mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-11-22 23:50:19 +00:00
15532df83d
Rather than the very C-like API we currently have, accepting a void* and a length, let's take a Bytes object instead. In almost all existing cases, the compiler figures out the length.
85 lines
1.8 KiB
C++
85 lines
1.8 KiB
C++
/*
|
|
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <AK/Platform.h>
|
|
#include <AK/Span.h>
|
|
#include <AK/StdLibExtras.h>
|
|
#include <AK/Types.h>
|
|
#include <stdlib.h>
|
|
|
|
#if defined(__unix__)
|
|
# include <unistd.h>
|
|
#endif
|
|
|
|
#if defined(AK_OS_MACOS)
|
|
# include <sys/random.h>
|
|
#endif
|
|
|
|
namespace AK {
|
|
|
|
inline void fill_with_random([[maybe_unused]] Bytes bytes)
|
|
{
|
|
#if defined(AK_OS_SERENITY) || defined(AK_OS_ANDROID)
|
|
arc4random_buf(bytes.data(), bytes.size());
|
|
#elif defined(OSS_FUZZ)
|
|
#else
|
|
auto fill_with_random_fallback = [&]() {
|
|
for (auto& byte : bytes)
|
|
byte = rand();
|
|
};
|
|
|
|
# if defined(__unix__) or defined(AK_OS_MACOS)
|
|
// The maximum permitted value for the getentropy length argument.
|
|
static constexpr size_t getentropy_length_limit = 256;
|
|
auto iterations = bytes.size() / getentropy_length_limit;
|
|
|
|
for (size_t i = 0; i < iterations; ++i) {
|
|
if (getentropy(bytes.data(), getentropy_length_limit) != 0) {
|
|
fill_with_random_fallback();
|
|
return;
|
|
}
|
|
|
|
bytes = bytes.slice(getentropy_length_limit);
|
|
}
|
|
|
|
if (bytes.is_empty() || getentropy(bytes.data(), bytes.size()) == 0)
|
|
return;
|
|
# endif
|
|
|
|
fill_with_random_fallback();
|
|
#endif
|
|
}
|
|
|
|
template<typename T>
|
|
inline T get_random()
|
|
{
|
|
T t;
|
|
fill_with_random({ &t, sizeof(T) });
|
|
return t;
|
|
}
|
|
|
|
u32 get_random_uniform(u32 max_bounds);
|
|
|
|
template<typename Collection>
|
|
inline void shuffle(Collection& collection)
|
|
{
|
|
// Fisher-Yates shuffle
|
|
for (size_t i = collection.size() - 1; i >= 1; --i) {
|
|
size_t j = get_random_uniform(i + 1);
|
|
AK::swap(collection[i], collection[j]);
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
#if USING_AK_GLOBALLY
|
|
using AK::fill_with_random;
|
|
using AK::get_random;
|
|
using AK::get_random_uniform;
|
|
using AK::shuffle;
|
|
#endif
|