transmission/libtransmission/file.cc

96 lines
2.3 KiB
C++

// This file Copyright © 2013-2022 Mnemosyne LLC.
// It may be used under GPLv2 (SPDX: GPL-2.0), GPLv3 (SPDX: GPL-3.0),
// or any future license endorsed by Mnemosyne LLC.
// License text can be found in the licenses/ folder.
#include <algorithm>
#include <string_view>
#include "transmission.h"
#include "error.h"
#include "file.h"
#include "tr-assert.h"
#include "utils.h"
using namespace std::literals;
bool tr_sys_file_read_line(tr_sys_file_t handle, char* buffer, size_t buffer_size, tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_FILE);
TR_ASSERT(buffer != nullptr);
TR_ASSERT(buffer_size > 0);
auto ret = bool{};
auto offset = size_t{};
while (buffer_size > 0)
{
size_t const bytes_needed = std::min(buffer_size, size_t{ 1024 });
auto bytes_read = uint64_t{};
ret = tr_sys_file_read(handle, buffer + offset, bytes_needed, &bytes_read, error);
if (!ret || (offset == 0 && bytes_read == 0))
{
ret = false;
break;
}
TR_ASSERT(bytes_read <= bytes_needed);
TR_ASSERT(bytes_read <= buffer_size);
int64_t delta = 0;
for (size_t i = 0; i < bytes_read; ++i)
{
if (buffer[offset] == '\n')
{
delta = i - (int64_t)bytes_read + 1;
break;
}
++offset;
--buffer_size;
}
if (delta != 0 || buffer_size == 0 || bytes_read == 0)
{
if (delta != 0)
{
ret = tr_sys_file_seek(handle, delta, TR_SEEK_CUR, nullptr, error);
if (!ret)
{
break;
}
}
if (offset > 0 && buffer[offset - 1] == '\r')
{
buffer[offset - 1] = '\0';
}
else
{
buffer[offset] = '\0';
}
break;
}
}
return ret;
}
bool tr_sys_file_write_line(tr_sys_file_t handle, std::string_view buffer, tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_FILE);
bool ret = tr_sys_file_write(handle, std::data(buffer), std::size(buffer), nullptr, error);
if (ret)
{
ret = tr_sys_file_write(handle, TR_NATIVE_EOL_STR, TR_NATIVE_EOL_STR_SIZE, nullptr, error);
}
return ret;
}