diff options
Diffstat (limited to 'sugar_network/db/blobs.py')
| -rw-r--r-- | sugar_network/db/blobs.py | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/sugar_network/db/blobs.py b/sugar_network/db/blobs.py new file mode 100644 index 0000000..da06483 --- /dev/null +++ b/sugar_network/db/blobs.py @@ -0,0 +1,146 @@ +# Copyright (C) 2014 Aleksey Lim +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <http://www.gnu.org/licenses/>. + +import os +import logging +import hashlib +from contextlib import contextmanager +from os.path import exists, abspath, join, isdir, isfile + +from sugar_network import toolkit +from sugar_network.toolkit.router import File +from sugar_network.toolkit import http, enforce + + +_META_SUFFIX = '.meta' + +_logger = logging.getLogger('db.blobs') +_root = None + + +def init(path): + global _root + _root = abspath(path) + if not exists(_root): + os.makedirs(_root) + + +def post(content, mime_type=None, digest_to_assert=None): + meta = [] + + @contextmanager + def write_blob(): + tmp_path = join(_path(), 'post') + if hasattr(content, 'read'): + with toolkit.new_file(tmp_path) as blob: + digest = hashlib.sha1() + while True: + chunk = content.read(toolkit.BUFFER_SIZE) + if not chunk: + break + blob.write(chunk) + digest.update(chunk) + yield blob, digest.hexdigest() + elif isinstance(content, dict): + enforce('location' in content, http.BadRequest, 'No location') + enforce('digest' in content, http.BadRequest, 'No digest') + meta.append(('status', '301 Moved Permanently')) + meta.append(('location', content['location'])) + with toolkit.new_file(tmp_path) as blob: + yield blob, content['digest'] + else: + with toolkit.new_file(tmp_path) as blob: + blob.write(content) + yield blob, hashlib.sha1(content).hexdigest() + + with write_blob() as (blob, digest): + if digest_to_assert and digest != digest_to_assert: + blob.unlink() + raise http.BadRequest('Digest mismatch') + path = _path(digest) + meta.append(('content-type', mime_type or 'application/octet-stream')) + with toolkit.new_file(path + _META_SUFFIX) as f: + for key, value in meta: + f.write('%s: %s\n' % (key, value)) + blob.name = path + + return File(path, digest, meta) + + +def update(digest, meta): + path = _path(digest) + _META_SUFFIX + enforce(exists(path), http.NotFound, 'No such blob') + meta_content = '' + for key, value in meta.items(): + meta_content += '%s: %s\n' % (key, value) + with toolkit.new_file(path) as f: + f.write(meta_content) + + +def get(digest): + path = _path(digest) + if not exists(path) or not exists(path + _META_SUFFIX): + return None + meta = [] + with file(path + _META_SUFFIX) as f: + for line in f: + key, value = line.split(':', 1) + meta.append((key, value.strip())) + return File(path, digest, meta) + + +def delete(digest): + path = _path(digest) + if exists(path + _META_SUFFIX): + os.unlink(path + _META_SUFFIX) + if exists(path): + os.unlink(path) + + +def diff(in_seq, out_seq=None): + if out_seq is None: + out_seq = toolkit.Sequence([]) + is_the_only_seq = not out_seq + + try: + root = _path() + for name in os.listdir(root): + dirpath = join(root, name) + if not isdir(dirpath) or os.stat(dirpath).st_ctime not in in_seq: + continue + for digest in os.listdir(dirpath): + if len(digest) != 40: + continue + path = join(dirpath, digest) + if not isfile(path): + continue + ctime = int(os.stat(path).st_ctime) + if ctime not in in_seq: + continue + blob = get(digest) + if blob is None: + continue + yield blob + out_seq.include(ctime, ctime) + if is_the_only_seq: + # There is only one diff, so, we can stretch it to remove all holes + out_seq.stretch() + except StopIteration: + pass + + +def _path(digest=None): + enforce(_root is not None, 'Blobs storage is not initialized') + return join(_root, digest[:3], digest) if digest else _root |