqualElElByKey; // comparison func
size_t _numPaths;
};
union {
UniqueArray* _uniqueArray;
MultiArray* _multiArray;
};
};
}
#endif