D5301: store: append to fncache if there are only new files to write

[yuja (Yuya Nishihara)]

yuja added a comment.


  > @@ -479,32 +481,45 @@
  > 
  >       fp.write(encodedir('\n'.join(self.entries) + '\n'))
  >   fp.close()
  >   self._dirty = False
  > 
  > +        if self.addls:
  >  +            # if we have just new entries, let's append them to the fncache
  >  +            tr.addbackup('fncache')
  >  +            fp = self.vfs('fncache', mode='ab', atomictemp=True)
  >  +            if self.addls:
  >  +                fp.write(encodedir('\n'.join(self.addls) + '\n'))
  >  +            fp.close()
  >  +            self.entries = None
  >  +            self.addls = set()
  
  It's probably better to write `entries | addls` at once if there are both
  adds and removes. Appending to an `atomictemp` file means the entire file
  is copied first.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D5301

To: pulkit, #hg-reviewers
Cc: yuja, mjpieters, mercurial-devel