lib/bup/rm.py

   1
   2 from __future__ import absolute_import
   3 import sys
   4
   5 from bup import compat, git, vfs
   6 from bup.client import ClientError
   7 from bup.compat import hexstr
   8 from bup.git import get_commit_items
   9 from bup.helpers import add_error, die_if_errors, log, saved_errors
  10
  11
  12 def append_commit(hash, parent, cp, writer):
  13     ci = get_commit_items(hash, cp)
  14     tree = ci.tree.decode('hex')
  15     author = '%s <%s>' % (ci.author_name, ci.author_mail)
  16     committer = '%s <%s>' % (ci.committer_name, ci.committer_mail)
  17     c = writer.new_commit(tree, parent,
  18                           author, ci.author_sec, ci.author_offset,
  19                           committer, ci.committer_sec, ci.committer_offset,
  20                           ci.message)
  21     return c, tree
  22
  23
  24 def filter_branch(tip_commit_hex, exclude, writer):
  25     # May return None if everything is excluded.
  26     commits = [x.decode('hex') for x in git.rev_list(tip_commit_hex)]
  27     commits.reverse()
  28     last_c, tree = None, None
  29     # Rather than assert that we always find an exclusion here, we'll
  30     # just let the StopIteration signal the error.
  31     first_exclusion = next(i for i, c in enumerate(commits) if exclude(c))
  32     if first_exclusion != 0:
  33         last_c = commits[first_exclusion - 1]
  34         tree = get_commit_items(last_c.encode('hex'),
  35                                 git.cp()).tree.decode('hex')
  36         commits = commits[first_exclusion:]
  37     for c in commits:
  38         if exclude(c):
  39             continue
  40         last_c, tree = append_commit(c.encode('hex'), last_c, git.cp(), writer)
  41     return last_c
  42
  43 def commit_oid(item):
  44     if isinstance(item, vfs.Commit):
  45         return item.coid
  46     assert isinstance(item, vfs.RevList)
  47     return item.oid
  48
  49 def rm_saves(saves, writer):
  50     assert(saves)
  51     first_branch_item = saves[0][1]
  52     for save, branch in saves: # Be certain they're all on the same branch
  53         assert(branch == first_branch_item)
  54     rm_commits = frozenset([commit_oid(save) for save, branch in saves])
  55     orig_tip = commit_oid(first_branch_item)
  56     new_tip = filter_branch(orig_tip.encode('hex'),
  57                             lambda x: x in rm_commits,
  58                             writer)
  59     assert(orig_tip)
  60     assert(new_tip != orig_tip)
  61     return orig_tip, new_tip
  62
  63
  64 def dead_items(repo, paths):
  65     """Return an optimized set of removals, reporting errors via
  66     add_error, and if there are any errors, return None, None."""
  67     dead_branches = {}
  68     dead_saves = {}
  69     # Scan for bad requests, and opportunities to optimize
  70     for path in paths:
  71         try:
  72             resolved = vfs.resolve(repo, path, follow=False)
  73         except vfs.IOError as e:
  74             add_error(e)
  75             continue
  76         else:
  77             leaf_name, leaf_item = resolved[-1]
  78             if not leaf_item:
  79                 add_error('error: cannot access %r in %r'
  80                           % ('/'.join(name for name, item in resolved),
  81                              path))
  82                 continue
  83             if isinstance(leaf_item, vfs.RevList):  # rm /foo
  84                 branchname = leaf_name
  85                 dead_branches[branchname] = leaf_item
  86                 dead_saves.pop(branchname, None)  # rm /foo obviates rm /foo/bar
  87             elif isinstance(leaf_item, vfs.Commit):  # rm /foo/bar
  88                 if leaf_name == 'latest':
  89                     add_error("error: cannot delete 'latest' symlink")
  90                 else:
  91                     branchname, branchitem = resolved[-2]
  92                     if branchname not in dead_branches:
  93                         dead = leaf_item, branchitem
  94                         dead_saves.setdefault(branchname, []).append(dead)
  95             else:
  96                 add_error("don't know how to remove %r yet" % path)
  97     if saved_errors:
  98         return None, None
  99     return dead_branches, dead_saves
 100
 101
 102 def bup_rm(repo, paths, compression=6, verbosity=None):
 103     dead_branches, dead_saves = dead_items(repo, paths)
 104     die_if_errors('not proceeding with any removals\n')
 105
 106     updated_refs = {}  # ref_name -> (original_ref, tip_commit(bin))
 107
 108     for branchname, branchitem in compat.items(dead_branches):
 109         ref = 'refs/heads/' + branchname
 110         assert(not ref in updated_refs)
 111         updated_refs[ref] = (branchitem.oid, None)
 112
 113     if dead_saves:
 114         writer = git.PackWriter(compression_level=compression)
 115         try:
 116             for branch, saves in compat.items(dead_saves):
 117                 assert(saves)
 118                 updated_refs['refs/heads/' + branch] = rm_saves(saves, writer)
 119         except:
 120             if writer:
 121                 writer.abort()
 122             raise
 123         else:
 124             if writer:
 125                 # Must close before we can update the ref(s) below.
 126                 writer.close()
 127
 128     # Only update the refs here, at the very end, so that if something
 129     # goes wrong above, the old refs will be undisturbed.  Make an attempt
 130     # to update each ref.
 131     for ref_name, info in compat.items(updated_refs):
 132         orig_ref, new_ref = info
 133         try:
 134             if not new_ref:
 135                 git.delete_ref(ref_name, orig_ref.encode('hex'))
 136             else:
 137                 git.update_ref(ref_name, new_ref, orig_ref)
 138                 if verbosity:
 139                     log('updated %r (%s%s)\n'
 140                         % (ref_name,
 141                            hexstr(orig_ref) + ' -> ' if orig_ref else '',
 142                            hexstr(new_ref)))
 143         except (git.GitError, ClientError) as ex:
 144             if new_ref:
 145                 add_error('while trying to update %r (%s%s): %s'
 146                           % (ref_name,
 147                              hexstr(orig_ref) + ' -> ' if orig_ref else '',
 148                              hexstr(new_ref),
 149                              ex))
 150             else:
 151                 add_error('while trying to delete %r (%s): %s'
 152                           % (ref_name, hexstr(orig_ref), ex))