diff --git a/swh/objstorage/api/client.py b/swh/objstorage/api/client.py index 1a670cb..22b0227 100644 --- a/swh/objstorage/api/client.py +++ b/swh/objstorage/api/client.py @@ -1,94 +1,94 @@ # Copyright (C) 2015-2016 The Software Heritage developers # See the AUTHORS file at the top-level directory of this distribution # License: GNU General Public License version 3, or any later version # See top-level LICENSE file for more information import pickle import requests from requests.exceptions import ConnectionError from ..objstorage import ObjStorage from ..exc import ObjStorageAPIError from .common import (decode_response, encode_data_client as encode_data) class RemoteObjStorage(ObjStorage): """ Proxy to a remote object storage. This class allows to connect to an object storage server via http protocol. Attributes: base_url (string): The url of the server to connect. Must end with a '/' session: The session to send requests. """ def __init__(self, base_url): self.base_url = base_url self.session = requests.Session() def url(self, endpoint): return '%s%s' % (self.base_url, endpoint) def post(self, endpoint, data): try: response = self.session.post( self.url(endpoint), data=encode_data(data), headers={'content-type': 'application/x-msgpack'}, ) except ConnectionError as e: print(str(e)) raise ObjStorageAPIError(e) # XXX: this breaks language-independence and should be # replaced by proper unserialization if response.status_code == 400: raise pickle.loads(decode_response(response)) return decode_response(response) def __contains__(self, obj_id): """ Indicates if the given object is present in the storage See base class [ObjStorage]. """ return self.post('content/contains', {'obj_id': obj_id}) def add(self, content, obj_id=None, check_presence=True): """ Add a new object to the object storage. See base class [ObjStorage]. """ - return self.post('content/add', {'bytes': content, 'obj_id': obj_id, + return self.post('content/add', {'content': content, 'obj_id': obj_id, 'check_presence': check_presence}) def get(self, obj_id): """ Retrieve the content of a given object. See base class [ObjStorage]. """ return self.post('content/get', {'obj_id': obj_id}) def get_batch(self, obj_ids): """ Retrieve content in bulk. See base class [ObjStorage]. """ return self.post('content/get/batch', {'obj_ids': obj_ids}) def check(self, obj_id): """ Perform an integrity check for a given object. See base class [ObjStorage]. """ self.post('content/check', {'obj_id': obj_id}) def get_random(self, batch_size): """ Get random ids of existing contents See base class [ObjStorage]. """ return self.post('content/get/random', {'batch_size': batch_size}) diff --git a/swh/objstorage/objstorage_pathslicing.py b/swh/objstorage/objstorage_pathslicing.py index 6b08998..4178505 100644 --- a/swh/objstorage/objstorage_pathslicing.py +++ b/swh/objstorage/objstorage_pathslicing.py @@ -1,299 +1,296 @@ # Copyright (C) 2015-2016 The Software Heritage developers # See the AUTHORS file at the top-level directory of this distribution # License: GNU General Public License version 3, or any later version # See top-level LICENSE file for more information import os import gzip import tempfile import random from contextlib import contextmanager from swh.core import hashutil from .objstorage import ObjStorage, compute_hash, ID_HASH_ALGO, ID_HASH_LENGTH from .exc import ObjNotFoundError, Error GZIP_BUFSIZ = 1048576 DIR_MODE = 0o755 FILE_MODE = 0o644 @contextmanager def _write_obj_file(hex_obj_id, objstorage): """ Context manager for writing object files to the object storage. During writing, data are written to a temporary file, which is atomically renamed to the right file name after closing. This context manager also takes care of (gzip) compressing the data on the fly. Usage sample: with _write_obj_file(hex_obj_id, objstorage): f.write(obj_data) Yields: a file-like object open for writing bytes. """ # Get the final paths and create the directory if absent. dir = objstorage._obj_dir(hex_obj_id) if not os.path.isdir(dir): os.makedirs(dir, DIR_MODE, exist_ok=True) path = os.path.join(dir, hex_obj_id) # Create a temporary file. (tmp, tmp_path) = tempfile.mkstemp(suffix='.tmp', prefix='hex_obj_id.', dir=dir) # Open the file and yield it for writing. tmp_f = os.fdopen(tmp, 'wb') with gzip.GzipFile(filename=tmp_path, fileobj=tmp_f) as f: yield f # Then close the temporary file and move it to the right directory. tmp_f.close() os.chmod(tmp_path, FILE_MODE) os.rename(tmp_path, path) @contextmanager def _read_obj_file(hex_obj_id, objstorage): """ Context manager for reading object file in the object storage. Usage sample: with _read_obj_file(hex_obj_id, objstorage) as f: b = f.read() Yields: a file-like object open for reading bytes. """ path = objstorage._obj_path(hex_obj_id) with gzip.GzipFile(path, 'rb') as f: yield f class PathSlicingObjStorage(ObjStorage): """ Implementation of the ObjStorage API based on the hash of the content. On disk, an object storage is a directory tree containing files named after their object IDs. An object ID is a checksum of its content, depending on the value of the ID_HASH_ALGO constant (see hashutil for its meaning). To avoid directories that contain too many files, the object storage has a given slicing. Each slicing correspond to a directory that is named according to the hash of its content. So for instance a file with SHA1 34973274ccef6ab4dfaaf86599792fa9c3fe4689 will be stored in the given object storages : - 0:2/2:4/4:6 : 34/97/32/34973274ccef6ab4dfaaf86599792fa9c3fe4689 - 0:1/0:5/ : 3/34973/34973274ccef6ab4dfaaf86599792fa9c3fe4689 The files in the storage are stored in gzipped compressed format. Attributes: root (string): path to the root directory of the storage on the disk. bounds: list of tuples that indicates the beginning and the end of each subdirectory for a content. """ def __init__(self, root, slicing): """ Create an object to access a hash-slicing based object storage. Args: root (string): path to the root directory of the storage on the disk. slicing (string): string that indicates the slicing to perform on the hash of the content to know the path where it should be stored. """ if not os.path.isdir(root): raise ValueError( 'PathSlicingObjStorage root "%s" is not a directory' % root ) self.root = root # Make a list of tuples where each tuple contains the beginning # and the end of each slicing. self.bounds = [ slice(*map(int, sbounds.split(':'))) for sbounds in slicing.split('/') if sbounds ] max_endchar = max(map(lambda bound: bound.stop, self.bounds)) if ID_HASH_LENGTH < max_endchar: raise ValueError( 'Algorithm %s has too short hash for slicing to char %d' % (ID_HASH_ALGO, max_endchar) ) def __contains__(self, obj_id): """ Indicates if the given object is present in the storage See base class [ObjStorage]. """ hex_obj_id = hashutil.hash_to_hex(obj_id) return os.path.exists(self._obj_path(hex_obj_id)) def __iter__(self): """iterate over the object identifiers currently available in the storage Warning: with the current implementation of the object storage, this method will walk the filesystem to list objects, meaning that listing all objects will be very slow for large storages. You almost certainly don't want to use this method in production. Return: iterator over object IDs """ def obj_iterator(): # XXX hackish: it does not verify that the depth of found files # matches the slicing depth of the storage for root, _dirs, files in os.walk(self.root): for f in files: yield bytes.fromhex(f) return obj_iterator() def __len__(self): """compute the number of objects available in the storage Warning: this currently uses `__iter__`, its warning about bad performances applies Return: number of objects contained in the storage """ return sum(1 for i in self) def _obj_dir(self, hex_obj_id): """ Compute the storage directory of an object. See also: PathSlicingObjStorage::_obj_path Args: hex_obj_id: object id as hexlified string. Returns: Path to the directory that contains the required object. """ slices = [hex_obj_id[bound] for bound in self.bounds] return os.path.join(self.root, *slices) def _obj_path(self, hex_obj_id): """ Compute the full path to an object into the current storage. See also: PathSlicingObjStorage::_obj_dir Args: hex_obj_id: object id as hexlified string. Returns: Path to the actual object corresponding to the given id. """ return os.path.join(self._obj_dir(hex_obj_id), hex_obj_id) - def add(self, bytes, obj_id=None, check_presence=True): + def add(self, content, obj_id=None, check_presence=True): """ Add a new object to the current object storage. See base class [ObjStorage]. """ if obj_id is None: - # Checksum is missing, compute it on the fly. - h = hashutil._new_hash(ID_HASH_ALGO, len(bytes)) - h.update(bytes) - obj_id = h.digest() + obj_id = compute_hash(content) if check_presence and obj_id in self: # If the object is already present, return immediatly. return obj_id hex_obj_id = hashutil.hash_to_hex(obj_id) with _write_obj_file(hex_obj_id, self) as f: - f.write(bytes) + f.write(content) return obj_id def get(self, obj_id): """ Retrieve the content of a given object. See base class [ObjStorage]. """ if obj_id not in self: raise ObjNotFoundError(obj_id) # Open the file and return its content as bytes hex_obj_id = hashutil.hash_to_hex(obj_id) with _read_obj_file(hex_obj_id, self) as f: return f.read() def check(self, obj_id): """ Perform an integrity check for a given object. See base class [ObjStorage]. """ if obj_id not in self: raise ObjNotFoundError(obj_id) hex_obj_id = hashutil.hash_to_hex(obj_id) try: with gzip.open(self._obj_path(hex_obj_id)) as f: length = None if ID_HASH_ALGO.endswith('_git'): # if the hashing algorithm is git-like, we need to know the # content size to hash on the fly. Do a first pass here to # compute the size length = 0 while True: chunk = f.read(GZIP_BUFSIZ) length += len(chunk) if not chunk: break f.rewind() checksums = hashutil._hash_file_obj(f, length, algorithms=[ID_HASH_ALGO]) actual_obj_id = checksums[ID_HASH_ALGO] if obj_id != actual_obj_id: raise Error( 'Corrupt object %s should have id %s' % (hashutil.hash_to_hex(obj_id), hashutil.hash_to_hex(actual_obj_id)) ) except (OSError, IOError): # IOError is for compatibility with older python versions raise Error('Corrupt object %s is not a gzip file' % obj_id) def get_random(self, batch_size): """ Get random ids of existing contents See base class [ObjStorage]. """ def get_random_content(self, batch_size): """ Get a batch of content inside a single directory. Returns: a tuple (batch size, batch). """ dirs = [] for level in range(len(self.bounds)): path = os.path.join(self.root, *dirs) dir_list = next(os.walk(path))[1] if 'tmp' in dir_list: dir_list.remove('tmp') dirs.append(random.choice(dir_list)) path = os.path.join(self.root, *dirs) content_list = next(os.walk(path))[2] length = min(batch_size, len(content_list)) return length, map(hashutil.hex_to_hash, random.sample(content_list, length)) while batch_size: length, it = get_random_content(self, batch_size) batch_size = batch_size - length yield from it