-import os, errno, zlib, time, sha, subprocess
+import os, errno, zlib, time, sha, subprocess, struct, mmap
from helpers import *
+verbose = 0
-def hash_raw(type, s):
- header = '%s %d\0' % (type, len(s))
+def repodir(sub = ''):
+ return os.path.join(os.environ.get('BUP_DIR', '.git'), sub)
+
+
+class PackIndex:
+ def __init__(self, filename):
+ self.name = filename
+ f = open(filename)
+ self.map = mmap.mmap(f.fileno(), 0,
+ mmap.MAP_SHARED, mmap.PROT_READ)
+ f.close() # map will persist beyond file close
+ assert(str(self.map[0:8]) == '\377tOc\0\0\0\2')
+ self.fanout = list(struct.unpack('!256I', buffer(self.map, 8, 256*4)))
+ self.fanout.append(0) # entry "-1"
+ nsha = self.fanout[255]
+ self.ofstable = buffer(self.map,
+ 8 + 256*4 + nsha*20 + nsha*4,
+ nsha*4)
+ self.ofs64table = buffer(self.map,
+ 8 + 256*4 + nsha*20 + nsha*4 + nsha*4)
+
+ def _ofs_from_idx(self, idx):
+ ofs = struct.unpack('!I', buffer(self.ofstable, idx*4, 4))[0]
+ if ofs & 0x80000000:
+ idx64 = ofs & 0x7fffffff
+ ofs = struct.unpack('!I', buffer(self.ofs64table, idx64*8, 8))[0]
+ return ofs
+
+ def _idx_from_hash(self, hash):
+ assert(len(hash) == 20)
+ b1 = ord(hash[0])
+ start = self.fanout[b1-1] # range -1..254
+ end = self.fanout[b1] # range 0..255
+ buf = buffer(self.map, 8 + 256*4, end*20)
+ want = buffer(hash)
+ while start < end:
+ mid = start + (end-start)/2
+ v = buffer(buf, mid*20, 20)
+ if v < want:
+ start = mid+1
+ elif v > want:
+ end = mid
+ else: # got it!
+ return mid
+ return None
+
+ def find_offset(self, hash):
+ idx = self._idx_from_hash(hash)
+ if idx != None:
+ return self._ofs_from_idx(idx)
+ return None
+
+ def exists(self, hash):
+ return (self._idx_from_hash(hash) != None) and True or None
+
+
+class MultiPackIndex:
+ def __init__(self, dir):
+ self.packs = []
+ self.also = {}
+ for f in os.listdir(dir):
+ if f.endswith('.idx'):
+ self.packs.append(PackIndex(os.path.join(dir, f)))
+
+ def exists(self, hash):
+ if hash in self.also:
+ return True
+ for i in range(len(self.packs)):
+ p = self.packs[i]
+ if p.exists(hash):
+ # reorder so most recently used packs are searched first
+ self.packs = [p] + self.packs[:i] + self.packs[i+1:]
+ return True
+ return None
+
+ def add(self, hash):
+ self.also[hash] = 1
+
+ def zap_also(self):
+ self.also = {}
+
+
+def calc_hash(type, content):
+ header = '%s %d\0' % (type, len(content))
sum = sha.sha(header)
- sum.update(s)
- hex = sum.hexdigest()
- dir = '.git/objects/%s' % hex[0:2]
- fn = '%s/%s' % (dir, hex[2:])
- if not os.path.exists(fn):
- #log('creating %s' % fn)
- try:
- os.mkdir(dir)
- except OSError, e:
- if e.errno != errno.EEXIST:
- raise
- tfn = '%s.%d' % (fn, os.getpid())
- f = open(tfn, 'w')
+ sum.update(content)
+ return sum.digest()
+
+
+_typemap = dict(blob=3, tree=2, commit=1, tag=8)
+class PackWriter:
+ def __init__(self):
+ self.count = 0
+ self.binlist = []
+ self.objcache = MultiPackIndex(repodir('objects/pack'))
+ self.filename = None
+ self.file = None
+
+ def __del__(self):
+ self.close()
+
+ def _open(self):
+ assert(not self.file)
+ self.objcache.zap_also()
+ self.filename = repodir('objects/bup%d' % os.getpid())
+ self.file = open(self.filename + '.pack', 'w+')
+ self.file.write('PACK\0\0\0\2\0\0\0\0')
+
+ def _write(self, bin, type, content):
+ if not self.file:
+ self._open()
+ f = self.file
+
+ if verbose:
+ log('>')
+
+ sz = len(content)
+ szbits = (sz & 0x0f) | (_typemap[type]<<4)
+ sz >>= 4
+ while 1:
+ if sz: szbits |= 0x80
+ f.write(chr(szbits))
+ if not sz:
+ break
+ szbits = sz & 0x7f
+ sz >>= 7
+
z = zlib.compressobj(1)
- f.write(z.compress(header))
- f.write(z.compress(s))
+ f.write(z.compress(content))
f.write(z.flush())
- f.close()
- os.rename(tfn, fn)
- else:
- #log('exists %s' % fn)
- pass
- return hex
+ self.count += 1
+ self.binlist.append(bin)
+ return bin
+
+ def write(self, type, content):
+ return self._write(calc_hash(type, content), type, content)
-def hash_blob(blob):
- return hash_raw('blob', blob)
+ def maybe_write(self, type, content):
+ bin = calc_hash(type, content)
+ if not self.objcache.exists(bin):
+ self._write(bin, type, content)
+ self.objcache.add(bin)
+ return bin
+ def new_blob(self, blob):
+ return self.maybe_write('blob', blob)
+
+ def new_tree(self, shalist):
+ shalist = sorted(shalist, key = lambda x: x[1])
+ l = ['%s %s\0%s' % (mode,name,bin)
+ for (mode,name,bin) in shalist]
+ return self.maybe_write('tree', ''.join(l))
+
+ def _new_commit(self, tree, parent, author, adate, committer, cdate, msg):
+ l = []
+ if tree: l.append('tree %s' % tree.encode('hex'))
+ if parent: l.append('parent %s' % parent)
+ if author: l.append('author %s %s' % (author, _git_date(adate)))
+ if committer: l.append('committer %s %s' % (committer, _git_date(cdate)))
+ l.append('')
+ l.append(msg)
+ return self.maybe_write('commit', '\n'.join(l))
+
+ def new_commit(self, ref, tree, msg):
+ now = time.time()
+ userline = '%s <%s@%s>' % (userfullname(), username(), hostname())
+ oldref = ref and _read_ref(ref) or None
+ commit = self._new_commit(tree, oldref,
+ userline, now, userline, now,
+ msg)
+ self.close() # UGLY: needed so _update_ref can see the new objects
+ if ref:
+ _update_ref(ref, commit.encode('hex'), oldref)
+ return commit
+
+ def abort(self):
+ f = self.file
+ if f:
+ self.file = None
+ f.close()
+ os.unlink(self.filename + '.pack')
+
+ def close(self):
+ f = self.file
+ if not f: return None
+ self.file = None
+
+ # update object count
+ f.seek(8)
+ cp = struct.pack('!i', self.count)
+ assert(len(cp) == 4)
+ f.write(cp)
+
+ # calculate the pack sha1sum
+ f.seek(0)
+ sum = sha.sha()
+ while 1:
+ b = f.read(65536)
+ sum.update(b)
+ if not b: break
+ f.write(sum.digest())
+
+ f.close()
-def gen_tree(shalist):
- shalist = sorted(shalist, key = lambda x: x[1])
- l = ['%s %s\0%s' % (mode,name,hex.decode('hex'))
- for (mode,name,hex) in shalist]
- return hash_raw('tree', ''.join(l))
+ p = subprocess.Popen(['git', 'index-pack', '-v',
+ self.filename + '.pack'],
+ preexec_fn = _gitenv,
+ stdout = subprocess.PIPE)
+ out = p.stdout.read().strip()
+ if p.wait() or not out:
+ raise Exception('git index-pack returned an error')
+ nameprefix = repodir('objects/pack/%s' % out)
+ os.rename(self.filename + '.pack', nameprefix + '.pack')
+ os.rename(self.filename + '.idx', nameprefix + '.idx')
+ return nameprefix
def _git_date(date):
return time.strftime('%s %z', time.localtime(date))
-def _gitenv(repo):
- os.environ['GIT_DIR'] = os.path.abspath(repo)
+def _gitenv():
+ os.environ['GIT_DIR'] = os.path.abspath(repodir())
-def _read_ref(repo, refname):
+def _read_ref(refname):
p = subprocess.Popen(['git', 'show-ref', '--', refname],
- preexec_fn = lambda: _gitenv(repo),
+ preexec_fn = _gitenv,
stdout = subprocess.PIPE)
out = p.stdout.read().strip()
p.wait()
return None
-def _update_ref(repo, refname, newval, oldval):
+def _update_ref(refname, newval, oldval):
if not oldval:
oldval = ''
p = subprocess.Popen(['git', 'update-ref', '--', refname, newval, oldval],
- preexec_fn = lambda: _gitenv(repo))
+ preexec_fn = _gitenv)
p.wait()
return newval
-def gen_commit(tree, parent, author, adate, committer, cdate, msg):
- l = []
- if tree: l.append('tree %s' % tree)
- if parent: l.append('parent %s' % parent)
- if author: l.append('author %s %s' % (author, _git_date(adate)))
- if committer: l.append('committer %s %s' % (committer, _git_date(cdate)))
- l.append('')
- l.append(msg)
- return hash_raw('commit', '\n'.join(l))
-
-
-def gen_commit_easy(ref, tree, msg):
- now = time.time()
- userline = '%s <%s@%s>' % (userfullname(), username(), hostname())
- oldref = ref and _read_ref('.git', ref) or None
- commit = gen_commit(tree, oldref, userline, now, userline, now, msg)
- if ref:
- _update_ref('.git', ref, commit, oldref)
- return commit
+def init_repo():
+ d = repodir()
+ if os.path.exists(d) and not os.path.isdir(os.path.join(d, '.')):
+ raise Exception('"%d" exists but is not a directory\n' % d)
+ p = subprocess.Popen(['git', 'init', '--bare'],
+ preexec_fn = _gitenv)
+ return p.wait()
projects / bup.git / blobdiff