X-Git-Url: https://arthur.barton.de/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fbup%2Fgit.py;h=70673a3d2f8377f1329d254cbb002b995c75ebd4;hb=c40b3dd5fd74e72024fbaad3daf5a958aefa1c54;hp=5710f054515be18ac3e77d5172edb1b7b609fb5c;hpb=c8d029faa649add017ba13755fb3e03c3975d204;p=bup.git diff --git a/lib/bup/git.py b/lib/bup/git.py index 5710f05..70673a3 100644 --- a/lib/bup/git.py +++ b/lib/bup/git.py @@ -3,23 +3,25 @@ bup repositories are in Git format. This library allows us to interact with the Git data structures. """ +from __future__ import absolute_import import errno, os, sys, zlib, time, subprocess, struct, stat, re, tempfile, glob from collections import namedtuple from itertools import islice +from numbers import Integral -from bup import _helpers, path, midx, bloom, xstat +from bup import _helpers, compat, hashsplit, path, midx, bloom, xstat from bup.helpers import (Sha1, add_error, chunkyreader, debug1, debug2, - hostname, log, merge_iter, mmap_read, mmap_readwrite, - progress, qprogress, unlink, username, userfullname, + fdatasync, + hostname, localtime, log, merge_iter, + mmap_read, mmap_readwrite, + parse_num, + progress, qprogress, shstr, stat_if_exists, + unlink, username, userfullname, utc_offset_str) - -max_pack_size = 1000*1000*1000 # larger packs will slow down pruning -max_pack_objects = 200*1000 # cache memory usage is about 83 bytes per object - verbose = 0 ignore_midx = 0 -repodir = None +repodir = None # The default repository, once initialized _typemap = { 'blob':3, 'tree':2, 'commit':1, 'tag':4 } _typermap = { 3:'blob', 2:'tree', 1:'commit', 4:'tag' } @@ -32,6 +34,30 @@ class GitError(Exception): pass +def _git_wait(cmd, p): + rv = p.wait() + if rv != 0: + raise GitError('%s returned %d' % (shstr(cmd), rv)) + +def _git_capture(argv): + p = subprocess.Popen(argv, stdout=subprocess.PIPE, preexec_fn = _gitenv()) + r = p.stdout.read() + _git_wait(repr(argv), p) + return r + +def git_config_get(option, repo_dir=None): + cmd = ('git', 'config', '--get', option) + p = subprocess.Popen(cmd, stdout=subprocess.PIPE, + preexec_fn=_gitenv(repo_dir=repo_dir)) + r = p.stdout.read() + rc = p.wait() + if rc == 0: + return r + if rc != 1: + raise GitError('%s returned %d' % (cmd, rc)) + return None + + def parse_tz_offset(s): """UTC offset in seconds.""" tz_off = (int(s[1:3]) * 60 * 60) + (int(s[3:5]) * 60) @@ -87,11 +113,25 @@ def parse_commit(content): def get_commit_items(id, cp): commit_it = cp.get(id) - assert(commit_it.next() == 'commit') + _, typ, _ = next(commit_it) + assert(typ == 'commit') commit_content = ''.join(commit_it) return parse_commit(commit_content) +def _local_git_date_str(epoch_sec): + return '%d %s' % (epoch_sec, utc_offset_str(epoch_sec)) + + +def _git_date_str(epoch_sec, tz_offset_sec): + offs = tz_offset_sec // 60 + return '%d %s%02d%02d' \ + % (epoch_sec, + '+' if offs >= 0 else '-', + abs(offs) // 60, + abs(offs) % 60) + + def repo(sub = '', repo_dir=None): """Get the path to the git repository or one of its subdirectories.""" global repodir @@ -237,6 +277,8 @@ def tree_decode(buf): def _encode_packobj(type, content, compression_level=1): + if compression_level not in (0, 1, 2, 3, 4, 5, 6, 7, 8, 9): + raise ValueError('invalid compression level %s' % compression_level) szout = '' sz = len(content) szbits = (sz & 0x0f) | (_typemap[type]<<4) @@ -248,10 +290,6 @@ def _encode_packobj(type, content, compression_level=1): break szbits = sz & 0x7f sz >>= 7 - if compression_level > 9: - compression_level = 9 - elif compression_level < 0: - compression_level = 0 z = zlib.compressobj(compression_level) yield szout yield z.compress(content) @@ -515,7 +553,7 @@ class PackIdxList: if self.bloom is None and os.path.exists(bfull): self.bloom = bloom.ShaBloom(bfull) self.packs = list(set(d.values())) - self.packs.sort(lambda x,y: -cmp(len(x),len(y))) + self.packs.sort(reverse=True, key=lambda x: len(x)) if self.bloom and self.bloom.valid() and len(self.bloom) >= len(self): self.do_bloom = True else: @@ -564,10 +602,17 @@ def idxmerge(idxlist, final_progress=True): def _make_objcache(): return PackIdxList(repo('objects/pack')) +# bup-gc assumes that it can disable all PackWriter activities +# (bloom/midx/cache) via the constructor and close() arguments. + class PackWriter: """Writes Git objects inside a pack file.""" - def __init__(self, objcache_maker=_make_objcache, compression_level=1): + def __init__(self, objcache_maker=_make_objcache, compression_level=1, + run_midx=True, on_pack_finish=None, + max_pack_size=None, max_pack_objects=None): + self.repo_dir = repo() self.file = None + self.parentfd = None self.count = 0 self.outbytes = 0 self.filename = None @@ -575,14 +620,40 @@ class PackWriter: self.objcache_maker = objcache_maker self.objcache = None self.compression_level = compression_level + self.run_midx=run_midx + self.on_pack_finish = on_pack_finish + if not max_pack_size: + max_pack_size = git_config_get('pack.packSizeLimit', + repo_dir=self.repo_dir) + if max_pack_size is not None: + max_pack_size = parse_num(max_pack_size) + if not max_pack_size: + # larger packs slow down pruning + max_pack_size = 1000 * 1000 * 1000 + self.max_pack_size = max_pack_size + # cache memory usage is about 83 bytes per object + self.max_pack_objects = max_pack_objects if max_pack_objects \ + else max(1, self.max_pack_size // 5000) def __del__(self): self.close() def _open(self): if not self.file: - (fd,name) = tempfile.mkstemp(suffix='.pack', dir=repo('objects')) - self.file = os.fdopen(fd, 'w+b') + objdir = dir = os.path.join(self.repo_dir, 'objects') + fd, name = tempfile.mkstemp(suffix='.pack', dir=objdir) + try: + self.file = os.fdopen(fd, 'w+b') + except: + os.close(fd) + raise + try: + self.parentfd = os.open(objdir, os.O_RDONLY) + except: + f = self.file + self.file = None + f.close() + raise assert(name.endswith('.pack')) self.filename = name[:-5] self.file.write('PACK\0\0\0\2\0\0\0\0') @@ -621,13 +692,14 @@ class PackWriter: size, crc = self._raw_write(_encode_packobj(type, content, self.compression_level), sha=sha) - if self.outbytes >= max_pack_size or self.count >= max_pack_objects: + if self.outbytes >= self.max_pack_size \ + or self.count >= self.max_pack_objects: self.breakpoint() return sha def breakpoint(self): """Clear byte and object counts and return the last processed id.""" - id = self._end() + id = self._end(self.run_midx) self.outbytes = self.count = 0 return id @@ -643,11 +715,16 @@ class PackWriter: self._require_objcache() return self.objcache.exists(id, want_source=want_source) + def just_write(self, sha, type, content): + """Write an object to the pack file, bypassing the objcache. Fails if + sha exists().""" + self._write(sha, type, content) + def maybe_write(self, type, content): """Write an object to the pack file if not present and return its id.""" sha = calc_hash(type, content) if not self.exists(sha): - self._write(sha, type, content) + self.just_write(sha, type, content) self._require_objcache() self.objcache.add(sha) return sha @@ -661,34 +738,45 @@ class PackWriter: content = tree_encode(shalist) return self.maybe_write('tree', content) - def _new_commit(self, tree, parent, author, adate, committer, cdate, msg): + def new_commit(self, tree, parent, + author, adate_sec, adate_tz, + committer, cdate_sec, cdate_tz, + msg): + """Create a commit object in the pack. The date_sec values must be + epoch-seconds, and if a tz is None, the local timezone is assumed.""" + if adate_tz: + adate_str = _git_date_str(adate_sec, adate_tz) + else: + adate_str = _local_git_date_str(adate_sec) + if cdate_tz: + cdate_str = _git_date_str(cdate_sec, cdate_tz) + else: + cdate_str = _local_git_date_str(cdate_sec) l = [] if tree: l.append('tree %s' % tree.encode('hex')) if parent: l.append('parent %s' % parent.encode('hex')) - if author: l.append('author %s %s' % (author, _git_date(adate))) - if committer: l.append('committer %s %s' % (committer, _git_date(cdate))) + if author: l.append('author %s %s' % (author, adate_str)) + if committer: l.append('committer %s %s' % (committer, cdate_str)) l.append('') l.append(msg) return self.maybe_write('commit', '\n'.join(l)) - def new_commit(self, parent, tree, date, msg): - """Create a commit object in the pack.""" - userline = '%s <%s@%s>' % (userfullname(), username(), hostname()) - commit = self._new_commit(tree, parent, - userline, date, userline, date, - msg) - return commit - def abort(self): """Remove the pack file from disk.""" f = self.file if f: - self.idx = None + pfd = self.parentfd self.file = None + self.parentfd = None + self.idx = None try: - os.unlink(self.filename + '.pack') + try: + os.unlink(self.filename + '.pack') + finally: + f.close() finally: - f.close() + if pfd is not None: + os.close(pfd) def _end(self, run_midx=True): f = self.file @@ -712,19 +800,28 @@ class PackWriter: sum.update(b) packbin = sum.digest() f.write(packbin) + fdatasync(f.fileno()) finally: f.close() obj_list_sha = self._write_pack_idx_v2(self.filename + '.idx', idx, packbin) - - nameprefix = repo('objects/pack/pack-%s' % obj_list_sha) + nameprefix = os.path.join(self.repo_dir, + 'objects/pack/pack-' + obj_list_sha) if os.path.exists(self.filename + '.map'): os.unlink(self.filename + '.map') os.rename(self.filename + '.pack', nameprefix + '.pack') os.rename(self.filename + '.idx', nameprefix + '.idx') + try: + os.fsync(self.parentfd) + finally: + os.close(self.parentfd) if run_midx: - auto_midx(repo('objects/pack')) + auto_midx(os.path.join(self.repo_dir, 'objects/pack')) + + if self.on_pack_finish: + self.on_pack_finish(nameprefix) + return nameprefix def close(self, run_midx=True): @@ -744,11 +841,15 @@ class PackWriter: idx_f = open(filename, 'w+b') try: idx_f.truncate(index_len) + fdatasync(idx_f.fileno()) idx_map = mmap_readwrite(idx_f, close=False) - count = _helpers.write_idx(filename, idx_map, idx, self.count) - assert(count == self.count) + try: + count = _helpers.write_idx(filename, idx_map, idx, self.count) + assert(count == self.count) + idx_map.flush() + finally: + idx_map.close() finally: - if idx_map: idx_map.close() idx_f.close() idx_f = open(filename, 'a+b') @@ -768,15 +869,12 @@ class PackWriter: for b in chunkyreader(idx_f): idx_sum.update(b) idx_f.write(idx_sum.digest()) + fdatasync(idx_f.fileno()) return namebase finally: idx_f.close() -def _git_date(date): - return '%d %s' % (date, utc_offset_str(date)) - - def _gitenv(repo_dir = None): if not repo_dir: repo_dir = repo() @@ -785,13 +883,13 @@ def _gitenv(repo_dir = None): return env -def list_refs(refname=None, repo_dir=None, +def list_refs(patterns=None, repo_dir=None, limit_to_heads=False, limit_to_tags=False): - """Yield (refname, hash) tuples for all repository refs unless a ref - name is specified. Given a ref name, only include tuples for that - particular ref. The limits restrict the result items to - refs/heads or refs/tags. If both limits are specified, items from - both sources will be included. + """Yield (refname, hash) tuples for all repository refs unless + patterns are specified. In that case, only include tuples for + refs matching those patterns (cf. git-show-ref(1)). The limits + restrict the result items to refs/heads or refs/tags. If both + limits are specified, items from both sources will be included. """ argv = ['git', 'show-ref'] @@ -800,8 +898,8 @@ def list_refs(refname=None, repo_dir=None, if limit_to_tags: argv.append('--tags') argv.append('--') - if refname: - argv += [refname] + if patterns: + argv.extend(patterns) p = subprocess.Popen(argv, preexec_fn = _gitenv(repo_dir), stdout = subprocess.PIPE) @@ -817,7 +915,7 @@ def list_refs(refname=None, repo_dir=None, def read_ref(refname, repo_dir = None): """Get the commit id of the most recent commit made on a given ref.""" - refs = list_refs(refname, repo_dir=repo_dir, limit_to_heads=True) + refs = list_refs(patterns=[refname], repo_dir=repo_dir, limit_to_heads=True) l = tuple(islice(refs, 2)) if l: assert(len(l) == 1) @@ -826,32 +924,52 @@ def read_ref(refname, repo_dir = None): return None -def rev_list(ref, count=None, repo_dir=None): - """Generate a list of reachable commits in reverse chronological order. +def rev_list_invocation(ref_or_refs, count=None, format=None): + if isinstance(ref_or_refs, compat.str_type): + refs = (ref_or_refs,) + else: + refs = ref_or_refs + argv = ['git', 'rev-list'] + if isinstance(count, Integral): + argv.extend(['-n', str(count)]) + elif count: + raise ValueError('unexpected count argument %r' % count) + + if format: + argv.append('--pretty=format:' + format) + for ref in refs: + assert not ref.startswith('-') + argv.append(ref) + argv.append('--') + return argv + - This generator walks through commits, from child to parent, that are - reachable via the specified ref and yields a series of tuples of the form - (date,hash). +def rev_list(ref_or_refs, count=None, parse=None, format=None, repo_dir=None): + """Yield information about commits as per "git rev-list". If a format + is not provided, yield one hex hash at a time. If a format is + provided, pass it to rev-list and call parse(git_stdout) for each + commit with the stream positioned just after the rev-list "commit + HASH" header line. When a format is provided yield (oidx, + parse(git_stdout)) for each commit. - If count is a non-zero integer, limit the number of commits to "count" - objects. """ - assert(not ref.startswith('-')) - opts = [] - if count: - opts += ['-n', str(atoi(count))] - argv = ['git', 'rev-list', '--pretty=format:%at'] + opts + [ref, '--'] - p = subprocess.Popen(argv, + assert bool(parse) == bool(format) + p = subprocess.Popen(rev_list_invocation(ref_or_refs, count=count, + format=format), preexec_fn = _gitenv(repo_dir), stdout = subprocess.PIPE) - commit = None - for row in p.stdout: - s = row.strip() - if s.startswith('commit '): - commit = s[7:].decode('hex') - else: - date = int(s) - yield (date, commit) + if not format: + for line in p.stdout: + yield line.strip() + else: + line = p.stdout.readline() + while line: + s = line.strip() + if not s.startswith('commit '): + raise Exception('unexpected line ' + s) + yield s[7:], parse(p.stdout) + line = p.stdout.readline() + rv = p.wait() # not fatal if rv: raise GitError, 'git rev-list returned error %d' % rv @@ -907,10 +1025,11 @@ def update_ref(refname, newval, oldval, repo_dir=None): _git_wait('git update-ref', p) -def delete_ref(refname): - """Delete a repository reference.""" +def delete_ref(refname, oldvalue=None): + """Delete a repository reference (see git update-ref(1)).""" assert(refname.startswith('refs/')) - p = subprocess.Popen(['git', 'update-ref', '-d', refname], + oldvalue = [] if not oldvalue else [oldvalue] + p = subprocess.Popen(['git', 'update-ref', '-d', refname] + oldvalue, preexec_fn = _gitenv()) _git_wait('git update-ref', p) @@ -955,21 +1074,20 @@ def init_repo(path=None): def check_repo_or_die(path=None): - """Make sure a bup repository exists, and abort if not. - If the path to a particular repository was not specified, this function - initializes the default repository automatically. - """ + """Check to see if a bup repository probably exists, and abort if not.""" guess_repo(path) - try: - os.stat(repo('objects/pack/.')) - except OSError as e: - if e.errno == errno.ENOENT: - log('error: %r is not a bup repository; run "bup init"\n' - % repo()) + top = repo() + pst = stat_if_exists(top + '/objects/pack') + if pst and stat.S_ISDIR(pst.st_mode): + return + if not pst: + top_st = stat_if_exists(top) + if not top_st: + log('error: repository %r does not exist (see "bup help init")\n' + % top) sys.exit(15) - else: - log('error: %s\n' % e) - sys.exit(14) + log('error: %r is not a repository\n' % top) + sys.exit(14) _ver = None @@ -999,19 +1117,6 @@ def ver(): return _ver -def _git_wait(cmd, p): - rv = p.wait() - if rv != 0: - raise GitError('%s returned %d' % (cmd, rv)) - - -def _git_capture(argv): - p = subprocess.Popen(argv, stdout=subprocess.PIPE, preexec_fn = _gitenv()) - r = p.stdout.read() - _git_wait(repr(argv), p) - return r - - class _AbortableIter: def __init__(self, it, onabort = None): self.it = it @@ -1023,7 +1128,7 @@ class _AbortableIter: def next(self): try: - return self.it.next() + return next(self.it) except StopIteration as e: self.done = True raise @@ -1050,14 +1155,9 @@ class CatPipe: self.repo_dir = repo_dir wanted = ('1','5','6') if ver() < wanted: - if not _ver_warned: - log('warning: git version < %s; bup will be slow.\n' - % '.'.join(wanted)) - _ver_warned = 1 - self.get = self._slow_get - else: - self.p = self.inprogress = None - self.get = self._fast_get + log('error: git version must be at least 1.5.6\n') + sys.exit(1) + self.p = self.inprogress = None def _abort(self): if self.p: @@ -1066,7 +1166,7 @@ class CatPipe: self.p = None self.inprogress = None - def _restart(self): + def restart(self): self._abort() self.p = subprocess.Popen(['git', 'cat-file', '--batch'], stdin=subprocess.PIPE, @@ -1075,35 +1175,39 @@ class CatPipe: bufsize = 4096, preexec_fn = _gitenv(self.repo_dir)) - def _fast_get(self, id): + def get(self, ref): + """Yield (oidx, type, size), followed by the data referred to by ref. + If ref does not exist, only yield (None, None, None). + + """ if not self.p or self.p.poll() != None: - self._restart() + self.restart() assert(self.p) poll_result = self.p.poll() assert(poll_result == None) if self.inprogress: - log('_fast_get: opening %r while %r is open\n' - % (id, self.inprogress)) + log('get: opening %r while %r is open\n' % (ref, self.inprogress)) assert(not self.inprogress) - assert(id.find('\n') < 0) - assert(id.find('\r') < 0) - assert(not id.startswith('-')) - self.inprogress = id - self.p.stdin.write('%s\n' % id) + assert(ref.find('\n') < 0) + assert(ref.find('\r') < 0) + assert(not ref.startswith('-')) + self.inprogress = ref + self.p.stdin.write('%s\n' % ref) self.p.stdin.flush() hdr = self.p.stdout.readline() if hdr.endswith(' missing\n'): self.inprogress = None - raise KeyError('blob %r is missing' % id) - spl = hdr.split(' ') - if len(spl) != 3 or len(spl[0]) != 40: - raise GitError('expected blob, got %r' % spl) - (hex, type, size) = spl - - it = _AbortableIter(chunkyreader(self.p.stdout, int(spl[2])), - onabort = self._abort) + yield None, None, None + return + info = hdr.split(' ') + if len(info) != 3 or len(info[0]) != 40: + raise GitError('expected object (id, type, size), got %r' % spl) + oidx, typ, size = info + size = int(size) + it = _AbortableIter(chunkyreader(self.p.stdout, size), + onabort=self._abort) try: - yield type + yield oidx, typ, size for blob in it: yield blob readline_result = self.p.stdout.readline() @@ -1113,38 +1217,24 @@ class CatPipe: it.abort() raise - def _slow_get(self, id): - assert(id.find('\n') < 0) - assert(id.find('\r') < 0) - assert(id[0] != '-') - type = _git_capture(['git', 'cat-file', '-t', id]).strip() - yield type - - p = subprocess.Popen(['git', 'cat-file', type, id], - stdout=subprocess.PIPE, - preexec_fn = _gitenv(self.repo_dir)) - for blob in chunkyreader(p.stdout): - yield blob - _git_wait('git cat-file', p) - def _join(self, it): - type = it.next() - if type == 'blob': + _, typ, _ = next(it) + if typ == 'blob': for blob in it: yield blob - elif type == 'tree': + elif typ == 'tree': treefile = ''.join(it) for (mode, name, sha) in tree_decode(treefile): for blob in self.join(sha.encode('hex')): yield blob - elif type == 'commit': + elif typ == 'commit': treeline = ''.join(it).split('\n')[0] assert(treeline.startswith('tree ')) for blob in self.join(treeline[5:]): yield blob else: raise GitError('invalid object type %r: expected blob/tree/commit' - % type) + % typ) def join(self, id): """Generate a list of the content of all blobs that can be reached @@ -1163,9 +1253,9 @@ _cp = {} def cp(repo_dir=None): """Create a CatPipe object or reuse the already existing one.""" - global _cp + global _cp, repodir if not repo_dir: - repo_dir = repo() + repo_dir = repodir or repo() repo_dir = os.path.abspath(repo_dir) cp = _cp.get(repo_dir) if not cp: @@ -1184,3 +1274,93 @@ def tags(repo_dir = None): tags[c] = [] tags[c].append(name) # more than one tag can point at 'c' return tags + + +class MissingObject(KeyError): + def __init__(self, oid): + self.oid = oid + KeyError.__init__(self, 'object %r is missing' % oid.encode('hex')) + + +WalkItem = namedtuple('WalkItem', ['oid', 'type', 'mode', + 'path', 'chunk_path', 'data']) +# The path is the mangled path, and if an item represents a fragment +# of a chunked file, the chunk_path will be the chunked subtree path +# for the chunk, i.e. ['', '2d3115e', ...]. The top-level path for a +# chunked file will have a chunk_path of ['']. So some chunk subtree +# of the file '/foo/bar/baz' might look like this: +# +# item.path = ['foo', 'bar', 'baz.bup'] +# item.chunk_path = ['', '2d3115e', '016b097'] +# item.type = 'tree' +# ... + + +def walk_object(cat_pipe, oidx, + stop_at=None, + include_data=None): + """Yield everything reachable from oidx via cat_pipe as a WalkItem, + stopping whenever stop_at(oidx) returns true. Throw MissingObject + if a hash encountered is missing from the repository, and don't + read or return blob content in the data field unless include_data + is set. + """ + # Maintain the pending stack on the heap to avoid stack overflow + pending = [(oidx, [], [], None)] + while len(pending): + oidx, parent_path, chunk_path, mode = pending.pop() + oid = oidx.decode('hex') + if stop_at and stop_at(oidx): + continue + + if (not include_data) and mode and stat.S_ISREG(mode): + # If the object is a "regular file", then it's a leaf in + # the graph, so we can skip reading the data if the caller + # hasn't requested it. + yield WalkItem(oid=oid, type='blob', + chunk_path=chunk_path, path=parent_path, + mode=mode, + data=None) + continue + + item_it = cat_pipe.get(oidx) + get_oidx, typ, _ = next(item_it) + if not get_oidx: + raise MissingObject(oidx.decode('hex')) + if typ not in ('blob', 'commit', 'tree'): + raise Exception('unexpected repository object type %r' % typ) + + # FIXME: set the mode based on the type when the mode is None + if typ == 'blob' and not include_data: + # Dump data until we can ask cat_pipe not to fetch it + for ignored in item_it: + pass + data = None + else: + data = ''.join(item_it) + + yield WalkItem(oid=oid, type=typ, + chunk_path=chunk_path, path=parent_path, + mode=mode, + data=(data if include_data else None)) + + if typ == 'commit': + commit_items = parse_commit(data) + for pid in commit_items.parents: + pending.append((pid, parent_path, chunk_path, mode)) + pending.append((commit_items.tree, parent_path, chunk_path, + hashsplit.GIT_MODE_TREE)) + elif typ == 'tree': + for mode, name, ent_id in tree_decode(data): + demangled, bup_type = demangle_name(name, mode) + if chunk_path: + sub_path = parent_path + sub_chunk_path = chunk_path + [name] + else: + sub_path = parent_path + [name] + if bup_type == BUP_CHUNKED: + sub_chunk_path = [''] + else: + sub_chunk_path = chunk_path + pending.append((ent_id.encode('hex'), sub_path, sub_chunk_path, + mode))