comparison mercurial/repoview.py @ 23378:47091002ae62

repoview: extract actual hidden cache writing in its own function

This will allow the generation of this cache within the transaction. Relying on
the transaction will reduce the chance of reader seeing bad cache.

23375:a179db3db9b9

    """
    h = util.sha1()
    h.update(''.join(repo.heads()))
    h.update(str(hash(frozenset(hideable))))
    return h.digest()

def trywritehiddencache(repo, hideable, hidden):
    """write cache of hidden changesets to disk

    Will not write the cache if a wlock cannot be obtained lazily.

    try:
        try:
            wlock = repo.wlock(wait=False)
            # write cache to file
            newhash = cachehash(repo, hideable)
            sortedset = sorted(hidden)
            data = struct.pack('>%ii' % len(sortedset), *sortedset)
            fh = repo.vfs.open(cachefile, 'w+b', atomictemp=True)
            fh.write(struct.pack(">H", cacheversion))
            fh.write(newhash)
            fh.write(data)
        except (IOError, OSError):
            repo.ui.debug('error writing hidden changesets cache')
        except error.LockHeld:
            repo.ui.debug('cannot obtain lock to write hidden changesets cache')
    finally:

23378:47091002ae62

    """
    h = util.sha1()
    h.update(''.join(repo.heads()))
    h.update(str(hash(frozenset(hideable))))
    return h.digest()

def _writehiddencache(cachefile, cachehash, hidden):
    """write hidden data to a cache file"""
    data = struct.pack('>%ii' % len(hidden), *sorted(hidden))
    cachefile.write(struct.pack(">H", cacheversion))
    cachefile.write(cachehash)
    cachefile.write(data)

def trywritehiddencache(repo, hideable, hidden):
    """write cache of hidden changesets to disk

    Will not write the cache if a wlock cannot be obtained lazily.

    try:
        try:
            wlock = repo.wlock(wait=False)
            # write cache to file
            newhash = cachehash(repo, hideable)
            fh = repo.vfs.open(cachefile, 'w+b', atomictemp=True)
            _writehiddencache(fh, newhash, hidden)
        except (IOError, OSError):
            repo.ui.debug('error writing hidden changesets cache')
        except error.LockHeld:
            repo.ui.debug('cannot obtain lock to write hidden changesets cache')
    finally: