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Atmosphere/libraries/libstratosphere/source/htcfs/htcfs_cache_manager.hpp
2021-02-24 04:06:54 -08:00

113 lines
3.8 KiB
C++

/*
* Copyright (c) 2018-2020 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <stratosphere.hpp>
namespace ams::htcfs {
class CacheManager {
private:
os::SdkMutex m_mutex;
void *m_cache;
size_t m_cache_size;
s64 m_cached_file_size;
size_t m_cached_data_size;
s32 m_cached_handle;
bool m_has_cached_handle;
public:
CacheManager(void *cache, size_t cache_size) : m_mutex(), m_cache(cache), m_cache_size(cache_size), m_cached_file_size(), m_cached_data_size(), m_cached_handle(), m_has_cached_handle() { /* ... */ }
public:
bool GetFileSize(s64 *out, s32 handle) {
/* Lock ourselves. */
std::scoped_lock lk(m_mutex);
/* Get the cached size, if we match. */
if (m_has_cached_handle && m_cached_handle == handle) {
*out = m_cached_file_size;
return true;
} else {
return false;
}
}
void Invalidate() {
/* Lock ourselves. */
std::scoped_lock lk(m_mutex);
/* Note that we have no handle. */
m_has_cached_handle = false;
}
void Invalidate(s32 handle) {
/* Lock ourselves. */
std::scoped_lock lk(m_mutex);
if (m_has_cached_handle && m_cached_handle == handle) {
/* Note that we have no handle. */
m_has_cached_handle = false;
}
}
void Record(s64 file_size, const void *data, s32 handle, size_t data_size) {
/* Lock ourselves. */
std::scoped_lock lk(m_mutex);
/* Set our cached file size. */
m_cached_file_size = file_size;
/* Set our cached data size. */
m_cached_data_size = std::min(m_cache_size, data_size);
/* Copy the data. */
std::memcpy(m_cache, data, m_cached_data_size);
/* Set our cache handle. */
m_cached_handle = handle;
/* Note that we have cached data. */
m_has_cached_handle = true;
}
bool ReadFile(size_t *out, void *dst, s32 handle, size_t offset, size_t size) {
/* Lock ourselves. */
std::scoped_lock lk(m_mutex);
/* Check that we have a cached file. */
if (!m_has_cached_handle) {
return false;
}
/* Check the file is our cached one. */
if (handle != m_cached_handle) {
return false;
}
/* Check that we can read data. */
if (offset + size > m_cached_data_size) {
return false;
}
/* Copy the cached data. */
std::memcpy(dst, static_cast<const u8 *>(m_cache) + offset, size);
/* Set the output read size. */
*out = size;
return true;
}
};
}