mirror of https://github.com/OpenTTD/OpenTTD.git
110 lines
1.7 KiB
C++
110 lines
1.7 KiB
C++
/* $Id$ */
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/** @file smallvec.h Simple vector class that allows allocating an item without the need to copy this->data needlessly. */
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#ifndef SMALLVEC_H
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#define SMALLVEC_H
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#include "../core/alloc_func.hpp"
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#include "../core/math_func.hpp"
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template <typename T, uint S>
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struct SmallVector {
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T *data;
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uint items;
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uint capacity;
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SmallVector() : data(NULL), items(0), capacity(0) { }
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~SmallVector()
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{
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free(this->data);
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}
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/**
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* Remove all items from the list.
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*/
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void Clear()
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{
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/* In fact we just reset the item counter avoiding the need to
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* probably reallocate the same amount of memory the list was
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* previously using. */
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this->items = 0;
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}
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/**
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* Compact the list down to the smallest block size boundary.
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*/
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void Compact()
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{
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uint capacity = Align(this->items, S);
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if (capacity >= this->capacity) return;
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this->capacity = capacity;
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this->data = ReallocT(this->data, this->capacity);
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}
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/**
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* Append an item and return it.
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*/
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T *Append()
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{
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if (this->items == this->capacity) {
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this->capacity += S;
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this->data = ReallocT(this->data, this->capacity);
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}
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return &this->data[this->items++];
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}
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/**
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* Get the number of items in the list.
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*/
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uint Length() const
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{
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return this->items;
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}
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const T *Begin() const
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{
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return this->data;
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}
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T *Begin()
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{
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return this->data;
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}
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const T *End() const
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{
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return &this->data[this->items];
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}
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T *End()
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{
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return &this->data[this->items];
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}
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const T *Get(uint index) const
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{
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return &this->data[index];
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}
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T *Get(uint index)
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{
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return &this->data[index];
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}
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const T &operator[](uint index) const
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{
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return this->data[index];
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}
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T &operator[](uint index)
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{
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return this->data[index];
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}
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};
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#endif /* SMALLVEC_H */
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