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/*
* Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/BitmapView.h>
#include <AK/Error.h>
#include <AK/Noncopyable.h>
#include <AK/Optional.h>
#include <AK/Platform.h>
#include <AK/StdLibExtras.h>
#include <AK/Try.h>
#include <AK/Types.h>
#include <AK/kmalloc.h>
namespace AK {
class Bitmap : public BitmapView {
AK_MAKE_NONCOPYABLE(Bitmap);
public:
static ErrorOr<Bitmap> try_create(size_t size, bool default_value)
{
VERIFY(size != 0);
auto* data = kmalloc(ceil_div(size, static_cast<size_t>(8)));
if (!data)
return Error::from_errno(ENOMEM);
auto bitmap = Bitmap { (u8*)data, size, true };
bitmap.fill(default_value);
return bitmap;
}
static Bitmap must_create(size_t size, bool default_value)
{
return MUST(try_create(size, default_value));
}
Bitmap() = default;
Bitmap(u8* data, size_t size, bool is_owning = false)
: BitmapView(data, size)
, m_is_owning(is_owning)
{
}
Bitmap(Bitmap&& other)
: BitmapView(exchange(other.m_data, nullptr), exchange(other.m_size, 0))
{
m_is_owning = exchange(other.m_is_owning, false);
}
Bitmap& operator=(Bitmap&& other)
{
if (this != &other) {
kfree_sized(m_data, size_in_bytes());
m_data = exchange(other.m_data, nullptr);
m_size = exchange(other.m_size, 0);
}
return *this;
}
~Bitmap()
{
if (m_is_owning) {
kfree_sized(m_data, size_in_bytes());
}
m_data = nullptr;
}
[[nodiscard]] BitmapView view() const { return *this; }
void set(size_t index, bool value)
{
VERIFY(index < m_size);
if (value)
m_data[index / 8] |= static_cast<u8>((1u << (index % 8)));
else
m_data[index / 8] &= static_cast<u8>(~(1u << (index % 8)));
}
// NOTE: There's a const method variant of this method at the parent class BitmapView.
[[nodiscard]] u8* data() { return m_data; }
void grow(size_t size, bool default_value)
{
VERIFY(size > m_size);
auto previous_size_bytes = size_in_bytes();
auto previous_size = m_size;
auto* previous_data = m_data;
m_size = size;
m_data = reinterpret_cast<u8*>(kmalloc(size_in_bytes()));
fill(default_value);
if (previous_data != nullptr) {
__builtin_memcpy(m_data, previous_data, previous_size_bytes);
if ((previous_size % 8) != 0)
set_range(previous_size, 8 - previous_size % 8, default_value);
kfree_sized(previous_data, previous_size_bytes);
}
}
template<bool VALUE, bool verify_that_all_bits_flip = false>
void set_range(size_t start, size_t len)
{
VERIFY(start < m_size);
VERIFY(start + len <= m_size);
if (len == 0)
return;
u8* first = &m_data[start / 8];
u8* last = &m_data[(start + len) / 8];
u8 byte_mask = bitmask_first_byte[start % 8];
if (first == last) {
byte_mask &= bitmask_last_byte[(start + len) % 8];
if constexpr (verify_that_all_bits_flip) {
if constexpr (VALUE) {
VERIFY((*first & byte_mask) == 0);
} else {
VERIFY((*first & byte_mask) == byte_mask);
}
}
if constexpr (VALUE)
*first |= byte_mask;
else
*first &= ~byte_mask;
} else {
if constexpr (verify_that_all_bits_flip) {
if constexpr (VALUE) {
VERIFY((*first & byte_mask) == 0);
} else {
VERIFY((*first & byte_mask) == byte_mask);
}
}
if constexpr (VALUE)
*first |= byte_mask;
else
*first &= ~byte_mask;
byte_mask = bitmask_last_byte[(start + len) % 8];
if constexpr (verify_that_all_bits_flip) {
if constexpr (VALUE) {
VERIFY((*last & byte_mask) == 0);
} else {
VERIFY((*last & byte_mask) == byte_mask);
}
}
if constexpr (VALUE)
*last |= byte_mask;
else
*last &= ~byte_mask;
if (++first < last) {
if constexpr (VALUE)
__builtin_memset(first, 0xFF, last - first);
else
__builtin_memset(first, 0x0, last - first);
}
}
}
void set_range(size_t start, size_t len, bool value)
{
if (value)
set_range<true, false>(start, len);
else
set_range<false, false>(start, len);
}
void set_range_and_verify_that_all_bits_flip(size_t start, size_t len, bool value)
{
if (value)
set_range<true, true>(start, len);
else
set_range<false, true>(start, len);
}
void fill(bool value)
{
__builtin_memset(m_data, value ? 0xff : 0x00, size_in_bytes());
}
private:
bool m_is_owning { true };
};
}
using AK::Bitmap;
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