]> arthur.barton.de Git - bup.git/blobdiff - lib/bup/git.py
git.py: allow the specification of a repo_dir to update_ref()
[bup.git] / lib / bup / git.py
index 1e2364aaf3b924e114eb6e264c34cd0eceb943db..4825a19820f813227304131ac79374d899000fb2 100644 (file)
@@ -3,6 +3,8 @@ bup repositories are in Git format. This library allows us to
 interact with the Git data structures.
 """
 import os, sys, zlib, time, subprocess, struct, stat, re, tempfile, glob
+from collections import namedtuple
+
 from bup.helpers import *
 from bup import _helpers, path, midx, bloom, xstat
 
@@ -24,18 +26,79 @@ class GitError(Exception):
     pass
 
 
-def repo(sub = ''):
+def parse_tz_offset(s):
+    """UTC offset in seconds."""
+    tz_off = (int(s[1:3]) * 60 * 60) + (int(s[3:5]) * 60)
+    if s[0] == '-':
+        return - tz_off
+    return tz_off
+
+
+# FIXME: derived from http://git.rsbx.net/Documents/Git_Data_Formats.txt
+# Make sure that's authoritative.
+_start_end_char = r'[^ .,:;<>"\'\0\n]'
+_content_char = r'[^\0\n<>]'
+_safe_str_rx = '(?:%s{1,2}|(?:%s%s*%s))' \
+    % (_start_end_char,
+       _start_end_char, _content_char, _start_end_char)
+_tz_rx = r'[-+]\d\d[0-5]\d'
+_parent_rx = r'(?:parent [abcdefABCDEF0123456789]{40}\n)'
+_commit_rx = re.compile(r'''tree (?P<tree>[abcdefABCDEF0123456789]{40})
+(?P<parents>%s*)author (?P<author_name>%s) <(?P<author_mail>%s)> (?P<asec>\d+) (?P<atz>%s)
+committer (?P<committer_name>%s) <(?P<committer_mail>%s)> (?P<csec>\d+) (?P<ctz>%s)
+
+(?P<message>(?:.|\n)*)''' % (_parent_rx,
+                             _safe_str_rx, _safe_str_rx, _tz_rx,
+                             _safe_str_rx, _safe_str_rx, _tz_rx))
+_parent_hash_rx = re.compile(r'\s*parent ([abcdefABCDEF0123456789]{40})\s*')
+
+
+# Note that the author_sec and committer_sec values are (UTC) epoch seconds.
+CommitInfo = namedtuple('CommitInfo', ['tree', 'parents',
+                                       'author_name', 'author_mail',
+                                       'author_sec', 'author_offset',
+                                       'committer_name', 'committer_mail',
+                                       'committer_sec', 'committer_offset',
+                                       'message'])
+
+def parse_commit(content):
+    commit_match = re.match(_commit_rx, content)
+    if not commit_match:
+        raise Exception('cannot parse commit %r' % content)
+    matches = commit_match.groupdict()
+    return CommitInfo(tree=matches['tree'],
+                      parents=re.findall(_parent_hash_rx, matches['parents']),
+                      author_name=matches['author_name'],
+                      author_mail=matches['author_mail'],
+                      author_sec=int(matches['asec']),
+                      author_offset=parse_tz_offset(matches['atz']),
+                      committer_name=matches['committer_name'],
+                      committer_mail=matches['committer_mail'],
+                      committer_sec=int(matches['csec']),
+                      committer_offset=parse_tz_offset(matches['ctz']),
+                      message=matches['message'])
+
+
+def get_commit_items(id, cp):
+    commit_it = cp.get(id)
+    assert(commit_it.next() == 'commit')
+    commit_content = ''.join(commit_it)
+    return parse_commit(commit_content)
+
+
+def repo(sub = '', repo_dir=None):
     """Get the path to the git repository or one of its subdirectories."""
     global repodir
-    if not repodir:
+    repo_dir = repo_dir or repodir
+    if not repo_dir:
         raise GitError('You should call check_repo_or_die()')
 
     # If there's a .git subdirectory, then the actual repo is in there.
-    gd = os.path.join(repodir, '.git')
+    gd = os.path.join(repo_dir, '.git')
     if os.path.exists(gd):
         repodir = gd
 
-    return os.path.join(repodir, sub)
+    return os.path.join(repo_dir, sub)
 
 
 def shorten_hash(s):
@@ -87,9 +150,10 @@ def mangle_name(name, mode, gitmode):
     """Mangle a file name to present an abstract name for segmented files.
     Mangled file names will have the ".bup" extension added to them. If a
     file's name already ends with ".bup", a ".bupl" extension is added to
-    disambiguate normal files from semgmented ones.
+    disambiguate normal files from segmented ones.
     """
     if stat.S_ISREG(mode) and not stat.S_ISREG(gitmode):
+        assert(stat.S_ISDIR(gitmode))
         return name + '.bup'
     elif name.endswith('.bup') or name[:-1].endswith('.bup'):
         return name + '.bupl'
@@ -105,9 +169,9 @@ def demangle_name(name):
     the following:
 
     * BUP_NORMAL  : files that should be read as-is from the repository
-    * BUP_CHUNKED : files that were chunked and need to be assembled
+    * BUP_CHUNKED : files that were chunked and need to be reassembled
 
-    For more information on the name mangling algorythm, see mangle_name()
+    For more information on the name mangling algorithm, see mangle_name()
     """
     if name.endswith('.bupl'):
         return (name[:-5], BUP_NORMAL)
@@ -406,6 +470,7 @@ class PackIdxList:
                                     '  used by %s\n') % (n, mxf))
                                 broken = True
                         if broken:
+                            mx.close()
                             del mx
                             unlink(full)
                         else:
@@ -427,6 +492,7 @@ class PackIdxList:
                     elif not ix.force_keep:
                         debug1('midx: removing redundant: %s\n'
                                % os.path.basename(ix.name))
+                        ix.close()
                         unlink(ix.name)
             for full in glob.glob(os.path.join(self.dir,'*.idx')):
                 if not d.get(full):
@@ -698,18 +764,24 @@ def _git_date(date):
     return '%d %s' % (date, time.strftime('%z', time.localtime(date)))
 
 
-def _gitenv():
-    os.environ['GIT_DIR'] = os.path.abspath(repo())
+def _gitenv(repo_dir = None):
+    if not repo_dir:
+        repo_dir = repo()
+    def env():
+        os.environ['GIT_DIR'] = os.path.abspath(repo_dir)
+    return env
 
 
-def list_refs(refname = None):
+def list_refs(refname = None, repo_dir = None):
     """Generate a list of tuples in the form (refname,hash).
     If a ref name is specified, list only this particular ref.
     """
     argv = ['git', 'show-ref', '--']
     if refname:
         argv += [refname]
-    p = subprocess.Popen(argv, preexec_fn = _gitenv, stdout = subprocess.PIPE)
+    p = subprocess.Popen(argv,
+                         preexec_fn = _gitenv(repo_dir),
+                         stdout = subprocess.PIPE)
     out = p.stdout.read().strip()
     rv = p.wait()  # not fatal
     if rv:
@@ -720,9 +792,9 @@ def list_refs(refname = None):
             yield (name, sha.decode('hex'))
 
 
-def read_ref(refname):
+def read_ref(refname, repo_dir = None):
     """Get the commit id of the most recent commit made on a given ref."""
-    l = list(list_refs(refname))
+    l = list(list_refs(refname, repo_dir))
     if l:
         assert(len(l) == 1)
         return l[0][1]
@@ -730,7 +802,7 @@ def read_ref(refname):
         return None
 
 
-def rev_list(ref, count=None):
+def rev_list(ref, count=None, repo_dir=None):
     """Generate a list of reachable commits in reverse chronological order.
 
     This generator walks through commits, from child to parent, that are
@@ -745,7 +817,9 @@ def rev_list(ref, count=None):
     if count:
         opts += ['-n', str(atoi(count))]
     argv = ['git', 'rev-list', '--pretty=format:%at'] + opts + [ref, '--']
-    p = subprocess.Popen(argv, preexec_fn = _gitenv, stdout = subprocess.PIPE)
+    p = subprocess.Popen(argv,
+                         preexec_fn = _gitenv(repo_dir),
+                         stdout = subprocess.PIPE)
     commit = None
     for row in p.stdout:
         s = row.strip()
@@ -759,16 +833,18 @@ def rev_list(ref, count=None):
         raise GitError, 'git rev-list returned error %d' % rv
 
 
-def get_commit_dates(refs):
-    """Get the dates for the specified commit refs."""
+def get_commit_dates(refs, repo_dir=None):
+    """Get the dates for the specified commit refs.  For now, every unique
+       string in refs must resolve to a different commit or this
+       function will fail."""
     result = []
-    cmd = ['git', 'show', '-s', '--pretty=format:%ct']
-    for chunk in batchpipe(cmd, refs, preexec_fn=_gitenv):
-        result += [int(x) for x in chunk.splitlines()]
+    for ref in refs:
+        commit = get_commit_items(ref, cp(repo_dir))
+        result.append(commit.author_sec)
     return result
 
 
-def rev_parse(committish):
+def rev_parse(committish, repo_dir=None):
     """Resolve the full hash for 'committish', if it exists.
 
     Should be roughly equivalent to 'git rev-parse'.
@@ -776,12 +852,12 @@ def rev_parse(committish):
     Returns the hex value of the hash if it is found, None if 'committish' does
     not correspond to anything.
     """
-    head = read_ref(committish)
+    head = read_ref(committish, repo_dir=repo_dir)
     if head:
         debug2("resolved from ref: commit = %s\n" % head.encode('hex'))
         return head
 
-    pL = PackIdxList(repo('objects/pack'))
+    pL = PackIdxList(repo('objects/pack', repo_dir=repo_dir))
 
     if len(committish) == 40:
         try:
@@ -795,14 +871,14 @@ def rev_parse(committish):
     return None
 
 
-def update_ref(refname, newval, oldval):
+def update_ref(refname, newval, oldval, repo_dir=None):
     """Change the commit pointed to by a branch."""
     if not oldval:
         oldval = ''
     assert(refname.startswith('refs/heads/'))
     p = subprocess.Popen(['git', 'update-ref', refname,
                           newval.encode('hex'), oldval.encode('hex')],
-                         preexec_fn = _gitenv)
+                         preexec_fn = _gitenv(repo_dir))
     _git_wait('git update-ref', p)
 
 
@@ -832,16 +908,16 @@ def init_repo(path=None):
     if os.path.exists(d) and not os.path.isdir(os.path.join(d, '.')):
         raise GitError('"%s" exists but is not a directory\n' % d)
     p = subprocess.Popen(['git', '--bare', 'init'], stdout=sys.stderr,
-                         preexec_fn = _gitenv)
+                         preexec_fn = _gitenv())
     _git_wait('git init', p)
     # Force the index version configuration in order to ensure bup works
     # regardless of the version of the installed Git binary.
     p = subprocess.Popen(['git', 'config', 'pack.indexVersion', '2'],
-                         stdout=sys.stderr, preexec_fn = _gitenv)
+                         stdout=sys.stderr, preexec_fn = _gitenv())
     _git_wait('git config', p)
     # Enable the reflog
     p = subprocess.Popen(['git', 'config', 'core.logAllRefUpdates', 'true'],
-                         stdout=sys.stderr, preexec_fn = _gitenv)
+                         stdout=sys.stderr, preexec_fn = _gitenv())
     _git_wait('git config', p)
 
 
@@ -897,7 +973,7 @@ def _git_wait(cmd, p):
 
 
 def _git_capture(argv):
-    p = subprocess.Popen(argv, stdout=subprocess.PIPE, preexec_fn = _gitenv)
+    p = subprocess.Popen(argv, stdout=subprocess.PIPE, preexec_fn = _gitenv())
     r = p.stdout.read()
     _git_wait(repr(argv), p)
     return r
@@ -936,8 +1012,9 @@ class _AbortableIter:
 _ver_warned = 0
 class CatPipe:
     """Link to 'git cat-file' that is used to retrieve blob data."""
-    def __init__(self):
+    def __init__(self, repo_dir = None):
         global _ver_warned
+        self.repo_dir = repo_dir
         wanted = ('1','5','6')
         if ver() < wanted:
             if not _ver_warned:
@@ -963,7 +1040,7 @@ class CatPipe:
                                   stdout=subprocess.PIPE,
                                   close_fds = True,
                                   bufsize = 4096,
-                                  preexec_fn = _gitenv)
+                                  preexec_fn = _gitenv(self.repo_dir))
 
     def _fast_get(self, id):
         if not self.p or self.p.poll() != None:
@@ -1012,7 +1089,7 @@ class CatPipe:
 
         p = subprocess.Popen(['git', 'cat-file', type, id],
                              stdout=subprocess.PIPE,
-                             preexec_fn = _gitenv)
+                             preexec_fn = _gitenv(self.repo_dir))
         for blob in chunkyreader(p.stdout):
             yield blob
         _git_wait('git cat-file', p)
@@ -1048,15 +1125,30 @@ class CatPipe:
         except StopIteration:
             log('booger!\n')
 
-def tags():
+
+_cp = {}
+
+def cp(repo_dir=None):
+    """Create a CatPipe object or reuse the already existing one."""
+    global _cp
+    if not repo_dir:
+        repo_dir = repo()
+    repo_dir = os.path.abspath(repo_dir)
+    cp = _cp.get(repo_dir)
+    if not cp:
+        cp = CatPipe(repo_dir)
+        _cp[repo_dir] = cp
+    return cp
+
+
+def tags(repo_dir = None):
     """Return a dictionary of all tags in the form {hash: [tag_names, ...]}."""
     tags = {}
-    for (n,c) in list_refs():
+    for (n,c) in list_refs(repo_dir = repo_dir):
         if n.startswith('refs/tags/'):
             name = n[10:]
             if not c in tags:
                 tags[c] = []
 
             tags[c].append(name)  # more than one tag can point at 'c'
-
     return tags