]> arthur.barton.de Git - bup.git/blobdiff - lib/bup/git.py
Retrieve the dates for all branches with one bulk git call in the VFS.
[bup.git] / lib / bup / git.py
index f3774bcd12829cc7c8e218b94c5b403228c4cb3b..2552c45fdcac4321b0b9f9718192b3353e4b2eb7 100644 (file)
@@ -4,14 +4,13 @@ interact with the Git data structures.
 """
 import os, sys, zlib, time, subprocess, struct, stat, re, tempfile, glob
 from bup.helpers import *
-from bup import _helpers, path, bloom
+from bup import _helpers, path, midx, bloom, xstat
 
-MIDX_VERSION = 4
-SEEK_END=2  # os.SEEK_END is not defined in python 2.4
+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
-home_repodir = os.path.expanduser('~/.bup')
 repodir = None
 
 _typemap =  { 'blob':3, 'tree':2, 'commit':1, 'tag':4 }
@@ -39,6 +38,11 @@ def repo(sub = ''):
     return os.path.join(repodir, sub)
 
 
+def shorten_hash(s):
+    return re.sub(r'([^0-9a-z]|\b)([0-9a-z]{7})[0-9a-z]{33}([^0-9a-z]|\b)',
+                  r'\1\2*\3', s)
+
+
 def repo_rel(path):
     full = os.path.abspath(path)
     fullrepo = os.path.abspath(repo(''))
@@ -48,7 +52,7 @@ def repo_rel(path):
         path = full[len(fullrepo):]
     if path.startswith('index-cache/'):
         path = path[len('index-cache/'):]
-    return path
+    return shorten_hash(path)
 
 
 def all_packdirs():
@@ -113,7 +117,53 @@ def demangle_name(name):
         return (name, BUP_NORMAL)
 
 
-def _encode_packobj(type, content):
+def calc_hash(type, content):
+    """Calculate some content's hash in the Git fashion."""
+    header = '%s %d\0' % (type, len(content))
+    sum = Sha1(header)
+    sum.update(content)
+    return sum.digest()
+
+
+def shalist_item_sort_key(ent):
+    (mode, name, id) = ent
+    assert(mode+0 == mode)
+    if stat.S_ISDIR(mode):
+        return name + '/'
+    else:
+        return name
+
+
+def tree_encode(shalist):
+    """Generate a git tree object from (mode,name,hash) tuples."""
+    shalist = sorted(shalist, key = shalist_item_sort_key)
+    l = []
+    for (mode,name,bin) in shalist:
+        assert(mode)
+        assert(mode+0 == mode)
+        assert(name)
+        assert(len(bin) == 20)
+        s = '%o %s\0%s' % (mode,name,bin)
+        assert(s[0] != '0')  # 0-padded octal is not acceptable in a git tree
+        l.append(s)
+    return ''.join(l)
+
+
+def tree_decode(buf):
+    """Generate a list of (mode,name,hash) from the git tree object in buf."""
+    ofs = 0
+    while ofs < len(buf):
+        z = buf.find('\0', ofs)
+        assert(z > ofs)
+        spl = buf[ofs:z].split(' ', 1)
+        assert(len(spl) == 2)
+        mode,name = spl
+        sha = buf[z+1:z+1+20]
+        ofs = z+1+20
+        yield (int(mode, 8), name, sha)
+
+
+def _encode_packobj(type, content, compression_level=1):
     szout = ''
     sz = len(content)
     szbits = (sz & 0x0f) | (_typemap[type]<<4)
@@ -125,14 +175,18 @@ def _encode_packobj(type, content):
             break
         szbits = sz & 0x7f
         sz >>= 7
-    z = zlib.compressobj(1)
+    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)
     yield z.flush()
 
 
-def _encode_looseobj(type, content):
-    z = zlib.compressobj(1)
+def _encode_looseobj(type, content, compression_level=1):
+    z = zlib.compressobj(compression_level)
     yield z.compress('%s %d\0' % (type, len(content)))
     yield z.compress(content)
     yield z.flush()
@@ -270,108 +324,6 @@ class PackIdxV2(PackIdx):
             yield buffer(self.map, 8 + 256*4 + 20*i, 20)
 
 
-extract_bits = _helpers.extract_bits
-
-class PackMidx:
-    """Wrapper which contains data from multiple index files.
-    Multiple index (.midx) files constitute a wrapper around index (.idx) files
-    and make it possible for bup to expand Git's indexing capabilities to vast
-    amounts of files.
-    """
-    def __init__(self, filename):
-        self.name = filename
-        self.force_keep = False
-        assert(filename.endswith('.midx'))
-        self.map = mmap_read(open(filename))
-        if str(self.map[0:4]) != 'MIDX':
-            log('Warning: skipping: invalid MIDX header in %r\n' % filename)
-            self.force_keep = True
-            return self._init_failed()
-        ver = struct.unpack('!I', self.map[4:8])[0]
-        if ver < MIDX_VERSION:
-            log('Warning: ignoring old-style (v%d) midx %r\n' 
-                % (ver, filename))
-            self.force_keep = False  # old stuff is boring  
-            return self._init_failed()
-        if ver > MIDX_VERSION:
-            log('Warning: ignoring too-new (v%d) midx %r\n'
-                % (ver, filename))
-            self.force_keep = True  # new stuff is exciting
-            return self._init_failed()
-
-        self.bits = _helpers.firstword(self.map[8:12])
-        self.entries = 2**self.bits
-        self.fanout = buffer(self.map, 12, self.entries*4)
-        self.sha_ofs = 12 + self.entries*4
-        self.nsha = nsha = self._fanget(self.entries-1)
-        self.shatable = buffer(self.map, self.sha_ofs, nsha*20)
-        self.which_ofs = self.sha_ofs + 20*nsha
-        self.whichlist = buffer(self.map, self.which_ofs, nsha*4)
-        self.idxnames = str(self.map[self.which_ofs + 4*nsha:]).split('\0')
-
-    def _init_failed(self):
-        self.bits = 0
-        self.entries = 1
-        self.fanout = buffer('\0\0\0\0')
-        self.shatable = buffer('\0'*20)
-        self.idxnames = []
-
-    def _fanget(self, i):
-        start = i*4
-        s = self.fanout[start:start+4]
-        return _helpers.firstword(s)
-
-    def _get(self, i):
-        return str(self.shatable[i*20:(i+1)*20])
-
-    def _get_idx_i(self, i):
-        return struct.unpack('!I', self.whichlist[i*4:(i+1)*4])[0]
-
-    def _get_idxname(self, i):
-        return self.idxnames[self._get_idx_i(i)]
-
-    def exists(self, hash, want_source=False):
-        """Return nonempty if the object exists in the index files."""
-        global _total_searches, _total_steps
-        _total_searches += 1
-        want = str(hash)
-        el = extract_bits(want, self.bits)
-        if el:
-            start = self._fanget(el-1)
-            startv = el << (32-self.bits)
-        else:
-            start = 0
-            startv = 0
-        end = self._fanget(el)
-        endv = (el+1) << (32-self.bits)
-        _total_steps += 1   # lookup table is a step
-        hashv = _helpers.firstword(hash)
-        #print '(%08x) %08x %08x %08x' % (extract_bits(want, 32), startv, hashv, endv)
-        while start < end:
-            _total_steps += 1
-            #print '! %08x %08x %08x   %d - %d' % (startv, hashv, endv, start, end)
-            mid = start + (hashv-startv)*(end-start-1)/(endv-startv)
-            #print '  %08x %08x %08x   %d %d %d' % (startv, hashv, endv, start, mid, end)
-            v = self._get(mid)
-            #print '    %08x' % self._num(v)
-            if v < want:
-                start = mid+1
-                startv = _helpers.firstword(v)
-            elif v > want:
-                end = mid
-                endv = _helpers.firstword(v)
-            else: # got it!
-                return want_source and self._get_idxname(mid) or True
-        return None
-
-    def __iter__(self):
-        for i in xrange(self._fanget(self.entries-1)):
-            yield buffer(self.shatable, i*20, 20)
-
-    def __len__(self):
-        return int(self._fanget(self.entries-1))
-
-
 _mpi_count = 0
 class PackIdxList:
     def __init__(self, dir):
@@ -402,11 +354,11 @@ class PackIdxList:
         _total_searches += 1
         if hash in self.also:
             return True
-        if self.do_bloom and self.bloom is not None:
-            _total_searches -= 1  # will be incremented by bloom
+        if self.do_bloom and self.bloom:
             if self.bloom.exists(hash):
                 self.do_bloom = False
             else:
+                _total_searches -= 1  # was counted by bloom
                 return None
         for i in xrange(len(self.packs)):
             p = self.packs[i]
@@ -435,17 +387,17 @@ class PackIdxList:
         self.do_bloom = False
         skip_midx = skip_midx or ignore_midx
         d = dict((p.name, p) for p in self.packs
-                 if not skip_midx or not isinstance(p, PackMidx))
+                 if not skip_midx or not isinstance(p, midx.PackMidx))
         if os.path.exists(self.dir):
             if not skip_midx:
                 midxl = []
                 for ix in self.packs:
-                    if isinstance(ix, PackMidx):
+                    if isinstance(ix, midx.PackMidx):
                         for name in ix.idxnames:
                             d[os.path.join(self.dir, name)] = ix
                 for full in glob.glob(os.path.join(self.dir,'*.midx')):
                     if not d.get(full):
-                        mx = PackMidx(full)
+                        mx = midx.PackMidx(full)
                         (mxd, mxf) = os.path.split(mx.name)
                         broken = False
                         for n in mx.idxnames:
@@ -458,7 +410,8 @@ class PackIdxList:
                             unlink(full)
                         else:
                             midxl.append(mx)
-                midxl.sort(lambda x,y: -cmp(len(x),len(y)))
+                midxl.sort(key=lambda ix:
+                           (-len(ix), -xstat.stat(ix.name).st_mtime))
                 for ix in midxl:
                     any_needed = False
                     for sub in ix.idxnames:
@@ -500,22 +453,6 @@ class PackIdxList:
         self.also.add(hash)
 
 
-def calc_hash(type, content):
-    """Calculate some content's hash in the Git fashion."""
-    header = '%s %d\0' % (type, len(content))
-    sum = Sha1(header)
-    sum.update(content)
-    return sum.digest()
-
-
-def _shalist_sort_key(ent):
-    (mode, name, id) = ent
-    if stat.S_ISDIR(int(mode, 8)):
-        return name + '/'
-    else:
-        return name
-
-
 def open_idx(filename):
     if filename.endswith('.idx'):
         f = open(filename, 'rb')
@@ -532,7 +469,7 @@ def open_idx(filename):
         else:
             raise GitError('%s: unrecognized idx file header' % filename)
     elif filename.endswith('.midx'):
-        return PackMidx(filename)
+        return midx.PackMidx(filename)
     else:
         raise GitError('idx filenames must end with .idx or .midx')
 
@@ -553,8 +490,8 @@ def _make_objcache():
     return PackIdxList(repo('objects/pack'))
 
 class PackWriter:
-    """Writes Git objects insid a pack file."""
-    def __init__(self, objcache_maker=_make_objcache):
+    """Writes Git objects inside a pack file."""
+    def __init__(self, objcache_maker=_make_objcache, compression_level=1):
         self.count = 0
         self.outbytes = 0
         self.filename = None
@@ -562,6 +499,7 @@ class PackWriter:
         self.idx = None
         self.objcache_maker = objcache_maker
         self.objcache = None
+        self.compression_level = compression_level
 
     def __del__(self):
         self.close()
@@ -605,7 +543,11 @@ class PackWriter:
             log('>')
         if not sha:
             sha = calc_hash(type, content)
-        size, crc = self._raw_write(_encode_packobj(type, content), sha=sha)
+        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:
+            self.breakpoint()
         return sha
 
     def breakpoint(self):
@@ -628,10 +570,10 @@ class PackWriter:
 
     def maybe_write(self, type, content):
         """Write an object to the pack file if not present and return its id."""
-        self._require_objcache()
         sha = calc_hash(type, content)
         if not self.exists(sha):
             self._write(sha, type, content)
+            self._require_objcache()
             self.objcache.add(sha)
         return sha
 
@@ -641,16 +583,8 @@ class PackWriter:
 
     def new_tree(self, shalist):
         """Create a tree object in the pack."""
-        shalist = sorted(shalist, key = _shalist_sort_key)
-        l = []
-        for (mode,name,bin) in shalist:
-            assert(mode)
-            assert(mode != '0')
-            assert(mode[0] != '0')
-            assert(name)
-            assert(len(bin) == 20)
-            l.append('%s %s\0%s' % (mode,name,bin))
-        return self.maybe_write('tree', ''.join(l))
+        content = tree_encode(shalist)
+        return self.maybe_write('tree', content)
 
     def _new_commit(self, tree, parent, author, adate, committer, cdate, msg):
         l = []
@@ -719,36 +653,45 @@ class PackWriter:
         return self._end(run_midx=run_midx)
 
     def _write_pack_idx_v2(self, filename, idx, packbin):
+        ofs64_count = 0
+        for section in idx:
+            for entry in section:
+                if entry[2] >= 2**31:
+                    ofs64_count += 1
+
+        # Length: header + fan-out + shas-and-crcs + overflow-offsets
+        index_len = 8 + (4 * 256) + (28 * self.count) + (8 * ofs64_count)
+        idx_map = None
         idx_f = open(filename, 'w+b')
-        idx_f.write('\377tOc\0\0\0\2')
-
-        ofs64_ofs = 8 + 4*256 + 28*self.count
-        idx_f.truncate(ofs64_ofs)
-        idx_f.seek(0)
-        idx_map = mmap_readwrite(idx_f, close=False)
-        idx_f.seek(0, SEEK_END)
-        count = _helpers.write_idx(idx_f, idx_map, idx, self.count)
-        assert(count == self.count)
-        idx_map.close()
-        idx_f.write(packbin)
-
-        idx_f.seek(0)
-        idx_sum = Sha1()
-        b = idx_f.read(8 + 4*256)
-        idx_sum.update(b)
-
-        obj_list_sum = Sha1()
-        for b in chunkyreader(idx_f, 20*self.count):
+        try:
+            idx_f.truncate(index_len)
+            idx_map = mmap_readwrite(idx_f, close=False)
+            count = _helpers.write_idx(filename, idx_map, idx, self.count)
+            assert(count == self.count)
+        finally:
+            if idx_map: idx_map.close()
+            idx_f.close()
+
+        idx_f = open(filename, 'a+b')
+        try:
+            idx_f.write(packbin)
+            idx_f.seek(0)
+            idx_sum = Sha1()
+            b = idx_f.read(8 + 4*256)
             idx_sum.update(b)
-            obj_list_sum.update(b)
-        namebase = obj_list_sum.hexdigest()
 
-        for b in chunkyreader(idx_f):
-            idx_sum.update(b)
-        idx_f.write(idx_sum.digest())
-        idx_f.close()
+            obj_list_sum = Sha1()
+            for b in chunkyreader(idx_f, 20*self.count):
+                idx_sum.update(b)
+                obj_list_sum.update(b)
+            namebase = obj_list_sum.hexdigest()
 
-        return namebase
+            for b in chunkyreader(idx_f):
+                idx_sum.update(b)
+            idx_f.write(idx_sum.digest())
+            return namebase
+        finally:
+            idx_f.close()
 
 
 def _git_date(date):
@@ -801,7 +744,7 @@ def rev_list(ref, count=None):
     opts = []
     if count:
         opts += ['-n', str(atoi(count))]
-    argv = ['git', 'rev-list', '--pretty=format:%ct'] + opts + [ref, '--']
+    argv = ['git', 'rev-list', '--pretty=format:%at'] + opts + [ref, '--']
     p = subprocess.Popen(argv, preexec_fn = _gitenv, stdout = subprocess.PIPE)
     commit = None
     for row in p.stdout:
@@ -816,11 +759,13 @@ def rev_list(ref, count=None):
         raise GitError, 'git rev-list returned error %d' % rv
 
 
-def rev_get_date(ref):
-    """Get the date of the latest commit on the specified ref."""
-    for (date, commit) in rev_list(ref, count=1):
-        return date
-    raise GitError, 'no such commit %r' % ref
+def get_commit_dates(refs):
+    """Get the dates for the specified commit refs."""
+    result = []
+    cmd = ['git', 'show', '-s', '--pretty=format:%ct']
+    for chunk in batchpipe(cmd, refs, preexec_fn=_gitenv):
+        result += chunk.splitlines()
+    return result
 
 
 def rev_parse(committish):
@@ -885,7 +830,7 @@ def init_repo(path=None):
     if parent and not os.path.exists(parent):
         raise GitError('parent directory "%s" does not exist\n' % parent)
     if os.path.exists(d) and not os.path.isdir(os.path.join(d, '.')):
-        raise GitError('"%d" exists but is not a directory\n' % d)
+        raise GitError('"%s" exists but is not a directory\n' % d)
     p = subprocess.Popen(['git', '--bare', 'init'], stdout=sys.stderr,
                          preexec_fn = _gitenv)
     _git_wait('git init', p)
@@ -894,6 +839,10 @@ def init_repo(path=None):
     p = subprocess.Popen(['git', 'config', 'pack.indexVersion', '2'],
                          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)
+    _git_wait('git config', p)
 
 
 def check_repo_or_die(path=None):
@@ -902,25 +851,16 @@ def check_repo_or_die(path=None):
     initializes the default repository automatically.
     """
     guess_repo(path)
-    if not os.path.isdir(repo('objects/pack/.')):
-        if repodir == home_repodir:
-            init_repo()
-        else:
-            log('error: %r is not a bup/git repository\n' % repo())
+    try:
+        os.stat(repo('objects/pack/.'))
+    except OSError, e:
+        if e.errno == errno.ENOENT:
+            log('error: %r is not a bup repository; run "bup init"\n'
+                % repo())
             sys.exit(15)
-
-
-def treeparse(buf):
-    """Generate a list of (mode, name, hash) tuples of objects from 'buf'."""
-    ofs = 0
-    while ofs < len(buf):
-        z = buf[ofs:].find('\0')
-        assert(z > 0)
-        spl = buf[ofs:ofs+z].split(' ', 1)
-        assert(len(spl) == 2)
-        sha = buf[ofs+z+1:ofs+z+1+20]
-        ofs += z+1+20
-        yield (spl[0], spl[1], sha)
+        else:
+            log('error: %s\n' % e)
+            sys.exit(14)
 
 
 _ver = None
@@ -1029,9 +969,10 @@ class CatPipe:
         if not self.p or self.p.poll() != None:
             self._restart()
         assert(self.p)
-        assert(self.p.poll() == None)
+        poll_result = self.p.poll()
+        assert(poll_result == None)
         if self.inprogress:
-            log('_fast_get: opening %r while %r is open'
+            log('_fast_get: opening %r while %r is open\n'
                 % (id, self.inprogress))
         assert(not self.inprogress)
         assert(id.find('\n') < 0)
@@ -1055,7 +996,8 @@ class CatPipe:
             yield type
             for blob in it:
                 yield blob
-            assert(self.p.stdout.readline() == '\n')
+            readline_result = self.p.stdout.readline()
+            assert(readline_result == '\n')
             self.inprogress = None
         except Exception, e:
             it.abort()
@@ -1082,7 +1024,7 @@ class CatPipe:
                 yield blob
         elif type == 'tree':
             treefile = ''.join(it)
-            for (mode, name, sha) in treeparse(treefile):
+            for (mode, name, sha) in tree_decode(treefile):
                 for blob in self.join(sha.encode('hex')):
                     yield blob
         elif type == 'commit':