foundationdb/recipes/python-recipes/micro_doc.py

122 lines
3.4 KiB
Python

#
# micro_doc.py
#
# This source file is part of the FoundationDB open source project
#
# Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
#
# 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 fdb
fdb.api_version(300)
db = fdb.open()
import itertools
import json
import random
doc_space = fdb.Subspace(('D',))
EMPTY_OBJECT = -2
EMPTY_ARRAY = -1
def to_tuples(item):
if item == {}:
return [(EMPTY_OBJECT, None)]
elif item == []:
return [(EMPTY_ARRAY, None)]
elif type(item) == dict:
return [(k,) + sub for k, v in item.iteritems() for sub in to_tuples(v)]
elif type(item) == list:
return [(k,) + sub for k, v in enumerate(item) for sub in to_tuples(v)]
else:
return [(item,)]
def from_tuples(tuples):
if not tuples:
return {}
first = tuples[0] # Determine kind of object from first tuple
if len(first) == 1:
return first[0] # Primitive value
if first == (EMPTY_OBJECT, None):
return {}
if first == (EMPTY_ARRAY, None):
return []
# For an object or array, we need to group the tuples by their first element
groups = [list(g) for k, g in itertools.groupby(tuples, lambda t:t[0])]
if first[0] == 0: # array
return [from_tuples([t[1:] for t in g]) for g in groups]
else: # object
return dict((g[0][0], from_tuples([t[1:] for t in g])) for g in groups)
@fdb.transactional
def insert_doc(tr, doc):
if type(doc) == str:
doc = json.loads(doc)
if 'doc_id' not in doc:
new_id = _get_new_id(tr)
doc['doc_id'] = new_id
for tup in to_tuples(doc):
tr[doc_space.pack((doc['doc_id'],) + tup[:-1])] = fdb.tuple.pack((tup[-1],))
return doc['doc_id']
@fdb.transactional
def _get_new_id(tr):
found = False
while (not found):
new_id = random.randint(0, 100000000)
found = True
for _ in tr[doc_space[new_id].range()]:
found = False
break
return new_id
@fdb.transactional
def get_doc(tr, doc_id, prefix=()):
v = tr[doc_space.pack((doc_id,) + prefix)]
if v.present():
return from_tuples([prefix + fdb.tuple.unpack(v)])
else:
return from_tuples([doc_space.unpack(k)[1:] + fdb.tuple.unpack(v)
for k, v in tr[doc_space.range((doc_id,) + prefix)]])
@fdb.transactional
def print_subspace(tr, subspace):
for k, v in tr[subspace.range()]:
print subspace.unpack(k), fdb.tuple.unpack(v)[0]
@fdb.transactional
def clear_subspace(tr, subspace):
tr.clear_range_startswith(subspace.key())
clear_subspace(db, doc_space)
def smoke_test():
h1 = {'user': {'jones': {'friend_of': 'smith', 'group': ['sales', 'service']}, 'smith': {'friend_of': 'jones', 'group': ['dev', 'research']}}}
id = insert_doc(db, h1)
print get_doc(db, id, ('user', 'smith', 'group'))
if __name__ == "__main__":
smoke_test()