mirror of
https://github.com/thegeeklab/ansible-later.git
synced 2024-11-26 06:40:42 +00:00
274 lines
8.8 KiB
Python
274 lines
8.8 KiB
Python
# 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
|
|
"""Contains implementations of database retrieveing objects"""
|
|
from gitdb.util import (
|
|
join,
|
|
LazyMixin,
|
|
hex_to_bin
|
|
)
|
|
|
|
from gitdb.utils.encoding import force_text
|
|
from gitdb.exc import (
|
|
BadObject,
|
|
AmbiguousObjectName
|
|
)
|
|
|
|
from itertools import chain
|
|
from functools import reduce
|
|
|
|
|
|
__all__ = ('ObjectDBR', 'ObjectDBW', 'FileDBBase', 'CompoundDB', 'CachingDB')
|
|
|
|
|
|
class ObjectDBR(object):
|
|
|
|
"""Defines an interface for object database lookup.
|
|
Objects are identified either by their 20 byte bin sha"""
|
|
|
|
def __contains__(self, sha):
|
|
return self.has_obj
|
|
|
|
#{ Query Interface
|
|
def has_object(self, sha):
|
|
"""
|
|
:return: True if the object identified by the given 20 bytes
|
|
binary sha is contained in the database"""
|
|
raise NotImplementedError("To be implemented in subclass")
|
|
|
|
def info(self, sha):
|
|
""" :return: OInfo instance
|
|
:param sha: bytes binary sha
|
|
:raise BadObject:"""
|
|
raise NotImplementedError("To be implemented in subclass")
|
|
|
|
def stream(self, sha):
|
|
""":return: OStream instance
|
|
:param sha: 20 bytes binary sha
|
|
:raise BadObject:"""
|
|
raise NotImplementedError("To be implemented in subclass")
|
|
|
|
def size(self):
|
|
""":return: amount of objects in this database"""
|
|
raise NotImplementedError()
|
|
|
|
def sha_iter(self):
|
|
"""Return iterator yielding 20 byte shas for all objects in this data base"""
|
|
raise NotImplementedError()
|
|
|
|
#} 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")
|
|
|
|
#} 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 not perform any accessablity checking as the base
|
|
might not yet be accessible, but become accessible before the first
|
|
access."""
|
|
super(FileDBBase, self).__init__()
|
|
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, force_text(rela_path))
|
|
#} END interface
|
|
|
|
|
|
class CachingDB(object):
|
|
|
|
"""A database which uses caches to speed-up access"""
|
|
|
|
#{ Interface
|
|
def update_cache(self, force=False):
|
|
"""
|
|
Call this method if the underlying data changed to trigger an update
|
|
of the internal caching structures.
|
|
|
|
:param force: if True, the update must be performed. Otherwise the implementation
|
|
may decide not to perform an update if it thinks nothing has changed.
|
|
:return: True if an update was performed as something change indeed"""
|
|
|
|
# END interface
|
|
|
|
|
|
def _databases_recursive(database, output):
|
|
"""Fill output list with database from db, in order. Deals with Loose, Packed
|
|
and compound databases."""
|
|
if isinstance(database, CompoundDB):
|
|
dbs = database.databases()
|
|
output.extend(db for db in dbs if not isinstance(db, CompoundDB))
|
|
for cdb in (db for db in dbs if isinstance(db, CompoundDB)):
|
|
_databases_recursive(cdb, output)
|
|
else:
|
|
output.append(database)
|
|
# END handle database type
|
|
|
|
|
|
class CompoundDB(ObjectDBR, LazyMixin, CachingDB):
|
|
|
|
"""A database which delegates calls to sub-databases.
|
|
|
|
Databases are stored in the lazy-loaded _dbs attribute.
|
|
Define _set_cache_ to update it with your databases"""
|
|
|
|
def _set_cache_(self, attr):
|
|
if attr == '_dbs':
|
|
self._dbs = list()
|
|
elif attr == '_db_cache':
|
|
self._db_cache = dict()
|
|
else:
|
|
super(CompoundDB, self)._set_cache_(attr)
|
|
|
|
def _db_query(self, sha):
|
|
""":return: database containing the given 20 byte sha
|
|
:raise BadObject:"""
|
|
# most databases use binary representations, prevent converting
|
|
# it every time a database is being queried
|
|
try:
|
|
return self._db_cache[sha]
|
|
except KeyError:
|
|
pass
|
|
# END first level cache
|
|
|
|
for db in self._dbs:
|
|
if db.has_object(sha):
|
|
self._db_cache[sha] = db
|
|
return db
|
|
# END for each database
|
|
raise BadObject(sha)
|
|
|
|
#{ ObjectDBR interface
|
|
|
|
def has_object(self, sha):
|
|
try:
|
|
self._db_query(sha)
|
|
return True
|
|
except BadObject:
|
|
return False
|
|
# END handle exceptions
|
|
|
|
def info(self, sha):
|
|
return self._db_query(sha).info(sha)
|
|
|
|
def stream(self, sha):
|
|
return self._db_query(sha).stream(sha)
|
|
|
|
def size(self):
|
|
""":return: total size of all contained databases"""
|
|
return reduce(lambda x, y: x + y, (db.size() for db in self._dbs), 0)
|
|
|
|
def sha_iter(self):
|
|
return chain(*(db.sha_iter() for db in self._dbs))
|
|
|
|
#} END object DBR Interface
|
|
|
|
#{ Interface
|
|
|
|
def databases(self):
|
|
""":return: tuple of database instances we use for lookups"""
|
|
return tuple(self._dbs)
|
|
|
|
def update_cache(self, force=False):
|
|
# something might have changed, clear everything
|
|
self._db_cache.clear()
|
|
stat = False
|
|
for db in self._dbs:
|
|
if isinstance(db, CachingDB):
|
|
stat |= db.update_cache(force)
|
|
# END if is caching db
|
|
# END for each database to update
|
|
return stat
|
|
|
|
def partial_to_complete_sha_hex(self, partial_hexsha):
|
|
"""
|
|
:return: 20 byte binary sha1 from the given less-than-40 byte hexsha (bytes or str)
|
|
:param partial_hexsha: hexsha with less than 40 byte
|
|
:raise AmbiguousObjectName: """
|
|
databases = list()
|
|
_databases_recursive(self, databases)
|
|
partial_hexsha = force_text(partial_hexsha)
|
|
len_partial_hexsha = len(partial_hexsha)
|
|
if len_partial_hexsha % 2 != 0:
|
|
partial_binsha = hex_to_bin(partial_hexsha + "0")
|
|
else:
|
|
partial_binsha = hex_to_bin(partial_hexsha)
|
|
# END assure successful binary conversion
|
|
|
|
candidate = None
|
|
for db in databases:
|
|
full_bin_sha = None
|
|
try:
|
|
if hasattr(db, 'partial_to_complete_sha_hex'):
|
|
full_bin_sha = db.partial_to_complete_sha_hex(partial_hexsha)
|
|
else:
|
|
full_bin_sha = db.partial_to_complete_sha(partial_binsha, len_partial_hexsha)
|
|
# END handle database type
|
|
except BadObject:
|
|
continue
|
|
# END ignore bad objects
|
|
if full_bin_sha:
|
|
if candidate and candidate != full_bin_sha:
|
|
raise AmbiguousObjectName(partial_hexsha)
|
|
candidate = full_bin_sha
|
|
# END handle candidate
|
|
# END for each db
|
|
if not candidate:
|
|
raise BadObject(partial_binsha)
|
|
return candidate
|
|
|
|
#} END interface
|