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// Copyright 2018 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_BASE_ADDRESS_REGION_H_
#define V8_BASE_ADDRESS_REGION_H_
#include <iostream>
#include "src/base/macros.h"
namespace v8 {
namespace base {
// Helper class representing an address region of certain size.
class AddressRegion {
public:
// Function object that compares the start address of two regions. Usable as
// compare function on std data structures and algorithms.
struct StartAddressLess {
bool operator()(base::AddressRegion a, base::AddressRegion b) const {
return a.begin() < b.begin();
}
};
using Address = uintptr_t;
constexpr AddressRegion() = default;
constexpr AddressRegion(Address address, size_t size)
: address_(address), size_(size) {}
Address begin() const { return address_; }
Address end() const { return address_ + size_; }
size_t size() const { return size_; }
void set_size(size_t size) { size_ = size; }
bool is_empty() const { return size_ == 0; }
bool contains(Address address) const {
STATIC_ASSERT(std::is_unsigned<Address>::value);
return (address - begin()) < size();
}
bool contains(Address address, size_t size) const {
STATIC_ASSERT(std::is_unsigned<Address>::value);
Address offset = address - begin();
return (offset < size_) && (offset + size <= size_);
}
bool contains(AddressRegion region) const {
return contains(region.address_, region.size_);
}
base::AddressRegion GetOverlap(AddressRegion region) const {
Address overlap_start = std::max(begin(), region.begin());
Address overlap_end =
std::max(overlap_start, std::min(end(), region.end()));
return {overlap_start, overlap_end - overlap_start};
}
bool operator==(AddressRegion other) const {
return address_ == other.address_ && size_ == other.size_;
}
bool operator!=(AddressRegion other) const {
return address_ != other.address_ || size_ != other.size_;
}
private:
Address address_ = 0;
size_t size_ = 0;
};
ASSERT_TRIVIALLY_COPYABLE(AddressRegion);
// Construct an AddressRegion from anything providing a {data()} and {size()}
// accessor.
template <typename Container,
typename = decltype(std::declval<Container>().data()),
typename = decltype(std::declval<Container>().size())>
inline constexpr AddressRegion AddressRegionOf(Container&& c) {
return AddressRegion{reinterpret_cast<AddressRegion::Address>(c.data()),
sizeof(*c.data()) * c.size()};
}
inline std::ostream& operator<<(std::ostream& out, AddressRegion region) {
return out << "[" << reinterpret_cast<void*>(region.begin()) << "+"
<< region.size() << "]";
}
} // namespace base
} // namespace v8
#endif // V8_BASE_ADDRESS_REGION_H_