diff options
Diffstat (limited to 'zen/file_access.cpp')
| -rw-r--r-- | zen/file_access.cpp | 262 |
1 files changed, 136 insertions, 126 deletions
diff --git a/zen/file_access.cpp b/zen/file_access.cpp index 0c28f325..d06202ba 100644 --- a/zen/file_access.cpp +++ b/zen/file_access.cpp @@ -31,51 +31,19 @@ namespace { -std::pair<Zstring, ItemType> getExistingPath(const Zstring& itemPath) //throw FileError +struct SysErrorCode : public zen::SysError { - try - { - return {itemPath, getItemType(itemPath)}; //throw FileError - } - catch (const FileError& e) //not existing or access error - { - const std::optional<Zstring> parentPath = getParentFolderPath(itemPath); - if (!parentPath) //device root - throw; - //else: let's dig deeper... don't bother checking Win32 codes; e.g. not existing item may have the codes: - // ERROR_FILE_NOT_FOUND, ERROR_PATH_NOT_FOUND, ERROR_INVALID_NAME, ERROR_INVALID_DRIVE, - // ERROR_NOT_READY, ERROR_INVALID_PARAMETER, ERROR_BAD_PATHNAME, ERROR_BAD_NETPATH => not reliable - - auto [existingPath, existingType] = getExistingPath(*parentPath); //throw FileError - - if (existingPath == *parentPath && existingType != ItemType::file /*obscure, but possible (and not an error)*/) - try - { - const Zstring itemName = afterLast(itemPath, FILE_NAME_SEPARATOR, IfNotFoundReturn::all); - assert(!itemName.empty()); - - traverseFolder(*parentPath, - [&](const FileInfo& fi) { if (fi.itemName == itemName) throw ItemType::file; }, //case-sensitive! itemPath must be normalized! - [&](const FolderInfo& fi) { if (fi.itemName == itemName) throw ItemType::folder; }, - [&](const SymlinkInfo& si) { if (si.itemName == itemName) throw ItemType::symlink; }, - [](const std::wstring& errorMsg) { throw FileError(errorMsg); }); - } - catch (const ItemType&) //finding the item after getItemType() previously failed is exceptional - { - throw FileError(_("Temporary access error:") + L' ' + e.toString()); - } + SysErrorCode(const std::string& functionName, ErrorCode ec) : SysError(formatSystemError(functionName, ec)), errorCode(ec) {} - return {std::move(existingPath), existingType}; - } -} -} + const ErrorCode errorCode; +}; -ItemType zen::getItemType(const Zstring& itemPath) //throw FileError +ItemType getItemTypeImpl(const Zstring& itemPath) //throw SysErrorCode { struct stat itemInfo = {}; if (::lstat(itemPath.c_str(), &itemInfo) != 0) - THROW_LAST_FILE_ERROR(replaceCpy(_("Cannot read file attributes of %x."), L"%x", fmtPath(itemPath)), "lstat"); + throw SysErrorCode("lstat", errno); if (S_ISLNK(itemInfo.st_mode)) return ItemType::symlink; @@ -83,35 +51,72 @@ ItemType zen::getItemType(const Zstring& itemPath) //throw FileError return ItemType::folder; return ItemType::file; //S_ISREG || S_ISCHR || S_ISBLK || S_ISFIFO || S_ISSOCK } +} -std::optional<ItemType> zen::itemStillExists(const Zstring& itemPath) //throw FileError +ItemType zen::getItemType(const Zstring& itemPath) //throw FileError { - const auto& [existingPath, existingType] = getExistingPath(itemPath); //throw FileError - if (existingPath == itemPath) - return existingType; - else - return {}; + try + { + return getItemTypeImpl(itemPath); //throw SysErrorCode + } + catch (const SysError& e) { throw FileError(replaceCpy(_("Cannot read file attributes of %x."), L"%x", fmtPath(itemPath)), e.toString()); } } -bool zen::fileAvailable(const Zstring& filePath) //noexcept +std::variant<ItemType, Zstring /*last existing parent path*/> zen::getItemTypeIfExists(const Zstring& itemPath) //throw FileError { - //symbolic links (broken or not) are also treated as existing files! - struct stat fileInfo = {}; - if (::stat(filePath.c_str(), &fileInfo) == 0) //follow symlinks! - return S_ISREG(fileInfo.st_mode); - return false; + try + { + try + { + //fast check: 1. perf 2. expected by getFolderStatusNonBlocking() + return getItemTypeImpl(itemPath); //throw SysErrorCode + } + catch (const SysErrorCode& e) //let's dig deeper, but *only* if error code sounds like "not existing" + { + const std::optional<Zstring> parentPath = getParentFolderPath(itemPath); + if (!parentPath) //device root => quick access test + throw; + if (e.errorCode == ENOENT) + { + const std::variant<ItemType, Zstring /*last existing parent path*/> parentTypeOrPath = getItemTypeIfExists(*parentPath); //throw FileError + + if (const ItemType* parentType = std::get_if<ItemType>(&parentTypeOrPath)) + { + if (*parentType == ItemType::file /*obscure, but possible*/) + throw SysError(replaceCpy(_("The name %x is already used by another item."), L"%x", fmtPath(getItemName(*parentPath)))); + + const Zstring itemName = getItemName(itemPath); + assert(!itemName.empty()); + + traverseFolder(*parentPath, //throw FileError + [&](const FileInfo& fi) { if (fi.itemName == itemName) throw SysError(_("Temporary access error:") + L' ' + e.toString()); }, + [&](const FolderInfo& fi) { if (fi.itemName == itemName) throw SysError(_("Temporary access error:") + L' ' + e.toString()); }, + [&](const SymlinkInfo& si) { if (si.itemName == itemName) throw SysError(_("Temporary access error:") + L' ' + e.toString()); }); + //- case-sensitive comparison! itemPath must be normalized! + //- finding the item after getItemType() previously failed is exceptional + + return *parentPath; + } + else + return parentTypeOrPath; + } + else + throw; + } + } + catch (const SysError& e) + { + throw FileError(replaceCpy(_("Cannot read file attributes of %x."), L"%x", fmtPath(itemPath)), e.toString()); + } } -bool zen::dirAvailable(const Zstring& dirPath) //noexcept +bool zen::itemExists(const Zstring& itemPath) //throw FileError { - //symbolic links (broken or not) are also treated as existing directories! - struct stat dirInfo = {}; - if (::stat(dirPath.c_str(), &dirInfo) == 0) //follow symlinks! - return S_ISDIR(dirInfo.st_mode); - return false; + const std::variant<ItemType, Zstring /*last existing parent path*/> typeOrPath = getItemTypeIfExists(itemPath); //throw FileError + return std::get_if<ItemType>(&typeOrPath); } @@ -125,7 +130,14 @@ namespace //- folderPath does not need to exist (yet) int64_t zen::getFreeDiskSpace(const Zstring& folderPath) //throw FileError { - const auto& [existingPath, existingType] = getExistingPath(folderPath); //throw FileError + const Zstring existingPath = [&] + { + const std::variant<ItemType, Zstring /*last existing parent path*/> typeOrPath = getItemTypeIfExists(folderPath); //throw FileError + if (std::get_if<ItemType>(&typeOrPath)) + return folderPath; + else + return std::get<Zstring>(typeOrPath); + }(); try { struct statfs info = {}; @@ -165,52 +177,42 @@ Zstring zen::getTempFolderPath() //throw FileError -void zen::removeFilePlain(const Zstring& filePath) //throw FileError +namespace { - const char* functionName = "unlink"; - if (::unlink(filePath.c_str()) != 0) - { - ErrorCode ec = getLastError(); //copy before directly/indirectly making other system calls! - //begin of "regular" error reporting - std::wstring errorDescr = formatSystemError(functionName, ec); - - throw FileError(replaceCpy(_("Cannot delete file %x."), L"%x", fmtPath(filePath)), errorDescr); - } } -void zen::removeSymlinkPlain(const Zstring& linkPath) //throw FileError +void zen::removeFilePlain(const Zstring& filePath) //throw FileError { - removeFilePlain(linkPath); //throw FileError + try + { + if (::unlink(filePath.c_str()) != 0) + THROW_LAST_SYS_ERROR("unlink"); + } + catch (const SysError& e) { throw FileError(replaceCpy(_("Cannot delete file %x."), L"%x", fmtPath(filePath)), e.toString()); } } + void zen::removeDirectoryPlain(const Zstring& dirPath) //throw FileError { - const char* functionName = "rmdir"; - if (::rmdir(dirPath.c_str()) != 0) + try { - ErrorCode ec = getLastError(); //copy before making other system calls! - bool symlinkExists = false; - try { symlinkExists = getItemType(dirPath) == ItemType::symlink; } /*throw FileError*/ catch (FileError&) {} //previous exception is more relevant + if (::rmdir(dirPath.c_str()) != 0) + THROW_LAST_SYS_ERROR("rmdir"); + } + catch (const SysError& e) { throw FileError(replaceCpy(_("Cannot delete directory %x."), L"%x", fmtPath(dirPath)), e.toString()); } +} - if (symlinkExists) - { - if (::unlink(dirPath.c_str()) != 0) - THROW_LAST_FILE_ERROR(replaceCpy(_("Cannot delete directory %x."), L"%x", fmtPath(dirPath)), "unlink"); - return; - } - //if (ec == ERROR_SHARING_VIOLATION) => getLockingProcesses() can't handle directory paths! :( RmGetList() fails with ERROR_ACCESS_DENIED - //https://blog.yaakov.online/failed-experiment-what-processes-have-a-lock-on-this-folder/ - throw FileError(replaceCpy(_("Cannot delete directory %x."), L"%x", fmtPath(dirPath)), formatSystemError(functionName, ec)); +void zen::removeSymlinkPlain(const Zstring& linkPath) //throw FileError +{ + try + { + if (::unlink(linkPath.c_str()) != 0) + THROW_LAST_SYS_ERROR("unlink"); } - /* Windows: may spuriously fail with ERROR_DIR_NOT_EMPTY(145) even though all child items have - successfully been *marked* for deletion, but some application still has a handle open! - e.g. Open "C:\Test\Dir1\Dir2" (filled with lots of files) in Explorer, then delete "C:\Test\Dir1" via ::RemoveDirectory() => Error 145 - Sample code: http://us.generation-nt.com/answer/createfile-directory-handles-removing-parent-help-29126332.html - Alternatives: 1. move file/empty folder to some other location, then DeleteFile()/RemoveDirectory() - 2. use CreateFile/FILE_FLAG_DELETE_ON_CLOSE *without* FILE_SHARE_DELETE instead of DeleteFile() => early failure */ + catch (const SysError& e) { throw FileError(replaceCpy(_("Cannot delete symbolic link %x."), L"%x", fmtPath(linkPath)), e.toString()); } } @@ -218,22 +220,23 @@ namespace { void removeDirectoryImpl(const Zstring& folderPath) //throw FileError { - std::vector<Zstring> filePaths; - std::vector<Zstring> symlinkPaths; std::vector<Zstring> folderPaths; + { + std::vector<Zstring> filePaths; + std::vector<Zstring> symlinkPaths; - //get all files and directories from current directory (WITHOUT subdirectories!) - traverseFolder(folderPath, - [&](const FileInfo& fi) { filePaths.push_back(fi.fullPath); }, - [&](const FolderInfo& fi) { folderPaths.push_back(fi.fullPath); }, //defer recursion => save stack space and allow deletion of extremely deep hierarchies! - [&](const SymlinkInfo& si) { symlinkPaths.push_back(si.fullPath); }, - [](const std::wstring& errorMsg) { throw FileError(errorMsg); }); + //get all files and directories from current directory (WITHOUT subdirectories!) + traverseFolder(folderPath, + [&](const FileInfo& fi) { filePaths.push_back(fi.fullPath); }, + [&](const FolderInfo& fi) { folderPaths.push_back(fi.fullPath); }, + [&](const SymlinkInfo& si) { symlinkPaths.push_back(si.fullPath); }); //throw FileError - for (const Zstring& filePath : filePaths) - removeFilePlain(filePath); //throw FileError + for (const Zstring& filePath : filePaths) + removeFilePlain(filePath); //throw FileError - for (const Zstring& symlinkPath : symlinkPaths) - removeSymlinkPlain(symlinkPath); //throw FileError + for (const Zstring& symlinkPath : symlinkPaths) + removeSymlinkPlain(symlinkPath); //throw FileError + } //=> save stack space and allow deletion of extremely deep hierarchies! //delete directories recursively for (const Zstring& subFolderPath : folderPaths) @@ -486,7 +489,7 @@ void zen::createDirectory(const Zstring& dirPath) //throw FileError, ErrorTarget try { //don't allow creating irregular folders! - const Zstring dirName = afterLast(dirPath, FILE_NAME_SEPARATOR, IfNotFoundReturn::all); + const Zstring dirName = getItemName(dirPath); //e.g. "...." https://social.technet.microsoft.com/Forums/windows/en-US/ffee2322-bb6b-4fdf-86f9-8f93cf1fa6cb/ if (std::all_of(dirName.begin(), dirName.end(), [](Zchar c) { return c == Zstr('.'); })) @@ -505,8 +508,6 @@ void zen::createDirectory(const Zstring& dirPath) //throw FileError, ErrorTarget const int ec = errno; //copy before directly or indirectly making other system calls! if (ec == EEXIST) throw ErrorTargetExisting(replaceCpy(_("Cannot create directory %x."), L"%x", fmtPath(dirPath)), formatSystemError("mkdir", ec)); - //else if (ec == ENOENT) - // throw ErrorTargetPathMissing(errorMsg, errorDescr); THROW_LAST_SYS_ERROR("mkdir"); } } @@ -516,34 +517,43 @@ void zen::createDirectory(const Zstring& dirPath) //throw FileError, ErrorTarget void zen::createDirectoryIfMissingRecursion(const Zstring& dirPath) //throw FileError { - const std::optional<Zstring> parentPath = getParentFolderPath(dirPath); - if (!parentPath) //device root - return; + //expect that path already exists (see: versioning, base folder, log file path) => check first + const std::variant<ItemType, Zstring /*last existing parent path*/> typeOrPath = getItemTypeIfExists(dirPath); //throw FileError - try //generally expect folder already exists (see: ffs_paths.cpp) => check first + if (const ItemType* type = std::get_if<ItemType>(&typeOrPath)) { - if (getItemType(dirPath) != ItemType::file) //throw FileError - return; + if (*type == ItemType::file /*obscure, but possible*/) + throw FileError(replaceCpy(_("Cannot create directory %x."), L"%x", fmtPath(dirPath)), + replaceCpy(_("The name %x is already used by another item."), L"%x", fmtPath(getItemName(dirPath)))); } - catch (FileError&) {} //not yet existing or access error? let's find out... + else + { + const Zstring existingDirPath = std::get<Zstring>(typeOrPath); + assert(startsWith(dirPath, existingDirPath)); - createDirectoryIfMissingRecursion(*parentPath); //throw FileError + const ZstringView relPath = makeStringView(dirPath.begin() + existingDirPath.size(), dirPath.end()); + const std::vector<ZstringView> namesMissing = splitCpy(relPath, FILE_NAME_SEPARATOR, SplitOnEmpty::skip); + assert(!namesMissing.empty()); - try - { - createDirectory(dirPath); //throw FileError, ErrorTargetExisting - return; - } - catch (FileError&) - { - try - { - if (getItemType(dirPath) != ItemType::file) //throw FileError - return; //already existing => possible, if createDirectoryIfMissingRecursion() is run in parallel - } - catch (FileError&) {} //not yet existing or access error + Zstring dirPathNew = existingDirPath; + for (const ZstringView folderName : namesMissing) + try + { + dirPathNew = appendPath(dirPathNew, Zstring(folderName)); - throw; + createDirectory(dirPathNew); //throw FileError + } + catch (FileError&) + { + try + { + if (getItemType(dirPathNew) != ItemType::file /*obscure, but possible*/) //throw FileError + continue; //already existing => possible, if createFolderIfMissingRecursion() is run in parallel + } + catch (FileError&) {} //not yet existing or access error + + throw; + } } } |