llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_vector.h

129 lines
2.6 KiB
C++

//===-- sanitizer_vector.h -------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is shared between sanitizers run-time libraries.
//
//===----------------------------------------------------------------------===//
// Low-fat STL-like vector container.
#ifndef SANITIZER_VECTOR_H
#define SANITIZER_VECTOR_H
#include "sanitizer_common/sanitizer_allocator_internal.h"
#include "sanitizer_common/sanitizer_libc.h"
namespace __sanitizer {
template<typename T>
class Vector {
public:
explicit Vector()
: begin_()
, end_()
, last_() {
}
~Vector() {
if (begin_)
InternalFree(begin_);
}
void Reset() {
if (begin_)
InternalFree(begin_);
begin_ = 0;
end_ = 0;
last_ = 0;
}
uptr Size() const {
return end_ - begin_;
}
T &operator[](uptr i) {
DCHECK_LT(i, end_ - begin_);
return begin_[i];
}
const T &operator[](uptr i) const {
DCHECK_LT(i, end_ - begin_);
return begin_[i];
}
T *PushBack() {
EnsureSize(Size() + 1);
T *p = &end_[-1];
internal_memset(p, 0, sizeof(*p));
return p;
}
T *PushBack(const T& v) {
EnsureSize(Size() + 1);
T *p = &end_[-1];
internal_memcpy(p, &v, sizeof(*p));
return p;
}
void PopBack() {
DCHECK_GT(end_, begin_);
end_--;
}
void Resize(uptr size) {
if (size == 0) {
end_ = begin_;
return;
}
uptr old_size = Size();
if (size <= old_size) {
end_ = begin_ + size;
return;
}
EnsureSize(size);
if (old_size < size) {
for (uptr i = old_size; i < size; i++)
internal_memset(&begin_[i], 0, sizeof(begin_[i]));
}
}
private:
T *begin_;
T *end_;
T *last_;
void EnsureSize(uptr size) {
if (size <= Size())
return;
if (size <= (uptr)(last_ - begin_)) {
end_ = begin_ + size;
return;
}
uptr cap0 = last_ - begin_;
uptr cap = cap0 * 5 / 4; // 25% growth
if (cap == 0)
cap = 16;
if (cap < size)
cap = size;
T *p = (T*)InternalAlloc(cap * sizeof(T));
if (cap0) {
internal_memcpy(p, begin_, cap0 * sizeof(T));
InternalFree(begin_);
}
begin_ = p;
end_ = begin_ + size;
last_ = begin_ + cap;
}
Vector(const Vector&);
void operator=(const Vector&);
};
} // namespace __sanitizer
#endif // #ifndef SANITIZER_VECTOR_H