graceful-fs

graceful-fs functions as a drop-in replacement for the fs module, making various improvements.

The improvements are meant to normalize behavior across different platforms and environments, and to make filesystem access more resilient to errors.

Improvements over fs module

graceful-fs:

  • keeps track of how many file descriptors are open, and by default limits this to 1024. Any further requests to open a file are put in a queue until new slots become available. If 1024 turns out to be too much, it decreases the limit further.
  • fixes lchmod for Node versions prior to 0.6.2.
  • implements fs.lutimes if possible. Otherwise it becomes a noop.
  • ignores EINVAL and EPERM errors in chown, fchown or lchown if the user isn't root.
  • makes lchmod and lchown become noops, if not available.
  • retries reading a file if read results in EAGAIN error.

On Windows, it retries renaming a file for up to one second if EACCESS or EPERM error occurs, likely because antivirus software has locked the directory.

Configuration

The maximum number of open file descriptors that graceful-fs manages may be adjusted by setting fs.MAX_OPEN to a different number. The default is 1024.