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Xenia-Canary/src/xenia/kernel/fs/devices/stfs_container_file.cc

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2.9 KiB
C++

/**
******************************************************************************
* Xenia : Xbox 360 Emulator Research Project *
******************************************************************************
* Copyright 2014 Ben Vanik. All rights reserved. *
* Released under the BSD license - see LICENSE in the root for more details. *
******************************************************************************
*/
#include "xenia/kernel/fs/devices/stfs_container_file.h"
#include <algorithm>
#include "xenia/kernel/fs/device.h"
#include "xenia/kernel/fs/devices/stfs_container_entry.h"
#include "xenia/kernel/fs/stfs.h"
namespace xe {
namespace kernel {
namespace fs {
STFSContainerFile::STFSContainerFile(KernelState* kernel_state, Mode mode,
STFSContainerEntry* entry)
: XFile(kernel_state, mode), entry_(entry) {}
STFSContainerFile::~STFSContainerFile() { delete entry_; }
const std::string& STFSContainerFile::path() const { return entry_->path(); }
const std::string& STFSContainerFile::name() const { return entry_->name(); }
Device* STFSContainerFile::device() const { return entry_->device(); }
X_STATUS STFSContainerFile::QueryInfo(
X_FILE_NETWORK_OPEN_INFORMATION* out_info) {
return entry_->QueryInfo(out_info);
}
X_STATUS STFSContainerFile::QueryDirectory(
X_FILE_DIRECTORY_INFORMATION* out_info, size_t length,
const char* file_name, bool restart) {
return entry_->QueryDirectory(out_info, length, file_name, restart);
}
X_STATUS STFSContainerFile::ReadSync(void* buffer, size_t buffer_length,
size_t byte_offset,
size_t* out_bytes_read) {
STFSEntry* stfs_entry = entry_->stfs_entry();
if (byte_offset >= stfs_entry->size) {
return X_STATUS_END_OF_FILE;
}
// Each block is 4096.
// Blocks may not be sequential, so we need to read by blocks and handle the
// offsets.
size_t real_length = std::min(buffer_length, stfs_entry->size - byte_offset);
size_t start_block = byte_offset / 4096;
size_t end_block =
std::min(stfs_entry->block_list.size(),
(size_t)ceil((byte_offset + real_length) / 4096.0));
uint8_t* dest_ptr = (uint8_t*)buffer;
size_t remaining_length = real_length;
for (size_t n = start_block; n < end_block; n++) {
auto& record = stfs_entry->block_list[n];
size_t offset = record.offset;
size_t read_length = std::min(remaining_length, record.length);
if (n == start_block) {
offset += byte_offset % 4096;
read_length = std::min(read_length, record.length - (byte_offset % 4096));
}
memcpy(dest_ptr, entry_->mmap()->data() + offset, read_length);
dest_ptr += read_length;
remaining_length -= read_length;
}
*out_bytes_read = real_length;
return X_STATUS_SUCCESS;
}
} // namespace fs
} // namespace kernel
} // namespace xe