diff --git a/swh/vault/backend.py b/swh/vault/backend.py index a085a97..8856ac8 100644 --- a/swh/vault/backend.py +++ b/swh/vault/backend.py @@ -1,290 +1,307 @@ # Copyright (C) 2017 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 smtplib import celery import psycopg2 import psycopg2.extras from functools import wraps from email.mime.text import MIMEText from swh.model import hashutil from swh.scheduler.utils import get_task from swh.vault.cache import VaultCache from swh.vault.cookers import get_cooker from swh.vault.cooking_tasks import SWHCookingTask # noqa cooking_task_name = 'swh.vault.cooking_tasks.SWHCookingTask' NOTIF_EMAIL_FROM = ('"Software Heritage Vault" ' '') NOTIF_EMAIL_SUBJECT = ("Bundle ready: {obj_type} {short_id}") NOTIF_EMAIL_BODY = """ You have requested the following bundle from the Software Heritage Vault: Object Type: {obj_type} Object ID: {hex_id} This bundle is now available for download at the following address: {url} Please keep in mind that this link might expire at some point, in which case you will need to request the bundle again. --\x20 The Software Heritage Developers """ # TODO: Imported from swh.scheduler.backend. Factorization needed. def autocommit(fn): @wraps(fn) def wrapped(self, *args, **kwargs): autocommit = False # TODO: I don't like using None, it's confusing for the user. how about # a NEW_CURSOR object()? if 'cursor' not in kwargs or not kwargs['cursor']: autocommit = True kwargs['cursor'] = self.cursor() try: ret = fn(self, *args, **kwargs) except: if autocommit: self.rollback() raise if autocommit: self.commit() return ret return wrapped # TODO: This has to be factorized with other database base classes and helpers # (swh.scheduler.backend.SchedulerBackend, swh.storage.db.BaseDb, ...) # The three first methods are imported from swh.scheduler.backend. class VaultBackend: """ Backend for the Software Heritage vault. """ def __init__(self, config): self.config = config self.cache = VaultCache(**self.config['cache']) self.db = None self.reconnect() self.smtp_server = smtplib.SMTP('localhost') def reconnect(self): + """Reconnect to the database.""" if not self.db or self.db.closed: self.db = psycopg2.connect( dsn=self.config['vault_db'], cursor_factory=psycopg2.extras.RealDictCursor, ) def close(self): + """Close the underlying database connection.""" self.db.close() def cursor(self): """Return a fresh cursor on the database, with auto-reconnection in case of failure""" cur = None # Get a fresh cursor and reconnect at most three times tries = 0 while True: tries += 1 try: cur = self.db.cursor() cur.execute('select 1') break except psycopg2.OperationalError: if tries < 3: self.reconnect() else: raise return cur def commit(self): """Commit a transaction""" self.db.commit() def rollback(self): """Rollback a transaction""" self.db.rollback() @autocommit def task_info(self, obj_type, obj_id, cursor=None): + """Fetch information from a bundle""" obj_id = hashutil.hash_to_bytes(obj_id) cursor.execute(''' SELECT id, type, object_id, task_uuid, task_status, sticky, ts_created, ts_done, ts_last_access, progress_msg FROM vault_bundle WHERE type = %s AND object_id = %s''', (obj_type, obj_id)) res = cursor.fetchone() if res: res['object_id'] = bytes(res['object_id']) return res def _send_task(task_uuid, args): + """Send a cooking task to the celery scheduler""" task = get_task(cooking_task_name) task.apply_async(args, task_id=task_uuid) @autocommit def create_task(self, obj_type, obj_id, sticky=False, cursor=None): + """Create and send a cooking task""" obj_id = hashutil.hash_to_bytes(obj_id) args = [self.config, obj_type, obj_id] CookerCls = get_cooker(obj_type) cooker = CookerCls(*args) cooker.check_exists() task_uuid = celery.uuid() cursor.execute(''' INSERT INTO vault_bundle (type, object_id, task_uuid, sticky) VALUES (%s, %s, %s, %s)''', (obj_type, obj_id, task_uuid, sticky)) self.commit() self._send_task(task_uuid, args) @autocommit def add_notif_email(self, obj_type, obj_id, email, cursor=None): + """Add an e-mail address to notify when a given bundle is ready""" obj_id = hashutil.hash_to_bytes(obj_id) cursor.execute(''' INSERT INTO vault_notif_email (email, bundle_id) VALUES (%s, (SELECT id FROM vault_bundle WHERE type = %s AND object_id = %s))''', (email, obj_type, obj_id)) @autocommit def cook_request(self, obj_type, obj_id, *, sticky=False, email=None, cursor=None): + """Main entry point for cooking requests. This starts a cooking task if + needed, and add the given e-mail to the notify list""" info = self.task_info(obj_type, obj_id) if info is None: self.create_task(obj_type, obj_id, sticky) if email is not None: if info is not None and info['task_status'] == 'done': self.send_notification(None, email, obj_type, obj_id) else: self.add_notif_email(obj_type, obj_id, email) info = self.task_info(obj_type, obj_id) return info @autocommit def is_available(self, obj_type, obj_id, cursor=None): + """Check whether a bundle is available for retrieval""" info = self.task_info(obj_type, obj_id, cursor=cursor) return (info is not None and info['task_status'] == 'done' and self.cache.is_cached(obj_type, obj_id)) @autocommit def fetch(self, obj_type, obj_id, cursor=None): + """Retrieve a bundle from the cache""" if not self.is_available(obj_type, obj_id, cursor=cursor): return None self.update_access_ts(obj_type, obj_id, cursor=cursor) return self.cache.get(obj_type, obj_id) @autocommit def update_access_ts(self, obj_type, obj_id, cursor=None): + """Update the last access timestamp of a bundle""" obj_id = hashutil.hash_to_bytes(obj_id) cursor.execute(''' UPDATE vault_bundle SET ts_last_access = NOW() WHERE type = %s AND object_id = %s''', (obj_type, obj_id)) @autocommit def set_status(self, obj_type, obj_id, status, cursor=None): + """Set the cooking status of a bundle""" obj_id = hashutil.hash_to_bytes(obj_id) req = (''' UPDATE vault_bundle SET task_status = %s ''' + (''', ts_done = NOW() ''' if status == 'done' else '') + '''WHERE type = %s AND object_id = %s''') cursor.execute(req, (status, obj_type, obj_id)) @autocommit def set_progress(self, obj_type, obj_id, progress, cursor=None): + """Set the cooking progress of a bundle""" obj_id = hashutil.hash_to_bytes(obj_id) cursor.execute(''' UPDATE vault_bundle SET progress_msg = %s WHERE type = %s AND object_id = %s''', (progress, obj_type, obj_id)) @autocommit def send_all_notifications(self, obj_type, obj_id, cursor=None): + """Send all the e-mails in the notification list of a bundle""" obj_id = hashutil.hash_to_bytes(obj_id) cursor.execute(''' SELECT vault_notif_email.id AS id, email FROM vault_notif_email INNER JOIN vault_bundle ON bundle_id = vault_bundle.id WHERE vault_bundle.type = %s AND vault_bundle.object_id = %s''', (obj_type, obj_id)) for d in cursor: self.send_notification(d['id'], d['email'], obj_type, obj_id) @autocommit def send_notification(self, n_id, email, obj_type, obj_id, cursor=None): + """Send the notification of a bundle to a specific e-mail""" hex_id = hashutil.hash_to_hex(obj_id) short_id = hex_id[:7] # TODO: instead of hardcoding this, we should probably: # * add a "fetch_url" field in the vault_notif_email table # * generate the url with flask.url_for() on the web-ui side # * send this url as part of the cook request and store it in # the table # * use this url for the notification e-mail url = ('https://archive.softwareheritage.org/api/1/vault/{}/{}/' 'raw'.format(obj_type, hex_id)) text = NOTIF_EMAIL_BODY.strip() text = text.format(obj_type=obj_type, hex_id=hex_id, url=url) msg = MIMEText(text) msg['Subject'] = (NOTIF_EMAIL_SUBJECT .format(obj_type=obj_type, short_id=short_id)) msg['From'] = NOTIF_EMAIL_FROM msg['To'] = email self.smtp_server.send_message(msg) if n_id is not None: cursor.execute(''' DELETE FROM vault_notif_email WHERE id = %s''', (n_id,)) @autocommit def _cache_expire(self, cond, *args, cursor=None): """Low-level expiration method, used by cache_expire_* methods""" # Embedded SELECT query to be able to use ORDER BY and LIMIT cursor.execute(''' DELETE FROM vault_bundle WHERE ctid IN ( SELECT ctid FROM vault_bundle WHERE sticky = false {} ) RETURNING type, object_id '''.format(cond), args) for d in cursor: self.cache.delete(d['type'], bytes(d['object_id'])) @autocommit def cache_expire_oldest(self, n=1, by='last_access', cursor=None): + """Expire the `n` oldest bundles""" assert by in ('created', 'done', 'last_access') filter = '''ORDER BY ts_{} LIMIT {}'''.format(by, n) return self._cache_expire(filter) @autocommit def cache_expire_until(self, date, by='last_access', cursor=None): + """Expire all the bundles until a certain date""" assert by in ('created', 'done', 'last_access') filter = '''AND ts_{} <= %s'''.format(by) return self._cache_expire(filter, date)