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zero-cost-nas/.eggs/gitdb-4.0.10-py3.8.egg/gitdb/db/loose.py

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+# Copyright (C) 2010, 2011 Sebastian Thiel (byronimo@gmail.com) and contributors
+#
+# This module is part of GitDB and is released under
+# the New BSD License: http://www.opensource.org/licenses/bsd-license.php
+from gitdb.db.base import (
+    FileDBBase,
+    ObjectDBR,
+    ObjectDBW
+)
+
+
+from gitdb.exc import (
+    BadObject,
+    AmbiguousObjectName
+)
+
+from gitdb.stream import (
+    DecompressMemMapReader,
+    FDCompressedSha1Writer,
+    FDStream,
+    Sha1Writer
+)
+
+from gitdb.base import (
+    OStream,
+    OInfo
+)
+
+from gitdb.util import (
+    file_contents_ro_filepath,
+    ENOENT,
+    hex_to_bin,
+    bin_to_hex,
+    exists,
+    chmod,
+    isdir,
+    isfile,
+    remove,
+    mkdir,
+    rename,
+    dirname,
+    basename,
+    join
+)
+
+from gitdb.fun import (
+    chunk_size,
+    loose_object_header_info,
+    write_object,
+    stream_copy
+)
+
+from gitdb.utils.encoding import force_bytes
+
+import tempfile
+import os
+import sys
+
+
+__all__ = ('LooseObjectDB', )
+
+
+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
+
+    # On windows we need to keep it writable, otherwise it cannot be removed
+    # either
+    new_objects_mode = int("444", 8)
+    if os.name == 'nt':
+        new_objects_mode = int("644", 8)
+
+    def __init__(self, root_path):
+        super().__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)
+
+    def partial_to_complete_sha_hex(self, partial_hexsha):
+        """:return: 20 byte binary sha1 string which matches the given name uniquely
+        :param name: hexadecimal partial name (bytes or ascii string)
+        :raise AmbiguousObjectName:
+        :raise BadObject: """
+        candidate = None
+        for binsha in self.sha_iter():
+            if bin_to_hex(binsha).startswith(force_bytes(partial_hexsha)):
+                # it can't ever find the same object twice
+                if candidate is not None:
+                    raise AmbiguousObjectName(partial_hexsha)
+                candidate = binsha
+        # END for each object
+        if candidate is None:
+            raise BadObject(partial_hexsha)
+        return candidate
+
+    #} 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(bin_to_hex(sha)))
+        try:
+            return file_contents_ro_filepath(db_path, flags=self._fd_open_flags)
+        except OSError as e:
+            if e.errno != ENOENT:
+                # try again without noatime
+                try:
+                    return file_contents_ro_filepath(db_path)
+                except OSError as new_e:
+                    raise BadObject(sha) from new_e
+                # didn't work because of our flag, don't try it again
+                self._fd_open_flags = 0
+            else:
+                raise BadObject(sha) from e
+            # END handle error
+        # END exception handling
+
+    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().set_ostream(stream)
+
+    def info(self, sha):
+        m = self._map_loose_object(sha)
+        try:
+            typ, size = loose_object_header_info(m)
+            return OInfo(sha, typ, size)
+        finally:
+            if hasattr(m, 'close'):
+                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(bin_to_hex(sha))
+            return True
+        except BadObject:
+            return False
+        # END check existence
+
+    def store(self, istream):
+        """note: The sha we produce will be hex by nature"""
+        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)
+
+            if istream.binsha is None:
+                writer = FDCompressedSha1Writer(fd)
+            else:
+                writer = FDStream(fd)
+            # END handle direct stream copies
+        # END handle custom writer
+
+        try:
+            try:
+                if istream.binsha is not None:
+                    # copy as much as possible, the actual uncompressed item size might
+                    # be smaller than the compressed version
+                    stream_copy(istream.read, writer.write, sys.maxsize, self.stream_chunk_size)
+                else:
+                    # write object with header, we have to make a new one
+                    write_object(istream.type, istream.size, istream.read, writer.write,
+                                 chunk_size=self.stream_chunk_size)
+                # END handle direct stream copies
+            finally:
+                if tmp_path:
+                    writer.close()
+            # END assure target stream is closed
+        except:
+            if tmp_path:
+                os.remove(tmp_path)
+            raise
+        # END assure tmpfile removal on error
+
+        hexsha = None
+        if istream.binsha:
+            hexsha = istream.hexsha
+        else:
+            hexsha = writer.sha(as_hex=True)
+        # END handle sha
+
+        if tmp_path:
+            obj_path = self.db_path(self.object_path(hexsha))
+            obj_dir = dirname(obj_path)
+            if not isdir(obj_dir):
+                mkdir(obj_dir)
+            # END handle destination directory
+            # rename onto existing doesn't work on NTFS
+            if isfile(obj_path):
+                remove(tmp_path)
+            else:
+                rename(tmp_path, obj_path)
+            # end rename only if needed
+
+            # make sure its readable for all ! It started out as rw-- tmp file
+            # but needs to be rwrr
+            chmod(obj_path, self.new_objects_mode)
+        # END handle dry_run
+
+        istream.binsha = hex_to_bin(hexsha)
+        return istream
+
+    def sha_iter(self):
+        # find all files which look like an object, extract sha from there
+        for root, dirs, files in os.walk(self.root_path()):
+            root_base = basename(root)
+            if len(root_base) != 2:
+                continue
+
+            for f in files:
+                if len(f) != 38:
+                    continue
+                yield hex_to_bin(root_base + f)
+            # END for each file
+        # END for each walk iteration
+
+    def size(self):
+        return len(tuple(self.sha_iter()))