Mercurial > hg
view hgext/censor.py @ 24663:7d01371e6358
commands: add ui.statuscopies config knob
statuscopies enables viewing of copies and moves in 'hg status' by default.
author | Mathias De Maré <mathias.demare@gmail.com> |
---|---|
date | Tue, 24 Mar 2015 21:25:57 +0100 |
parents | 1bcfecbbf569 |
children | 5e111acc1170 |
line wrap: on
line source
# Copyright (C) 2015 - Mike Edgar <adgar@google.com> # # This extension enables removal of file content at a given revision, # rewriting the data/metadata of successive revisions to preserve revision log # integrity. """erase file content at a given revision The censor command instructs Mercurial to erase all content of a file at a given revision *without updating the changeset hash.* This allows existing history to remain valid while preventing future clones/pulls from receiving the erased data. Typical uses for censor are due to security or legal requirements, including:: * Passwords, private keys, crytographic material * Licensed data/code/libraries for which the license has expired * Personally Identifiable Information or other private data Censored file revisions are listed in a tracked file called .hgcensored stored in the repository root. The censor command adds an entry to the .hgcensored file in the working directory and commits it (much like ``hg tag`` and .hgtags). The censored file data is then replaced with a pointer to the new commit, enabling verification. Censored nodes can interrupt mercurial's typical operation whenever the excised data needs to be materialized. Some commands, like ``hg cat``/``hg revert``, simply fail when asked to produce censored data. Others, like ``hg verify`` and ``hg update``, must be capable of tolerating censored data to continue to function in a meaningful way. Such commands only tolerate censored file revisions if they are allowed by the policy specified by the "censor.allow" config option. """ from mercurial.node import short from mercurial import cmdutil, error, filelog, revlog, scmutil, util from mercurial.i18n import _ cmdtable = {} command = cmdutil.command(cmdtable) testedwith = 'internal' @command('censor', [('r', 'rev', '', _('censor file from specified revision'), _('REV')), ('t', 'tombstone', '', _('replacement tombstone data'), _('TEXT'))], _('-r REV [-t TEXT] [FILE]')) def censor(ui, repo, path, rev='', tombstone='', **opts): if not path: raise util.Abort(_('must specify file path to censor')) if not rev: raise util.Abort(_('must specify revision to censor')) flog = repo.file(path) if not len(flog): raise util.Abort(_('cannot censor file with no history')) rev = scmutil.revsingle(repo, rev, rev).rev() try: ctx = repo[rev] except KeyError: raise util.Abort(_('invalid revision identifier %s') % rev) try: fctx = ctx.filectx(path) except error.LookupError: raise util.Abort(_('file does not exist at revision %s') % rev) fnode = fctx.filenode() headctxs = [repo[c] for c in repo.heads()] heads = [c for c in headctxs if path in c and c.filenode(path) == fnode] if heads: headlist = ', '.join([short(c.node()) for c in heads]) raise util.Abort(_('cannot censor file in heads (%s)') % headlist, hint=_('clean/delete and commit first')) wctx = repo[None] wp = wctx.parents() if ctx.node() in [p.node() for p in wp]: raise util.Abort(_('cannot censor working directory'), hint=_('clean/delete/update first')) flogv = flog.version & 0xFFFF if flogv != revlog.REVLOGNG: raise util.Abort( _('censor does not support revlog version %d') % (flogv,)) tombstone = filelog.packmeta({"censored": tombstone}, "") crev = fctx.filerev() if len(tombstone) > flog.rawsize(crev): raise util.Abort(_( 'censor tombstone must be no longer than censored data')) # Using two files instead of one makes it easy to rewrite entry-by-entry idxread = repo.svfs(flog.indexfile, 'r') idxwrite = repo.svfs(flog.indexfile, 'wb', atomictemp=True) if flog.version & revlog.REVLOGNGINLINEDATA: dataread, datawrite = idxread, idxwrite else: dataread = repo.svfs(flog.datafile, 'r') datawrite = repo.svfs(flog.datafile, 'wb', atomictemp=True) # Copy all revlog data up to the entry to be censored. rio = revlog.revlogio() offset = flog.start(crev) for chunk in util.filechunkiter(idxread, limit=crev * rio.size): idxwrite.write(chunk) for chunk in util.filechunkiter(dataread, limit=offset): datawrite.write(chunk) def rewriteindex(r, newoffs, newdata=None): """Rewrite the index entry with a new data offset and optional new data. The newdata argument, if given, is a tuple of three positive integers: (new compressed, new uncompressed, added flag bits). """ offlags, comp, uncomp, base, link, p1, p2, nodeid = flog.index[r] flags = revlog.gettype(offlags) if newdata: comp, uncomp, nflags = newdata flags |= nflags offlags = revlog.offset_type(newoffs, flags) e = (offlags, comp, uncomp, r, link, p1, p2, nodeid) idxwrite.write(rio.packentry(e, None, flog.version, r)) idxread.seek(rio.size, 1) def rewrite(r, offs, data, nflags=revlog.REVIDX_DEFAULT_FLAGS): """Write the given full text to the filelog with the given data offset. Returns: The integer number of data bytes written, for tracking data offsets. """ flag, compdata = flog.compress(data) newcomp = len(flag) + len(compdata) rewriteindex(r, offs, (newcomp, len(data), nflags)) datawrite.write(flag) datawrite.write(compdata) dataread.seek(flog.length(r), 1) return newcomp # Rewrite censored revlog entry with (padded) tombstone data. pad = ' ' * (flog.rawsize(crev) - len(tombstone)) offset += rewrite(crev, offset, tombstone + pad, revlog.REVIDX_ISCENSORED) # Rewrite all following filelog revisions fixing up offsets and deltas. for srev in xrange(crev + 1, len(flog)): if crev in flog.parentrevs(srev): # Immediate children of censored node must be re-added as fulltext. try: revdata = flog.revision(srev) except error.CensoredNodeError, e: revdata = e.tombstone dlen = rewrite(srev, offset, revdata) else: # Copy any other revision data verbatim after fixing up the offset. rewriteindex(srev, offset) dlen = flog.length(srev) for chunk in util.filechunkiter(dataread, limit=dlen): datawrite.write(chunk) offset += dlen idxread.close() idxwrite.close() if dataread is not idxread: dataread.close() datawrite.close()