Mercurial > hg
view hgext/censor.py @ 36066:2ad145fbde54
wireprotoserver: add context manager mechanism for redirecting stdio
Today, proto.redirect() sets up redirecting stdio and proto.restore()
undoes that. The API is a bit wonky because restore() is only
implemented on the HTTP protocol. Furthermore, not all calls to
redirect() are obviously paired with calls to restore(). For
example, the call to restore() for "unbundle" requests is handled
by the response handler for the HTTP protocol.
This commit introduces a new method on the protocol handler interface
to maybe capture stdio. It emits a file object or None depending on
whether stdio capture is used by the transport.
To prove it works, the "pushkey" wire protocol command has been
updated to use the new API.
I'm not convinced this is the best mechanism to capture stdio. I may
need to come up with something better once the new wire protocol
emerges into existence. But it is strictly better than before because
it removes variance in the wire protocol handler interface. It
therefore gets us closer to a unified interface between the SSH and
HTTP transports.
Differential Revision: https://phab.mercurial-scm.org/D2081
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Wed, 07 Feb 2018 20:17:47 -0800 |
parents | 46ba2cdda476 |
children | 0596d27457c6 |
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# 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, cryptographic material * Licensed data/code/libraries for which the license has expired * Personally Identifiable Information or other private data 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 "censor.policy=ignore" config option. """ from __future__ import absolute_import from mercurial.i18n import _ from mercurial.node import short from mercurial import ( error, filelog, lock as lockmod, registrar, revlog, scmutil, util, ) cmdtable = {} command = registrar.command(cmdtable) # Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for # extensions which SHIP WITH MERCURIAL. Non-mainline extensions should # be specifying the version(s) of Mercurial they are tested with, or # leave the attribute unspecified. testedwith = 'ships-with-hg-core' @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): wlock = lock = None try: wlock = repo.wlock() lock = repo.lock() return _docensor(ui, repo, path, rev, tombstone, **opts) finally: lockmod.release(lock, wlock) def _docensor(ui, repo, path, rev='', tombstone='', **opts): if not path: raise error.Abort(_('must specify file path to censor')) if not rev: raise error.Abort(_('must specify revision to censor')) wctx = repo[None] m = scmutil.match(wctx, (path,)) if m.anypats() or len(m.files()) != 1: raise error.Abort(_('can only specify an explicit filename')) path = m.files()[0] flog = repo.file(path) if not len(flog): raise error.Abort(_('cannot censor file with no history')) rev = scmutil.revsingle(repo, rev, rev).rev() try: ctx = repo[rev] except KeyError: raise error.Abort(_('invalid revision identifier %s') % rev) try: fctx = ctx.filectx(path) except error.LookupError: raise error.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 error.Abort(_('cannot censor file in heads (%s)') % headlist, hint=_('clean/delete and commit first')) wp = wctx.parents() if ctx.node() in [p.node() for p in wp]: raise error.Abort(_('cannot censor working directory'), hint=_('clean/delete/update first')) flogv = flog.version & 0xFFFF if flogv != revlog.REVLOGV1: raise error.Abort( _('censor does not support revlog version %d') % (flogv,)) tombstone = filelog.packmeta({"censored": tombstone}, "") crev = fctx.filerev() if len(tombstone) > flog.rawsize(crev): raise error.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.FLAG_INLINE_DATA: 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 as 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()