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transmission/libtransmission/file-posix.cc
Charles Kerr c472cbd88d
refactor: only use [[maybe_unused]] if arg might be used (#2033) 
* refactor: [[maybe_unused]] iff arg _might_ be used

If the arg is never used, comment out its name.
If the arg is _sometimes_ used e.g. with ifdefs, use [[maybe_unused]].
2021-10-24 11:41:54 -05:00

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/*
* This file Copyright (C) 2013-2017 Mnemosyne LLC
*
* It may be used under the GNU GPL versions 2 or 3
* or any future license endorsed by Mnemosyne LLC.
*
*/
#undef _GNU_SOURCE
#define _GNU_SOURCE
#include <algorithm>
#include <array>
#include <cerrno>
#include <climits> /* PATH_MAX */
#include <cstdint> /* SIZE_MAX */
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <dirent.h>
#include <fcntl.h> /* O_LARGEFILE, posix_fadvise(), [posix_]fallocate(), fcntl() */
#include <libgen.h> /* basename(), dirname() */
#include <sys/file.h> /* flock() */
#include <sys/mman.h> /* mmap(), munmap() */
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h> /* lseek(), write(), ftruncate(), pread(), pwrite(), pathconf(), etc */
#include <vector>
#ifdef HAVE_XFS_XFS_H
#include <xfs/xfs.h>
#endif
/* OS-specific file copy (copy_file_range, sendfile64, or copyfile). */
#if defined(__linux__)
#include <linux/version.h>
/* Linux's copy_file_range(2) is buggy prior to 5.3. */
#if defined(HAVE_COPY_FILE_RANGE) && LINUX_VERSION_CODE >= KERNEL_VERSION(5, 3, 0)
#define USE_COPY_FILE_RANGE
#elif defined(HAVE_SENDFILE64)
#include <sys/sendfile.h>
#define USE_SENDFILE64
#endif
#elif defined(__APPLE__) && defined(HAVE_COPYFILE)
#include <copyfile.h>
#ifndef COPYFILE_CLONE /* macos < 10.12 */
#define COPYFILE_CLONE 0
#endif
#define USE_COPYFILE
#elif defined(HAVE_COPY_FILE_RANGE)
/* Presently this is only FreeBSD 13+. */
#define USE_COPY_FILE_RANGE
#endif /* __linux__ */
#include "transmission.h"
#include "error.h"
#include "file.h"
#include "log.h"
#include "platform.h"
#include "tr-assert.h"
#include "utils.h"
#ifndef O_LARGEFILE
#define O_LARGEFILE 0
#endif
#ifndef O_BINARY
#define O_BINARY 0
#endif
#ifndef O_SEQUENTIAL
#define O_SEQUENTIAL 0
#endif
#ifndef O_CLOEXEC
#define O_CLOEXEC 0
#endif
#ifndef PATH_MAX
#define PATH_MAX 4096
#endif
/* don't use pread/pwrite on old versions of uClibc because they're buggy.
* https://trac.transmissionbt.com/ticket/3826 */
#if defined(__UCLIBC__) && !TR_UCLIBC_CHECK_VERSION(0, 9, 28)
#undef HAVE_PREAD
#undef HAVE_PWRITE
#endif
#ifdef __APPLE__
#ifndef HAVE_PREAD
#define HAVE_PREAD
#endif
#ifndef HAVE_PWRITE
#define HAVE_PWRITE
#endif
#ifndef HAVE_MKDTEMP
#define HAVE_MKDTEMP
#endif
#endif
static void set_system_error(tr_error** error, int code)
{
if (error == nullptr)
{
return;
}
tr_error_set_literal(error, code, tr_strerror(code));
}
static void set_system_error_if_file_found(tr_error** error, int code)
{
if (code != ENOENT)
{
set_system_error(error, code);
}
}
static void stat_to_sys_path_info(struct stat const* sb, tr_sys_path_info* info)
{
if (S_ISREG(sb->st_mode))
{
info->type = TR_SYS_PATH_IS_FILE;
}
else if (S_ISDIR(sb->st_mode))
{
info->type = TR_SYS_PATH_IS_DIRECTORY;
}
else
{
info->type = TR_SYS_PATH_IS_OTHER;
}
info->size = (uint64_t)sb->st_size;
info->last_modified_at = sb->st_mtime;
}
static void set_file_for_single_pass(tr_sys_file_t handle)
{
/* Set hints about the lookahead buffer and caching. It's okay
for these to fail silently, so don't let them affect errno */
int const err = errno;
if (handle == TR_BAD_SYS_FILE)
{
return;
}
#ifdef HAVE_POSIX_FADVISE
(void)posix_fadvise(handle, 0, 0, POSIX_FADV_SEQUENTIAL);
#endif
#ifdef __APPLE__
(void)fcntl(handle, F_RDAHEAD, 1);
(void)fcntl(handle, F_NOCACHE, 1);
#endif
errno = err;
}
#ifndef HAVE_MKDIRP
static bool create_path_require_dir(char const* path, tr_error** error)
{
struct stat sb;
if (stat(path, &sb) == -1)
{
set_system_error(error, errno);
return false;
}
if ((sb.st_mode & S_IFMT) != S_IFDIR)
{
tr_error_set(error, ENOTDIR, _("File \"%s\" is in the way"), path);
return false;
}
return true;
}
static bool create_path(char const* path_in, int permissions, tr_error** error)
{
/* make a temporary copy of path */
char* path = tr_strdup(path_in);
/* walk past the root */
char* p = path;
while (*p == TR_PATH_DELIMITER)
{
++p;
}
char* path_end = p + strlen(p);
while (path_end > path && *path_end == TR_PATH_DELIMITER)
{
--path_end;
}
char* pp;
bool ret = false;
tr_error* my_error = nullptr;
/* Go one level up on each iteration and attempt to create */
for (pp = path_end; pp != nullptr; pp = strrchr(p, TR_PATH_DELIMITER))
{
*pp = '\0';
ret = mkdir(path, permissions) != -1;
if (ret)
{
break;
}
if (errno == EEXIST)
{
ret = create_path_require_dir(path, &my_error);
if (ret)
{
break;
}
goto FAILURE;
}
if (errno != ENOENT)
{
set_system_error(&my_error, errno);
goto FAILURE;
}
}
if (ret && pp == path_end)
{
goto CLEANUP;
}
/* Go one level down on each iteration and attempt to create */
for (pp = pp == nullptr ? p + strlen(p) : pp; pp < path_end; pp += strlen(pp))
{
*pp = TR_PATH_DELIMITER;
if (mkdir(path, permissions) == -1)
{
break;
}
}
ret = create_path_require_dir(path, &my_error);
if (ret)
{
goto CLEANUP;
}
FAILURE:
TR_ASSERT(!ret);
TR_ASSERT(my_error != nullptr);
tr_logAddError(_("Couldn't create \"%1$s\": %2$s"), path, my_error->message);
tr_error_propagate(error, &my_error);
CLEANUP:
TR_ASSERT(my_error == nullptr);
tr_free(path);
return ret;
}
#endif
bool tr_sys_path_exists(char const* path, tr_error** error)
{
TR_ASSERT(path != nullptr);
bool ret = access(path, F_OK) != -1;
if (!ret)
{
set_system_error_if_file_found(error, errno);
}
return ret;
}
bool tr_sys_path_get_info(char const* path, int flags, tr_sys_path_info* info, tr_error** error)
{
TR_ASSERT(path != nullptr);
TR_ASSERT(info != nullptr);
bool ret;
struct stat sb;
if ((flags & TR_SYS_PATH_NO_FOLLOW) == 0)
{
ret = stat(path, &sb) != -1;
}
else
{
ret = lstat(path, &sb) != -1;
}
if (ret)
{
stat_to_sys_path_info(&sb, info);
}
else
{
set_system_error(error, errno);
}
return ret;
}
bool tr_sys_path_is_relative(char const* path)
{
TR_ASSERT(path != nullptr);
return path[0] != '/';
}
bool tr_sys_path_is_same(char const* path1, char const* path2, tr_error** error)
{
TR_ASSERT(path1 != nullptr);
TR_ASSERT(path2 != nullptr);
bool ret = false;
struct stat sb1;
struct stat sb2;
if (stat(path1, &sb1) != -1 && stat(path2, &sb2) != -1)
{
ret = sb1.st_dev == sb2.st_dev && sb1.st_ino == sb2.st_ino;
}
else
{
set_system_error_if_file_found(error, errno);
}
return ret;
}
char* tr_sys_path_resolve(char const* path, tr_error** error)
{
TR_ASSERT(path != nullptr);
char* ret = nullptr;
#if defined(HAVE_CANONICALIZE_FILE_NAME)
ret = canonicalize_file_name(path);
#endif
if (ret == nullptr)
{
char tmp[PATH_MAX];
ret = realpath(path, tmp);
if (ret != nullptr)
{
ret = tr_strdup(ret);
}
}
if (ret == nullptr)
{
set_system_error(error, errno);
}
return ret;
}
char* tr_sys_path_basename(char const* path, tr_error** error)
{
TR_ASSERT(path != nullptr);
char* ret = nullptr;
char* tmp;
tmp = tr_strdup(path);
ret = basename(tmp);
if (ret != nullptr)
{
ret = tr_strdup(ret);
}
else
{
set_system_error(error, errno);
}
tr_free(tmp);
return ret;
}
char* tr_sys_path_dirname(char const* path, tr_error** error)
{
TR_ASSERT(path != nullptr);
char* tmp = tr_strdup(path);
char* ret = dirname(tmp);
if (ret != nullptr)
{
ret = tr_strdup(ret);
}
else
{
set_system_error(error, errno);
}
tr_free(tmp);
return ret;
}
bool tr_sys_path_rename(char const* src_path, char const* dst_path, tr_error** error)
{
TR_ASSERT(src_path != nullptr);
TR_ASSERT(dst_path != nullptr);
bool ret = rename(src_path, dst_path) != -1;
if (!ret)
{
set_system_error(error, errno);
}
return ret;
}
/* We try to do a fast (in-kernel) copy using a variety of non-portable system
* calls. If the current implementation does not support in-kernel copying, we
* use a user-space fallback instead. */
bool tr_sys_path_copy(char const* src_path, char const* dst_path, tr_error** error)
{
TR_ASSERT(src_path != nullptr);
TR_ASSERT(dst_path != nullptr);
#if defined(USE_COPYFILE)
if (copyfile(src_path, dst_path, nullptr, COPYFILE_CLONE | COPYFILE_ALL) < 0)
{
set_system_error(error, errno);
return false;
}
return true;
#else /* USE_COPYFILE */
/* Other OSes require us to copy between file descriptors, so open them. */
tr_sys_file_t in = tr_sys_file_open(src_path, TR_SYS_FILE_READ | TR_SYS_FILE_SEQUENTIAL, 0, error);
if (in == TR_BAD_SYS_FILE)
{
tr_error_prefix(error, "Unable to open source file: ");
return false;
}
tr_sys_path_info info;
if (!tr_sys_file_get_info(in, &info, error))
{
tr_error_prefix(error, "Unable to get information on source file: ");
tr_sys_file_close(in, nullptr);
return false;
}
tr_sys_file_t out = tr_sys_file_open(dst_path, TR_SYS_FILE_WRITE | TR_SYS_FILE_CREATE | TR_SYS_FILE_TRUNCATE, 0666, error);
if (out == TR_BAD_SYS_FILE)
{
tr_error_prefix(error, "Unable to open destination file: ");
tr_sys_file_close(in, nullptr);
return false;
}
uint64_t file_size = info.size;
#if defined(USE_COPY_FILE_RANGE) || defined(USE_SENDFILE64)
while (file_size > 0)
{
size_t const chunk_size = std::min(file_size, uint64_t{ SSIZE_MAX });
ssize_t const copied =
#ifdef USE_COPY_FILE_RANGE
copy_file_range(in, nullptr, out, nullptr, chunk_size, 0);
#elif defined(USE_SENDFILE64)
sendfile64(out, in, nullptr, chunk_size);
#else
#error File copy mechanism not implemented.
#endif
TR_ASSERT(copied == -1 || copied >= 0); /* -1 for error; some non-negative value otherwise. */
if (copied == -1)
{
set_system_error(error, errno);
break;
}
TR_ASSERT(copied >= 0 && ((uint64_t)copied) <= file_size);
TR_ASSERT(copied >= 0 && ((uint64_t)copied) <= chunk_size);
file_size -= copied;
}
#else /* USE_COPY_FILE_RANGE || USE_SENDFILE64 */
/* Fallback to user-space copy. */
size_t const buflen = 1024 * 1024; /* 1024 KiB buffer */
auto* buf = static_cast<char*>(tr_malloc(buflen));
while (file_size > 0)
{
uint64_t const chunk_size = std::min(file_size, uint64_t{ buflen });
uint64_t bytes_read;
uint64_t bytes_written;
if (!tr_sys_file_read(in, buf, chunk_size, &bytes_read, error))
{
break;
}
if (!tr_sys_file_write(out, buf, bytes_read, &bytes_written, error))
{
break;
}
TR_ASSERT(bytes_read == bytes_written);
TR_ASSERT(bytes_written <= file_size);
file_size -= bytes_written;
}
/* cleanup */
tr_free(buf);
#endif /* USE_COPY_FILE_RANGE || USE_SENDFILE64 */
/* cleanup */
tr_sys_file_close(out, nullptr);
tr_sys_file_close(in, nullptr);
if (file_size != 0)
{
tr_error_prefix(error, "Unable to read/write: ");
return false;
}
return true;
#endif /* USE_COPYFILE */
}
bool tr_sys_path_remove(char const* path, tr_error** error)
{
TR_ASSERT(path != nullptr);
bool ret = remove(path) != -1;
if (!ret)
{
set_system_error(error, errno);
}
return ret;
}
char* tr_sys_path_native_separators(char* path)
{
return path;
}
tr_sys_file_t tr_sys_file_get_std(tr_std_sys_file_t std_file, tr_error** error)
{
tr_sys_file_t ret = TR_BAD_SYS_FILE;
switch (std_file)
{
case TR_STD_SYS_FILE_IN:
ret = STDIN_FILENO;
break;
case TR_STD_SYS_FILE_OUT:
ret = STDOUT_FILENO;
break;
case TR_STD_SYS_FILE_ERR:
ret = STDERR_FILENO;
break;
default:
TR_ASSERT_MSG(false, "unknown standard file %d", (int)std_file);
set_system_error(error, EINVAL);
}
return ret;
}
tr_sys_file_t tr_sys_file_open(char const* path, int flags, int permissions, tr_error** error)
{
TR_ASSERT(path != nullptr);
TR_ASSERT((flags & (TR_SYS_FILE_READ | TR_SYS_FILE_WRITE)) != 0);
struct native_map_item
{
int symbolic_mask;
int symbolic_value;
int native_value;
};
auto constexpr native_map = std::array<native_map_item, 8>{
{ { TR_SYS_FILE_READ | TR_SYS_FILE_WRITE, TR_SYS_FILE_READ | TR_SYS_FILE_WRITE, O_RDWR },
{ TR_SYS_FILE_READ | TR_SYS_FILE_WRITE, TR_SYS_FILE_READ, O_RDONLY },
{ TR_SYS_FILE_READ | TR_SYS_FILE_WRITE, TR_SYS_FILE_WRITE, O_WRONLY },
{ TR_SYS_FILE_CREATE, TR_SYS_FILE_CREATE, O_CREAT },
{ TR_SYS_FILE_CREATE_NEW, TR_SYS_FILE_CREATE_NEW, O_CREAT | O_EXCL },
{ TR_SYS_FILE_APPEND, TR_SYS_FILE_APPEND, O_APPEND },
{ TR_SYS_FILE_TRUNCATE, TR_SYS_FILE_TRUNCATE, O_TRUNC },
{ TR_SYS_FILE_SEQUENTIAL, TR_SYS_FILE_SEQUENTIAL, O_SEQUENTIAL } }
};
int native_flags = O_BINARY | O_LARGEFILE | O_CLOEXEC;
for (auto const& item : native_map)
{
if ((flags & item.symbolic_mask) == item.symbolic_value)
{
native_flags |= item.native_value;
}
}
tr_sys_file_t ret = open(path, native_flags, permissions);
if (ret != TR_BAD_SYS_FILE)
{
if ((flags & TR_SYS_FILE_SEQUENTIAL) != 0)
{
set_file_for_single_pass(ret);
}
}
else
{
set_system_error(error, errno);
}
return ret;
}
tr_sys_file_t tr_sys_file_open_temp(char* path_template, tr_error** error)
{
TR_ASSERT(path_template != nullptr);
tr_sys_file_t ret = mkstemp(path_template);
if (ret == TR_BAD_SYS_FILE)
{
set_system_error(error, errno);
}
set_file_for_single_pass(ret);
return ret;
}
bool tr_sys_file_close(tr_sys_file_t handle, tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_FILE);
bool ret = close(handle) != -1;
if (!ret)
{
set_system_error(error, errno);
}
return ret;
}
bool tr_sys_file_get_info(tr_sys_file_t handle, tr_sys_path_info* info, tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_FILE);
TR_ASSERT(info != nullptr);
struct stat sb;
bool ret = fstat(handle, &sb) != -1;
if (ret)
{
stat_to_sys_path_info(&sb, info);
}
else
{
set_system_error(error, errno);
}
return ret;
}
bool tr_sys_file_seek(tr_sys_file_t handle, int64_t offset, tr_seek_origin_t origin, uint64_t* new_offset, tr_error** error)
{
static_assert(TR_SEEK_SET == SEEK_SET, "values should match");
static_assert(TR_SEEK_CUR == SEEK_CUR, "values should match");
static_assert(TR_SEEK_END == SEEK_END, "values should match");
TR_ASSERT(handle != TR_BAD_SYS_FILE);
TR_ASSERT(origin == TR_SEEK_SET || origin == TR_SEEK_CUR || origin == TR_SEEK_END);
bool ret = false;
off_t my_new_offset;
static_assert(sizeof(*new_offset) >= sizeof(my_new_offset), "");
my_new_offset = lseek(handle, offset, origin);
if (my_new_offset != -1)
{
if (new_offset != nullptr)
{
*new_offset = my_new_offset;
}
ret = true;
}
else
{
set_system_error(error, errno);
}
return ret;
}
bool tr_sys_file_read(tr_sys_file_t handle, void* buffer, uint64_t size, uint64_t* bytes_read, tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_FILE);
TR_ASSERT(buffer != nullptr || size == 0);
bool ret = false;
ssize_t my_bytes_read;
static_assert(sizeof(*bytes_read) >= sizeof(my_bytes_read), "");
my_bytes_read = read(handle, buffer, size);
if (my_bytes_read != -1)
{
if (bytes_read != nullptr)
{
*bytes_read = my_bytes_read;
}
ret = true;
}
else
{
set_system_error(error, errno);
}
return ret;
}
bool tr_sys_file_read_at(
tr_sys_file_t handle,
void* buffer,
uint64_t size,
uint64_t offset,
uint64_t* bytes_read,
tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_FILE);
TR_ASSERT(buffer != nullptr || size == 0);
/* seek requires signed offset, so it should be in mod range */
TR_ASSERT(offset < UINT64_MAX / 2);
bool ret = false;
ssize_t my_bytes_read;
static_assert(sizeof(*bytes_read) >= sizeof(my_bytes_read), "");
#ifdef HAVE_PREAD
my_bytes_read = pread(handle, buffer, size, offset);
#else
if (lseek(handle, offset, SEEK_SET) != -1)
{
my_bytes_read = read(handle, buffer, size);
}
else
{
my_bytes_read = -1;
}
#endif
if (my_bytes_read != -1)
{
if (bytes_read != nullptr)
{
*bytes_read = my_bytes_read;
}
ret = true;
}
else
{
set_system_error(error, errno);
}
return ret;
}
bool tr_sys_file_write(tr_sys_file_t handle, void const* buffer, uint64_t size, uint64_t* bytes_written, tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_FILE);
TR_ASSERT(buffer != nullptr || size == 0);
bool ret = false;
ssize_t my_bytes_written;
static_assert(sizeof(*bytes_written) >= sizeof(my_bytes_written), "");
my_bytes_written = write(handle, buffer, size);
if (my_bytes_written != -1)
{
if (bytes_written != nullptr)
{
*bytes_written = my_bytes_written;
}
ret = true;
}
else
{
set_system_error(error, errno);
}
return ret;
}
bool tr_sys_file_write_at(
tr_sys_file_t handle,
void const* buffer,
uint64_t size,
uint64_t offset,
uint64_t* bytes_written,
tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_FILE);
TR_ASSERT(buffer != nullptr || size == 0);
/* seek requires signed offset, so it should be in mod range */
TR_ASSERT(offset < UINT64_MAX / 2);
bool ret = false;
ssize_t my_bytes_written;
static_assert(sizeof(*bytes_written) >= sizeof(my_bytes_written), "");
#ifdef HAVE_PWRITE
my_bytes_written = pwrite(handle, buffer, size, offset);
#else
if (lseek(handle, offset, SEEK_SET) != -1)
{
my_bytes_written = write(handle, buffer, size);
}
else
{
my_bytes_written = -1;
}
#endif
if (my_bytes_written != -1)
{
if (bytes_written != nullptr)
{
*bytes_written = my_bytes_written;
}
ret = true;
}
else
{
set_system_error(error, errno);
}
return ret;
}
bool tr_sys_file_flush(tr_sys_file_t handle, tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_FILE);
bool ret = fsync(handle) != -1;
if (!ret)
{
set_system_error(error, errno);
}
return ret;
}
bool tr_sys_file_truncate(tr_sys_file_t handle, uint64_t size, tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_FILE);
bool ret = ftruncate(handle, size) != -1;
if (!ret)
{
set_system_error(error, errno);
}
return ret;
}
bool tr_sys_file_advise(
[[maybe_unused]] tr_sys_file_t handle,
[[maybe_unused]] uint64_t offset,
[[maybe_unused]] uint64_t size,
[[maybe_unused]] tr_sys_file_advice_t advice,
[[maybe_unused]] tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_FILE);
TR_ASSERT(size > 0);
TR_ASSERT(advice == TR_SYS_FILE_ADVICE_WILL_NEED || advice == TR_SYS_FILE_ADVICE_DONT_NEED);
bool ret = true;
#if defined(HAVE_POSIX_FADVISE)
int const native_advice = advice == TR_SYS_FILE_ADVICE_WILL_NEED ?
POSIX_FADV_WILLNEED :
(advice == TR_SYS_FILE_ADVICE_DONT_NEED ? POSIX_FADV_DONTNEED : POSIX_FADV_NORMAL);
TR_ASSERT(native_advice != POSIX_FADV_NORMAL);
int const code = posix_fadvise(handle, offset, size, native_advice);
if (code != 0)
{
set_system_error(error, code);
ret = false;
}
#elif defined(__APPLE__)
if (advice == TR_SYS_FILE_ADVICE_WILL_NEED)
{
auto radv = radvisory{};
radv.ra_offset = offset;
radv.ra_count = size;
ret = fcntl(handle, F_RDADVISE, &radv) != -1;
if (!ret)
{
set_system_error(error, errno);
}
}
#endif
return ret;
}
namespace
{
#ifdef HAVE_FALLOCATE64
bool preallocate_fallocate64(tr_sys_file_t handle, uint64_t size)
{
return fallocate64(handle, 0, 0, size) == 0;
}
#endif
#ifdef HAVE_XFS_XFS_H
bool full_preallocate_xfs(tr_sys_file_t handle, uint64_t size)
{
if (!platform_test_xfs_fd(handle)) // true if on xfs filesystem
{
return false;
}
xfs_flock64_t fl;
fl.l_whence = 0;
fl.l_start = 0;
fl.l_len = size;
// The blocks are allocated, but not zeroed, and the file size does not change
bool ok = xfsctl(nullptr, handle, XFS_IOC_RESVSP64, &fl) != -1;
if (ok)
{
ok = ftruncate(handle, size) == 0;
}
return ok;
}
#endif
#ifdef __APPLE__
bool full_preallocate_apple(tr_sys_file_t handle, uint64_t size)
{
fstore_t fst;
fst.fst_flags = F_ALLOCATEALL;
fst.fst_posmode = F_PEOFPOSMODE;
fst.fst_offset = 0;
fst.fst_length = size;
fst.fst_bytesalloc = 0;
bool ok = fcntl(handle, F_PREALLOCATE, &fst) != -1;
if (ok)
{
ok = ftruncate(handle, size) == 0;
}
return ok;
}
#endif
#ifdef HAVE_POSIX_FALLOCATE
bool full_preallocate_posix(tr_sys_file_t handle, uint64_t size)
{
return posix_fallocate(handle, 0, size) == 0;
}
#endif
} // unnamed namespace
bool tr_sys_file_preallocate(tr_sys_file_t handle, uint64_t size, int flags, tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_FILE);
using prealloc_func = bool (*)(tr_sys_file_t, uint64_t);
// these approaches are fast and should be tried first
auto approaches = std::vector<prealloc_func>{
#ifdef HAVE_FALLOCATE64
preallocate_fallocate64
#endif
};
// these approaches are sometimes slower in some settings (e.g.
// a slow zeroing of all the preallocated space) so only use them
// if specified by `flags`
if ((flags & TR_SYS_FILE_PREALLOC_SPARSE) == 0)
{
// TODO: these functions haven't been reviewed in awhile.
// It's possible that some are faster now & should be promoted
// to 'always try' and/or replaced with fresher platform API.
approaches.insert(
std::end(approaches),
{
#ifdef HAVE_XFS_XFS_H
full_preallocate_xfs,
#endif
#ifdef __APPLE__
full_preallocate_apple,
#endif
#ifdef HAVE_POSIX_FALLOCATE
full_preallocate_posix,
#endif
});
}
for (auto& approach : approaches) // try until one of them works
{
errno = 0;
auto const success = approach(handle, size);
if (success)
{
return success;
}
if (errno == ENOSPC) // disk full, so subsequent approaches will fail too
{
break;
}
}
set_system_error(error, errno);
return false;
}
void* tr_sys_file_map_for_reading(tr_sys_file_t handle, uint64_t offset, uint64_t size, tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_FILE);
TR_ASSERT(size > 0);
void* ret = mmap(nullptr, size, PROT_READ, MAP_SHARED, handle, offset);
if (ret == MAP_FAILED) // NOLINT(performance-no-int-to-ptr)
{
set_system_error(error, errno);
ret = nullptr;
}
return ret;
}
bool tr_sys_file_unmap(void const* address, uint64_t size, tr_error** error)
{
TR_ASSERT(address != nullptr);
TR_ASSERT(size > 0);
bool ret = munmap((void*)address, size) != -1;
if (!ret)
{
set_system_error(error, errno);
}
return ret;
}
bool tr_sys_file_lock([[maybe_unused]] tr_sys_file_t handle, [[maybe_unused]] int operation, tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_FILE);
TR_ASSERT((operation & ~(TR_SYS_FILE_LOCK_SH | TR_SYS_FILE_LOCK_EX | TR_SYS_FILE_LOCK_NB | TR_SYS_FILE_LOCK_UN)) == 0);
TR_ASSERT(
!!(operation & TR_SYS_FILE_LOCK_SH) + !!(operation & TR_SYS_FILE_LOCK_EX) + !!(operation & TR_SYS_FILE_LOCK_UN) == 1);
bool ret;
#if defined(F_OFD_SETLK)
struct flock fl = {};
switch (operation & (TR_SYS_FILE_LOCK_SH | TR_SYS_FILE_LOCK_EX | TR_SYS_FILE_LOCK_UN))
{
case TR_SYS_FILE_LOCK_SH:
fl.l_type = F_RDLCK;
break;
case TR_SYS_FILE_LOCK_EX:
fl.l_type = F_WRLCK;
break;
case TR_SYS_FILE_LOCK_UN:
fl.l_type = F_UNLCK;
break;
}
fl.l_whence = SEEK_SET;
do
{
ret = fcntl(handle, (operation & TR_SYS_FILE_LOCK_NB) != 0 ? F_OFD_SETLK : F_OFD_SETLKW, &fl) != -1;
} while (!ret && errno == EINTR);
if (!ret && errno == EAGAIN)
{
errno = EWOULDBLOCK;
}
#elif defined(HAVE_FLOCK)
int native_operation = 0;
if ((operation & TR_SYS_FILE_LOCK_SH) != 0)
{
native_operation |= LOCK_SH;
}
if ((operation & TR_SYS_FILE_LOCK_EX) != 0)
{
native_operation |= LOCK_EX;
}
if ((operation & TR_SYS_FILE_LOCK_NB) != 0)
{
native_operation |= LOCK_NB;
}
if ((operation & TR_SYS_FILE_LOCK_UN) != 0)
{
native_operation |= LOCK_UN;
}
do
{
ret = flock(handle, native_operation) != -1;
} while (!ret && errno == EINTR);
#else
errno = ENOSYS;
ret = false;
#endif
if (!ret)
{
set_system_error(error, errno);
}
return ret;
}
char* tr_sys_dir_get_current(tr_error** error)
{
char* ret;
ret = getcwd(nullptr, 0);
if (ret == nullptr && (errno == EINVAL || errno == ERANGE))
{
size_t size = PATH_MAX;
char* tmp = nullptr;
do
{
tmp = tr_renew(char, tmp, size);
if (tmp == nullptr)
{
break;
}
ret = getcwd(tmp, size);
size += 2048;
} while (ret == nullptr && errno == ERANGE);
if (ret == nullptr)
{
int const err = errno;
tr_free(tmp);
errno = err;
}
}
if (ret == nullptr)
{
set_system_error(error, errno);
}
return ret;
}
bool tr_sys_dir_create(char const* path, int flags, int permissions, tr_error** error)
{
TR_ASSERT(path != nullptr);
bool ret;
tr_error* my_error = nullptr;
if ((flags & TR_SYS_DIR_CREATE_PARENTS) != 0)
{
#ifdef HAVE_MKDIRP
ret = mkdirp(path, permissions) != -1;
#else
ret = create_path(path, permissions, &my_error);
#endif
}
else
{
ret = mkdir(path, permissions) != -1;
}
if (!ret && errno == EEXIST)
{
struct stat sb;
if (stat(path, &sb) != -1 && S_ISDIR(sb.st_mode))
{
tr_error_clear(&my_error);
ret = true;
}
else
{
errno = EEXIST;
}
}
if (!ret)
{
if (my_error != nullptr)
{
tr_error_propagate(error, &my_error);
}
else
{
set_system_error(error, errno);
}
}
return ret;
}
bool tr_sys_dir_create_temp(char* path_template, tr_error** error)
{
TR_ASSERT(path_template != nullptr);
bool ret;
#ifdef HAVE_MKDTEMP
ret = mkdtemp(path_template) != nullptr;
#else
ret = mktemp(path_template) != nullptr && mkdir(path_template, 0700) != -1;
#endif
if (!ret)
{
set_system_error(error, errno);
}
return ret;
}
tr_sys_dir_t tr_sys_dir_open(char const* path, tr_error** error)
{
TR_ASSERT(path != nullptr);
DIR* ret = opendir(path);
if (ret == nullptr)
{
set_system_error(error, errno);
return TR_BAD_SYS_DIR;
}
return (tr_sys_dir_t)ret;
}
char const* tr_sys_dir_read_name(tr_sys_dir_t handle, tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_DIR);
char const* ret = nullptr;
errno = 0;
struct dirent const* const entry = readdir((DIR*)handle);
if (entry != nullptr)
{
ret = entry->d_name;
}
else if (errno != 0)
{
set_system_error(error, errno);
}
return ret;
}
bool tr_sys_dir_close(tr_sys_dir_t handle, tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_DIR);
bool ret = closedir((DIR*)handle) != -1;
if (!ret)
{
set_system_error(error, errno);
}
return ret;
}
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