hgext/infinitepush/fileindexapi.py

strip: introduce a soft strip option

This is the first user-accessible way to use the archived phase introduced in
4.8. This implements a feature discussed during the Stockholm sprint, using
the archived phase for hiding changesets.

The archived phase behaves exactly as stripping: changesets are no longer
visible, but pulling/unbundling them will make then reappear. The only notable
difference is that unlike hard stripping, soft stripping does not affect
obsmarkers.

The next changeset will make use of the archived phase for history rewriting
command. However, having a way to manually trigger the feature first seems a
necessary step before exposing users to this phase; there is a way to
un-archived changesets (unbundling), so there must be a way to archive them
again.

Adding a flag to strip is a good way to provide access to the feature without
taking a too big risk on the final UI we want. The flag is experimental so it
won't be exposed by default.

Using the archived phase is faster and less traumatic for the repository than
actually stripping changesets.

# Infinite push
#
# Copyright 2016 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""
    [infinitepush]
    # Server-side option. Used only if indextype=disk.
    # Filesystem path to the index store
    indexpath = PATH
"""

from __future__ import absolute_import

import os

from mercurial import util

from mercurial.utils import stringutil

from . import indexapi

class fileindexapi(indexapi.indexapi):
    def __init__(self, repo):
        super(fileindexapi, self).__init__()
        self._repo = repo
        root = repo.ui.config('infinitepush', 'indexpath')
        if not root:
            root = os.path.join('scratchbranches', 'index')

        self._nodemap = os.path.join(root, 'nodemap')
        self._bookmarkmap = os.path.join(root, 'bookmarkmap')
        self._metadatamap = os.path.join(root, 'nodemetadatamap')
        self._lock = None

    def __enter__(self):
        self._lock = self._repo.wlock()
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        if self._lock:
            self._lock.__exit__(exc_type, exc_val, exc_tb)

    def addbundle(self, bundleid, nodesctx):
        for node in nodesctx:
            nodepath = os.path.join(self._nodemap, node.hex())
            self._write(nodepath, bundleid)

    def addbookmark(self, bookmark, node):
        bookmarkpath = os.path.join(self._bookmarkmap, bookmark)
        self._write(bookmarkpath, node)

    def addmanybookmarks(self, bookmarks):
        for bookmark, node in bookmarks.items():
            self.addbookmark(bookmark, node)

    def deletebookmarks(self, patterns):
        for pattern in patterns:
            for bookmark, _ in self._listbookmarks(pattern):
                bookmarkpath = os.path.join(self._bookmarkmap, bookmark)
                self._delete(bookmarkpath)

    def getbundle(self, node):
        nodepath = os.path.join(self._nodemap, node)
        return self._read(nodepath)

    def getnode(self, bookmark):
        bookmarkpath = os.path.join(self._bookmarkmap, bookmark)
        return self._read(bookmarkpath)

    def getbookmarks(self, query):
        return dict(self._listbookmarks(query))

    def saveoptionaljsonmetadata(self, node, jsonmetadata):
        vfs = self._repo.vfs
        vfs.write(os.path.join(self._metadatamap, node), jsonmetadata)

    def _listbookmarks(self, pattern):
        if pattern.endswith('*'):
            pattern = 're:^' + pattern[:-1] + '.*'
        kind, pat, matcher = stringutil.stringmatcher(pattern)
        prefixlen = len(self._bookmarkmap) + 1
        for dirpath, _, books in self._repo.vfs.walk(self._bookmarkmap):
            for book in books:
                bookmark = os.path.join(dirpath, book)[prefixlen:]
                bookmark = util.pconvert(bookmark)
                if not matcher(bookmark):
                    continue
                yield bookmark, self._read(os.path.join(dirpath, book))

    def _write(self, path, value):
        vfs = self._repo.vfs
        dirname = vfs.dirname(path)
        if not vfs.exists(dirname):
            vfs.makedirs(dirname)

        vfs.write(path, value)

    def _read(self, path):
        vfs = self._repo.vfs
        if not vfs.exists(path):
            return None
        return vfs.read(path)

    def _delete(self, path):
        vfs = self._repo.vfs
        if not vfs.exists(path):
            return
        return vfs.unlink(path)