datastore.py

# Copyright 2014 Google Inc. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import datetime
import os
import pytz
import unittest2

from gcloud import datastore
from gcloud.datastore.entity import Entity
from gcloud.datastore.key import Key
from gcloud.datastore.query import Query
from gcloud.datastore.transaction import Transaction
# This assumes the command is being run via tox hence the
# repository root is the current directory.
from regression import populate_datastore


DATASET_ID = os.getenv('GCLOUD_TESTS_DATASET_ID')
datastore.set_default_dataset(dataset_id=DATASET_ID)
datastore.set_default_connection()


class TestDatastore(unittest2.TestCase):

    def setUp(self):
        self.case_entities_to_delete = []

    def tearDown(self):
        with Transaction():
            for entity in self.case_entities_to_delete:
                entity.key.delete()


class TestDatastoreAllocateIDs(TestDatastore):

    def test_allocate_ids(self):
        num_ids = 10
        allocated_keys = datastore.allocate_ids(Key('Kind'), num_ids)
        self.assertEqual(len(allocated_keys), num_ids)

        unique_ids = set()
        for key in allocated_keys:
            unique_ids.add(key.id)
            self.assertEqual(key.name, None)
            self.assertNotEqual(key.id, None)

        self.assertEqual(len(unique_ids), num_ids)


class TestDatastoreSave(TestDatastore):

    def _get_post(self, id_or_name=None, post_content=None):
        post_content = post_content or {
            'title': u'How to make the perfect pizza in your grill',
            'tags': [u'pizza', u'grill'],
            'publishedAt': datetime.datetime(2001, 1, 1, tzinfo=pytz.utc),
            'author': u'Silvano',
            'isDraft': False,
            'wordCount': 400,
            'rating': 5.0,
        }
        # Create an entity with the given content.
        entity = Entity(key=Key('Post'))
        entity.update(post_content)

        # Update the entity key.
        if id_or_name is not None:
            entity.key = entity.key.completed_key(id_or_name)

        return entity

    def _generic_test_post(self, name=None, key_id=None):
        entity = self._get_post(id_or_name=(name or key_id))
        entity.save()

        # Register entity to be deleted.
        self.case_entities_to_delete.append(entity)

        if name is not None:
            self.assertEqual(entity.key.name, name)
        if key_id is not None:
            self.assertEqual(entity.key.id, key_id)
        retrieved_entity = entity.key.get()
        # Check the keys are the same.
        self.assertTrue(retrieved_entity.key is entity.key)

        # Check the data is the same.
        retrieved_dict = dict(retrieved_entity.items())
        entity_dict = dict(entity.items())
        self.assertEqual(retrieved_dict, entity_dict)

    def test_post_with_name(self):
        self._generic_test_post(name='post1')

    def test_post_with_id(self):
        self._generic_test_post(key_id=123456789)

    def test_post_with_generated_id(self):
        self._generic_test_post()

    def test_save_multiple(self):
        with Transaction():
            entity1 = self._get_post()
            entity1.save()
            # Register entity to be deleted.
            self.case_entities_to_delete.append(entity1)

            second_post_content = {
                'title': u'How to make the perfect homemade pasta',
                'tags': [u'pasta', u'homemade'],
                'publishedAt': datetime.datetime(2001, 1, 1),
                'author': u'Silvano',
                'isDraft': False,
                'wordCount': 450,
                'rating': 4.5,
            }
            entity2 = self._get_post(post_content=second_post_content)
            entity2.save()
            # Register entity to be deleted.
            self.case_entities_to_delete.append(entity2)

        keys = [entity1.key, entity2.key]
        matches = datastore.get_entities(keys)
        self.assertEqual(len(matches), 2)

    def test_empty_kind(self):
        query = Query(kind='Post')
        posts = list(query.fetch(limit=2))
        self.assertEqual(posts, [])


class TestDatastoreSaveKeys(TestDatastore):

    def test_save_key_self_reference(self):
        key = Key('Person', 'name')
        entity = Entity(key=key)
        entity['fullName'] = u'Full name'
        entity['linkedTo'] = key  # Self reference.

        entity.save()
        self.case_entities_to_delete.append(entity)

        query = Query(kind='Person')
        query.add_filter('linkedTo', '=', key)

        stored_persons = list(query.fetch(limit=2))
        self.assertEqual(len(stored_persons), 1)

        stored_person = stored_persons[0]
        self.assertEqual(stored_person['fullName'], entity['fullName'])
        self.assertEqual(stored_person.key.path, key.path)
        self.assertEqual(stored_person.key.namespace, key.namespace)


class TestDatastoreQuery(TestDatastore):

    @classmethod
    def setUpClass(cls):
        super(TestDatastoreQuery, cls).setUpClass()
        cls.CHARACTERS = populate_datastore.CHARACTERS
        cls.ANCESTOR_KEY = Key(*populate_datastore.ANCESTOR)

    def _base_query(self):
        return Query(kind='Character', ancestor=self.ANCESTOR_KEY)

    def test_limit_queries(self):
        limit = 5
        query = self._base_query()

        # Fetch characters.
        iterator = query.fetch(limit=limit)
        character_entities, _, cursor = iterator.next_page()
        self.assertEqual(len(character_entities), limit)

        # Check cursor after fetch.
        self.assertTrue(cursor is not None)

        # Fetch remaining of characters.
        new_character_entities = list(iterator)
        characters_remaining = len(self.CHARACTERS) - limit
        self.assertEqual(len(new_character_entities), characters_remaining)

    def test_query_simple_filter(self):
        query = self._base_query()
        query.add_filter('appearances', '>=', 20)
        expected_matches = 6
        # We expect 6, but allow the query to get 1 extra.
        entities = list(query.fetch(limit=expected_matches + 1))
        self.assertEqual(len(entities), expected_matches)

    def test_query_multiple_filters(self):
        query = self._base_query()
        query.add_filter('appearances', '>=', 26)
        query.add_filter('family', '=', 'Stark')
        expected_matches = 4
        # We expect 4, but allow the query to get 1 extra.
        entities = list(query.fetch(limit=expected_matches + 1))
        self.assertEqual(len(entities), expected_matches)

    def test_ancestor_query(self):
        filtered_query = self._base_query()

        expected_matches = 8
        # We expect 8, but allow the query to get 1 extra.
        entities = list(filtered_query.fetch(limit=expected_matches + 1))
        self.assertEqual(len(entities), expected_matches)

    def test_query___key___filter(self):
        rickard_key = Key(*populate_datastore.RICKARD)

        query = self._base_query()
        query.add_filter('__key__', '=', rickard_key)
        expected_matches = 1
        # We expect 1, but allow the query to get 1 extra.
        entities = list(query.fetch(limit=expected_matches + 1))
        self.assertEqual(len(entities), expected_matches)

    def test_ordered_query(self):
        query = self._base_query()
        query.order = 'appearances'
        expected_matches = 8
        # We expect 8, but allow the query to get 1 extra.
        entities = list(query.fetch(limit=expected_matches + 1))
        self.assertEqual(len(entities), expected_matches)

        # Actually check the ordered data returned.
        self.assertEqual(entities[0]['name'], self.CHARACTERS[0]['name'])
        self.assertEqual(entities[7]['name'], self.CHARACTERS[3]['name'])

    def test_projection_query(self):
        filtered_query = self._base_query()
        filtered_query.projection = ['name', 'family']

        # NOTE: There are 9 responses because of Catelyn. She has both
        #       Stark and Tully as her families, hence occurs twice in
        #       the results.
        expected_matches = 9
        # We expect 9, but allow the query to get 1 extra.
        entities = list(filtered_query.fetch(limit=expected_matches + 1))
        self.assertEqual(len(entities), expected_matches)

        arya_entity = entities[0]
        arya_dict = dict(arya_entity.items())
        self.assertEqual(arya_dict, {'name': 'Arya', 'family': 'Stark'})

        catelyn_stark_entity = entities[2]
        catelyn_stark_dict = dict(catelyn_stark_entity.items())
        self.assertEqual(catelyn_stark_dict,
                         {'name': 'Catelyn', 'family': 'Stark'})

        catelyn_tully_entity = entities[3]
        catelyn_tully_dict = dict(catelyn_tully_entity.items())
        self.assertEqual(catelyn_tully_dict,
                         {'name': 'Catelyn', 'family': 'Tully'})

        # Check both Catelyn keys are the same.
        catelyn_stark_key = catelyn_stark_entity.key
        catelyn_tully_key = catelyn_tully_entity.key
        self.assertEqual(catelyn_stark_key.path, catelyn_tully_key.path)
        self.assertEqual(catelyn_stark_key.namespace,
                         catelyn_tully_key.namespace)
        # Also check the dataset_id since both retrieved from datastore.
        self.assertEqual(catelyn_stark_key.dataset_id,
                         catelyn_tully_key.dataset_id)

        sansa_entity = entities[8]
        sansa_dict = dict(sansa_entity.items())
        self.assertEqual(sansa_dict, {'name': 'Sansa', 'family': 'Stark'})

    def test_query_paginate_with_offset(self):
        page_query = self._base_query()
        page_query.order = 'appearances'
        offset = 2
        limit = 3
        iterator = page_query.fetch(limit=limit, offset=offset)

        # Fetch characters.
        entities, _, cursor = iterator.next_page()
        self.assertEqual(len(entities), limit)
        self.assertEqual(entities[0]['name'], 'Robb')
        self.assertEqual(entities[1]['name'], 'Bran')
        self.assertEqual(entities[2]['name'], 'Catelyn')

        # Fetch next set of characters.
        new_iterator = page_query.fetch(limit=limit, offset=0,
                                        start_cursor=cursor)
        entities = list(new_iterator)
        self.assertEqual(len(entities), limit)
        self.assertEqual(entities[0]['name'], 'Sansa')
        self.assertEqual(entities[1]['name'], 'Jon Snow')
        self.assertEqual(entities[2]['name'], 'Arya')

    def test_query_paginate_with_start_cursor(self):
        page_query = self._base_query()
        page_query.order = 'appearances'
        limit = 3
        offset = 2
        iterator = page_query.fetch(limit=limit, offset=offset)

        # Fetch characters.
        entities, _, cursor = iterator.next_page()
        self.assertEqual(len(entities), limit)

        # Use cursor to create a fresh query.
        fresh_query = self._base_query()
        fresh_query.order = 'appearances'

        new_entities = list(fresh_query.fetch(start_cursor=cursor,
                                              limit=limit))
        characters_remaining = len(self.CHARACTERS) - limit - offset
        self.assertEqual(len(new_entities), characters_remaining)
        self.assertEqual(new_entities[0]['name'], 'Sansa')
        self.assertEqual(new_entities[2]['name'], 'Arya')

    def test_query_group_by(self):
        query = self._base_query()
        query.group_by = ['alive']

        expected_matches = 2
        # We expect 2, but allow the query to get 1 extra.
        entities = list(query.fetch(limit=expected_matches + 1))
        self.assertEqual(len(entities), expected_matches)

        self.assertEqual(entities[0]['name'], 'Catelyn')
        self.assertEqual(entities[1]['name'], 'Arya')


class TestDatastoreTransaction(TestDatastore):

    def test_transaction(self):
        entity = Entity(key=Key('Company', 'Google'))
        entity['url'] = u'www.google.com'

        with Transaction():
            retrieved_entity = entity.key.get()
            if retrieved_entity is None:
                entity.save()
                self.case_entities_to_delete.append(entity)

        # This will always return after the transaction.
        retrieved_entity = entity.key.get()
        self.case_entities_to_delete.append(retrieved_entity)
        retrieved_dict = dict(retrieved_entity.items())
        entity_dict = dict(entity.items())
        self.assertEqual(retrieved_dict, entity_dict)