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arangodb/lib/Basics/vector.cpp

300 lines
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
////////////////////////////////////////////////////////////////////////////////
#include "vector.h"
#include <string.h>
////////////////////////////////////////////////////////////////////////////////
/// @brief grow rate
////////////////////////////////////////////////////////////////////////////////
#define GROW_FACTOR (1.2)
////////////////////////////////////////////////////////////////////////////////
/// @brief initializes a vector
////////////////////////////////////////////////////////////////////////////////
void TRI_InitVector(TRI_vector_t* vector, size_t elementSize) {
vector->_buffer = nullptr;
vector->_lengthX = 0;
vector->_capacityX = 0;
vector->_elementSizeX = static_cast<uint32_t>(elementSize);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief initializes a vector, with user-definable settings
////////////////////////////////////////////////////////////////////////////////
int TRI_InitVector2(TRI_vector_t* vector, size_t elementSize, size_t initialCapacity) {
// init vector as usual
TRI_InitVector(vector, elementSize);
if (initialCapacity != 0) {
vector->_buffer = static_cast<char*>(TRI_Allocate(
(initialCapacity * static_cast<size_t>(vector->_elementSizeX))));
if (vector->_buffer == nullptr) {
return TRI_ERROR_OUT_OF_MEMORY;
}
}
vector->_capacityX = static_cast<uint32_t>(initialCapacity);
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief destroys a vector, but does not free the pointer
////////////////////////////////////////////////////////////////////////////////
void TRI_DestroyVector(TRI_vector_t* vector) {
if (vector->_buffer != nullptr) {
TRI_Free(vector->_buffer);
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief ensures a vector has space for extraCapacity more items
////////////////////////////////////////////////////////////////////////////////
int TRI_ReserveVector(TRI_vector_t* vector, size_t extraCapacity) {
size_t oldLength = static_cast<size_t>(vector->_lengthX);
size_t minLength = oldLength + extraCapacity;
if (static_cast<size_t>(vector->_capacityX) >= minLength) {
return TRI_ERROR_NO_ERROR;
}
size_t newSize = static_cast<size_t>(vector->_capacityX);
while (newSize < minLength) {
newSize = (size_t)(1 + GROW_FACTOR * newSize);
}
auto newBuffer = static_cast<char*>(
TRI_Reallocate(vector->_buffer, newSize * static_cast<size_t>(vector->_elementSizeX)));
if (newBuffer == nullptr) {
return TRI_ERROR_OUT_OF_MEMORY;
}
vector->_buffer = newBuffer;
vector->_capacityX = static_cast<uint32_t>(newSize);
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief adjusts the length of the vector
////////////////////////////////////////////////////////////////////////////////
void TRI_SetLengthVector(TRI_vector_t* vector, size_t n) {
vector->_lengthX = static_cast<uint32_t>(n);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief resizes the vector
////////////////////////////////////////////////////////////////////////////////
int TRI_ResizeVector(TRI_vector_t* vector, size_t n) {
if (static_cast<size_t>(vector->_lengthX) == n) {
return TRI_ERROR_NO_ERROR;
}
if (static_cast<size_t>(vector->_capacityX) < n) {
size_t newSize = n;
auto newBuffer = static_cast<char*>(
TRI_Reallocate(vector->_buffer, newSize * static_cast<size_t>(vector->_elementSizeX)));
if (newBuffer == nullptr) {
return TRI_ERROR_OUT_OF_MEMORY;
}
vector->_capacityX = static_cast<uint32_t>(n);
vector->_buffer = newBuffer;
}
vector->_lengthX = static_cast<uint32_t>(n);
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief adds an element at the end
////////////////////////////////////////////////////////////////////////////////
int TRI_PushBackVector(TRI_vector_t* vector, void const* element) {
size_t const elementSize = static_cast<size_t>(vector->_elementSizeX);
if (vector->_lengthX == vector->_capacityX) {
size_t newSize =
(size_t)(1 + (GROW_FACTOR * static_cast<size_t>(vector->_capacityX)));
auto newBuffer =
static_cast<char*>(TRI_Reallocate(vector->_buffer, newSize * elementSize));
if (newBuffer == nullptr) {
return TRI_ERROR_OUT_OF_MEMORY;
}
vector->_capacityX = static_cast<uint32_t>(newSize);
vector->_buffer = newBuffer;
}
memcpy(vector->_buffer + static_cast<size_t>(vector->_lengthX) * elementSize,
element, elementSize);
vector->_lengthX++;
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief removes an element
////////////////////////////////////////////////////////////////////////////////
void TRI_RemoveVector(TRI_vector_t* vector, size_t n) {
if (n < static_cast<size_t>(vector->_lengthX)) {
if (n + 1 < static_cast<size_t>(vector->_lengthX)) {
size_t const elementSize = static_cast<size_t>(vector->_elementSizeX);
memmove(vector->_buffer + n * elementSize, vector->_buffer + (n + 1) * elementSize,
(static_cast<size_t>(vector->_lengthX) - n - 1) * elementSize);
}
--vector->_lengthX;
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief returns an element to the vector after borrowing it via
/// TRI_NextVector. This will also decrease the vector length by one.
/// The caller must ensure that the element has been fetched from the vector
/// before.
////////////////////////////////////////////////////////////////////////////////
void TRI_ReturnVector(TRI_vector_t* vector) {
TRI_ASSERT(vector->_lengthX > 0);
vector->_lengthX--;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief increases vector length by one and returns the address of the
/// uninitialized element at the new position
////////////////////////////////////////////////////////////////////////////////
void* TRI_NextVector(TRI_vector_t* vector) {
// ensure the vector has enough capacity for another element
int res = TRI_ReserveVector(vector, 1);
if (res != TRI_ERROR_NO_ERROR) {
// out of memory
return nullptr;
}
++vector->_lengthX;
TRI_ASSERT(vector->_lengthX <= vector->_capacityX);
TRI_ASSERT(vector->_buffer != nullptr);
return TRI_AtVector(vector, static_cast<size_t>(vector->_lengthX - 1));
}
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the element at a given position
////////////////////////////////////////////////////////////////////////////////
void* TRI_AtVector(TRI_vector_t const* vector, size_t pos) {
if (vector->_buffer == nullptr || pos >= static_cast<size_t>(vector->_lengthX)) {
return nullptr;
}
return static_cast<void*>(vector->_buffer + pos * static_cast<size_t>(vector->_elementSizeX));
}
////////////////////////////////////////////////////////////////////////////////
/// @brief inserts an element at a given position
////////////////////////////////////////////////////////////////////////////////
int TRI_InsertVector(TRI_vector_t* vector, void const* element, size_t n) {
size_t const elementSize = static_cast<size_t>(vector->_elementSizeX);
// ...........................................................................
// Check and see if we need to extend the vector
// ...........................................................................
if (vector->_lengthX >= vector->_capacityX || n >= static_cast<size_t>(vector->_capacityX)) {
size_t newSize =
(size_t)(1 + (GROW_FACTOR * static_cast<size_t>(vector->_capacityX)));
if (n >= newSize) {
newSize = n + 1;
}
TRI_ASSERT(newSize > n);
auto newBuffer = static_cast<char*>(TRI_Allocate(newSize * elementSize));
if (newBuffer == nullptr) {
return TRI_ERROR_OUT_OF_MEMORY;
}
vector->_capacityX = static_cast<uint32_t>(newSize);
if (vector->_buffer != nullptr) {
memcpy(newBuffer, vector->_buffer, static_cast<size_t>(vector->_lengthX) * elementSize);
TRI_Free(vector->_buffer);
}
vector->_buffer = newBuffer;
}
if (n < static_cast<size_t>(vector->_lengthX)) {
memmove(vector->_buffer + (elementSize * (n + 1)),
vector->_buffer + (elementSize * n),
elementSize * (static_cast<size_t>(vector->_lengthX) - n));
++vector->_lengthX;
} else {
vector->_lengthX = static_cast<uint32_t>(n + 1);
}
memcpy(vector->_buffer + (elementSize * n), element, elementSize);
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief sets an element at a given position
////////////////////////////////////////////////////////////////////////////////
void TRI_SetVector(TRI_vector_t* vector, size_t pos, void const* element) {
if (pos < static_cast<size_t>(vector->_lengthX)) {
size_t const elementSize = static_cast<size_t>(vector->_elementSizeX);
memcpy((void*)(vector->_buffer + pos * elementSize), element, elementSize);
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the beginning
////////////////////////////////////////////////////////////////////////////////
void* TRI_BeginVector(TRI_vector_t const* vector) { return vector->_buffer; }