// Tries to refresh the lstat cache (_fileCache).
// This method should not throw. Instead, we store the results, and we will throw when the user attempts to access any of the properties when there was a failure
internal void RefreshCaches(ReadOnlySpan <char> path)
{
path = Path.TrimEndingDirectorySeparator(path);
#if !TARGET_BROWSER
_isReadOnlyCache = -1;
#endif
int rv = Interop.Sys.LStat(path, out _fileCache);
if (rv < 0)
{
Interop.ErrorInfo errorInfo = Interop.Sys.GetLastErrorInfo();
if (errorInfo.Error == Interop.Error.ENOENT || // A component of the path does not exist, or path is an empty string
errorInfo.Error == Interop.Error.ENOTDIR) // A component of the path prefix of path is not a directory
{
_state = InitializedNotExists;
}
else
{
Debug.Assert(errorInfo.RawErrno > 0); // Expect a positive integer
_state = errorInfo.RawErrno; // Initialized with error.
}
return;
}
// Check if the main path is a directory, or a link to a directory.
int fileType = _fileCache.Mode & Interop.Sys.FileTypes.S_IFMT;
bool isDirectory = fileType == Interop.Sys.FileTypes.S_IFDIR ||
(fileType == Interop.Sys.FileTypes.S_IFLNK &&
Interop.Sys.Stat(path, out Interop.Sys.FileStatus target) == 0 &&
(target.Mode & Interop.Sys.FileTypes.S_IFMT) == Interop.Sys.FileTypes.S_IFDIR);
_state = isDirectory ? InitializedExistsDir : InitializedExistsFile;
}
/// <summary>Wrapper for getpwuid_r.</summary>
/// <param name="buf">The scratch buffer to pass into getpwuid_r.</param>
/// <param name="bufLen">The length of <paramref name="buf"/>.</param>
/// <param name="path">The resulting path; null if the user didn't have an entry.</param>
/// <returns>true if the call was successful (path may still be null); false is a larger buffer is needed.</returns>
private static unsafe bool TryGetHomeDirectoryFromPasswd(byte* buf, int bufLen, out string path)
{
// Call getpwuid_r to get the passwd struct
Interop.Sys.Passwd passwd;
int error = Interop.Sys.GetPwUidR(Interop.Sys.GetEUid(), out passwd, buf, bufLen);
// If the call succeeds, give back the home directory path retrieved
if (error == 0)
{
Debug.Assert(passwd.HomeDirectory != null);
path = Marshal.PtrToStringAnsi((IntPtr)passwd.HomeDirectory);
return true;
}
// If the current user's entry could not be found, give back null
// path, but still return true as false indicates the buffer was
// too small.
if (error == -1)
{
path = null;
return true;
}
var errorInfo = new Interop.ErrorInfo(error);
// If the call failed because the buffer was too small, return false to
// indicate the caller should try again with a larger buffer.
if (errorInfo.Error == Interop.Error.ERANGE)
{
path = null;
return false;
}
// Otherwise, fail.
throw new IOException(errorInfo.GetErrorMessage(), errorInfo.RawErrno);
}
private void EnsureStatInitialized()
{
if (_fileStatusInitialized == -1)
{
Refresh();
}
if (_fileStatusInitialized != 0)
{
int errno = _fileStatusInitialized;
_fileStatusInitialized = -1;
var errorInfo = new Interop.ErrorInfo(errno);
// Windows distinguishes between whether the directory or the file isn't found,
// and throws a different exception in these cases. We attempt to approximate that
// here; there is a race condition here, where something could change between
// when the error occurs and our checks, but it's the best we can do, and the
// worst case in such a race condition (which could occur if the file system is
// being manipulated concurrently with these checks) is that we throw a
// FileNotFoundException instead of DirectoryNotFoundexception.
// directoryError is true only if a FileNotExists error was provided and the parent
// directory of the file represented by _fullPath is nonexistent
bool directoryError = (errorInfo.Error == Interop.Error.ENOENT && !Directory.Exists(Path.GetDirectoryName(PathHelpers.TrimEndingDirectorySeparator(FullPath)))); // The destFile's path is invalid
throw Interop.GetExceptionForIoErrno(errorInfo, FullPath, directoryError);
}
}
