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arangodb/lib/Basics/associative.h

486 lines
22 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// @brief associative array implementation
///
/// @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 Martin Schoenert
/// @author Copyright 2014, ArangoDB GmbH, Cologne, Germany
/// @author Copyright 2006-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGODB_BASICS_C_ASSOCIATIVE_H
#define ARANGODB_BASICS_C_ASSOCIATIVE_H 1
#include <functional>
#include "Basics/Common.h"
#include "Basics/locks.h"
// -----------------------------------------------------------------------------
// --SECTION-- ASSOCIATIVE ARRAY
// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------
// --SECTION-- public types
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief associative array
////////////////////////////////////////////////////////////////////////////////
typedef struct TRI_associative_array_s {
uint64_t (*hashKey) (struct TRI_associative_array_s*, void*);
uint64_t (*hashElement) (struct TRI_associative_array_s*, void*);
void (*clearElement) (struct TRI_associative_array_s*, void*);
bool (*isEmptyElement) (struct TRI_associative_array_s*, void*);
bool (*isEqualKeyElement) (struct TRI_associative_array_s*, void*, void*);
bool (*isEqualElementElement) (struct TRI_associative_array_s*, void*, void*);
uint32_t _elementSize;
uint32_t _nrAlloc; // the size of the table
uint32_t _nrUsed; // the number of used entries
char* _table; // the table itself
#ifdef TRI_INTERNAL_STATS
uint64_t _nrFinds; // statistics: number of lookup calls
uint64_t _nrAdds; // statistics: number of insert calls
uint64_t _nrRems; // statistics: number of remove calls
uint64_t _nrResizes; // statistics: number of resizes
uint64_t _nrProbesF; // statistics: number of misses while looking up
uint64_t _nrProbesA; // statistics: number of misses while inserting
uint64_t _nrProbesD; // statistics: number of misses while removing
uint64_t _nrProbesR; // statistics: number of misses while adding
#endif
TRI_memory_zone_t* _memoryZone;
}
TRI_associative_array_t;
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief initialises an array
////////////////////////////////////////////////////////////////////////////////
int TRI_InitAssociativeArray (TRI_associative_array_t*,
TRI_memory_zone_t*,
size_t elementSize,
uint64_t (*hashKey) (TRI_associative_array_t*, void*),
uint64_t (*hashElement) (TRI_associative_array_t*, void*),
void (*clearElement) (TRI_associative_array_t*, void*),
bool (*isEmptyElement) (TRI_associative_array_t*, void*),
bool (*isEqualKeyElement) (TRI_associative_array_t*, void*, void*),
bool (*isEqualElementElement) (TRI_associative_array_t*, void*, void*));
////////////////////////////////////////////////////////////////////////////////
/// @brief destroys an array, but does not free the pointer
////////////////////////////////////////////////////////////////////////////////
void TRI_DestroyAssociativeArray (TRI_associative_array_t*);
////////////////////////////////////////////////////////////////////////////////
/// @brief destroys an array and frees the pointer
////////////////////////////////////////////////////////////////////////////////
void TRI_FreeAssociativeArray (TRI_memory_zone_t*, TRI_associative_array_t*);
// -----------------------------------------------------------------------------
// --SECTION-- public functions
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief lookups an element given a key
////////////////////////////////////////////////////////////////////////////////
void* TRI_LookupByKeyAssociativeArray (TRI_associative_array_t*, void* key);
////////////////////////////////////////////////////////////////////////////////
/// @brief finds an element given a key, returns NULL if not found
////////////////////////////////////////////////////////////////////////////////
void* TRI_FindByKeyAssociativeArray (TRI_associative_array_t*, void* key);
////////////////////////////////////////////////////////////////////////////////
/// @brief lookups an element given an element
////////////////////////////////////////////////////////////////////////////////
void* TRI_LookupByElementAssociativeArray (TRI_associative_array_t*, void* element);
////////////////////////////////////////////////////////////////////////////////
/// @brief finds an element given an element, returns NULL if not found
////////////////////////////////////////////////////////////////////////////////
void* TRI_FindByElementAssociativeArray (TRI_associative_array_t*, void* element);
////////////////////////////////////////////////////////////////////////////////
/// @brief adds an element to the array
////////////////////////////////////////////////////////////////////////////////
bool TRI_InsertElementAssociativeArray (TRI_associative_array_t*, void* element, bool overwrite);
////////////////////////////////////////////////////////////////////////////////
/// @brief adds an key/element to the array
////////////////////////////////////////////////////////////////////////////////
bool TRI_InsertKeyAssociativeArray (TRI_associative_array_t*, void* key, void* element, bool overwrite);
////////////////////////////////////////////////////////////////////////////////
/// @brief removes an element from the array
////////////////////////////////////////////////////////////////////////////////
bool TRI_RemoveElementAssociativeArray (TRI_associative_array_t*, void* element, void* old);
////////////////////////////////////////////////////////////////////////////////
/// @brief removes an key/element to the array
////////////////////////////////////////////////////////////////////////////////
bool TRI_RemoveKeyAssociativeArray (TRI_associative_array_t*, void* key, void* old);
////////////////////////////////////////////////////////////////////////////////
/// @brief get the number of elements from the array
////////////////////////////////////////////////////////////////////////////////
size_t TRI_GetLengthAssociativeArray (const TRI_associative_array_t* const);
// -----------------------------------------------------------------------------
// --SECTION-- ASSOCIATIVE POINTERS
// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------
// --SECTION-- public types
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief associative array of pointers
////////////////////////////////////////////////////////////////////////////////
typedef struct TRI_associative_pointer_s {
uint64_t (*hashKey) (struct TRI_associative_pointer_s*, void const*);
uint64_t (*hashElement) (struct TRI_associative_pointer_s*, void const*);
bool (*isEqualKeyElement) (struct TRI_associative_pointer_s*, void const*, void const*);
bool (*isEqualElementElement) (struct TRI_associative_pointer_s*, void const*, void const*);
uint32_t _nrAlloc; // the size of the table
uint32_t _nrUsed; // the number of used entries
void** _table; // the table itself
#ifdef TRI_INTERNAL_STATS
uint64_t _nrFinds; // statistics: number of lookup calls
uint64_t _nrAdds; // statistics: number of insert calls
uint64_t _nrRems; // statistics: number of remove calls
uint64_t _nrResizes; // statistics: number of resizes
uint64_t _nrProbesF; // statistics: number of misses while looking up
uint64_t _nrProbesA; // statistics: number of misses while inserting
uint64_t _nrProbesD; // statistics: number of misses while removing
uint64_t _nrProbesR; // statistics: number of misses while adding
#endif
TRI_memory_zone_t* _memoryZone;
}
TRI_associative_pointer_t;
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief initialises an array
////////////////////////////////////////////////////////////////////////////////
int TRI_InitAssociativePointer (TRI_associative_pointer_t* array,
TRI_memory_zone_t*,
uint64_t (*hashKey) (TRI_associative_pointer_t*, void const*),
uint64_t (*hashElement) (TRI_associative_pointer_t*, void const*),
bool (*isEqualKeyElement) (TRI_associative_pointer_t*, void const*, void const*),
bool (*isEqualElementElement) (TRI_associative_pointer_t*, void const*, void const*));
////////////////////////////////////////////////////////////////////////////////
/// @brief destroys an array, but does not free the pointer
////////////////////////////////////////////////////////////////////////////////
void TRI_DestroyAssociativePointer (TRI_associative_pointer_t*);
////////////////////////////////////////////////////////////////////////////////
/// @brief destroys an array and frees the pointer
////////////////////////////////////////////////////////////////////////////////
void TRI_FreeAssociativePointer (TRI_memory_zone_t*, TRI_associative_pointer_t*);
// -----------------------------------------------------------------------------
// --SECTION-- public functions
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief General hash function that can be used to hash a pointer
////////////////////////////////////////////////////////////////////////////////
uint64_t TRI_HashPointerKeyAssociativePointer (TRI_associative_pointer_t*,
void const*);
////////////////////////////////////////////////////////////////////////////////
/// @brief General hash function that can be used to hash a string key
////////////////////////////////////////////////////////////////////////////////
uint64_t TRI_HashStringKeyAssociativePointer (TRI_associative_pointer_t*,
void const*);
////////////////////////////////////////////////////////////////////////////////
/// @brief General function to determine equality of two string values
////////////////////////////////////////////////////////////////////////////////
bool TRI_EqualStringKeyAssociativePointer (TRI_associative_pointer_t*,
void const*,
void const*);
////////////////////////////////////////////////////////////////////////////////
/// @brief reserves space in the array for extra elements
////////////////////////////////////////////////////////////////////////////////
bool TRI_ReserveAssociativePointer (TRI_associative_pointer_t*,
int32_t);
////////////////////////////////////////////////////////////////////////////////
/// @brief lookups an element given a key
////////////////////////////////////////////////////////////////////////////////
void* TRI_LookupByKeyAssociativePointer (TRI_associative_pointer_t*,
void const* key);
////////////////////////////////////////////////////////////////////////////////
/// @brief lookups an element given an element
////////////////////////////////////////////////////////////////////////////////
void* TRI_LookupByElementAssociativePointer (TRI_associative_pointer_t*,
void const* element);
////////////////////////////////////////////////////////////////////////////////
/// @brief adds an element to the array
////////////////////////////////////////////////////////////////////////////////
void* TRI_InsertElementAssociativePointer (TRI_associative_pointer_t*,
void* element,
bool overwrite);
////////////////////////////////////////////////////////////////////////////////
/// @brief adds an key/element to the array
////////////////////////////////////////////////////////////////////////////////
void* TRI_InsertKeyAssociativePointer (TRI_associative_pointer_t*,
void const* key,
void* element,
bool overwrite);
////////////////////////////////////////////////////////////////////////////////
/// @brief adds an key/element to the array
/// returns a status code, and *found will contain a found element (if any)
////////////////////////////////////////////////////////////////////////////////
int TRI_InsertKeyAssociativePointer2 (TRI_associative_pointer_t*,
void const*,
void*,
void const**);
////////////////////////////////////////////////////////////////////////////////
/// @brief removes an element from the array
////////////////////////////////////////////////////////////////////////////////
void* TRI_RemoveElementAssociativePointer (TRI_associative_pointer_t*,
void const* element);
////////////////////////////////////////////////////////////////////////////////
/// @brief removes an key/element to the array
////////////////////////////////////////////////////////////////////////////////
void* TRI_RemoveKeyAssociativePointer (TRI_associative_pointer_t*,
void const* key);
////////////////////////////////////////////////////////////////////////////////
/// @brief get the number of elements from the array
////////////////////////////////////////////////////////////////////////////////
size_t TRI_GetLengthAssociativePointer (const TRI_associative_pointer_t* const);
// -----------------------------------------------------------------------------
// --SECTION-- ASSOCIATIVE SYNCED
// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------
// --SECTION-- public types
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief associative array of synced pointers
///
/// Note that lookup, insert, and remove are protected using a read-write lock.
////////////////////////////////////////////////////////////////////////////////
typedef struct TRI_associative_synced_s {
uint64_t (*hashKey) (struct TRI_associative_synced_s*, void const*);
uint64_t (*hashElement) (struct TRI_associative_synced_s*, void const*);
bool (*isEqualKeyElement) (struct TRI_associative_synced_s*, void const*, void const*);
bool (*isEqualElementElement) (struct TRI_associative_synced_s*, void const*, void const*);
uint32_t _nrAlloc; // the size of the table
uint32_t _nrUsed; // the number of used entries
void** _table; // the table itself
TRI_read_write_lock_t _lock;
TRI_memory_zone_t* _memoryZone;
}
TRI_associative_synced_t;
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief initialises an array
////////////////////////////////////////////////////////////////////////////////
int TRI_InitAssociativeSynced (TRI_associative_synced_t* array,
TRI_memory_zone_t*,
uint64_t (*hashKey) (TRI_associative_synced_t*, void const*),
uint64_t (*hashElement) (TRI_associative_synced_t*, void const*),
bool (*isEqualKeyElement) (TRI_associative_synced_t*, void const*, void const*),
bool (*isEqualElementElement) (TRI_associative_synced_t*, void const*, void const*));
////////////////////////////////////////////////////////////////////////////////
/// @brief destroys an array, but does not free the pointer
////////////////////////////////////////////////////////////////////////////////
void TRI_DestroyAssociativeSynced (TRI_associative_synced_t*);
////////////////////////////////////////////////////////////////////////////////
/// @brief destroys an array and frees the pointer
////////////////////////////////////////////////////////////////////////////////
void TRI_FreeAssociativeSynced (TRI_memory_zone_t*, TRI_associative_synced_t*);
// -----------------------------------------------------------------------------
// --SECTION-- public functions
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief lookups an element given a key
////////////////////////////////////////////////////////////////////////////////
void const* TRI_LookupByKeyAssociativeSynced (TRI_associative_synced_t*, void const* key);
////////////////////////////////////////////////////////////////////////////////
/// @brief lookups an element given a key and calls the callback function while
/// the read-lock is held
////////////////////////////////////////////////////////////////////////////////
template<typename T>
T TRI_ProcessByKeyAssociativeSynced (TRI_associative_synced_t* array,
void const* key,
std::function<T(void const*)> callback) {
// compute the hash
uint64_t hash = array->hashKey(array, key);
// search the table
TRI_ReadLockReadWriteLock(&array->_lock);
uint64_t i = hash % array->_nrAlloc;
while (array->_table[i] != NULL && ! array->isEqualKeyElement(array, key, array->_table[i])) {
i = TRI_IncModU64(i, array->_nrAlloc);
}
T result = callback(array->_table[i]);
TRI_ReadUnlockReadWriteLock(&array->_lock);
// return whatever we found
return result;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief lookups an element given an element
////////////////////////////////////////////////////////////////////////////////
void const* TRI_LookupByElementAssociativeSynced (TRI_associative_synced_t*,
void const*);
////////////////////////////////////////////////////////////////////////////////
/// @brief adds an element to the array
////////////////////////////////////////////////////////////////////////////////
void* TRI_InsertElementAssociativeSynced (TRI_associative_synced_t*,
void*,
bool);
////////////////////////////////////////////////////////////////////////////////
/// @brief adds an key/element to the array
////////////////////////////////////////////////////////////////////////////////
void* TRI_InsertKeyAssociativeSynced (TRI_associative_synced_t*,
void const*,
void*,
bool);
////////////////////////////////////////////////////////////////////////////////
/// @brief removes an element from the array
////////////////////////////////////////////////////////////////////////////////
void* TRI_RemoveElementAssociativeSynced (TRI_associative_synced_t*,
void const*);
////////////////////////////////////////////////////////////////////////////////
/// @brief removes an key/element to the array
////////////////////////////////////////////////////////////////////////////////
void* TRI_RemoveKeyAssociativeSynced (TRI_associative_synced_t*,
void const*);
////////////////////////////////////////////////////////////////////////////////
/// @brief get the number of elements from the array
////////////////////////////////////////////////////////////////////////////////
size_t TRI_GetLengthAssociativeSynced (TRI_associative_synced_t* const);
#endif
// -----------------------------------------------------------------------------
// --SECTION-- END-OF-FILE
// -----------------------------------------------------------------------------
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