minetest/src/filesys.cpp
asrelo cfa9c83d33
Improve fs::PathStartsWith to handle empty strings (#14877)
`""` does not refer to a proper path, and `fs::PathStartsWith(path, "")` should just return `false`. This is also the case in libraries in other languages where I looked, seems to be common.

The new behavior:
* check early, if `prefix` is empty - return if path is empty or not,
* no special processing for when `path` is empty, the function meets characters in `prefix` and returns false anyway.
2024-08-11 20:19:14 +02:00

1054 lines
26 KiB
C++

/*
Minetest
Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "filesys.h"
#include "util/string.h"
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cerrno>
#include <fstream>
#include <atomic>
#include "log.h"
#include "config.h"
#include "porting.h"
#ifndef SERVER
#include "irr_ptr.h"
#include <IFileArchive.h>
#include <IFileSystem.h>
#endif
#ifdef __linux__
#include <fcntl.h>
#include <sys/ioctl.h>
#ifndef FICLONE
#define FICLONE _IOW(0x94, 9, int)
#endif
#endif
// Error from last OS call as string
#ifdef _WIN32
#define LAST_OS_ERROR() porting::ConvertError(GetLastError())
#else
#define LAST_OS_ERROR() strerror(errno)
#endif
namespace fs
{
#ifdef _WIN32
/***********
* Windows *
***********/
#include <windows.h>
#include <shlwapi.h>
#include <io.h>
#include <direct.h>
std::vector<DirListNode> GetDirListing(const std::string &pathstring)
{
std::vector<DirListNode> listing;
WIN32_FIND_DATA FindFileData;
HANDLE hFind = INVALID_HANDLE_VALUE;
DWORD dwError;
std::string dirSpec = pathstring + "\\*";
// Find the first file in the directory.
hFind = FindFirstFile(dirSpec.c_str(), &FindFileData);
if (hFind == INVALID_HANDLE_VALUE) {
dwError = GetLastError();
if (dwError != ERROR_FILE_NOT_FOUND && dwError != ERROR_PATH_NOT_FOUND) {
errorstream << "GetDirListing: FindFirstFile error."
<< " Error is " << dwError << std::endl;
}
} else {
// NOTE:
// Be very sure to not include '..' in the results, it will
// result in an epic failure when deleting stuff.
DirListNode node;
node.name = FindFileData.cFileName;
node.dir = FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY;
if (node.name != "." && node.name != "..")
listing.push_back(node);
// List all the other files in the directory.
while (FindNextFile(hFind, &FindFileData) != 0) {
DirListNode node;
node.name = FindFileData.cFileName;
node.dir = FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY;
if(node.name != "." && node.name != "..")
listing.push_back(node);
}
dwError = GetLastError();
FindClose(hFind);
if (dwError != ERROR_NO_MORE_FILES) {
errorstream << "GetDirListing: FindNextFile error."
<< " Error is " << dwError << std::endl;
listing.clear();
return listing;
}
}
return listing;
}
bool CreateDir(const std::string &path)
{
bool r = CreateDirectory(path.c_str(), NULL);
if(r == true)
return true;
if(GetLastError() == ERROR_ALREADY_EXISTS)
return true;
return false;
}
bool PathExists(const std::string &path)
{
return (GetFileAttributes(path.c_str()) != INVALID_FILE_ATTRIBUTES);
}
bool IsPathAbsolute(const std::string &path)
{
return !PathIsRelative(path.c_str());
}
bool IsDir(const std::string &path)
{
DWORD attr = GetFileAttributes(path.c_str());
return (attr != INVALID_FILE_ATTRIBUTES &&
(attr & FILE_ATTRIBUTE_DIRECTORY));
}
bool IsExecutable(const std::string &path)
{
DWORD type;
return GetBinaryType(path.c_str(), &type) != 0;
}
bool IsDirDelimiter(char c)
{
return c == '/' || c == '\\';
}
bool RecursiveDelete(const std::string &path)
{
infostream << "Recursively deleting \"" << path << "\"" << std::endl;
if (!IsDir(path)) {
infostream << "RecursiveDelete: Deleting file " << path << std::endl;
if (!DeleteFile(path.c_str())) {
errorstream << "RecursiveDelete: Failed to delete file "
<< path << std::endl;
return false;
}
return true;
}
infostream << "RecursiveDelete: Deleting content of directory "
<< path << std::endl;
std::vector<DirListNode> content = GetDirListing(path);
for (const DirListNode &n: content) {
std::string fullpath = path + DIR_DELIM + n.name;
if (!RecursiveDelete(fullpath)) {
errorstream << "RecursiveDelete: Failed to recurse to "
<< fullpath << std::endl;
return false;
}
}
infostream << "RecursiveDelete: Deleting directory " << path << std::endl;
if (!RemoveDirectory(path.c_str())) {
errorstream << "Failed to recursively delete directory "
<< path << std::endl;
return false;
}
return true;
}
bool DeleteSingleFileOrEmptyDirectory(const std::string &path)
{
DWORD attr = GetFileAttributes(path.c_str());
bool is_directory = (attr != INVALID_FILE_ATTRIBUTES &&
(attr & FILE_ATTRIBUTE_DIRECTORY));
if(!is_directory)
{
bool did = DeleteFile(path.c_str());
return did;
}
else
{
bool did = RemoveDirectory(path.c_str());
return did;
}
}
std::string TempPath()
{
DWORD bufsize = GetTempPath(0, NULL);
if(bufsize == 0){
errorstream<<"GetTempPath failed, error = "<<GetLastError()<<std::endl;
return "";
}
std::string buf;
buf.resize(bufsize);
DWORD len = GetTempPath(bufsize, &buf[0]);
if(len == 0 || len > bufsize){
errorstream<<"GetTempPath failed, error = "<<GetLastError()<<std::endl;
return "";
}
buf.resize(len);
return buf;
}
std::string CreateTempFile()
{
std::string path = TempPath() + DIR_DELIM "MT_XXXXXX";
_mktemp_s(&path[0], path.size() + 1); // modifies path
HANDLE file = CreateFile(path.c_str(), GENERIC_WRITE, 0, nullptr,
CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, nullptr);
if (file == INVALID_HANDLE_VALUE)
return "";
CloseHandle(file);
return path;
}
std::string CreateTempDir()
{
std::string path = TempPath() + DIR_DELIM "MT_XXXXXX";
_mktemp_s(&path[0], path.size() + 1); // modifies path
// will error if it already exists
if (!CreateDirectory(path.c_str(), nullptr))
return "";
return path;
}
bool CopyFileContents(const std::string &source, const std::string &target)
{
BOOL ok = CopyFileEx(source.c_str(), target.c_str(), nullptr, nullptr,
nullptr, COPY_FILE_ALLOW_DECRYPTED_DESTINATION);
if (!ok) {
errorstream << "copying " << source << " to " << target
<< " failed: " << GetLastError() << std::endl;
return false;
}
// docs: "File attributes for the existing file are copied to the new file."
// This is not our intention so get rid of unwanted attributes:
DWORD attr = GetFileAttributes(target.c_str());
if (attr == INVALID_FILE_ATTRIBUTES) {
errorstream << target << ": file disappeared after copy" << std::endl;
return false;
}
attr &= ~(FILE_ATTRIBUTE_READONLY | FILE_ATTRIBUTE_HIDDEN);
SetFileAttributes(target.c_str(), attr);
tracestream << "copied " << source << " to " << target
<< " using CopyFileEx" << std::endl;
return true;
}
#else
/*********
* POSIX *
*********/
#include <sys/types.h>
#include <dirent.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
std::vector<DirListNode> GetDirListing(const std::string &pathstring)
{
std::vector<DirListNode> listing;
DIR *dp;
struct dirent *dirp;
if((dp = opendir(pathstring.c_str())) == NULL) {
//infostream<<"Error("<<errno<<") opening "<<pathstring<<std::endl;
return listing;
}
while ((dirp = readdir(dp)) != NULL) {
// NOTE:
// Be very sure to not include '..' in the results, it will
// result in an epic failure when deleting stuff.
if(strcmp(dirp->d_name, ".") == 0 || strcmp(dirp->d_name, "..") == 0)
continue;
DirListNode node;
node.name = dirp->d_name;
int isdir = -1; // -1 means unknown
/*
POSIX doesn't define d_type member of struct dirent and
certain filesystems on glibc/Linux will only return
DT_UNKNOWN for the d_type member.
Also we don't know whether symlinks are directories or not.
*/
#ifdef _DIRENT_HAVE_D_TYPE
if(dirp->d_type != DT_UNKNOWN && dirp->d_type != DT_LNK)
isdir = (dirp->d_type == DT_DIR);
#endif /* _DIRENT_HAVE_D_TYPE */
/*
Was d_type DT_UNKNOWN, DT_LNK or nonexistent?
If so, try stat().
*/
if(isdir == -1) {
struct stat statbuf{};
if (stat((pathstring + "/" + node.name).c_str(), &statbuf))
continue;
isdir = ((statbuf.st_mode & S_IFDIR) == S_IFDIR);
}
node.dir = isdir;
listing.push_back(node);
}
closedir(dp);
return listing;
}
bool CreateDir(const std::string &path)
{
int r = mkdir(path.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
if (r == 0) {
return true;
}
// If already exists, return true
if (errno == EEXIST)
return true;
return false;
}
bool PathExists(const std::string &path)
{
struct stat st{};
return (stat(path.c_str(),&st) == 0);
}
bool IsPathAbsolute(const std::string &path)
{
return path[0] == '/';
}
bool IsDir(const std::string &path)
{
struct stat statbuf{};
if(stat(path.c_str(), &statbuf))
return false; // Actually error; but certainly not a directory
return ((statbuf.st_mode & S_IFDIR) == S_IFDIR);
}
bool IsExecutable(const std::string &path)
{
return access(path.c_str(), X_OK) == 0;
}
bool IsDirDelimiter(char c)
{
return c == '/';
}
bool RecursiveDelete(const std::string &path)
{
/*
Execute the 'rm' command directly, by fork() and execve()
*/
infostream<<"Removing \""<<path<<"\""<<std::endl;
pid_t child_pid = fork();
if(child_pid == 0)
{
// Child
const char *argv[4] = {
#ifdef __ANDROID__
"/system/bin/rm",
#else
"/bin/rm",
#endif
"-rf",
path.c_str(),
NULL
};
verbosestream<<"Executing '"<<argv[0]<<"' '"<<argv[1]<<"' '"
<<argv[2]<<"'"<<std::endl;
execv(argv[0], const_cast<char**>(argv));
// Execv shouldn't return. Failed.
_exit(1);
}
else
{
// Parent
int child_status;
pid_t tpid;
do{
tpid = wait(&child_status);
}while(tpid != child_pid);
return (child_status == 0);
}
}
bool DeleteSingleFileOrEmptyDirectory(const std::string &path)
{
if (IsDir(path)) {
bool did = (rmdir(path.c_str()) == 0);
if (!did)
errorstream << "rmdir errno: " << errno << ": " << strerror(errno)
<< std::endl;
return did;
}
bool did = (unlink(path.c_str()) == 0);
if (!did)
errorstream << "unlink errno: " << errno << ": " << strerror(errno)
<< std::endl;
return did;
}
std::string TempPath()
{
/*
Should the environment variables TMPDIR, TMP and TEMP
and the macro P_tmpdir (if defined by stdio.h) be checked
before falling back on /tmp?
Probably not, because this function is intended to be
compatible with lua's os.tmpname which under the default
configuration hardcodes mkstemp("/tmp/lua_XXXXXX").
*/
#ifdef __ANDROID__
return porting::path_cache;
#else
return DIR_DELIM "tmp";
#endif
}
std::string CreateTempFile()
{
std::string path = TempPath() + DIR_DELIM "MT_XXXXXX";
int fd = mkstemp(&path[0]); // modifies path
if (fd == -1)
return "";
close(fd);
return path;
}
std::string CreateTempDir()
{
std::string path = TempPath() + DIR_DELIM "MT_XXXXXX";
auto r = mkdtemp(&path[0]); // modifies path
if (!r)
return "";
return path;
}
namespace {
struct FileDeleter {
void operator()(FILE *stream) {
fclose(stream);
}
};
typedef std::unique_ptr<FILE, FileDeleter> FileUniquePtr;
}
bool CopyFileContents(const std::string &source, const std::string &target)
{
FileUniquePtr sourcefile, targetfile;
#ifdef __linux__
// Try to clone using Copy-on-Write (CoW). This is instant but supported
// only by some filesystems.
int srcfd, tgtfd;
srcfd = open(source.c_str(), O_RDONLY);
if (srcfd == -1) {
errorstream << source << ": can't open for reading: "
<< strerror(errno) << std::endl;
return false;
}
tgtfd = open(target.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0644);
if (tgtfd == -1) {
errorstream << target << ": can't open for writing: "
<< strerror(errno) << std::endl;
close(srcfd);
return false;
}
if (ioctl(tgtfd, FICLONE, srcfd) == 0) {
tracestream << "copied " << source << " to " << target
<< " using FICLONE" << std::endl;
close(srcfd);
close(tgtfd);
return true;
}
// fallback to normal copy, but no need to reopen the files
sourcefile.reset(fdopen(srcfd, "rb"));
targetfile.reset(fdopen(tgtfd, "wb"));
goto fallback;
#endif
sourcefile.reset(fopen(source.c_str(), "rb"));
targetfile.reset(fopen(target.c_str(), "wb"));
fallback:
if (!sourcefile) {
errorstream << source << ": can't open for reading: "
<< strerror(errno) << std::endl;
return false;
}
if (!targetfile) {
errorstream << target << ": can't open for writing: "
<< strerror(errno) << std::endl;
return false;
}
size_t total = 0;
bool done = false;
char readbuffer[BUFSIZ];
while (!done) {
size_t readbytes = fread(readbuffer, 1,
sizeof(readbuffer), sourcefile.get());
total += readbytes;
if (ferror(sourcefile.get())) {
errorstream << source << ": IO error: "
<< strerror(errno) << std::endl;
return false;
}
if (readbytes > 0)
fwrite(readbuffer, 1, readbytes, targetfile.get());
if (feof(sourcefile.get())) {
// flush destination file to catch write errors (e.g. disk full)
fflush(targetfile.get());
done = true;
}
if (ferror(targetfile.get())) {
errorstream << target << ": IO error: "
<< strerror(errno) << std::endl;
return false;
}
}
tracestream << "copied " << total << " bytes from "
<< source << " to " << target << std::endl;
return true;
}
#endif
/****************************
* portable implementations *
****************************/
void GetRecursiveDirs(std::vector<std::string> &dirs, const std::string &dir)
{
static const std::set<char> chars_to_ignore = { '_', '.' };
if (dir.empty() || !IsDir(dir))
return;
dirs.push_back(dir);
fs::GetRecursiveSubPaths(dir, dirs, false, chars_to_ignore);
}
std::vector<std::string> GetRecursiveDirs(const std::string &dir)
{
std::vector<std::string> result;
GetRecursiveDirs(result, dir);
return result;
}
void GetRecursiveSubPaths(const std::string &path,
std::vector<std::string> &dst,
bool list_files,
const std::set<char> &ignore)
{
std::vector<DirListNode> content = GetDirListing(path);
for (const auto &n : content) {
std::string fullpath = path + DIR_DELIM + n.name;
if (ignore.count(n.name[0]))
continue;
if (list_files || n.dir)
dst.push_back(fullpath);
if (n.dir)
GetRecursiveSubPaths(fullpath, dst, list_files, ignore);
}
}
bool RecursiveDeleteContent(const std::string &path)
{
infostream<<"Removing content of \""<<path<<"\""<<std::endl;
std::vector<DirListNode> list = GetDirListing(path);
for (const DirListNode &dln : list) {
if(trim(dln.name) == "." || trim(dln.name) == "..")
continue;
std::string childpath = path + DIR_DELIM + dln.name;
bool r = RecursiveDelete(childpath);
if(!r) {
errorstream << "Removing \"" << childpath << "\" failed" << std::endl;
return false;
}
}
return true;
}
bool CreateAllDirs(const std::string &path)
{
std::vector<std::string> tocreate;
std::string basepath = path;
while(!PathExists(basepath))
{
tocreate.push_back(basepath);
basepath = RemoveLastPathComponent(basepath);
if(basepath.empty())
break;
}
for(int i=tocreate.size()-1;i>=0;i--)
if(!CreateDir(tocreate[i]))
return false;
return true;
}
bool CopyDir(const std::string &source, const std::string &target)
{
if(PathExists(source)){
if(!PathExists(target)){
fs::CreateAllDirs(target);
}
bool retval = true;
std::vector<DirListNode> content = fs::GetDirListing(source);
for (const auto &dln : content) {
std::string sourcechild = source + DIR_DELIM + dln.name;
std::string targetchild = target + DIR_DELIM + dln.name;
if(dln.dir){
if(!fs::CopyDir(sourcechild, targetchild)){
retval = false;
}
}
else {
if(!fs::CopyFileContents(sourcechild, targetchild)){
retval = false;
}
}
}
return retval;
}
return false;
}
bool MoveDir(const std::string &source, const std::string &target)
{
infostream << "Moving \"" << source << "\" to \"" << target << "\"" << std::endl;
// If target exists as empty folder delete, otherwise error
if (fs::PathExists(target)) {
if (rmdir(target.c_str()) != 0) {
errorstream << "MoveDir: target \"" << target
<< "\" exists as file or non-empty folder" << std::endl;
return false;
}
}
// Try renaming first which is instant
if (fs::Rename(source, target))
return true;
infostream << "MoveDir: rename not possible, will copy instead" << std::endl;
bool retval = fs::CopyDir(source, target);
if (retval)
retval &= fs::RecursiveDelete(source);
return retval;
}
bool PathStartsWith(const std::string &path, const std::string &prefix)
{
if (prefix.empty())
return path.empty();
size_t pathsize = path.size();
size_t pathpos = 0;
size_t prefixsize = prefix.size();
size_t prefixpos = 0;
for(;;){
// Test if current characters at path and prefix are delimiter OR EOS
bool delim1 = pathpos == pathsize
|| IsDirDelimiter(path[pathpos]);
bool delim2 = prefixpos == prefixsize
|| IsDirDelimiter(prefix[prefixpos]);
// Return false if it's delimiter/EOS in one path but not in the other
if(delim1 != delim2)
return false;
if(delim1){
// Skip consequent delimiters in path, in prefix
while(pathpos < pathsize &&
IsDirDelimiter(path[pathpos]))
++pathpos;
while(prefixpos < prefixsize &&
IsDirDelimiter(prefix[prefixpos]))
++prefixpos;
// Return true if prefix has ended (at delimiter/EOS)
if(prefixpos == prefixsize)
return true;
// Return false if path has ended (at delimiter/EOS)
// while prefix did not.
if(pathpos == pathsize)
return false;
}
else{
// Skip pairwise-equal characters in path and prefix until
// delimiter/EOS in path or prefix.
// Return false if differing characters are met.
size_t len = 0;
do{
char pathchar = path[pathpos+len];
char prefixchar = prefix[prefixpos+len];
if(FILESYS_CASE_INSENSITIVE){
pathchar = my_tolower(pathchar);
prefixchar = my_tolower(prefixchar);
}
if(pathchar != prefixchar)
return false;
++len;
} while(pathpos+len < pathsize
&& !IsDirDelimiter(path[pathpos+len])
&& prefixpos+len < prefixsize
&& !IsDirDelimiter(
prefix[prefixpos+len]));
pathpos += len;
prefixpos += len;
}
}
}
std::string RemoveLastPathComponent(const std::string &path,
std::string *removed, int count)
{
if(removed)
removed->clear();
size_t remaining = path.size();
for(int i = 0; i < count; ++i){
// strip a dir delimiter
while(remaining != 0 && IsDirDelimiter(path[remaining-1]))
remaining--;
// strip a path component
size_t component_end = remaining;
while(remaining != 0 && !IsDirDelimiter(path[remaining-1]))
remaining--;
size_t component_start = remaining;
// strip a dir delimiter
while(remaining != 0 && IsDirDelimiter(path[remaining-1]))
remaining--;
if(removed){
std::string component = path.substr(component_start,
component_end - component_start);
if(i)
*removed = component + DIR_DELIM + *removed;
else
*removed = component;
}
}
return path.substr(0, remaining);
}
std::string RemoveRelativePathComponents(std::string path)
{
size_t pos = path.size();
size_t dotdot_count = 0;
while (pos != 0) {
size_t component_with_delim_end = pos;
// skip a dir delimiter
while (pos != 0 && IsDirDelimiter(path[pos-1]))
pos--;
// strip a path component
size_t component_end = pos;
while (pos != 0 && !IsDirDelimiter(path[pos-1]))
pos--;
size_t component_start = pos;
std::string component = path.substr(component_start,
component_end - component_start);
bool remove_this_component = false;
if (component == ".") {
remove_this_component = true;
} else if (component == "..") {
remove_this_component = true;
dotdot_count += 1;
} else if (dotdot_count != 0) {
remove_this_component = true;
dotdot_count -= 1;
}
if (remove_this_component) {
while (pos != 0 && IsDirDelimiter(path[pos-1]))
pos--;
if (component_start == 0) {
// We need to remove the delemiter too
path = path.substr(component_with_delim_end, std::string::npos);
} else {
path = path.substr(0, pos) + DIR_DELIM +
path.substr(component_with_delim_end, std::string::npos);
}
if (pos > 0)
pos++;
}
}
if (dotdot_count > 0)
return "";
// remove trailing dir delimiters
pos = path.size();
while (pos != 0 && IsDirDelimiter(path[pos-1]))
pos--;
return path.substr(0, pos);
}
std::string AbsolutePath(const std::string &path)
{
#ifdef _WIN32
char *abs_path = _fullpath(NULL, path.c_str(), MAX_PATH);
#else
char *abs_path = realpath(path.c_str(), NULL);
#endif
if (!abs_path) return "";
std::string abs_path_str(abs_path);
free(abs_path);
return abs_path_str;
}
const char *GetFilenameFromPath(const char *path)
{
const char *filename = strrchr(path, DIR_DELIM_CHAR);
// Consistent with IsDirDelimiter this function handles '/' too
if (DIR_DELIM_CHAR != '/') {
const char *tmp = strrchr(path, '/');
if (tmp && tmp > filename)
filename = tmp;
}
return filename ? filename + 1 : path;
}
// Note: this is not safe if two MT processes try this at the same time (FIXME?)
bool safeWriteToFile(const std::string &path, std::string_view content)
{
// Prevent two threads from writing to the same temporary file
static std::atomic<u16> g_file_counter;
const std::string tmp_file = path + ".~mt" + itos(g_file_counter.fetch_add(1));
// Write data to a temporary file
std::string write_error;
#ifdef _WIN32
// We've observed behavior suggesting that the MSVC implementation of std::ofstream::flush doesn't
// actually flush, so we use win32 APIs.
HANDLE handle = CreateFile(tmp_file.c_str(), GENERIC_WRITE, 0, nullptr,
CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, nullptr);
if (handle == INVALID_HANDLE_VALUE) {
errorstream << "Failed to open file: " << LAST_OS_ERROR() << std::endl;
return false;
}
DWORD bytes_written;
if (!WriteFile(handle, content.data(), content.size(), &bytes_written, nullptr))
write_error = LAST_OS_ERROR();
else if (!FlushFileBuffers(handle))
write_error = LAST_OS_ERROR();
CloseHandle(handle);
#else
auto os = open_ofstream(tmp_file.c_str(), true);
if (!os.good())
return false;
os << content << std::flush;
os.close();
if (os.fail())
write_error = "iostream fail";
#endif
if (!write_error.empty()) {
errorstream << "Failed to write file: " << write_error << std::endl;
remove(tmp_file.c_str());
return false;
}
std::string rename_error;
// Move the finished temporary file over the real file
#ifdef _WIN32
// When creating the file, it can cause Windows Search indexer, virus scanners and other apps
// to query the file. This can make the move file call below fail.
// We retry up to 5 times, with a 1ms sleep between, before we consider the whole operation failed
for (int attempt = 0; attempt < 5; attempt++) {
auto ok = MoveFileEx(tmp_file.c_str(), path.c_str(),
MOVEFILE_REPLACE_EXISTING | MOVEFILE_WRITE_THROUGH);
if (ok) {
rename_error.clear();
break;
}
rename_error = LAST_OS_ERROR();
sleep_ms(1);
}
#else
// On POSIX compliant systems rename() is specified to be able to swap the
// file in place of the destination file, making this a truly error-proof
// transaction.
if (rename(tmp_file.c_str(), path.c_str()) != 0)
rename_error = LAST_OS_ERROR();
#endif
if (!rename_error.empty()) {
errorstream << "Failed to overwrite \"" << path << "\": " << rename_error << std::endl;
remove(tmp_file.c_str());
return false;
}
return true;
}
#ifndef SERVER
bool extractZipFile(io::IFileSystem *fs, const char *filename, const std::string &destination)
{
// Be careful here not to touch the global file hierarchy in Irrlicht
// since this function needs to be thread-safe!
io::IArchiveLoader *zip_loader = nullptr;
for (u32 i = 0; i < fs->getArchiveLoaderCount(); i++) {
if (fs->getArchiveLoader(i)->isALoadableFileFormat(io::EFAT_ZIP)) {
zip_loader = fs->getArchiveLoader(i);
break;
}
}
if (!zip_loader) {
warningstream << "fs::extractZipFile(): Irrlicht said it doesn't support ZIPs." << std::endl;
return false;
}
irr_ptr<io::IFileArchive> opened_zip(zip_loader->createArchive(filename, false, false));
if (!opened_zip)
return false;
const io::IFileList* files_in_zip = opened_zip->getFileList();
for (u32 i = 0; i < files_in_zip->getFileCount(); i++) {
if (files_in_zip->isDirectory(i))
continue; // ignore, we create dirs as necessary
const auto &filename = files_in_zip->getFullFileName(i);
std::string fullpath = destination + DIR_DELIM;
fullpath += filename.c_str();
fullpath = fs::RemoveRelativePathComponents(fullpath);
if (!fs::PathStartsWith(fullpath, destination)) {
warningstream << "fs::extractZipFile(): refusing to extract file \""
<< filename.c_str() << "\"" << std::endl;
continue;
}
std::string fullpath_dir = fs::RemoveLastPathComponent(fullpath);
if (!fs::PathExists(fullpath_dir) && !fs::CreateAllDirs(fullpath_dir))
return false;
irr_ptr<io::IReadFile> toread(opened_zip->createAndOpenFile(i));
auto os = open_ofstream(fullpath.c_str(), true);
if (!os.good())
return false;
char buffer[4096];
long total_read = 0;
while (total_read < toread->getSize()) {
long bytes_read = toread->read(buffer, sizeof(buffer));
bool error = true;
if (bytes_read != 0) {
os.write(buffer, bytes_read);
error = os.fail();
}
if (error) {
os.close();
remove(fullpath.c_str());
return false;
}
total_read += bytes_read;
}
}
return true;
}
#endif
bool ReadFile(const std::string &path, std::string &out, bool log_error)
{
auto is = open_ifstream(path.c_str(), log_error, std::ios::ate);
if (!is.good())
return false;
auto size = is.tellg();
out.resize(size);
is.seekg(0);
is.read(&out[0], size);
return !is.fail();
}
bool Rename(const std::string &from, const std::string &to)
{
return rename(from.c_str(), to.c_str()) == 0;
}
bool OpenStream(std::filebuf &stream, const char *filename,
std::ios::openmode mode, bool log_error, bool log_warn)
{
assert((mode & std::ios::in) || (mode & std::ios::out));
assert(!stream.is_open());
// C++ dropped the ball hard for file opening error handling, there's not even
// an implementation-defined mechanism for returning any kind of error code or message.
if (!stream.open(filename, mode)) {
if (log_warn || log_error) {
std::string msg = LAST_OS_ERROR();
(log_error ? errorstream : warningstream)
<< "Failed to open \"" << filename << "\": " << msg << std::endl;
}
return false;
}
return true;
}
} // namespace fs