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arangodb/arangod/Indexes/HashIndex.h

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////////////////////////////////////////////////////////////////////////////////
/// @brief hash index
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2014 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
/// @author Copyright 2014, ArangoDB GmbH, Cologne, Germany
/// @author Copyright 2011-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGODB_INDEXES_HASH_INDEX_H
#define ARANGODB_INDEXES_HASH_INDEX_H 1
#include "Basics/Common.h"
#include "Basics/AssocMulti.h"
#include "Basics/AssocUnique.h"
#include "Indexes/PathBasedIndex.h"
#include "Indexes/IndexIterator.h"
#include "VocBase/shaped-json.h"
#include "VocBase/vocbase.h"
#include "VocBase/voc-types.h"
#include "VocBase/document-collection.h"
#include "VocBase/VocShaper.h"
struct TRI_json_t;
////////////////////////////////////////////////////////////////////////////////
/// @brief hash index query parameter
////////////////////////////////////////////////////////////////////////////////
struct TRI_hash_index_search_value_t {
TRI_hash_index_search_value_t ();
~TRI_hash_index_search_value_t ();
TRI_hash_index_search_value_t (TRI_hash_index_search_value_t const&) = delete;
TRI_hash_index_search_value_t& operator= (TRI_hash_index_search_value_t const&) = delete;
void reserve (size_t);
void destroy ();
size_t _length;
struct TRI_shaped_json_s* _values;
};
// -----------------------------------------------------------------------------
// --SECTION-- class HashIndex
// -----------------------------------------------------------------------------
namespace triagens {
namespace aql {
class SortCondition;
}
namespace arango {
class HashIndexIterator final : public IndexIterator {
public:
HashIndexIterator (HashIndex const* index,
std::vector<TRI_hash_index_search_value_t*>& keys)
: _index(index),
_keys(keys),
_position(0),
_buffer(),
_posInBuffer(0) {
}
~HashIndexIterator() {
for (auto& it : _keys) {
delete it;
}
}
TRI_doc_mptr_t* next () override;
void reset () override;
private:
HashIndex const* _index;
std::vector<TRI_hash_index_search_value_t*> _keys;
size_t _position;
std::vector<TRI_doc_mptr_t*> _buffer;
size_t _posInBuffer;
};
class HashIndex final : public PathBasedIndex {
// -----------------------------------------------------------------------------
// --SECTION-- constructors / destructors
// -----------------------------------------------------------------------------
public:
HashIndex () = delete;
HashIndex (TRI_idx_iid_t,
struct TRI_document_collection_t*,
std::vector<std::vector<triagens::basics::AttributeName>> const&,
bool,
bool);
explicit HashIndex (struct TRI_json_t const*);
~HashIndex ();
// -----------------------------------------------------------------------------
// --SECTION-- public methods
// -----------------------------------------------------------------------------
public:
IndexType type () const override final {
return Index::TRI_IDX_TYPE_HASH_INDEX;
}
bool isSorted () const override final {
return false;
}
bool hasSelectivityEstimate () const override final {
return true;
}
double selectivityEstimate () const override final;
size_t memory () const override final;
triagens::basics::Json toJson (TRI_memory_zone_t*, bool) const override final;
triagens::basics::Json toJsonFigures (TRI_memory_zone_t*) const override final;
int insert (struct TRI_doc_mptr_t const*, bool) override final;
int remove (struct TRI_doc_mptr_t const*, bool) override final;
int batchInsert (std::vector<TRI_doc_mptr_t const*> const*,
size_t) override final;
int sizeHint (size_t) override final;
bool hasBatchInsert () const override final {
return true;
}
std::vector<std::vector<std::pair<TRI_shape_pid_t, bool>>> const& paths () const {
return _paths;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief locates entries in the hash index given shaped json objects
////////////////////////////////////////////////////////////////////////////////
int lookup (TRI_hash_index_search_value_t*,
std::vector<TRI_doc_mptr_t*>&) const;
////////////////////////////////////////////////////////////////////////////////
/// @brief locates entries in the hash index given shaped json objects
////////////////////////////////////////////////////////////////////////////////
int lookup (TRI_hash_index_search_value_t*,
std::vector<TRI_doc_mptr_copy_t>&,
TRI_index_element_t*&,
size_t batchSize) const;
bool supportsFilterCondition (triagens::aql::AstNode const*,
triagens::aql::Variable const*,
size_t,
size_t&,
double&) const override;
IndexIterator* iteratorForCondition (IndexIteratorContext*,
triagens::aql::Ast*,
triagens::aql::AstNode const*,
triagens::aql::Variable const*,
bool) const override;
triagens::aql::AstNode* specializeCondition (triagens::aql::AstNode*,
triagens::aql::Variable const*) const override;
// -----------------------------------------------------------------------------
// --SECTION-- private methods
// -----------------------------------------------------------------------------
private:
int insertUnique (struct TRI_doc_mptr_t const*, bool);
int batchInsertUnique (std::vector<TRI_doc_mptr_t const*> const*, size_t);
int insertMulti (struct TRI_doc_mptr_t const*, bool);
int batchInsertMulti (std::vector<TRI_doc_mptr_t const*> const*, size_t);
int removeUniqueElement (TRI_index_element_t*, bool);
int removeUnique (struct TRI_doc_mptr_t const*, bool);
int removeMultiElement (TRI_index_element_t*, bool);
int removeMulti (struct TRI_doc_mptr_t const*, bool);
bool accessFitsIndex (triagens::aql::AstNode const* access,
triagens::aql::AstNode const* other,
triagens::aql::Variable const* reference,
std::unordered_set<size_t>& found) const;
// -----------------------------------------------------------------------------
// --SECTION-- private classes
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief given an element generates a hash integer
////////////////////////////////////////////////////////////////////////////////
private:
class HashElementFunc {
size_t _numFields;
public:
HashElementFunc (size_t n)
: _numFields(n) {
}
uint64_t operator() (TRI_index_element_t const* element,
bool byKey = true) {
uint64_t hash = 0x0123456789abcdef;
for (size_t j = 0; j < _numFields; j++) {
char const* data;
size_t length;
TRI_InspectShapedSub(&element->subObjects()[j],
element->document(), data, length);
// ignore the sid for hashing
// only hash the data block
hash = fasthash64(data, length, hash);
}
if (byKey) {
return hash;
}
TRI_doc_mptr_t* ptr = element->document();
return fasthash64(&ptr, sizeof(TRI_doc_mptr_t*), hash);
}
};
////////////////////////////////////////////////////////////////////////////////
/// @brief determines if a key corresponds to an element
////////////////////////////////////////////////////////////////////////////////
class IsEqualElementElementByKey {
size_t _numFields;
public:
IsEqualElementElementByKey (size_t n)
: _numFields(n) {
}
bool operator() (TRI_index_element_t const* left,
TRI_index_element_t const* right) {
TRI_ASSERT_EXPENSIVE(left->document() != nullptr);
TRI_ASSERT_EXPENSIVE(right->document() != nullptr);
if (left->document() == right->document()) {
return true;
}
for (size_t j = 0; j < _numFields; ++j) {
TRI_shaped_sub_t* leftSub = &left->subObjects()[j];
TRI_shaped_sub_t* rightSub = &right->subObjects()[j];
if (leftSub->_sid != rightSub->_sid) {
return false;
}
char const* leftData;
size_t leftLength;
TRI_InspectShapedSub(leftSub, left->document(),
leftData, leftLength);
char const* rightData;
size_t rightLength;
TRI_InspectShapedSub(rightSub, right->document(),
rightData, rightLength);
if (leftLength != rightLength) {
return false;
}
if (leftLength > 0 &&
memcmp(leftData, rightData, leftLength) != 0) {
return false;
}
}
return true;
}
};
// -----------------------------------------------------------------------------
// --SECTION-- private variables
// -----------------------------------------------------------------------------
private:
////////////////////////////////////////////////////////////////////////////////
/// @brief the actual hash index (unique type)
////////////////////////////////////////////////////////////////////////////////
typedef triagens::basics::AssocUnique<TRI_hash_index_search_value_t,
TRI_index_element_t>
TRI_HashArray_t;
struct UniqueArray {
UniqueArray () = delete;
UniqueArray (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
};
////////////////////////////////////////////////////////////////////////////////
/// @brief the actual hash index (multi type)
////////////////////////////////////////////////////////////////////////////////
typedef triagens::basics::AssocMulti<TRI_hash_index_search_value_t,
TRI_index_element_t,
uint32_t, true>
TRI_HashArrayMulti_t;
struct MultiArray {
MultiArray () = delete;
MultiArray (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
};
union {
UniqueArray* _uniqueArray;
MultiArray* _multiArray;
};
};
}
}
#endif
// -----------------------------------------------------------------------------
// --SECTION-- END-OF-FILE
// -----------------------------------------------------------------------------
// Local Variables:
// mode: outline-minor
// outline-regexp: "/// @brief\\|/// {@inheritDoc}\\|/// @page\\|// --SECTION--\\|/// @\\}"
// End:
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