diff options
Diffstat (limited to 'lib/git/odb')
| -rw-r--r-- | lib/git/odb/__init__.py | 6 | ||||
| -rw-r--r-- | lib/git/odb/db.py | 337 | ||||
| -rw-r--r-- | lib/git/odb/fun.py | 108 | ||||
| -rw-r--r-- | lib/git/odb/stream.py | 446 | ||||
| -rw-r--r-- | lib/git/odb/utils.py | 38 |
5 files changed, 935 insertions, 0 deletions
diff --git a/lib/git/odb/__init__.py b/lib/git/odb/__init__.py new file mode 100644 index 00000000..5789d7eb --- /dev/null +++ b/lib/git/odb/__init__.py @@ -0,0 +1,6 @@ +"""Initialize the object database module""" + +# default imports +from db import * +from stream import * + diff --git a/lib/git/odb/db.py b/lib/git/odb/db.py new file mode 100644 index 00000000..a8de28ec --- /dev/null +++ b/lib/git/odb/db.py @@ -0,0 +1,337 @@ +"""Contains implementations of database retrieveing objects""" +from git.utils import IndexFileSHA1Writer +from git.errors import ( + InvalidDBRoot, + BadObject, + BadObjectType + ) + +from stream import ( + DecompressMemMapReader, + FDCompressedSha1Writer, + Sha1Writer, + OStream, + OInfo + ) + +from utils import ( + ENOENT, + to_hex_sha, + exists, + hex_to_bin, + isdir, + mkdir, + rename, + dirname, + join + ) + +from fun import ( + chunk_size, + loose_object_header_info, + write_object + ) + +import tempfile +import mmap +import os + + +__all__ = ('ObjectDBR', 'ObjectDBW', 'FileDBBase', 'LooseObjectDB', 'PackedDB', + 'CompoundDB', 'ReferenceDB', 'GitObjectDB' ) + +class ObjectDBR(object): + """Defines an interface for object database lookup. + Objects are identified either by hex-sha (40 bytes) or + by sha (20 bytes)""" + + def __contains__(self, sha): + return self.has_obj + + #{ Query Interface + def has_object(self, sha): + """ + :return: True if the object identified by the given 40 byte hexsha or 20 bytes + binary sha is contained in the database + :raise BadObject:""" + raise NotImplementedError("To be implemented in subclass") + + def info(self, sha): + """ :return: OInfo instance + :param sha: 40 bytes hexsha or 20 bytes binary sha + :raise BadObject:""" + raise NotImplementedError("To be implemented in subclass") + + def info_async(self, input_channel): + """Retrieve information of a multitude of objects asynchronously + :param input_channel: Channel yielding the sha's of the objects of interest + :return: Channel yielding OInfo|InvalidOInfo, in any order""" + raise NotImplementedError("To be implemented in subclass") + + def stream(self, sha): + """:return: OStream instance + :param sha: 40 bytes hexsha or 20 bytes binary sha + :raise BadObject:""" + raise NotImplementedError("To be implemented in subclass") + + def stream_async(self, input_channel): + """Retrieve the OStream of multiple objects + :param input_channel: see ``info`` + :param max_threads: see ``ObjectDBW.store`` + :return: Channel yielding OStream|InvalidOStream instances in any order""" + raise NotImplementedError("To be implemented in subclass") + + #} END query interface + +class ObjectDBW(object): + """Defines an interface to create objects in the database""" + + def __init__(self, *args, **kwargs): + self._ostream = None + + #{ Edit Interface + def set_ostream(self, stream): + """Adjusts the stream to which all data should be sent when storing new objects + :param stream: if not None, the stream to use, if None the default stream + will be used. + :return: previously installed stream, or None if there was no override + :raise TypeError: if the stream doesn't have the supported functionality""" + cstream = self._ostream + self._ostream = stream + return cstream + + def ostream(self): + """:return: overridden output stream this instance will write to, or None + if it will write to the default stream""" + return self._ostream + + def store(self, istream): + """Create a new object in the database + :return: the input istream object with its sha set to its corresponding value + :param istream: IStream compatible instance. If its sha is already set + to a value, the object will just be stored in the our database format, + in which case the input stream is expected to be in object format ( header + contents ). + :raise IOError: if data could not be written""" + raise NotImplementedError("To be implemented in subclass") + + def store_async(self, input_channel): + """Create multiple new objects in the database asynchronously. The method will + return right away, returning an output channel which receives the results as + they are computed. + + :return: Channel yielding your IStream which served as input, in any order. + The IStreams sha will be set to the sha it received during the process, + or its error attribute will be set to the exception informing about the error. + :param input_channel: Channel yielding IStream instance. + As the same instances will be used in the output channel, you can create a map + between the id(istream) -> istream + :note:As some ODB implementations implement this operation as atomic, they might + abort the whole operation if one item could not be processed. Hence check how + many items have actually been produced.""" + raise NotImplementedError("To be implemented in subclass") + + #} END edit interface + + +class FileDBBase(object): + """Provides basic facilities to retrieve files of interest, including + caching facilities to help mapping hexsha's to objects""" + + def __init__(self, root_path): + """Initialize this instance to look for its files at the given root path + All subsequent operations will be relative to this path + :raise InvalidDBRoot: + :note: The base will perform basic checking for accessability, but the subclass + is required to verify that the root_path contains the database structure it needs""" + super(FileDBBase, self).__init__() + if not os.path.isdir(root_path): + raise InvalidDBRoot(root_path) + self._root_path = root_path + + + #{ Interface + def root_path(self): + """:return: path at which this db operates""" + return self._root_path + + def db_path(self, rela_path): + """ + :return: the given relative path relative to our database root, allowing + to pontentially access datafiles""" + return join(self._root_path, rela_path) + #} END interface + + + +class LooseObjectDB(FileDBBase, ObjectDBR, ObjectDBW): + """A database which operates on loose object files""" + + # CONFIGURATION + # chunks in which data will be copied between streams + stream_chunk_size = chunk_size + + + def __init__(self, root_path): + super(LooseObjectDB, self).__init__(root_path) + self._hexsha_to_file = dict() + # Additional Flags - might be set to 0 after the first failure + # Depending on the root, this might work for some mounts, for others not, which + # is why it is per instance + self._fd_open_flags = getattr(os, 'O_NOATIME', 0) + + #{ Interface + def object_path(self, hexsha): + """ + :return: path at which the object with the given hexsha would be stored, + relative to the database root""" + return join(hexsha[:2], hexsha[2:]) + + def readable_db_object_path(self, hexsha): + """ + :return: readable object path to the object identified by hexsha + :raise BadObject: If the object file does not exist""" + try: + return self._hexsha_to_file[hexsha] + except KeyError: + pass + # END ignore cache misses + + # try filesystem + path = self.db_path(self.object_path(hexsha)) + if exists(path): + self._hexsha_to_file[hexsha] = path + return path + # END handle cache + raise BadObject(hexsha) + + #} END interface + + def _map_loose_object(self, sha): + """ + :return: memory map of that file to allow random read access + :raise BadObject: if object could not be located""" + db_path = self.db_path(self.object_path(to_hex_sha(sha))) + try: + fd = os.open(db_path, os.O_RDONLY|self._fd_open_flags) + except OSError,e: + if e.errno != ENOENT: + # try again without noatime + try: + fd = os.open(db_path, os.O_RDONLY) + except OSError: + raise BadObject(to_hex_sha(sha)) + # didn't work because of our flag, don't try it again + self._fd_open_flags = 0 + else: + raise BadObject(to_hex_sha(sha)) + # END handle error + # END exception handling + try: + return mmap.mmap(fd, 0, access=mmap.ACCESS_READ) + finally: + os.close(fd) + # END assure file is closed + + def set_ostream(self, stream): + """:raise TypeError: if the stream does not support the Sha1Writer interface""" + if stream is not None and not isinstance(stream, Sha1Writer): + raise TypeError("Output stream musst support the %s interface" % Sha1Writer.__name__) + return super(LooseObjectDB, self).set_ostream(stream) + + def info(self, sha): + m = self._map_loose_object(sha) + try: + type, size = loose_object_header_info(m) + return OInfo(sha, type, size) + finally: + m.close() + # END assure release of system resources + + def stream(self, sha): + m = self._map_loose_object(sha) + type, size, stream = DecompressMemMapReader.new(m, close_on_deletion = True) + return OStream(sha, type, size, stream) + + def has_object(self, sha): + try: + self.readable_db_object_path(to_hex_sha(sha)) + return True + except BadObject: + return False + # END check existance + + def store(self, istream): + """note: The sha we produce will be hex by nature""" + assert istream.sha is None, "Direct istream writing not yet implemented" + tmp_path = None + writer = self.ostream() + if writer is None: + # open a tmp file to write the data to + fd, tmp_path = tempfile.mkstemp(prefix='obj', dir=self._root_path) + writer = FDCompressedSha1Writer(fd) + # END handle custom writer + + try: + try: + write_object(istream.type, istream.size, istream.read, writer.write, + chunk_size=self.stream_chunk_size) + except: + if tmp_path: + os.remove(tmp_path) + raise + # END assure tmpfile removal on error + finally: + if tmp_path: + writer.close() + # END assure target stream is closed + + sha = writer.sha(as_hex=True) + + if tmp_path: + obj_path = self.db_path(self.object_path(sha)) + obj_dir = dirname(obj_path) + if not isdir(obj_dir): + mkdir(obj_dir) + # END handle destination directory + rename(tmp_path, obj_path) + # END handle dry_run + + istream.sha = sha + return istream + + +class PackedDB(FileDBBase, ObjectDBR): + """A database operating on a set of object packs""" + + +class CompoundDB(ObjectDBR): + """A database which delegates calls to sub-databases""" + + +class ReferenceDB(CompoundDB): + """A database consisting of database referred to in a file""" + + +#class GitObjectDB(CompoundDB, ObjectDBW): +class GitObjectDB(LooseObjectDB): + """A database representing the default git object store, which includes loose + objects, pack files and an alternates file + + It will create objects only in the loose object database. + :note: for now, we use the git command to do all the lookup, just until he + have packs and the other implementations + """ + def __init__(self, root_path, git): + """Initialize this instance with the root and a git command""" + super(GitObjectDB, self).__init__(root_path) + self._git = git + + def info(self, sha): + t = self._git.get_object_header(sha) + return OInfo(t[0], t[1], t[2]) + + def stream(self, sha): + """For now, all lookup is done by git itself""" + t = self._git.stream_object_data(sha) + return OStream(t[0], t[1], t[2], t[3]) + diff --git a/lib/git/odb/fun.py b/lib/git/odb/fun.py new file mode 100644 index 00000000..870a6f02 --- /dev/null +++ b/lib/git/odb/fun.py @@ -0,0 +1,108 @@ +"""Contains basic c-functions which usually contain performance critical code +Keeping this code separate from the beginning makes it easier to out-source +it into c later, if required""" + +from git.errors import ( + BadObjectType + ) + +import zlib +decompressobj = zlib.decompressobj + + +# INVARIANTS +type_id_to_type_map = { + 1 : "commit", + 2 : "tree", + 3 : "blob", + 4 : "tag" + } + +# used when dealing with larger streams +chunk_size = 1000*1000 + +__all__ = ('is_loose_object', 'loose_object_header_info', 'object_header_info', + 'write_object' ) + +#{ Routines + +def is_loose_object(m): + """:return: True the file contained in memory map m appears to be a loose object. + Only the first two bytes are needed""" + b0, b1 = map(ord, m[:2]) + word = (b0 << 8) + b1 + return b0 == 0x78 and (word % 31) == 0 + +def loose_object_header_info(m): + """:return: tuple(type_string, uncompressed_size_in_bytes) the type string of the + object as well as its uncompressed size in bytes. + :param m: memory map from which to read the compressed object data""" + decompress_size = 8192 # is used in cgit as well + hdr = decompressobj().decompress(m, decompress_size) + type_name, size = hdr[:hdr.find("\0")].split(" ") + return type_name, int(size) + +def object_header_info(m): + """:return: tuple(type_string, uncompressed_size_in_bytes + :param mmap: mapped memory map. It will be + seeked to the actual start of the object contents, which can be used + to initialize a zlib decompress object. + :note: This routine can only handle new-style objects which are assumably contained + in packs + """ + assert not is_loose_object(m), "Use loose_object_header_info instead" + + c = b0 # first byte + i = 1 # next char to read + type_id = (c >> 4) & 7 # numeric type + size = c & 15 # starting size + s = 4 # starting bit-shift size + while c & 0x80: + c = ord(m[i]) + i += 1 + size += (c & 0x7f) << s + s += 7 + # END character loop + + # finally seek the map to the start of the data stream + m.seek(i) + try: + return (type_id_to_type_map[type_id], size) + except KeyError: + # invalid object type - we could try to be smart now and decode part + # of the stream to get the info, problem is that we had trouble finding + # the exact start of the content stream + raise BadObjectType(type_id) + # END handle exceptions + +def write_object(type, size, read, write, chunk_size=chunk_size): + """Write the object as identified by type, size and source_stream into the + target_stream + + :param type: type string of the object + :param size: amount of bytes to write from source_stream + :param read: read method of a stream providing the content data + :param write: write method of the output stream + :param close_target_stream: if True, the target stream will be closed when + the routine exits, even if an error is thrown + :return: The actual amount of bytes written to stream, which includes the header and a trailing newline""" + tbw = 0 # total num bytes written + dbw = 0 # num data bytes written + + # WRITE HEADER: type SP size NULL + tbw += write("%s %i\0" % (type, size)) + + # WRITE ALL DATA UP TO SIZE + while True: + cs = min(chunk_size, size-dbw) + data_len = write(read(cs)) + dbw += data_len + if data_len < cs or dbw == size: + tbw += dbw + break + # END check for stream end + # END duplicate data + return tbw + + +#} END routines diff --git a/lib/git/odb/stream.py b/lib/git/odb/stream.py new file mode 100644 index 00000000..d1181382 --- /dev/null +++ b/lib/git/odb/stream.py @@ -0,0 +1,446 @@ +import zlib +from cStringIO import StringIO +from git.utils import make_sha +import errno + +from utils import ( + to_hex_sha, + to_bin_sha, + write, + close + ) + +__all__ = ('OInfo', 'OStream', 'IStream', 'InvalidOInfo', 'InvalidOStream', + 'DecompressMemMapReader', 'FDCompressedSha1Writer') + + +# ZLIB configuration +# used when compressing objects - 1 to 9 ( slowest ) +Z_BEST_SPEED = 1 + + +#{ ODB Bases + +class OInfo(tuple): + """Carries information about an object in an ODB, provdiing information + about the sha of the object, the type_string as well as the uncompressed size + in bytes. + + It can be accessed using tuple notation and using attribute access notation:: + + assert dbi[0] == dbi.sha + assert dbi[1] == dbi.type + assert dbi[2] == dbi.size + + The type is designed to be as lighteight as possible.""" + __slots__ = tuple() + + def __new__(cls, sha, type, size): + return tuple.__new__(cls, (sha, type, size)) + + def __init__(self, *args): + tuple.__init__(self) + + #{ Interface + @property + def sha(self): + return self[0] + + @property + def type(self): + return self[1] + + @property + def size(self): + return self[2] + #} END interface + + +class OStream(OInfo): + """Base for object streams retrieved from the database, providing additional + information about the stream. + Generally, ODB streams are read-only as objects are immutable""" + __slots__ = tuple() + + def __new__(cls, sha, type, size, stream, *args, **kwargs): + """Helps with the initialization of subclasses""" + return tuple.__new__(cls, (sha, type, size, stream)) + + + def __init__(self, *args, **kwargs): + tuple.__init__(self) + #{ Interface + + def is_compressed(self): + """:return: True if reads of this stream yield zlib compressed data. Default False + :note: this does not imply anything about the actual internal storage. + Hence the data could be uncompressed, but read compressed, or vice versa""" + raise False + + #} END interface + + #{ Stream Reader Interface + + def read(self, size=-1): + return self[3].read(size) + + #} END stream reader interface + + +class IStream(list): + """Represents an input content stream to be fed into the ODB. It is mutable to allow + the ODB to record information about the operations outcome right in this instance. + + It provides interfaces for the OStream and a StreamReader to allow the instance + to blend in without prior conversion. + + The only method your content stream must support is 'read'""" + __slots__ = tuple() + + def __new__(cls, type, size, stream, sha=None, compressed=False): + return list.__new__(cls, (sha, type, size, stream, compressed, None)) + + def __init__(self, type, size, stream, sha=None, compressed=None): + list.__init__(self, (sha, type, size, stream, compressed, None)) + + #{ Interface + + def hexsha(self): + """:return: our sha, hex encoded, 40 bytes""" + return to_hex_sha(self[0]) + + def binsha(self): + """:return: our sha as binary, 20 bytes""" + return to_bin_sha(self[0]) + + def _error(self): + """:return: the error that occurred when processing the stream, or None""" + return self[5] + + def _set_error(self, exc): + """Set this input stream to the given exc, may be None to reset the error""" + self[5] = exc + + error = property(_error, _set_error) + + #} END interface + + #{ Stream Reader Interface + + def read(self, size=-1): + """Implements a simple stream reader interface, passing the read call on + to our internal stream""" + return self[3].read(size) + + #} END stream reader interface + + #{ interface + + def _set_sha(self, sha): + self[0] = sha + + def _sha(self): + return self[0] + + sha = property(_sha, _set_sha) + + + def _type(self): + return self[1] + + def _set_type(self, type): + self[1] = type + + type = property(_type, _set_type) + + def _size(self): + return self[2] + + def _set_size(self, size): + self[2] = size + + size = property(_size, _set_size) + + def _stream(self): + return self[3] + + def _set_stream(self, stream): + self[3] = stream + + stream = property(_stream, _set_stream) + + #} END odb info interface + + #{ OStream interface + + def is_compressed(self): + return self[4] + + #} END OStream interface + + +class InvalidOInfo(tuple): + """Carries information about a sha identifying an object which is invalid in + the queried database. The exception attribute provides more information about + the cause of the issue""" + __slots__ = tuple() + + def __new__(cls, sha, exc): + return tuple.__new__(cls, (sha, exc)) + + def __init__(self, sha, exc): + tuple.__init__(self, (sha, exc)) + + @property + def sha(self): + return self[0] + + @property + def error(self): + """:return: exception instance explaining the failure""" + return self[1] + + +class InvalidOStream(InvalidOInfo): + """Carries information about an invalid ODB stream""" + __slots__ = tuple() + +#} END ODB Bases + + +#{ RO Streams + +class DecompressMemMapReader(object): + """Reads data in chunks from a memory map and decompresses it. The client sees + only the uncompressed data, respective file-like read calls are handling on-demand + buffered decompression accordingly + + A constraint on the total size of bytes is activated, simulating + a logical file within a possibly larger physical memory area + + To read efficiently, you clearly don't want to read individual bytes, instead, + read a few kilobytes at least. + + :note: The chunk-size should be carefully selected as it will involve quite a bit + of string copying due to the way the zlib is implemented. Its very wasteful, + hence we try to find a good tradeoff between allocation time and number of + times we actually allocate. An own zlib implementation would be good here + to better support streamed reading - it would only need to keep the mmap + and decompress it into chunks, thats all ... """ + __slots__ = ('_m', '_zip', '_buf', '_buflen', '_br', '_cws', '_cwe', '_s', '_close') + + max_read_size = 512*1024 + + def __init__(self, m, close_on_deletion, size): + """Initialize with mmap for stream reading""" + self._m = m + self._zip = zlib.decompressobj() + self._buf = None # buffer of decompressed bytes + self._buflen = 0 # length of bytes in buffer + self._s = size # size of uncompressed data to read in total + self._br = 0 # num uncompressed bytes read + self._cws = 0 # start byte of compression window + self._cwe = 0 # end byte of compression window + self._close = close_on_deletion # close the memmap on deletion ? + + def __del__(self): + if self._close: + self._m.close() + # END handle resource freeing + + @classmethod + def new(self, m, close_on_deletion=False): + """Create a new DecompressMemMapReader instance for acting as a read-only stream + This method parses the object header from m and returns the parsed + type and size, as well as the created stream instance. + :param m: memory map on which to oparate + :param close_on_deletion: if True, the memory map will be closed once we are + being deleted""" + inst = DecompressMemMapReader(m, close_on_deletion, 0) + + # read header + maxb = 512 # should really be enough, cgit uses 8192 I believe + inst._s = maxb + hdr = inst.read(maxb) + hdrend = hdr.find("\0") + type, size = hdr[:hdrend].split(" ") + size = int(size) + inst._s = size + + # adjust internal state to match actual header length that we ignore + # The buffer will be depleted first on future reads + inst._br = 0 + hdrend += 1 # count terminating \0 + inst._buf = StringIO(hdr[hdrend:]) + inst._buflen = len(hdr) - hdrend + + return type, size, inst + + def read(self, size=-1): + if size < 1: + size = self._s - self._br + else: + size = min(size, self._s - self._br) + # END clamp size + + if size == 0: + return str() + # END handle depletion + + # protect from memory peaks + # If he tries to read large chunks, our memory patterns get really bad + # as we end up copying a possibly huge chunk from our memory map right into + # memory. This might not even be possible. Nonetheless, try to dampen the + # effect a bit by reading in chunks, returning a huge string in the end. + # Our performance now depends on StringIO. This way we don't need two large + # buffers in peak times, but only one large one in the end which is + # the return buffer + # NO: We don't do it - if the user thinks its best, he is right. If he + # has trouble, he will start reading in chunks. According to our tests + # its still faster if we read 10 Mb at once instead of chunking it. + + # if size > self.max_read_size: + # sio = StringIO() + # while size: + # read_size = min(self.max_read_size, size) + # data = self.read(read_size) + # sio.write(data) + # size -= len(data) + # if len(data) < read_size: + # break + # # END data loop + # sio.seek(0) + # return sio.getvalue() + # # END handle maxread + # + # deplete the buffer, then just continue using the decompress object + # which has an own buffer. We just need this to transparently parse the + # header from the zlib stream + dat = str() + if self._buf: + if self._buflen >= size: + # have enough data + dat = self._buf.read(size) + self._buflen -= size + self._br += size + return dat + else: + dat = self._buf.read() # ouch, duplicates data + size -= self._buflen + self._br += self._buflen + + self._buflen = 0 + self._buf = None + # END handle buffer len + # END handle buffer + + # decompress some data + # Abstract: zlib needs to operate on chunks of our memory map ( which may + # be large ), as it will otherwise and always fill in the 'unconsumed_tail' + # attribute which possible reads our whole map to the end, forcing + # everything to be read from disk even though just a portion was requested. + # As this would be a nogo, we workaround it by passing only chunks of data, + # moving the window into the memory map along as we decompress, which keeps + # the tail smaller than our chunk-size. This causes 'only' the chunk to be + # copied once, and another copy of a part of it when it creates the unconsumed + # tail. We have to use it to hand in the appropriate amount of bytes durin g + # the next read. + tail = self._zip.unconsumed_tail + if tail: + # move the window, make it as large as size demands. For code-clarity, + # we just take the chunk from our map again instead of reusing the unconsumed + # tail. The latter one would safe some memory copying, but we could end up + # with not getting enough data uncompressed, so we had to sort that out as well. + # Now we just assume the worst case, hence the data is uncompressed and the window + # needs to be as large as the uncompressed bytes we want to read. + self._cws = self._cwe - len(tail) + self._cwe = self._cws + size + + + indata = self._m[self._cws:self._cwe] # another copy ... :( + # get the actual window end to be sure we don't use it for computations + self._cwe = self._cws + len(indata) + else: + cws = self._cws + self._cws = self._cwe + self._cwe = cws + size + indata = self._m[self._cws:self._cwe] # ... copy it again :( + # END handle tail + + dcompdat = self._zip.decompress(indata, size) + + self._br += len(dcompdat) + if dat: + dcompdat = dat + dcompdat + + return dcompdat + +#} END RO streams + + +#{ W Streams + +class Sha1Writer(object): + """Simple stream writer which produces a sha whenever you like as it degests + everything it is supposed to write""" + + def __init__(self): + self.sha1 = make_sha("") + + #{ Stream Interface + + def write(self, data): + """:raise IOError: If not all bytes could be written + :return: lenght of incoming data""" + self.sha1.update(data) + return len(data) + + # END stream interface + + #{ Interface + + def sha(self, as_hex = False): + """:return: sha so far + :param as_hex: if True, sha will be hex-encoded, binary otherwise""" + if as_hex: + return self.sha1.hexdigest() + return self.sha1.digest() + + #} END interface + +class FDCompressedSha1Writer(Sha1Writer): + """Digests data written to it, making the sha available, then compress the + data and write it to the file descriptor + :note: operates on raw file descriptors + :note: for this to work, you have to use the close-method of this instance""" + __slots__ = ("fd", "sha1", "zip") + + # default exception + exc = IOError("Failed to write all bytes to filedescriptor") + + def __init__(self, fd): + super(FDCompressedSha1Writer, self).__init__() + self.fd = fd + self.zip = zlib.compressobj(Z_BEST_SPEED) + + #{ Stream Interface + + def write(self, data): + """:raise IOError: If not all bytes could be written + :return: lenght of incoming data""" + self.sha1.update(data) + cdata = self.zip.compress(data) + bytes_written = write(self.fd, cdata) + if bytes_written != len(cdata): + raise self.exc + return len(data) + + def close(self): + remainder = self.zip.flush() + if write(self.fd, remainder) != len(remainder): + raise self.exc + return close(self.fd) + + #} END stream interface + +#} END W streams diff --git a/lib/git/odb/utils.py b/lib/git/odb/utils.py new file mode 100644 index 00000000..6863e97b --- /dev/null +++ b/lib/git/odb/utils.py @@ -0,0 +1,38 @@ +import binascii +import os +import errno + +#{ Routines + +hex_to_bin = binascii.a2b_hex +bin_to_hex = binascii.b2a_hex + +def to_hex_sha(sha): + """:return: hexified version of sha""" + if len(sha) == 40: + return sha + return bin_to_hex(sha) + +def to_bin_sha(sha): + if len(sha) == 20: + return sha + return hex_to_bin(sha) + +# errors +ENOENT = errno.ENOENT + +# os shortcuts +exists = os.path.exists +mkdir = os.mkdir +isdir = os.path.isdir +rename = os.rename +dirname = os.path.dirname +join = os.path.join +read = os.read +write = os.write +close = os.close + + +#} END Routines + + |