diff options
Diffstat (limited to 'zen/file_io.cpp')
| -rw-r--r-- | zen/file_io.cpp | 71 |
1 files changed, 47 insertions, 24 deletions
diff --git a/zen/file_io.cpp b/zen/file_io.cpp index 77fcb691..f935de7a 100644 --- a/zen/file_io.cpp +++ b/zen/file_io.cpp @@ -24,7 +24,7 @@ FileInput::FileInput(const Zstring& filename) : //throw FileError, ErrorNotExis filename_(filename) { #ifdef FFS_WIN - fileHandle = ::CreateFile(zen::applyLongPathPrefix(filename).c_str(), + fileHandle = ::CreateFile(applyLongPathPrefix(filename).c_str(), GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_DELETE, nullptr, @@ -123,31 +123,54 @@ FileOutput::FileOutput(const Zstring& filename, AccessFlag access) : //throw Fil filename_(filename) { #ifdef FFS_WIN - fileHandle = ::CreateFile(zen::applyLongPathPrefix(filename).c_str(), - GENERIC_READ | GENERIC_WRITE, - /* http://msdn.microsoft.com/en-us/library/aa363858(v=vs.85).aspx - quote: When an application creates a file across a network, it is better - to use GENERIC_READ | GENERIC_WRITE for dwDesiredAccess than to use GENERIC_WRITE alone. - The resulting code is faster, because the redirector can use the cache manager and send fewer SMBs with more data. - This combination also avoids an issue where writing to a file across a network can occasionally return ERROR_ACCESS_DENIED. */ - FILE_SHARE_DELETE, //FILE_SHARE_DELETE is required to rename file while handle is open! - nullptr, - access == ACC_OVERWRITE ? CREATE_ALWAYS : CREATE_NEW, - FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, - nullptr); + const DWORD dwCreationDisposition = access == FileOutput::ACC_OVERWRITE ? CREATE_ALWAYS : CREATE_NEW; + + auto getHandle = [&](DWORD dwFlagsAndAttributes) + { + return ::CreateFile(applyLongPathPrefix(filename).c_str(), + GENERIC_READ | GENERIC_WRITE, + /* http://msdn.microsoft.com/en-us/library/aa363858(v=vs.85).aspx + quote: When an application creates a file across a network, it is better + to use GENERIC_READ | GENERIC_WRITE for dwDesiredAccess than to use GENERIC_WRITE alone. + The resulting code is faster, because the redirector can use the cache manager and send fewer SMBs with more data. + This combination also avoids an issue where writing to a file across a network can occasionally return ERROR_ACCESS_DENIED. */ + FILE_SHARE_DELETE, //FILE_SHARE_DELETE is required to rename file while handle is open! + nullptr, + dwCreationDisposition, + dwFlagsAndAttributes | FILE_FLAG_SEQUENTIAL_SCAN, + nullptr); + }; + + fileHandle = getHandle(FILE_ATTRIBUTE_NORMAL); if (fileHandle == INVALID_HANDLE_VALUE) { - const DWORD lastError = ::GetLastError(); - const std::wstring errorMessage = replaceCpy(_("Cannot write file %x."), L"%x", fmtFileName(filename_)) + L"\n\n" + zen::getLastErrorFormatted(lastError); - - if (lastError == ERROR_FILE_EXISTS || //confirmed to be used - lastError == ERROR_ALREADY_EXISTS) //comment on msdn claims, this one is used on Windows Mobile 6 - throw ErrorTargetExisting(errorMessage); - - if (lastError == ERROR_PATH_NOT_FOUND) - throw ErrorTargetPathMissing(errorMessage); - - throw FileError(errorMessage); + DWORD lastError = ::GetLastError(); + + //CREATE_ALWAYS fails with ERROR_ACCESS_DENIED if the existing file is hidden or "system" http://msdn.microsoft.com/en-us/library/windows/desktop/aa363858(v=vs.85).aspx + if (lastError == ERROR_ACCESS_DENIED && + dwCreationDisposition == CREATE_ALWAYS) + { + const DWORD attrib = ::GetFileAttributes(applyLongPathPrefix(filename).c_str()); + if (attrib != INVALID_FILE_ATTRIBUTES) + { + fileHandle = getHandle(attrib); //retry + lastError = ::GetLastError(); + } + } + //"regular" error handling + if (fileHandle == INVALID_HANDLE_VALUE) + { + const std::wstring errorMessage = replaceCpy(_("Cannot write file %x."), L"%x", fmtFileName(filename_)) + L"\n\n" + zen::getLastErrorFormatted(lastError); + + if (lastError == ERROR_FILE_EXISTS || //confirmed to be used + lastError == ERROR_ALREADY_EXISTS) //comment on msdn claims, this one is used on Windows Mobile 6 + throw ErrorTargetExisting(errorMessage); + + if (lastError == ERROR_PATH_NOT_FOUND) + throw ErrorTargetPathMissing(errorMessage); + + throw FileError(errorMessage); + } } #elif defined FFS_LINUX |