diff options
| -rwxr-xr-x | scripts/combo-layer | 391 |
1 files changed, 389 insertions, 2 deletions
diff --git a/scripts/combo-layer b/scripts/combo-layer index 9297d5973d..92525cac14 100755 --- a/scripts/combo-layer +++ b/scripts/combo-layer @@ -28,6 +28,9 @@ import subprocess import tempfile import ConfigParser import re +import copy +import pipes +import shutil from collections import OrderedDict from string import Template @@ -653,8 +656,7 @@ def action_update(conf, args): action_pull(conf, ['arg0'] + components) if history: - logger.error("update with history not implemented yet") - sys.exit(1) + update_with_history(conf, components, revisions, repos) else: update_with_patches(conf, components, revisions, repos) @@ -888,6 +890,391 @@ def action_splitpatch(conf, args): else: logger.info(patch_filename) +def update_with_history(conf, components, revisions, repos): + '''Update all components with full history. + + Works by importing all commits reachable from a component's + current head revision. If those commits are rooted in an already + imported commit, their content gets mixed with the content of the + combined repo of that commit (new or modified files overwritten, + removed files removed). + + The last commit is an artificial merge commit that merges all the + updated components into the combined repository. + + The HEAD ref only gets updated at the very end. All intermediate work + happens in a worktree which will get garbage collected by git eventually + after a failure. + ''' + # Remember current HEAD and what we need to add to it. + head = runcmd("git rev-parse HEAD").strip() + additional_heads = {} + + # Track the mapping between original commit and commit in the + # combined repo. We do not have to distinguish between components, + # because commit hashes are different anyway. Often we can + # skip find_revs() entirely (for example, when all new commits + # are derived from the last imported revision). + # + # Using "head" (typically the merge commit) instead of the actual + # commit for the component leads to a nicer history in the combined + # repo. + old2new_revs = {} + for name in repos: + repo = conf.repos[name] + revision = repo['last_revision'] + if revision: + old2new_revs[revision] = head + + def add_p(parents): + '''Insert -p before each entry.''' + parameters = [] + for p in parents: + parameters.append('-p') + parameters.append(p) + return parameters + + # Do all intermediate work with a separate work dir and index, + # chosen via env variables (can't use "git worktree", it is too + # new). This is useful (no changes to current work tree unless the + # update succeeds) and required (otherwise we end up temporarily + # removing the combo-layer hooks that we currently use when + # importing a new component). + # + # Not cleaned up after a failure at the moment. + wdir = os.path.join(os.getcwd(), ".git", "combo-layer") + windex = wdir + ".index" + if os.path.isdir(wdir): + shutil.rmtree(wdir) + os.mkdir(wdir) + wenv = copy.deepcopy(os.environ) + wenv["GIT_WORK_TREE"] = wdir + wenv["GIT_INDEX_FILE"] = windex + # This one turned out to be needed in practice. + wenv["GIT_OBJECT_DIRECTORY"] = os.path.join(os.getcwd(), ".git", "objects") + wargs = {"destdir": wdir, "env": wenv} + + for name in repos: + revision = revisions.get(name, None) + repo = conf.repos[name] + ldir = repo['local_repo_dir'] + dest_dir = repo['dest_dir'] + branch = repo.get('branch', "master") + hook = repo.get('hook', None) + largs = {"destdir": ldir, "env": None} + file_include = repo.get('file_filter', '').split() + file_include.sort() # make sure that short entries like '.' come first. + file_exclude = repo.get('file_exclude', '').split() + + def include_file(file): + if not file_include: + # No explicit filter set, include file. + return True + for filter in file_include: + if filter == '.': + # Another special case: include current directory and thus all files. + return True + if os.path.commonprefix((filter, file)) == filter: + # Included in directory or direct file match. + return True + # Check for wildcard match *with* allowing * to match /, i.e. + # src/*.c does match src/foobar/*.c. That's not how it is done elsewhere + # when passing the filtering to "git archive", but it is unclear what + # the intended semantic is (the comment on file_exclude that "append a * wildcard + # at the end" to match the full content of a directories implies that + # slashes are indeed not special), so here we simply do what's easy to + # implement in Python. + logger.debug('fnmatch(%s, %s)' % (file, filter)) + if fnmatch.fnmatchcase(file, filter): + return True + return False + + def exclude_file(file): + for filter in file_exclude: + if fnmatch.fnmatchcase(file, filter): + return True + return False + + def file_filter(files): + '''Clean up file list so that only included files remain.''' + index = 0 + while index < len(files): + file = files[index] + if not include_file(file) or exclude_file(file): + del files[index] + else: + index += 1 + + + # Generate the revision list. + logger.info("Analyzing commits from %s..." % name) + top_revision = revision or branch + if not check_rev_branch(name, ldir, top_revision, branch): + sys.exit(1) + + last_revision = repo['last_revision'] + rev_list_args = "--full-history --sparse --topo-order --reverse" + if not last_revision: + logger.info("Warning: last_revision of component %s is not set, starting from the first commit" % name) + rev_list_args = rev_list_args + ' ' + top_revision + else: + if not check_rev_branch(name, ldir, last_revision, branch): + sys.exit(1) + rev_list_args = "%s %s..%s" % (rev_list_args, last_revision, top_revision) + + # By definition, the current HEAD contains the latest imported + # commit of each component. We use that as initial mapping even + # though the commits do not match exactly because + # a) it always works (in contrast to find_revs, which relies on special + # commit messages) + # b) it is faster than find_revs, which will only be called on demand + # and can be skipped entirely in most cases + # c) last but not least, the combined history looks nicer when all + # new commits are rooted in the same merge commit + old2new_revs[last_revision] = head + + # We care about all commits (--full-history and --sparse) and + # we want reconstruct the topology and thus do not care + # about ordering by time (--topo-order). We ask for the ones + # we need to import first to be listed first (--reverse). + revs = runcmd("git rev-list %s" % rev_list_args, **largs).split() + logger.debug("To be imported: %s" % revs) + # Now 'revs' contains all revisions reachable from the top revision. + # All revisions derived from the 'last_revision' definitely are new, + # whereas the others may or may not have been imported before. For + # a linear history in the component, that second set will be empty. + # To distinguish between them, we also get the shorter list + # of revisions starting at the ancestor. + if last_revision: + ancestor_revs = runcmd("git rev-list --ancestry-path %s" % rev_list_args, **largs).split() + else: + ancestor_revs = [] + logger.debug("Ancestors: %s" % ancestor_revs) + + # Now import each revision. + logger.info("Importing commits from %s..." % name) + def import_rev(rev): + global scanned_revs + + # If it is part of the new commits, we definitely need + # to import it. Otherwise we need to check, we might have + # imported it before. If it was imported and we merely + # fail to find it because commit messages did not track + # the mapping, then we end up importing it again. So + # combined repos using "updating with history" really should + # enable the "From ... rev:" commit header modifications. + if rev not in ancestor_revs and rev not in old2new_revs and not scanned_revs: + logger.debug("Revision %s triggers log analysis." % rev) + find_revs(old2new_revs, head) + scanned_revs = True + new_rev = old2new_revs.get(rev, None) + if new_rev: + return new_rev + + # If the commit is not in the original list of revisions + # to be imported, then it must be a parent of one of those + # commits and it was skipped during earlier imports or not + # found. Importing such merge commits leads to very ugly + # history (long cascade of merge commits which all point + # to to older commits) when switching from "update via + # patches" to "update with history". + # + # We can avoid importing merge commits if all non-merge commits + # reachable from it were already imported. In that case we + # can root the new commits in the current head revision. + def is_imported(prev): + parents = runcmd("git show --no-patch --pretty=format:%P " + prev, **largs).split() + if len(parents) > 1: + for p in parents: + if not is_imported(p): + logger.debug("Must import %s because %s is not imported." % (rev, p)) + return False + return True + elif prev in old2new_revs: + return True + else: + logger.debug("Must import %s because %s is not imported." % (rev, prev)) + return False + if rev not in revs and is_imported(rev): + old2new_revs[rev] = head + return head + + # Need to import rev. Collect some information about it. + logger.debug("Importing %s" % rev) + (parents, author_name, author_email, author_timestamp, body) = \ + runcmd("git show --no-patch --pretty=format:%P%x00%an%x00%ae%x00%at%x00%B " + rev, **largs).split(chr(0)) + parents = parents.split() + if parents: + # Arbitrarily pick the first parent as base. It may or may not have + # been imported before. For example, if the parent is a merge commit + # and previously the combined repository used patching as update + # method, then the actual merge commit parent never was imported. + # To cover this, We recursively import parents. + parent = parents[0] + new_parent = import_rev(parent) + # Clean index and working tree. TODO: can we combine this and the + # next into one command with less file IO? + # "git reset --hard" does not work, it changes HEAD of the parent + # repo, which we wanted to avoid. Probably need to keep + # track of the rev that corresponds to the index and use apply_commit(). + runcmd("git rm -q --ignore-unmatch -rf .", **wargs) + # Update index and working tree to match the parent. + runcmd("git checkout -q -f %s ." % new_parent, **wargs) + else: + parent = None + # Clean index and working tree. + runcmd("git rm -q --ignore-unmatch -rf .", **wargs) + + # Modify index and working tree such that it mirrors the commit. + apply_commit(parent, rev, largs, wargs, dest_dir, file_filter=file_filter) + + # Now commit. + new_tree = runcmd("git write-tree", **wargs).strip() + env = copy.deepcopy(wenv) + env['GIT_AUTHOR_NAME'] = author_name + env['GIT_AUTHOR_EMAIL'] = author_email + env['GIT_AUTHOR_DATE'] = author_timestamp + if hook: + # Need to turn the verbatim commit message into something resembling a patch header + # for the hook. + with tempfile.NamedTemporaryFile(delete=False) as patch: + patch.write('Subject: [PATCH] ') + patch.write(body) + patch.write('\n---\n') + patch.close() + runcmd([hook, patch.name, rev, name]) + with open(patch.name) as f: + body = f.read()[len('Subject: [PATCH] '):][:-len('\n---\n')] + + # We can skip non-merge commits that did not change any files. Those are typically + # the result of file filtering, although they could also have been introduced + # intentionally upstream, in which case we drop some information here. + if len(parents) == 1: + parent_rev = import_rev(parents[0]) + old_tree = runcmd("git show -s --pretty=format:%T " + parent_rev, **wargs).strip() + commit = old_tree != new_tree + if not commit: + new_rev = parent_rev + else: + commit = True + if commit: + new_rev = runcmd("git commit-tree".split() + add_p([import_rev(p) for p in parents]) + + ["-m", body, new_tree], + env=env).strip() + old2new_revs[rev] = new_rev + + return new_rev + + if revs: + for rev in revs: + import_rev(rev) + # Remember how to update our current head. New components get added, + # updated components get the delta between current head and the updated component + # applied. + additional_heads[old2new_revs[revs[-1]]] = head if repo['last_revision'] else None + repo['last_revision'] = revs[-1] + + # Now construct the final merge commit. We create the tree by + # starting with the head and applying the changes from each + # components imported head revision. + if additional_heads: + runcmd("git reset --hard", **wargs) + for rev, base in additional_heads.iteritems(): + apply_commit(base, rev, wargs, wargs, None) + + # Commit with all component branches as parents as well as the previous head. + logger.info("Writing final merge commit...") + msg = conf_commit_msg(conf, components) + new_tree = runcmd("git write-tree", **wargs).strip() + new_rev = runcmd("git commit-tree".split() + + add_p([head] + additional_heads.keys()) + + ["-m", msg, new_tree], + **wargs).strip() + # And done! This is the first time we change the HEAD in the actual work tree. + runcmd("git reset --hard %s" % new_rev) + + # Update and stage the (potentially modified) + # combo-layer.conf, but do not commit separately. + for name in repos: + repo = conf.repos[name] + rev = repo['last_revision'] + conf.update(name, "last_revision", rev) + if commit_conf_file(conf, components, False): + # Must augment the previous commit. + runcmd("git commit --amend -C HEAD") + + +scanned_revs = False +def find_revs(old2new, head): + '''Construct mapping from original commit hash to commit hash in + combined repo by looking at the commit messages. Depends on the + "From ... rev: ..." convention.''' + logger.info("Analyzing log messages to find previously imported commits...") + num_known = len(old2new) + log = runcmd("git log --grep='From .* rev: [a-fA-F0-9][a-fA-F0-9]*' --pretty=format:%H%x00%B%x00 " + head).split(chr(0)) + regex = re.compile(r'From .* rev: ([a-fA-F0-9]+)') + for new_rev, body in zip(*[iter(log)]* 2): + # Use the last one, in the unlikely case there are more than one. + rev = regex.findall(body)[-1] + if rev not in old2new: + old2new[rev] = new_rev.strip() + logger.info("Found %d additional commits, leading to: %s" % (len(old2new) - num_known, old2new)) + + +def apply_commit(parent, rev, largs, wargs, dest_dir, file_filter=None): + '''Compare revision against parent, remove files deleted in the + commit, re-write new or modified ones. Moves them into dest_dir. + Optionally filters files. + ''' + if not dest_dir: + dest_dir = "." + # -r recurses into sub-directories, given is the full overview of + # what changed. We do not care about copy/edits or renames, so we + # can disable those with --no-renames (but we still parse them, + # because it was not clear from git documentation whether C and M + # lines can still occur). + logger.debug("Applying changes between %s and %s in %s" % (parent, rev, largs["destdir"])) + delete = [] + update = [] + if parent: + # Apply delta. + changes = runcmd("git diff-tree --no-commit-id --no-renames --name-status -r --raw -z %s %s" % (parent, rev), **largs).split(chr(0)) + for status, name in zip(*[iter(changes)]*2): + if status[0] in "ACMRT": + update.append(name) + elif status[0] in "D": + delete.append(name) + else: + logger.error("Unknown status %s of file %s in revision %s" % (status, name, rev)) + sys.exit(1) + else: + # Copy all files. + update.extend(runcmd("git ls-tree -r --name-only -z %s" % rev, **largs).split(chr(0))) + + # Include/exclude files as define in the component config. + # Both updated and deleted file lists get filtered, because it might happen + # that a file gets excluded, pulled from a different component, and then the + # excluded file gets deleted. In that case we must keep the copy. + if file_filter: + file_filter(update) + file_filter(delete) + + # We export into a tar archive here and extract with tar because it is simple (no + # need to implement file and symlink writing ourselves) and gives us some degree + # of parallel IO. The downside is that we have to pass the list of files via + # command line parameters - hopefully there will never be too many at once. + if update: + target = os.path.join(wargs["destdir"], dest_dir) + if not os.path.isdir(target): + os.makedirs(target) + runcmd("git archive %s %s | tar -C %s -xf -" % (rev, ' '.join([pipes.quote(x) for x in update]), pipes.quote(target)), **largs) + runcmd("git add -f".split() + [os.path.join(dest_dir, x) for x in update], **wargs) + if delete: + for path in delete: + if dest_dir: + path = os.path.join(dest_dir, path) + runcmd("git rm -f --ignore-unmatch".split() + [os.path.join(dest_dir, x) for x in delete], **wargs) + def action_error(conf, args): logger.info("invalid action %s" % args[0]) |