[pkg] unify client and server into a single python package

We have been discussing about this merge for a while.
Its main goal is to simplify things: code navigation, but also
packaging.

The rationale is that the code is more cohesive in this way, and there's
only one source package to install.

Dependencies that are only for the server or the client will not be
installed by default, and they are expected to be provided by the
environment. There are setuptools extras defined for the client and the
server.

Debianization is still expected to split the single source package into
3 binaries.

Another avantage is that the documentation can now install a single
package with a single step, and therefore include the docstrings into
the generated docs.

- Resolves: #8896

1 files changed, 642 insertions, 0 deletions

diff --git a/src/leap/soledad/common/backend.py b/src/leap/soledad/common/backend.py
new file mode 100644
index 00000000..4a29ca87
--- /dev/null
+++ b/src/leap/soledad/common/backend.py
@@ -0,0 +1,642 @@
+# -*- coding: utf-8 -*-
+# backend.py
+# Copyright (C) 2015 LEAP
+#
+# 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/>.
+
+
+"""A L2DB generic backend."""
+
+import functools
+
+from leap.soledad.common.document import ServerDocument
+from leap.soledad.common.l2db import vectorclock
+from leap.soledad.common.l2db.errors import (
+    RevisionConflict,
+    InvalidDocId,
+    ConflictedDoc,
+    DocumentDoesNotExist,
+    DocumentAlreadyDeleted,
+)
+from leap.soledad.common.l2db.backends import CommonBackend
+from leap.soledad.common.l2db.backends import CommonSyncTarget
+
+
+class SoledadBackend(CommonBackend):
+    BATCH_SUPPORT = False
+
+    """
+    A L2DB backend implementation.
+    """
+
+    def __init__(self, database, replica_uid=None):
+        """
+        Create a new backend.
+
+        :param database: the database implementation
+        :type database: Database
+        :param replica_uid: an optional unique replica identifier
+        :type replica_uid: str
+        """
+        # save params
+        self._factory = ServerDocument
+        self._real_replica_uid = None
+        self._cache = None
+        self._dbname = database._dbname
+        self._database = database
+        self.batching = False
+        if replica_uid is not None:
+            self._set_replica_uid(replica_uid)
+
+    def batch_start(self):
+        if not self.BATCH_SUPPORT:
+            return
+        self.batching = True
+        self.after_batch_callbacks = {}
+        self._database.batch_start()
+        if not self._cache:
+            # batching needs cache
+            self._cache = {}
+        self._get_generation()  # warm up gen info
+
+    def batch_end(self):
+        if not self.BATCH_SUPPORT:
+            return
+        self._database.batch_end()
+        self.batching = False
+        for name in self.after_batch_callbacks:
+            self.after_batch_callbacks[name]()
+        self.after_batch_callbacks = None
+
+    @property
+    def cache(self):
+        if self._cache is not None:
+            return self._cache
+        else:
+            return {}
+
+    def init_caching(self, cache):
+        """
+        Start using cache by setting internal _cache attribute.
+
+        :param cache: the cache instance, anything that behaves like a dict
+        :type cache: dict
+        """
+        self._cache = cache
+
+    def get_sync_target(self):
+        """
+        Return a SyncTarget object, for another u1db to synchronize with.
+
+        :return: The sync target.
+        :rtype: SoledadSyncTarget
+        """
+        return SoledadSyncTarget(self)
+
+    def delete_database(self):
+        """
+        Delete a U1DB database.
+        """
+        self._database.delete_database()
+
+    def close(self):
+        """
+        Release any resources associated with this database.
+
+        :return: True if db was succesfully closed.
+        :rtype: bool
+        """
+        self._database.close()
+        return True
+
+    def __del__(self):
+        """
+        Close the database upon garbage collection.
+        """
+        self.close()
+
+    def _set_replica_uid(self, replica_uid):
+        """
+        Force the replica uid to be set.
+
+        :param replica_uid: The new replica uid.
+        :type replica_uid: str
+        """
+        self._database.set_replica_uid(replica_uid)
+        self._real_replica_uid = replica_uid
+        self.cache['replica_uid'] = self._real_replica_uid
+
+    def _get_replica_uid(self):
+        """
+        Get the replica uid.
+
+        :return: The replica uid.
+        :rtype: str
+        """
+        if self._real_replica_uid is not None:
+            self.cache['replica_uid'] = self._real_replica_uid
+            return self._real_replica_uid
+        if 'replica_uid' in self.cache:
+            return self.cache['replica_uid']
+        self._real_replica_uid = self._database.get_replica_uid()
+        self._set_replica_uid(self._real_replica_uid)
+        return self._real_replica_uid
+
+    _replica_uid = property(_get_replica_uid, _set_replica_uid)
+
+    replica_uid = property(_get_replica_uid)
+
+    def _get_generation(self):
+        """
+        Return the current generation.
+
+        :return: The current generation.
+        :rtype: int
+
+        :raise SoledadError: Raised by database on operation failure
+        """
+        return self._get_generation_info()[0]
+
+    def _get_generation_info(self):
+        """
+        Return the current generation.
+
+        :return: A tuple containing the current generation and transaction id.
+        :rtype: (int, str)
+
+        :raise SoledadError: Raised by database on operation failure
+        """
+        cur_gen, newest_trans_id = self._database.get_generation_info()
+        return (cur_gen, newest_trans_id)
+
+    def _get_trans_id_for_gen(self, generation):
+        """
+        Get the transaction id corresponding to a particular generation.
+
+        :param generation: The generation for which to get the transaction id.
+        :type generation: int
+
+        :return: The transaction id for C{generation}.
+        :rtype: str
+
+        :raise InvalidGeneration: Raised when the generation does not exist.
+
+        """
+        return self._database.get_trans_id_for_gen(generation)
+
+    def _get_transaction_log(self):
+        """
+        This is only for the test suite, it is not part of the api.
+
+        :return: The complete transaction log.
+        :rtype: [(str, str)]
+
+        """
+        return self._database.get_transaction_log()
+
+    def _get_doc(self, doc_id, check_for_conflicts=False):
+        """
+        Extract the document from storage.
+
+        This can return None if the document doesn't exist.
+
+        :param doc_id: The unique document identifier
+        :type doc_id: str
+        :param check_for_conflicts: If set to False, then the conflict check
+                                    will be skipped.
+        :type check_for_conflicts: bool
+
+        :return: The document.
+        :rtype: ServerDocument
+        """
+        return self._database.get_doc(doc_id, check_for_conflicts)
+
+    def get_doc(self, doc_id, include_deleted=False):
+        """
+        Get the JSON string for the given document.
+
+        :param doc_id: The unique document identifier
+        :type doc_id: str
+        :param include_deleted: If set to True, deleted documents will be
+            returned with empty content. Otherwise asking for a deleted
+            document will return None.
+        :type include_deleted: bool
+
+        :return: A document object.
+        :rtype: ServerDocument.
+        """
+        doc = self._get_doc(doc_id, check_for_conflicts=True)
+        if doc is None:
+            return None
+        if doc.is_tombstone() and not include_deleted:
+            return None
+        return doc
+
+    def get_all_docs(self, include_deleted=False):
+        """
+        Get the JSON content for all documents in the database.
+
+        :param include_deleted: If set to True, deleted documents will be
+                                returned with empty content. Otherwise deleted
+                                documents will not be included in the results.
+        :type include_deleted: bool
+
+        :return: (generation, [ServerDocument])
+            The current generation of the database, followed by a list of all
+            the documents in the database.
+        :rtype: (int, [ServerDocument])
+        """
+        return self._database.get_all_docs(include_deleted)
+
+    def _put_doc(self, old_doc, doc):
+        """
+        Put the document in the backend database.
+
+        Note that C{old_doc} must have been fetched with the parameter
+        C{check_for_conflicts} equal to True, so we can properly update the
+        new document using the conflict information from the old one.
+
+        :param old_doc: The old document version.
+        :type old_doc: ServerDocument
+        :param doc: The document to be put.
+        :type doc: ServerDocument
+        """
+        self._database.save_document(old_doc, doc,
+                                     self._allocate_transaction_id())
+
+    def put_doc(self, doc):
+        """
+        Update a document.
+
+        If the document currently has conflicts, put will fail.
+        If the database specifies a maximum document size and the document
+        exceeds it, put will fail and raise a DocumentTooBig exception.
+
+        :param doc: A Document with new content.
+        :return: new_doc_rev - The new revision identifier for the document.
+            The Document object will also be updated.
+
+        :raise InvalidDocId: Raised if the document's id is invalid.
+        :raise DocumentTooBig: Raised if the document size is too big.
+        :raise ConflictedDoc: Raised if the document has conflicts.
+        """
+        if doc.doc_id is None:
+            raise InvalidDocId()
+        self._check_doc_id(doc.doc_id)
+        self._check_doc_size(doc)
+        old_doc = self._get_doc(doc.doc_id, check_for_conflicts=True)
+        if old_doc and old_doc.has_conflicts:
+            raise ConflictedDoc()
+        if old_doc and doc.rev is None and old_doc.is_tombstone():
+            new_rev = self._allocate_doc_rev(old_doc.rev)
+        else:
+            if old_doc is not None:
+                    if old_doc.rev != doc.rev:
+                        raise RevisionConflict()
+            else:
+                if doc.rev is not None:
+                    raise RevisionConflict()
+            new_rev = self._allocate_doc_rev(doc.rev)
+        doc.rev = new_rev
+        self._put_doc(old_doc, doc)
+        return new_rev
+
+    def whats_changed(self, old_generation=0):
+        """
+        Return a list of documents that have changed since old_generation.
+
+        :param old_generation: The generation of the database in the old
+                               state.
+        :type old_generation: int
+
+        :return: (generation, trans_id, [(doc_id, generation, trans_id),...])
+                 The current generation of the database, its associated
+                 transaction id, and a list of of changed documents since
+                 old_generation, represented by tuples with for each document
+                 its doc_id and the generation and transaction id corresponding
+                 to the last intervening change and sorted by generation (old
+                 changes first)
+        :rtype: (int, str, [(str, int, str)])
+        """
+        return self._database.whats_changed(old_generation)
+
+    def delete_doc(self, doc):
+        """
+        Mark a document as deleted.
+
+        Will abort if the current revision doesn't match doc.rev.
+        This will also set doc.content to None.
+
+        :param doc: The document to mark as deleted.
+        :type doc: ServerDocument.
+
+        :raise DocumentDoesNotExist: Raised if the document does not
+                                            exist.
+        :raise RevisionConflict: Raised if the revisions do not match.
+        :raise DocumentAlreadyDeleted: Raised if the document is
+                                              already deleted.
+        :raise ConflictedDoc: Raised if the doc has conflicts.
+        """
+        old_doc = self._get_doc(doc.doc_id, check_for_conflicts=True)
+        if old_doc is None:
+            raise DocumentDoesNotExist
+        if old_doc.rev != doc.rev:
+            raise RevisionConflict()
+        if old_doc.is_tombstone():
+            raise DocumentAlreadyDeleted
+        if old_doc.has_conflicts:
+            raise ConflictedDoc()
+        new_rev = self._allocate_doc_rev(doc.rev)
+        doc.rev = new_rev
+        doc.make_tombstone()
+        self._put_doc(old_doc, doc)
+        return new_rev
+
+    def get_doc_conflicts(self, doc_id):
+        """
+        Get the conflicted versions of a document.
+
+        :param doc_id: The document id.
+        :type doc_id: str
+
+        :return: A list of conflicted versions of the document.
+        :rtype: list
+        """
+        return self._database.get_doc_conflicts(doc_id)
+
+    def _get_replica_gen_and_trans_id(self, other_replica_uid):
+        """
+        Return the last known generation and transaction id for the other db
+        replica.
+
+        When you do a synchronization with another replica, the Database keeps
+        track of what generation the other database replica was at, and what
+        the associated transaction id was.  This is used to determine what data
+        needs to be sent, and if two databases are claiming to be the same
+        replica.
+
+        :param other_replica_uid: The identifier for the other replica.
+        :type other_replica_uid: str
+
+        :return: A tuple containing the generation and transaction id we
+                 encountered during synchronization. If we've never
+                 synchronized with the replica, this is (0, '').
+        :rtype: (int, str)
+        """
+        if other_replica_uid in self.cache:
+            return self.cache[other_replica_uid]
+        gen, trans_id = \
+            self._database.get_replica_gen_and_trans_id(other_replica_uid)
+        self.cache[other_replica_uid] = (gen, trans_id)
+        return (gen, trans_id)
+
+    def _set_replica_gen_and_trans_id(self, other_replica_uid,
+                                      other_generation, other_transaction_id):
+        """
+        Set the last-known generation and transaction id for the other
+        database replica.
+
+        We have just performed some synchronization, and we want to track what
+        generation the other replica was at. See also
+        _get_replica_gen_and_trans_id.
+
+        :param other_replica_uid: The U1DB identifier for the other replica.
+        :type other_replica_uid: str
+        :param other_generation: The generation number for the other replica.
+        :type other_generation: int
+        :param other_transaction_id: The transaction id associated with the
+            generation.
+        :type other_transaction_id: str
+        """
+        if other_replica_uid is not None and other_generation is not None:
+            self.cache[other_replica_uid] = (other_generation,
+                                             other_transaction_id)
+            self._database.set_replica_gen_and_trans_id(other_replica_uid,
+                                                        other_generation,
+                                                        other_transaction_id)
+
+    def _do_set_replica_gen_and_trans_id(
+            self, other_replica_uid, other_generation, other_transaction_id):
+        """
+        _put_doc_if_newer from super class is calling it. So we declare this.
+
+        :param other_replica_uid: The U1DB identifier for the other replica.
+        :type other_replica_uid: str
+        :param other_generation: The generation number for the other replica.
+        :type other_generation: int
+        :param other_transaction_id: The transaction id associated with the
+                                     generation.
+        :type other_transaction_id: str
+        """
+        args = [other_replica_uid, other_generation, other_transaction_id]
+        callback = functools.partial(self._set_replica_gen_and_trans_id, *args)
+        if self.batching:
+            self.after_batch_callbacks['set_source_info'] = callback
+        else:
+            callback()
+
+    def _force_doc_sync_conflict(self, doc):
+        """
+        Add a conflict and force a document put.
+
+        :param doc: The document to be put.
+        :type doc: ServerDocument
+        """
+        my_doc = self._get_doc(doc.doc_id)
+        self._prune_conflicts(doc, vectorclock.VectorClockRev(doc.rev))
+        doc.add_conflict(self._factory(doc.doc_id, my_doc.rev,
+                                       my_doc.get_json()))
+        doc.has_conflicts = True
+        self._put_doc(my_doc, doc)
+
+    def resolve_doc(self, doc, conflicted_doc_revs):
+        """
+        Mark a document as no longer conflicted.
+
+        We take the list of revisions that the client knows about that it is
+        superseding. This may be a different list from the actual current
+        conflicts, in which case only those are removed as conflicted.  This
+        may fail if the conflict list is significantly different from the
+        supplied information. (sync could have happened in the background from
+        the time you GET_DOC_CONFLICTS until the point where you RESOLVE)
+
+        :param doc: A Document with the new content to be inserted.
+        :type doc: ServerDocument
+        :param conflicted_doc_revs: A list of revisions that the new content
+                                    supersedes.
+        :type conflicted_doc_revs: [str]
+
+        :raise SoledadError: Raised by database on operation failure
+        """
+        cur_doc = self._get_doc(doc.doc_id, check_for_conflicts=True)
+        new_rev = self._ensure_maximal_rev(cur_doc.rev,
+                                           conflicted_doc_revs)
+        superseded_revs = set(conflicted_doc_revs)
+        doc.rev = new_rev
+        # this backend stores conflicts as properties of the documents, so we
+        # have to copy these conflicts over to the document being updated.
+        if cur_doc.rev in superseded_revs:
+            # the newer doc version will supersede the one in the database, so
+            # we copy conflicts before updating the backend.
+            doc.set_conflicts(cur_doc.get_conflicts())  # copy conflicts over.
+            doc.delete_conflicts(superseded_revs)
+            self._put_doc(cur_doc, doc)
+        else:
+            # the newer doc version does not supersede the one in the
+            # database, so we will add a conflict to the database and copy
+            # those over to the document the user has in her hands.
+            cur_doc.add_conflict(doc)
+            cur_doc.delete_conflicts(superseded_revs)
+            self._put_doc(cur_doc, cur_doc)  # just update conflicts
+            # backend has been updated with current conflicts, now copy them
+            # to the current document.
+            doc.set_conflicts(cur_doc.get_conflicts())
+
+    def _put_doc_if_newer(self, doc, save_conflict, replica_uid, replica_gen,
+                          replica_trans_id='', number_of_docs=None,
+                          doc_idx=None, sync_id=None):
+        """
+        Insert/update document into the database with a given revision.
+
+        This api is used during synchronization operations.
+
+        If a document would conflict and save_conflict is set to True, the
+        content will be selected as the 'current' content for doc.doc_id,
+        even though doc.rev doesn't supersede the currently stored revision.
+        The currently stored document will be added to the list of conflict
+        alternatives for the given doc_id.
+
+        This forces the new content to be 'current' so that we get convergence
+        after synchronizing, even if people don't resolve conflicts. Users can
+        then notice that their content is out of date, update it, and
+        synchronize again. (The alternative is that users could synchronize and
+        think the data has propagated, but their local copy looks fine, and the
+        remote copy is never updated again.)
+
+        :param doc: A document object
+        :type doc: ServerDocument
+        :param save_conflict: If this document is a conflict, do you want to
+                              save it as a conflict, or just ignore it.
+        :type save_conflict: bool
+        :param replica_uid: A unique replica identifier.
+        :type replica_uid: str
+        :param replica_gen: The generation of the replica corresponding to the
+                            this document. The replica arguments are optional,
+                            but are used during synchronization.
+        :type replica_gen: int
+        :param replica_trans_id: The transaction_id associated with the
+                                 generation.
+        :type replica_trans_id: str
+        :param number_of_docs: The total amount of documents sent on this sync
+                               session.
+        :type number_of_docs: int
+        :param doc_idx: The index of the current document being sent.
+        :type doc_idx: int
+        :param sync_id: The id of the current sync session.
+        :type sync_id: str
+
+        :return: (state, at_gen) -  If we don't have doc_id already, or if
+                 doc_rev supersedes the existing document revision, then the
+                 content will be inserted, and state is 'inserted'.  If
+                 doc_rev is less than or equal to the existing revision, then
+                 the put is ignored and state is respecitvely 'superseded' or
+                 'converged'.  If doc_rev is not strictly superseded or
+                 supersedes, then state is 'conflicted'. The document will not
+                 be inserted if save_conflict is False.  For 'inserted' or
+                 'converged', at_gen is the insertion/current generation.
+        :rtype: (str, int)
+        """
+        if not isinstance(doc, ServerDocument):
+            doc = self._factory(doc.doc_id, doc.rev, doc.get_json())
+        my_doc = self._get_doc(doc.doc_id, check_for_conflicts=True)
+        if my_doc:
+            doc.set_conflicts(my_doc.get_conflicts())
+        return CommonBackend._put_doc_if_newer(self, doc, save_conflict,
+                                               replica_uid, replica_gen,
+                                               replica_trans_id)
+
+    def _put_and_update_indexes(self, cur_doc, doc):
+        self._put_doc(cur_doc, doc)
+
+    def get_docs(self, doc_ids, check_for_conflicts=True,
+                 include_deleted=False, read_content=True):
+        """
+        Get the JSON content for many documents.
+
+        :param doc_ids: A list of document identifiers or None for all.
+        :type doc_ids: list
+        :param check_for_conflicts: If set to False, then the conflict check
+                                    will be skipped, and 'None' will be
+                                    returned instead of True/False.
+        :type check_for_conflicts: bool
+        :param include_deleted: If set to True, deleted documents will be
+                                returned with empty content. Otherwise deleted
+                                documents will not be included in the results.
+        :return: iterable giving the Document object for each document id
+                 in matching doc_ids order.
+        :rtype: iterable
+        """
+        return self._database.get_docs(doc_ids, check_for_conflicts,
+                                       include_deleted, read_content)
+
+    def _prune_conflicts(self, doc, doc_vcr):
+        """
+        Prune conflicts that are older then the current document's revision, or
+        whose content match to the current document's content.
+        Originally in u1db.CommonBackend
+
+        :param doc: The document to have conflicts pruned.
+        :type doc: ServerDocument
+        :param doc_vcr: A vector clock representing the current document's
+                        revision.
+        :type doc_vcr: u1db.vectorclock.VectorClock
+        """
+        if doc.has_conflicts:
+            autoresolved = False
+            c_revs_to_prune = []
+            for c_doc in doc._conflicts:
+                c_vcr = vectorclock.VectorClockRev(c_doc.rev)
+                if doc_vcr.is_newer(c_vcr):
+                    c_revs_to_prune.append(c_doc.rev)
+                elif doc.same_content_as(c_doc):
+                    c_revs_to_prune.append(c_doc.rev)
+                    doc_vcr.maximize(c_vcr)
+                    autoresolved = True
+            if autoresolved:
+                doc_vcr.increment(self._replica_uid)
+                doc.rev = doc_vcr.as_str()
+            doc.delete_conflicts(c_revs_to_prune)
+
+
+class SoledadSyncTarget(CommonSyncTarget):
+
+    """
+    Functionality for using a SoledadBackend as a synchronization target.
+    """
+
+    def get_sync_info(self, source_replica_uid):
+        source_gen, source_trans_id = self._db._get_replica_gen_and_trans_id(
+            source_replica_uid)
+        my_gen, my_trans_id = self._db._get_generation_info()
+        return (
+            self._db._replica_uid, my_gen, my_trans_id, source_gen,
+            source_trans_id)
+
+    def record_sync_info(self, source_replica_uid, source_replica_generation,
+                         source_replica_transaction_id):
+        if self._trace_hook:
+            self._trace_hook('record_sync_info')
+        self._db._set_replica_gen_and_trans_id(
+            source_replica_uid, source_replica_generation,
+            source_replica_transaction_id)