view mercurial/bundlerepo.py @ 24545:9e0c67e84896

json: implement {tags} template

Tags is pretty easy to implement. Let's start there.

The output is slightly different from `hg tags -Tjson`. For reference,
the CLI has the following output:

  [
   {
    "node": "e2049974f9a23176c2addb61d8f5b86e0d620490",
    "rev": 29880,
    "tag": "tip",
    "type": ""
   },
   ...
  ]

Our output has the format:

  {
    "node": "0aeb19ea57a6d223bacddda3871cb78f24b06510",
    "tags": [
      {
        "node": "e2049974f9a23176c2addb61d8f5b86e0d620490",
        "tag": "tag1",
        "date": [1427775457.0, 25200]
      },
      ...
    ]
  }

"rev" is omitted because it isn't a reliable identifier. We shouldn't
be exposing them in web APIs and giving the impression it remotely
resembles a stable identifier. Perhaps we could one day hide this behind
a config option (it might be useful to expose when running servers
locally).

The "type" of the tag isn't defined because this information isn't yet
exposed to the hgweb templater (it could be in a follow-up) and because
it is questionable whether different types should be exposed at all.
(Should the web interface really be exposing "local" tags?)

We use an object for the outer type instead of Array for a few reasons.
First, it is extensible. If we ever need to throw more global properties
into the output, we can do that without breaking backwards compatibility
(property additions should be backwards compatible). Second, uniformity
in web APIs is nice. Having everything return objects seems much saner than
a mix of array and object. Third, there are security issues with arrays
in older browsers. The JSON web services world almost never uses arrays
as the main type for this reason.

Another possibly controversial part about this patch is how dates are
defined. While JSON has a Date type, it is based on the JavaScript Date
type, which is widely considered a pile of garbage. It is a non-starter
for this reason.

Many of Mercurial's built-in date filters drop seconds resolution. So
that's a non-starter as well, since we want the API to be lossless where
possible. rfc3339date, rfc822date, isodatesec, and date are all lossless.
However, they each require the client to perform string parsing on top of
JSON decoding. While date parsing libraries are pretty ubiquitous, some
languages don't have them out of the box. However, pretty much every
programming language can deal with UNIX timestamps (which are just
integers or floats). So, we choose to use Mercurial's internal date
representation, which in JSON is modeled as float seconds since UNIX
epoch and an integer timezone offset from UTC (keep in mind
JavaScript/JSON models all "Numbers" as double prevision floating point
numbers, so there isn't a difference between ints and floats in JSON).

# bundlerepo.py - repository class for viewing uncompressed bundles
#
# Copyright 2006, 2007 Benoit Boissinot <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

"""Repository class for viewing uncompressed bundles.

This provides a read-only repository interface to bundles as if they
were part of the actual repository.
"""

from node import nullid
from i18n import _
import os, tempfile, shutil
import changegroup, util, mdiff, discovery, cmdutil, scmutil, exchange
import localrepo, changelog, manifest, filelog, revlog, error, phases, bundle2

class bundlerevlog(revlog.revlog):
    def __init__(self, opener, indexfile, bundle, linkmapper):
        # How it works:
        # To retrieve a revision, we need to know the offset of the revision in
        # the bundle (an unbundle object). We store this offset in the index
        # (start). The base of the delta is stored in the base field.
        #
        # To differentiate a rev in the bundle from a rev in the revlog, we
        # check revision against repotiprev.
        opener = scmutil.readonlyvfs(opener)
        revlog.revlog.__init__(self, opener, indexfile)
        self.bundle = bundle
        n = len(self)
        self.repotiprev = n - 1
        chain = None
        self.bundlerevs = set() # used by 'bundle()' revset expression
        while True:
            chunkdata = bundle.deltachunk(chain)
            if not chunkdata:
                break
            node = chunkdata['node']
            p1 = chunkdata['p1']
            p2 = chunkdata['p2']
            cs = chunkdata['cs']
            deltabase = chunkdata['deltabase']
            delta = chunkdata['delta']

            size = len(delta)
            start = bundle.tell() - size

            link = linkmapper(cs)
            if node in self.nodemap:
                # this can happen if two branches make the same change
                chain = node
                self.bundlerevs.add(self.nodemap[node])
                continue

            for p in (p1, p2):
                if p not in self.nodemap:
                    raise error.LookupError(p, self.indexfile,
                                            _("unknown parent"))

            if deltabase not in self.nodemap:
                raise LookupError(deltabase, self.indexfile,
                                  _('unknown delta base'))

            baserev = self.rev(deltabase)
            # start, size, full unc. size, base (unused), link, p1, p2, node
            e = (revlog.offset_type(start, 0), size, -1, baserev, link,
                 self.rev(p1), self.rev(p2), node)
            self.index.insert(-1, e)
            self.nodemap[node] = n
            self.bundlerevs.add(n)
            chain = node
            n += 1

    def _chunk(self, rev):
        # Warning: in case of bundle, the diff is against what we stored as
        # delta base, not against rev - 1
        # XXX: could use some caching
        if rev <= self.repotiprev:
            return revlog.revlog._chunk(self, rev)
        self.bundle.seek(self.start(rev))
        return self.bundle.read(self.length(rev))

    def revdiff(self, rev1, rev2):
        """return or calculate a delta between two revisions"""
        if rev1 > self.repotiprev and rev2 > self.repotiprev:
            # hot path for bundle
            revb = self.index[rev2][3]
            if revb == rev1:
                return self._chunk(rev2)
        elif rev1 <= self.repotiprev and rev2 <= self.repotiprev:
            return revlog.revlog.revdiff(self, rev1, rev2)

        return mdiff.textdiff(self.revision(self.node(rev1)),
                              self.revision(self.node(rev2)))

    def revision(self, nodeorrev):
        """return an uncompressed revision of a given node or revision
        number.
        """
        if isinstance(nodeorrev, int):
            rev = nodeorrev
            node = self.node(rev)
        else:
            node = nodeorrev
            rev = self.rev(node)

        if node == nullid:
            return ""

        text = None
        chain = []
        iterrev = rev
        # reconstruct the revision if it is from a changegroup
        while iterrev > self.repotiprev:
            if self._cache and self._cache[1] == iterrev:
                text = self._cache[2]
                break
            chain.append(iterrev)
            iterrev = self.index[iterrev][3]
        if text is None:
            text = self.baserevision(iterrev)

        while chain:
            delta = self._chunk(chain.pop())
            text = mdiff.patches(text, [delta])

        self._checkhash(text, node, rev)
        self._cache = (node, rev, text)
        return text

    def baserevision(self, nodeorrev):
        # Revlog subclasses may override 'revision' method to modify format of
        # content retrieved from revlog. To use bundlerevlog with such class one
        # needs to override 'baserevision' and make more specific call here.
        return revlog.revlog.revision(self, nodeorrev)

    def addrevision(self, text, transaction, link, p1=None, p2=None, d=None):
        raise NotImplementedError
    def addgroup(self, revs, linkmapper, transaction):
        raise NotImplementedError
    def strip(self, rev, minlink):
        raise NotImplementedError
    def checksize(self):
        raise NotImplementedError

class bundlechangelog(bundlerevlog, changelog.changelog):
    def __init__(self, opener, bundle):
        changelog.changelog.__init__(self, opener)
        linkmapper = lambda x: x
        bundlerevlog.__init__(self, opener, self.indexfile, bundle,
                              linkmapper)

    def baserevision(self, nodeorrev):
        # Although changelog doesn't override 'revision' method, some extensions
        # may replace this class with another that does. Same story with
        # manifest and filelog classes.
        return changelog.changelog.revision(self, nodeorrev)

class bundlemanifest(bundlerevlog, manifest.manifest):
    def __init__(self, opener, bundle, linkmapper):
        manifest.manifest.__init__(self, opener)
        bundlerevlog.__init__(self, opener, self.indexfile, bundle,
                              linkmapper)

    def baserevision(self, nodeorrev):
        return manifest.manifest.revision(self, nodeorrev)

class bundlefilelog(bundlerevlog, filelog.filelog):
    def __init__(self, opener, path, bundle, linkmapper, repo):
        filelog.filelog.__init__(self, opener, path)
        bundlerevlog.__init__(self, opener, self.indexfile, bundle,
                              linkmapper)
        self._repo = repo

    def baserevision(self, nodeorrev):
        return filelog.filelog.revision(self, nodeorrev)

class bundlepeer(localrepo.localpeer):
    def canpush(self):
        return False

class bundlephasecache(phases.phasecache):
    def __init__(self, *args, **kwargs):
        super(bundlephasecache, self).__init__(*args, **kwargs)
        if util.safehasattr(self, 'opener'):
            self.opener = scmutil.readonlyvfs(self.opener)

    def write(self):
        raise NotImplementedError

    def _write(self, fp):
        raise NotImplementedError

    def _updateroots(self, phase, newroots, tr):
        self.phaseroots[phase] = newroots
        self.invalidate()
        self.dirty = True

class bundlerepository(localrepo.localrepository):
    def __init__(self, ui, path, bundlename):
        self._tempparent = None
        try:
            localrepo.localrepository.__init__(self, ui, path)
        except error.RepoError:
            self._tempparent = tempfile.mkdtemp()
            localrepo.instance(ui, self._tempparent, 1)
            localrepo.localrepository.__init__(self, ui, self._tempparent)
        self.ui.setconfig('phases', 'publish', False, 'bundlerepo')

        if path:
            self._url = 'bundle:' + util.expandpath(path) + '+' + bundlename
        else:
            self._url = 'bundle:' + bundlename

        self.tempfile = None
        f = util.posixfile(bundlename, "rb")
        self.bundlefile = self.bundle = exchange.readbundle(ui, f, bundlename)
        if self.bundle.compressed():
            fdtemp, temp = self.vfs.mkstemp(prefix="hg-bundle-",
                                            suffix=".hg10un")
            self.tempfile = temp
            fptemp = os.fdopen(fdtemp, 'wb')

            try:
                fptemp.write("HG10UN")
                while True:
                    chunk = self.bundle.read(2**18)
                    if not chunk:
                        break
                    fptemp.write(chunk)
            finally:
                fptemp.close()

            f = self.vfs.open(self.tempfile, mode="rb")
            self.bundlefile = self.bundle = exchange.readbundle(ui, f,
                                                                bundlename,
                                                                self.vfs)

        if isinstance(self.bundle, bundle2.unbundle20):
            cgparts = [part for part in self.bundle.iterparts()
                       if (part.type == 'b2x:changegroup')
                       and (part.params.get('version', '01')
                            in changegroup.packermap)]

            if not cgparts:
                raise util.Abort('No changegroups found')
            version = cgparts[0].params.get('version', '01')
            cgparts = [p for p in cgparts
                       if p.params.get('version', '01') == version]
            if len(cgparts) > 1:
                raise NotImplementedError("Can't process multiple changegroups")
            part = cgparts[0]

            part.seek(0)
            self.bundle = changegroup.packermap[version][1](part, 'UN')

        # dict with the mapping 'filename' -> position in the bundle
        self.bundlefilespos = {}

        self.firstnewrev = self.changelog.repotiprev + 1
        phases.retractboundary(self, None, phases.draft,
                               [ctx.node() for ctx in self[self.firstnewrev:]])

    @localrepo.unfilteredpropertycache
    def _phasecache(self):
        return bundlephasecache(self, self._phasedefaults)

    @localrepo.unfilteredpropertycache
    def changelog(self):
        # consume the header if it exists
        self.bundle.changelogheader()
        c = bundlechangelog(self.svfs, self.bundle)
        self.manstart = self.bundle.tell()
        return c

    @localrepo.unfilteredpropertycache
    def manifest(self):
        self.bundle.seek(self.manstart)
        # consume the header if it exists
        self.bundle.manifestheader()
        m = bundlemanifest(self.svfs, self.bundle, self.changelog.rev)
        self.filestart = self.bundle.tell()
        return m

    @localrepo.unfilteredpropertycache
    def manstart(self):
        self.changelog
        return self.manstart

    @localrepo.unfilteredpropertycache
    def filestart(self):
        self.manifest
        return self.filestart

    def url(self):
        return self._url

    def file(self, f):
        if not self.bundlefilespos:
            self.bundle.seek(self.filestart)
            while True:
                chunkdata = self.bundle.filelogheader()
                if not chunkdata:
                    break
                fname = chunkdata['filename']
                self.bundlefilespos[fname] = self.bundle.tell()
                while True:
                    c = self.bundle.deltachunk(None)
                    if not c:
                        break

        if f in self.bundlefilespos:
            self.bundle.seek(self.bundlefilespos[f])
            return bundlefilelog(self.svfs, f, self.bundle,
                                 self.changelog.rev, self)
        else:
            return filelog.filelog(self.svfs, f)

    def close(self):
        """Close assigned bundle file immediately."""
        self.bundlefile.close()
        if self.tempfile is not None:
            self.vfs.unlink(self.tempfile)
        if self._tempparent:
            shutil.rmtree(self._tempparent, True)

    def cancopy(self):
        return False

    def peer(self):
        return bundlepeer(self)

    def getcwd(self):
        return os.getcwd() # always outside the repo


def instance(ui, path, create):
    if create:
        raise util.Abort(_('cannot create new bundle repository'))
    parentpath = ui.config("bundle", "mainreporoot", "")
    if not parentpath:
        # try to find the correct path to the working directory repo
        parentpath = cmdutil.findrepo(os.getcwd())
        if parentpath is None:
            parentpath = ''
    if parentpath:
        # Try to make the full path relative so we get a nice, short URL.
        # In particular, we don't want temp dir names in test outputs.
        cwd = os.getcwd()
        if parentpath == cwd:
            parentpath = ''
        else:
            cwd = os.path.join(cwd,'')
            if parentpath.startswith(cwd):
                parentpath = parentpath[len(cwd):]
    u = util.url(path)
    path = u.localpath()
    if u.scheme == 'bundle':
        s = path.split("+", 1)
        if len(s) == 1:
            repopath, bundlename = parentpath, s[0]
        else:
            repopath, bundlename = s
    else:
        repopath, bundlename = parentpath, path
    return bundlerepository(ui, repopath, bundlename)

class bundletransactionmanager(object):
    def transaction(self):
        return None

    def close(self):
        raise NotImplementedError

    def release(self):
        raise NotImplementedError

def getremotechanges(ui, repo, other, onlyheads=None, bundlename=None,
                     force=False):
    '''obtains a bundle of changes incoming from other

    "onlyheads" restricts the returned changes to those reachable from the
      specified heads.
    "bundlename", if given, stores the bundle to this file path permanently;
      otherwise it's stored to a temp file and gets deleted again when you call
      the returned "cleanupfn".
    "force" indicates whether to proceed on unrelated repos.

    Returns a tuple (local, csets, cleanupfn):

    "local" is a local repo from which to obtain the actual incoming
      changesets; it is a bundlerepo for the obtained bundle when the
      original "other" is remote.
    "csets" lists the incoming changeset node ids.
    "cleanupfn" must be called without arguments when you're done processing
      the changes; it closes both the original "other" and the one returned
      here.
    '''
    tmp = discovery.findcommonincoming(repo, other, heads=onlyheads,
                                       force=force)
    common, incoming, rheads = tmp
    if not incoming:
        try:
            if bundlename:
                os.unlink(bundlename)
        except OSError:
            pass
        return repo, [], other.close

    commonset = set(common)
    rheads = [x for x in rheads if x not in commonset]

    bundle = None
    bundlerepo = None
    localrepo = other.local()
    if bundlename or not localrepo:
        # create a bundle (uncompressed if other repo is not local)

        if other.capable('getbundle'):
            cg = other.getbundle('incoming', common=common, heads=rheads)
        elif onlyheads is None and not other.capable('changegroupsubset'):
            # compat with older servers when pulling all remote heads
            cg = other.changegroup(incoming, "incoming")
            rheads = None
        else:
            cg = other.changegroupsubset(incoming, rheads, 'incoming')
        if localrepo:
            bundletype = "HG10BZ"
        else:
            bundletype = "HG10UN"
        fname = bundle = changegroup.writebundle(ui, cg, bundlename, bundletype)
        # keep written bundle?
        if bundlename:
            bundle = None
        if not localrepo:
            # use the created uncompressed bundlerepo
            localrepo = bundlerepo = bundlerepository(repo.baseui, repo.root,
                                                      fname)
            # this repo contains local and other now, so filter out local again
            common = repo.heads()
    if localrepo:
        # Part of common may be remotely filtered
        # So use an unfiltered version
        # The discovery process probably need cleanup to avoid that
        localrepo = localrepo.unfiltered()

    csets = localrepo.changelog.findmissing(common, rheads)

    if bundlerepo:
        reponodes = [ctx.node() for ctx in bundlerepo[bundlerepo.firstnewrev:]]
        remotephases = other.listkeys('phases')

        pullop = exchange.pulloperation(bundlerepo, other, heads=reponodes)
        pullop.trmanager = bundletransactionmanager()
        exchange._pullapplyphases(pullop, remotephases)

    def cleanup():
        if bundlerepo:
            bundlerepo.close()
        if bundle:
            os.unlink(bundle)
        other.close()

    return (localrepo, csets, cleanup)