0679e7a8bf
Native file watching is notoriously unreliable on several Windows file systems (e.g. NTFS, since network file systems have trouble supporting change notifications). However, disabling native file watching for all Windows developers was probably a step too far, since it *could* work just fine, and we still have the fs.watchFile-based safety net, which no longer hogs idle CPU cycles for unchanged files. You can explicitly disable native file watching and use polling instead by setting METEOR_WATCH_FORCE_POLLING to a truthy value. Should help with #9175.
This folder contains modules that help communicating with the file-system.
files vs fs and files.path* vs path
Since the Meteor tool was originally written to work on Mac OS X and Linux but
now is also required to work on Windows, there has been a decision to abstract
the file-system calls to fs and path modules and make them go through the
files.js lib.
All path and files manipulations in the tools code assumes it is running in a
unixy environment, where the path separator is / and the default line-break
symbol is \n; calls like rename and unlink are atomic and the file-system
always works as you expect.
The files.js file tries its best to simulate this behavior on Windows,
converting slashes, file contents and running FS operations in a
"try/sleep/repeat" loop when an EBUSY error is returned. Operations on Windows
happen to be slower, especially moving folders and symlinking (which is done by
copying the directory instead).
It is advised to use files.readFile and others instead of
fs.readFileSync. The methods are Fiberized and are converted on Windows.
Also files.pathJoin instead of path.join and others to properly preserve the
unixy feel of paths: /C/Users/IEUser/AppData/Local instead of
C:\Users\IEUser\AppData\Local.
mini-files
Some code is shared between the tool libs (this folder) and the code that gets
copied to a built bundle (boot.js). The shared code is stored in
mini-files.js.
File watching
Since node.js doesn't ship a stable library to watch a folder on all file-systems, a wrapper is used. The wrapper checks if the native functionality works, if not (while on Windows, or a virtualized shared file-system like in VirtualBox), polling is used.
Watchset
A specific data-structure that is a set of files and directories paths observed by the file-watcher.