5c7c3b3a00
d4ee7ba prevector: assert successful allocation (Cory Fields) c5f008a don't throw std::bad_alloc when out of memory. Instead, terminate immediately (Cory Fields) Tree-SHA512: 699ce8df5b1775a99c71d3cfc952b45da1c0091e1a4b6adfac52d5be6144c3d98f88ac3af90e5c73fff2f74666a499feb4a34434683ce5979814e869c0aeddc3
505 lines
17 KiB
C++
505 lines
17 KiB
C++
// Copyright (c) 2015 The Bitcoin Core developers
|
|
// Distributed under the MIT software license, see the accompanying
|
|
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
|
|
|
|
#ifndef _BITCOIN_PREVECTOR_H_
|
|
#define _BITCOIN_PREVECTOR_H_
|
|
|
|
#include <assert.h>
|
|
#include <stdlib.h>
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
|
|
#include <iterator>
|
|
|
|
#pragma pack(push, 1)
|
|
/** Implements a drop-in replacement for std::vector<T> which stores up to N
|
|
* elements directly (without heap allocation). The types Size and Diff are
|
|
* used to store element counts, and can be any unsigned + signed type.
|
|
*
|
|
* Storage layout is either:
|
|
* - Direct allocation:
|
|
* - Size _size: the number of used elements (between 0 and N)
|
|
* - T direct[N]: an array of N elements of type T
|
|
* (only the first _size are initialized).
|
|
* - Indirect allocation:
|
|
* - Size _size: the number of used elements plus N + 1
|
|
* - Size capacity: the number of allocated elements
|
|
* - T* indirect: a pointer to an array of capacity elements of type T
|
|
* (only the first _size are initialized).
|
|
*
|
|
* The data type T must be movable by memmove/realloc(). Once we switch to C++,
|
|
* move constructors can be used instead.
|
|
*/
|
|
template<unsigned int N, typename T, typename Size = uint32_t, typename Diff = int32_t>
|
|
class prevector {
|
|
public:
|
|
typedef Size size_type;
|
|
typedef Diff difference_type;
|
|
typedef T value_type;
|
|
typedef value_type& reference;
|
|
typedef const value_type& const_reference;
|
|
typedef value_type* pointer;
|
|
typedef const value_type* const_pointer;
|
|
|
|
class iterator {
|
|
T* ptr;
|
|
public:
|
|
typedef Diff difference_type;
|
|
typedef T value_type;
|
|
typedef T* pointer;
|
|
typedef T& reference;
|
|
typedef std::random_access_iterator_tag iterator_category;
|
|
iterator(T* ptr_) : ptr(ptr_) {}
|
|
T& operator*() const { return *ptr; }
|
|
T* operator->() const { return ptr; }
|
|
T& operator[](size_type pos) { return ptr[pos]; }
|
|
const T& operator[](size_type pos) const { return ptr[pos]; }
|
|
iterator& operator++() { ptr++; return *this; }
|
|
iterator& operator--() { ptr--; return *this; }
|
|
iterator operator++(int) { iterator copy(*this); ++(*this); return copy; }
|
|
iterator operator--(int) { iterator copy(*this); --(*this); return copy; }
|
|
difference_type friend operator-(iterator a, iterator b) { return (&(*a) - &(*b)); }
|
|
iterator operator+(size_type n) { return iterator(ptr + n); }
|
|
iterator& operator+=(size_type n) { ptr += n; return *this; }
|
|
iterator operator-(size_type n) { return iterator(ptr - n); }
|
|
iterator& operator-=(size_type n) { ptr -= n; return *this; }
|
|
bool operator==(iterator x) const { return ptr == x.ptr; }
|
|
bool operator!=(iterator x) const { return ptr != x.ptr; }
|
|
bool operator>=(iterator x) const { return ptr >= x.ptr; }
|
|
bool operator<=(iterator x) const { return ptr <= x.ptr; }
|
|
bool operator>(iterator x) const { return ptr > x.ptr; }
|
|
bool operator<(iterator x) const { return ptr < x.ptr; }
|
|
};
|
|
|
|
class reverse_iterator {
|
|
T* ptr;
|
|
public:
|
|
typedef Diff difference_type;
|
|
typedef T value_type;
|
|
typedef T* pointer;
|
|
typedef T& reference;
|
|
typedef std::bidirectional_iterator_tag iterator_category;
|
|
reverse_iterator(T* ptr_) : ptr(ptr_) {}
|
|
T& operator*() { return *ptr; }
|
|
const T& operator*() const { return *ptr; }
|
|
T* operator->() { return ptr; }
|
|
const T* operator->() const { return ptr; }
|
|
reverse_iterator& operator--() { ptr++; return *this; }
|
|
reverse_iterator& operator++() { ptr--; return *this; }
|
|
reverse_iterator operator++(int) { reverse_iterator copy(*this); ++(*this); return copy; }
|
|
reverse_iterator operator--(int) { reverse_iterator copy(*this); --(*this); return copy; }
|
|
bool operator==(reverse_iterator x) const { return ptr == x.ptr; }
|
|
bool operator!=(reverse_iterator x) const { return ptr != x.ptr; }
|
|
};
|
|
|
|
class const_iterator {
|
|
const T* ptr;
|
|
public:
|
|
typedef Diff difference_type;
|
|
typedef const T value_type;
|
|
typedef const T* pointer;
|
|
typedef const T& reference;
|
|
typedef std::random_access_iterator_tag iterator_category;
|
|
const_iterator(const T* ptr_) : ptr(ptr_) {}
|
|
const_iterator(iterator x) : ptr(&(*x)) {}
|
|
const T& operator*() const { return *ptr; }
|
|
const T* operator->() const { return ptr; }
|
|
const T& operator[](size_type pos) const { return ptr[pos]; }
|
|
const_iterator& operator++() { ptr++; return *this; }
|
|
const_iterator& operator--() { ptr--; return *this; }
|
|
const_iterator operator++(int) { const_iterator copy(*this); ++(*this); return copy; }
|
|
const_iterator operator--(int) { const_iterator copy(*this); --(*this); return copy; }
|
|
difference_type friend operator-(const_iterator a, const_iterator b) { return (&(*a) - &(*b)); }
|
|
const_iterator operator+(size_type n) { return const_iterator(ptr + n); }
|
|
const_iterator& operator+=(size_type n) { ptr += n; return *this; }
|
|
const_iterator operator-(size_type n) { return const_iterator(ptr - n); }
|
|
const_iterator& operator-=(size_type n) { ptr -= n; return *this; }
|
|
bool operator==(const_iterator x) const { return ptr == x.ptr; }
|
|
bool operator!=(const_iterator x) const { return ptr != x.ptr; }
|
|
bool operator>=(const_iterator x) const { return ptr >= x.ptr; }
|
|
bool operator<=(const_iterator x) const { return ptr <= x.ptr; }
|
|
bool operator>(const_iterator x) const { return ptr > x.ptr; }
|
|
bool operator<(const_iterator x) const { return ptr < x.ptr; }
|
|
};
|
|
|
|
class const_reverse_iterator {
|
|
const T* ptr;
|
|
public:
|
|
typedef Diff difference_type;
|
|
typedef const T value_type;
|
|
typedef const T* pointer;
|
|
typedef const T& reference;
|
|
typedef std::bidirectional_iterator_tag iterator_category;
|
|
const_reverse_iterator(T* ptr_) : ptr(ptr_) {}
|
|
const_reverse_iterator(reverse_iterator x) : ptr(&(*x)) {}
|
|
const T& operator*() const { return *ptr; }
|
|
const T* operator->() const { return ptr; }
|
|
const_reverse_iterator& operator--() { ptr++; return *this; }
|
|
const_reverse_iterator& operator++() { ptr--; return *this; }
|
|
const_reverse_iterator operator++(int) { const_reverse_iterator copy(*this); ++(*this); return copy; }
|
|
const_reverse_iterator operator--(int) { const_reverse_iterator copy(*this); --(*this); return copy; }
|
|
bool operator==(const_reverse_iterator x) const { return ptr == x.ptr; }
|
|
bool operator!=(const_reverse_iterator x) const { return ptr != x.ptr; }
|
|
};
|
|
|
|
private:
|
|
size_type _size;
|
|
union direct_or_indirect {
|
|
char direct[sizeof(T) * N];
|
|
struct {
|
|
size_type capacity;
|
|
char* indirect;
|
|
};
|
|
} _union;
|
|
|
|
T* direct_ptr(difference_type pos) { return reinterpret_cast<T*>(_union.direct) + pos; }
|
|
const T* direct_ptr(difference_type pos) const { return reinterpret_cast<const T*>(_union.direct) + pos; }
|
|
T* indirect_ptr(difference_type pos) { return reinterpret_cast<T*>(_union.indirect) + pos; }
|
|
const T* indirect_ptr(difference_type pos) const { return reinterpret_cast<const T*>(_union.indirect) + pos; }
|
|
bool is_direct() const { return _size <= N; }
|
|
|
|
void change_capacity(size_type new_capacity) {
|
|
if (new_capacity <= N) {
|
|
if (!is_direct()) {
|
|
T* indirect = indirect_ptr(0);
|
|
T* src = indirect;
|
|
T* dst = direct_ptr(0);
|
|
memcpy(dst, src, size() * sizeof(T));
|
|
free(indirect);
|
|
_size -= N + 1;
|
|
}
|
|
} else {
|
|
if (!is_direct()) {
|
|
/* FIXME: Because malloc/realloc here won't call new_handler if allocation fails, assert
|
|
success. These should instead use an allocator or new/delete so that handlers
|
|
are called as necessary, but performance would be slightly degraded by doing so. */
|
|
_union.indirect = static_cast<char*>(realloc(_union.indirect, ((size_t)sizeof(T)) * new_capacity));
|
|
assert(_union.indirect);
|
|
_union.capacity = new_capacity;
|
|
} else {
|
|
char* new_indirect = static_cast<char*>(malloc(((size_t)sizeof(T)) * new_capacity));
|
|
assert(new_indirect);
|
|
T* src = direct_ptr(0);
|
|
T* dst = reinterpret_cast<T*>(new_indirect);
|
|
memcpy(dst, src, size() * sizeof(T));
|
|
_union.indirect = new_indirect;
|
|
_union.capacity = new_capacity;
|
|
_size += N + 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
T* item_ptr(difference_type pos) { return is_direct() ? direct_ptr(pos) : indirect_ptr(pos); }
|
|
const T* item_ptr(difference_type pos) const { return is_direct() ? direct_ptr(pos) : indirect_ptr(pos); }
|
|
|
|
public:
|
|
void assign(size_type n, const T& val) {
|
|
clear();
|
|
if (capacity() < n) {
|
|
change_capacity(n);
|
|
}
|
|
while (size() < n) {
|
|
_size++;
|
|
new(static_cast<void*>(item_ptr(size() - 1))) T(val);
|
|
}
|
|
}
|
|
|
|
template<typename InputIterator>
|
|
void assign(InputIterator first, InputIterator last) {
|
|
size_type n = last - first;
|
|
clear();
|
|
if (capacity() < n) {
|
|
change_capacity(n);
|
|
}
|
|
while (first != last) {
|
|
_size++;
|
|
new(static_cast<void*>(item_ptr(size() - 1))) T(*first);
|
|
++first;
|
|
}
|
|
}
|
|
|
|
prevector() : _size(0) {}
|
|
|
|
explicit prevector(size_type n) : _size(0) {
|
|
resize(n);
|
|
}
|
|
|
|
explicit prevector(size_type n, const T& val = T()) : _size(0) {
|
|
change_capacity(n);
|
|
while (size() < n) {
|
|
_size++;
|
|
new(static_cast<void*>(item_ptr(size() - 1))) T(val);
|
|
}
|
|
}
|
|
|
|
template<typename InputIterator>
|
|
prevector(InputIterator first, InputIterator last) : _size(0) {
|
|
size_type n = last - first;
|
|
change_capacity(n);
|
|
while (first != last) {
|
|
_size++;
|
|
new(static_cast<void*>(item_ptr(size() - 1))) T(*first);
|
|
++first;
|
|
}
|
|
}
|
|
|
|
prevector(const prevector<N, T, Size, Diff>& other) : _size(0) {
|
|
change_capacity(other.size());
|
|
const_iterator it = other.begin();
|
|
while (it != other.end()) {
|
|
_size++;
|
|
new(static_cast<void*>(item_ptr(size() - 1))) T(*it);
|
|
++it;
|
|
}
|
|
}
|
|
|
|
prevector(prevector<N, T, Size, Diff>&& other) : _size(0) {
|
|
swap(other);
|
|
}
|
|
|
|
prevector& operator=(const prevector<N, T, Size, Diff>& other) {
|
|
if (&other == this) {
|
|
return *this;
|
|
}
|
|
resize(0);
|
|
change_capacity(other.size());
|
|
const_iterator it = other.begin();
|
|
while (it != other.end()) {
|
|
_size++;
|
|
new(static_cast<void*>(item_ptr(size() - 1))) T(*it);
|
|
++it;
|
|
}
|
|
return *this;
|
|
}
|
|
|
|
prevector& operator=(prevector<N, T, Size, Diff>&& other) {
|
|
swap(other);
|
|
return *this;
|
|
}
|
|
|
|
size_type size() const {
|
|
return is_direct() ? _size : _size - N - 1;
|
|
}
|
|
|
|
bool empty() const {
|
|
return size() == 0;
|
|
}
|
|
|
|
iterator begin() { return iterator(item_ptr(0)); }
|
|
const_iterator begin() const { return const_iterator(item_ptr(0)); }
|
|
iterator end() { return iterator(item_ptr(size())); }
|
|
const_iterator end() const { return const_iterator(item_ptr(size())); }
|
|
|
|
reverse_iterator rbegin() { return reverse_iterator(item_ptr(size() - 1)); }
|
|
const_reverse_iterator rbegin() const { return const_reverse_iterator(item_ptr(size() - 1)); }
|
|
reverse_iterator rend() { return reverse_iterator(item_ptr(-1)); }
|
|
const_reverse_iterator rend() const { return const_reverse_iterator(item_ptr(-1)); }
|
|
|
|
size_t capacity() const {
|
|
if (is_direct()) {
|
|
return N;
|
|
} else {
|
|
return _union.capacity;
|
|
}
|
|
}
|
|
|
|
T& operator[](size_type pos) {
|
|
return *item_ptr(pos);
|
|
}
|
|
|
|
const T& operator[](size_type pos) const {
|
|
return *item_ptr(pos);
|
|
}
|
|
|
|
void resize(size_type new_size) {
|
|
if (size() > new_size) {
|
|
erase(item_ptr(new_size), end());
|
|
}
|
|
if (new_size > capacity()) {
|
|
change_capacity(new_size);
|
|
}
|
|
while (size() < new_size) {
|
|
_size++;
|
|
new(static_cast<void*>(item_ptr(size() - 1))) T();
|
|
}
|
|
}
|
|
|
|
void reserve(size_type new_capacity) {
|
|
if (new_capacity > capacity()) {
|
|
change_capacity(new_capacity);
|
|
}
|
|
}
|
|
|
|
void shrink_to_fit() {
|
|
change_capacity(size());
|
|
}
|
|
|
|
void clear() {
|
|
resize(0);
|
|
}
|
|
|
|
iterator insert(iterator pos, const T& value) {
|
|
size_type p = pos - begin();
|
|
size_type new_size = size() + 1;
|
|
if (capacity() < new_size) {
|
|
change_capacity(new_size + (new_size >> 1));
|
|
}
|
|
memmove(item_ptr(p + 1), item_ptr(p), (size() - p) * sizeof(T));
|
|
_size++;
|
|
new(static_cast<void*>(item_ptr(p))) T(value);
|
|
return iterator(item_ptr(p));
|
|
}
|
|
|
|
void insert(iterator pos, size_type count, const T& value) {
|
|
size_type p = pos - begin();
|
|
size_type new_size = size() + count;
|
|
if (capacity() < new_size) {
|
|
change_capacity(new_size + (new_size >> 1));
|
|
}
|
|
memmove(item_ptr(p + count), item_ptr(p), (size() - p) * sizeof(T));
|
|
_size += count;
|
|
for (size_type i = 0; i < count; i++) {
|
|
new(static_cast<void*>(item_ptr(p + i))) T(value);
|
|
}
|
|
}
|
|
|
|
template<typename InputIterator>
|
|
void insert(iterator pos, InputIterator first, InputIterator last) {
|
|
size_type p = pos - begin();
|
|
difference_type count = last - first;
|
|
size_type new_size = size() + count;
|
|
if (capacity() < new_size) {
|
|
change_capacity(new_size + (new_size >> 1));
|
|
}
|
|
memmove(item_ptr(p + count), item_ptr(p), (size() - p) * sizeof(T));
|
|
_size += count;
|
|
while (first != last) {
|
|
new(static_cast<void*>(item_ptr(p))) T(*first);
|
|
++p;
|
|
++first;
|
|
}
|
|
}
|
|
|
|
iterator erase(iterator pos) {
|
|
return erase(pos, pos + 1);
|
|
}
|
|
|
|
iterator erase(iterator first, iterator last) {
|
|
iterator p = first;
|
|
char* endp = (char*)&(*end());
|
|
while (p != last) {
|
|
(*p).~T();
|
|
_size--;
|
|
++p;
|
|
}
|
|
memmove(&(*first), &(*last), endp - ((char*)(&(*last))));
|
|
return first;
|
|
}
|
|
|
|
void push_back(const T& value) {
|
|
size_type new_size = size() + 1;
|
|
if (capacity() < new_size) {
|
|
change_capacity(new_size + (new_size >> 1));
|
|
}
|
|
new(item_ptr(size())) T(value);
|
|
_size++;
|
|
}
|
|
|
|
void pop_back() {
|
|
erase(end() - 1, end());
|
|
}
|
|
|
|
T& front() {
|
|
return *item_ptr(0);
|
|
}
|
|
|
|
const T& front() const {
|
|
return *item_ptr(0);
|
|
}
|
|
|
|
T& back() {
|
|
return *item_ptr(size() - 1);
|
|
}
|
|
|
|
const T& back() const {
|
|
return *item_ptr(size() - 1);
|
|
}
|
|
|
|
void swap(prevector<N, T, Size, Diff>& other) {
|
|
std::swap(_union, other._union);
|
|
std::swap(_size, other._size);
|
|
}
|
|
|
|
~prevector() {
|
|
clear();
|
|
if (!is_direct()) {
|
|
free(_union.indirect);
|
|
_union.indirect = NULL;
|
|
}
|
|
}
|
|
|
|
bool operator==(const prevector<N, T, Size, Diff>& other) const {
|
|
if (other.size() != size()) {
|
|
return false;
|
|
}
|
|
const_iterator b1 = begin();
|
|
const_iterator b2 = other.begin();
|
|
const_iterator e1 = end();
|
|
while (b1 != e1) {
|
|
if ((*b1) != (*b2)) {
|
|
return false;
|
|
}
|
|
++b1;
|
|
++b2;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool operator!=(const prevector<N, T, Size, Diff>& other) const {
|
|
return !(*this == other);
|
|
}
|
|
|
|
bool operator<(const prevector<N, T, Size, Diff>& other) const {
|
|
if (size() < other.size()) {
|
|
return true;
|
|
}
|
|
if (size() > other.size()) {
|
|
return false;
|
|
}
|
|
const_iterator b1 = begin();
|
|
const_iterator b2 = other.begin();
|
|
const_iterator e1 = end();
|
|
while (b1 != e1) {
|
|
if ((*b1) < (*b2)) {
|
|
return true;
|
|
}
|
|
if ((*b2) < (*b1)) {
|
|
return false;
|
|
}
|
|
++b1;
|
|
++b2;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
size_t allocated_memory() const {
|
|
if (is_direct()) {
|
|
return 0;
|
|
} else {
|
|
return ((size_t)(sizeof(T))) * _union.capacity;
|
|
}
|
|
}
|
|
|
|
value_type* data() {
|
|
return item_ptr(0);
|
|
}
|
|
|
|
const value_type* data() const {
|
|
return item_ptr(0);
|
|
}
|
|
};
|
|
#pragma pack(pop)
|
|
|
|
#endif
|