Refactor ScanDirectoryTreeAndCallback to separate errors and retvals

ScanDirectoryTreeAndCallback, before this change, coupled error/return
codes and actual return values (number of entries found). This caused
confusion and difficulty interpreting the precise way the function
worked.

Supersedes, and closes #1255.
master
archshift 2015-11-26 00:34:26 +07:00
parent 913be80782
commit b3cfcf55ea
3 changed files with 62 additions and 57 deletions

@ -119,13 +119,14 @@ void GameList::LoadInterfaceLayout(QSettings& settings)
void GameListWorker::AddFstEntriesToGameList(const std::string& dir_path, bool deep_scan)
{
const auto callback = [&](const std::string& directory,
const std::string& virtual_name) -> int {
const auto callback = [&](unsigned* num_entries_out,
const std::string& directory,
const std::string& virtual_name) -> bool {
std::string physical_name = directory + DIR_SEP + virtual_name;
if (stop_processing)
return -1; // A negative return value breaks the callback loop.
return false; // Breaks the callback loop.
if (deep_scan && FileUtil::IsDirectory(physical_name)) {
AddFstEntriesToGameList(physical_name, true);
@ -135,11 +136,11 @@ void GameListWorker::AddFstEntriesToGameList(const std::string& dir_path, bool d
Loader::FileType guessed_filetype = Loader::GuessFromExtension(filename_extension);
if (guessed_filetype == Loader::FileType::Unknown)
return 0;
return true;
Loader::FileType filetype = Loader::IdentifyFile(physical_name);
if (filetype == Loader::FileType::Unknown) {
LOG_WARNING(Frontend, "File %s is of indeterminate type and is possibly corrupted.", physical_name.c_str());
return 0;
return true;
}
if (guessed_filetype != filetype) {
LOG_WARNING(Frontend, "Filetype and extension of file %s do not match.", physical_name.c_str());
@ -152,9 +153,10 @@ void GameListWorker::AddFstEntriesToGameList(const std::string& dir_path, bool d
});
}
return 0; // We don't care about the found entries
return true;
};
FileUtil::ScanDirectoryTreeAndCallback(dir_path, callback);
FileUtil::ForeachDirectoryEntry(nullptr, dir_path, callback);
}
void GameListWorker::run()

@ -420,11 +420,13 @@ bool CreateEmptyFile(const std::string &filename)
}
int ScanDirectoryTreeAndCallback(const std::string &directory, std::function<int(const std::string&, const std::string&)> callback)
bool ForeachDirectoryEntry(unsigned* num_entries_out, const std::string &directory, DirectoryEntryCallable callback)
{
LOG_TRACE(Common_Filesystem, "directory %s", directory.c_str());
// How many files + directories we found
int found_entries = 0;
unsigned found_entries = 0;
#ifdef _WIN32
// Find the first file in the directory.
WIN32_FIND_DATA ffd;
@ -432,7 +434,7 @@ int ScanDirectoryTreeAndCallback(const std::string &directory, std::function<int
HANDLE handle_find = FindFirstFile(Common::UTF8ToTStr(directory + "\\*").c_str(), &ffd);
if (handle_find == INVALID_HANDLE_VALUE) {
FindClose(handle_find);
return found_entries;
return false;
}
// windows loop
do {
@ -442,25 +444,20 @@ int ScanDirectoryTreeAndCallback(const std::string &directory, std::function<int
DIR *dirp = opendir(directory.c_str());
if (!dirp)
return 0;
return false;
// non windows loop
while (!readdir_r(dirp, &dirent, &result) && result) {
const std::string virtual_name(result->d_name);
#endif
// check for "." and ".."
if (((virtual_name[0] == '.') && (virtual_name[1] == '\0')) ||
((virtual_name[0] == '.') && (virtual_name[1] == '.') &&
(virtual_name[2] == '\0')))
if (virtual_name == "." || virtual_name == "..")
continue;
int ret = callback(directory, virtual_name);
if (ret < 0) {
if (ret != -1)
found_entries = ret;
unsigned ret_entries;
if (!callback(&ret_entries, directory, virtual_name))
break;
}
found_entries += ret;
found_entries += ret_entries;
#ifdef _WIN32
} while (FindNextFile(handle_find, &ffd) != 0);
@ -469,16 +466,18 @@ int ScanDirectoryTreeAndCallback(const std::string &directory, std::function<int
}
closedir(dirp);
#endif
// Return number of entries found.
return found_entries;
// num_entries_out is allowed to be specified nullptr, in which case we shouldn't try to set it
if (num_entries_out != nullptr)
*num_entries_out = found_entries;
}
int ScanDirectoryTree(const std::string &directory, FSTEntry& parent_entry)
unsigned ScanDirectoryTree(const std::string &directory, FSTEntry& parent_entry)
{
const auto callback = [&parent_entry](const std::string& directory,
const std::string& virtual_name) -> int {
const auto callback = [&parent_entry](unsigned* num_entries_out,
const std::string& directory,
const std::string& virtual_name) -> bool {
FSTEntry entry;
int found_entries = 0;
entry.virtualName = virtual_name;
entry.physicalName = directory + DIR_SEP + virtual_name;
@ -486,41 +485,40 @@ int ScanDirectoryTree(const std::string &directory, FSTEntry& parent_entry)
entry.isDirectory = true;
// is a directory, lets go inside
entry.size = ScanDirectoryTree(entry.physicalName, entry);
found_entries += (int)entry.size;
*num_entries_out += (int)entry.size;
} else { // is a file
entry.isDirectory = false;
entry.size = GetSize(entry.physicalName);
}
++found_entries;
(*num_entries_out)++;
// Push into the tree
parent_entry.children.push_back(entry);
return found_entries;
return true;
};
return ScanDirectoryTreeAndCallback(directory, callback);
unsigned num_entries;
return ForeachDirectoryEntry(&num_entries, directory, callback) ? num_entries : 0;
}
bool DeleteDirRecursively(const std::string &directory)
{
const static auto callback = [](const std::string& directory,
const std::string& virtual_name) -> int {
const static auto callback = [](unsigned* num_entries_out,
const std::string& directory,
const std::string& virtual_name) -> bool {
std::string new_path = directory + DIR_SEP_CHR + virtual_name;
if (IsDirectory(new_path)) {
if (!DeleteDirRecursively(new_path)) {
return -2;
}
} else if (!Delete(new_path)) {
return -2;
}
return 0;
if (IsDirectory(new_path))
return DeleteDirRecursively(new_path);
return Delete(new_path);
};
if (ScanDirectoryTreeAndCallback(directory, callback) == -2) {
if (!ForeachDirectoryEntry(nullptr, directory, callback))
return false;
}
FileUtil::DeleteDir(directory);
// Delete the outermost directory
FileUtil::DeleteDir(directory);
return true;
}

@ -98,19 +98,24 @@ bool Copy(const std::string &srcFilename, const std::string &destFilename);
bool CreateEmptyFile(const std::string &filename);
/**
* Scans the directory tree, calling the callback for each file/directory found.
* The callback must return the number of files and directories which the provided path contains.
* If the callback's return value is -1, the callback loop is broken immediately.
* If the callback's return value is otherwise negative, the callback loop is broken immediately
* and the callback's return value is returned from this function (to allow for error handling).
* @param directory the parent directory to start scanning from
* @param callback The callback which will be called for each file/directory. It is called
* with the arguments (const std::string& directory, const std::string& virtual_name).
* The `directory `parameter is the path to the directory which contains the file/directory.
* The `virtual_name` parameter is the incomplete file path, without any directory info.
* @return the total number of files/directories found
* @param num_entries_out to be assigned by the callable with the number of iterated directory entries, never null
* @param directory the path to the enclosing directory
* @param virtual_name the entry name, without any preceding directory info
* @return whether handling the entry succeeded
*/
int ScanDirectoryTreeAndCallback(const std::string &directory, std::function<int(const std::string&, const std::string&)> callback);
using DirectoryEntryCallable = std::function<bool(unsigned* num_entries_out,
const std::string& directory,
const std::string& virtual_name)>;
/**
* Scans a directory, calling the callback for each file/directory contained within.
* If the callback returns failure, scanning halts and this function returns failure as well
* @param num_entries_out assigned by the function with the number of iterated directory entries, can be null
* @param directory the directory to scan
* @param callback The callback which will be called for each entry
* @return whether scanning the directory succeeded
*/
bool ForeachDirectoryEntry(unsigned* num_entries_out, const std::string &directory, DirectoryEntryCallable callback);
/**
* Scans the directory tree, storing the results.
@ -118,7 +123,7 @@ int ScanDirectoryTreeAndCallback(const std::string &directory, std::function<int
* @param parent_entry FSTEntry where the filesystem tree results will be stored.
* @return the total number of files/directories found
*/
int ScanDirectoryTree(const std::string &directory, FSTEntry& parent_entry);
unsigned ScanDirectoryTree(const std::string &directory, FSTEntry& parent_entry);
// deletes the given directory and anything under it. Returns true on success.
bool DeleteDirRecursively(const std::string &directory);