feat: Support parameters

This commit allows users to pass some types of Python values as
parameters. Supported types are as follows.

* Basic types
  * string
  * integer
  * `float`
  * `bool`(`True`/`False`)
  * `None`
* Collection
  * `dict` -- only basic types can be key
  * `list`/`tuple`

agensgraph/__init__.py

@@ -21,6 +21,7 @@
 from agensgraph._vertex import Vertex, cast_vertex as _cast_vertex
 from agensgraph._edge import Edge, cast_edge as _cast_edge
 from agensgraph._graphpath import Path, cast_graphpath as _cast_graphpath
+from agensgraph._property import Property
 
 _GRAPHID_OID = 7002
 _VERTEX_OID = 7012
@@ -40,5 +41,5 @@
 PATH = _ext.new_type((_GRAPHPATH_OID,), 'PATH', _cast_graphpath)
 _ext.register_type(PATH)
 
-__all__ = ['GraphId', 'Vertex', 'Edge', 'Path',
+__all__ = ['GraphId', 'Vertex', 'Edge', 'Path', 'Property',
            'GRAPHID', 'VERTEX', 'EDGE', 'PATH']

agensgraph/_property.py

@@ -0,0 +1,148 @@
+'''
+Copyright (c) 2014-2018, Bitnine Inc.
+
+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 sys
+
+from psycopg2.extensions import ISQLQuote
+from psycopg2.extras import json
+
+# borrowed from simplejson's compat.py
+if sys.version_info[0] < 3:
+    string_types = (basestring,)
+    integer_types = (int, long)
+    def dict_items(o):
+        return o.iteritems()
+else:
+    string_types = (str,)
+    integer_types = (int,)
+    def dict_items(o):
+        return o.items()
+
+def quote_string(s):
+    s = s[1:-1]
+    s = "'" + s.replace("'", "''") + "'"
+    return s
+
+class PropertyEncoder(object):
+    def encode(self, o):
+        chunks = self.iterencode(o)
+        if not isinstance(chunks, (list, tuple)):
+            chunks = list(chunks)
+        return ''.join(chunks)
+
+    def iterencode(self, o):
+        markers = {}
+        _iterencode = _make_iterencode(markers, json.dumps, quote_string)
+        return _iterencode(o)
+
+def _make_iterencode(markers, _encoder, _quote_string,
+                     dict=dict,
+                     float=float,
+                     id=id,
+                     isinstance=isinstance,
+                     list=list,
+                     tuple=tuple,
+                     string_types=string_types,
+                     integer_types=integer_types,
+                     dict_items=dict_items):
+    def _iterencode_list(o):
+        if not o:
+            yield '[]'
+            return
+
+        markerid = id(o)
+        if markerid in markers:
+            raise ValueError('Circular reference detected')
+        markers[markerid] = o
+
+        yield '['
+        first = True
+        for e in o:
+            if first:
+                first = False
+            else:
+                yield ','
+
+            for chunk in _iterencode(e):
+                yield chunk
+        yield ']'
+
+        del markers[markerid]
+
+    def _iterencode_dict(o):
+        if not o:
+            yield '{}'
+            return
+
+        markerid = id(o)
+        if markerid in markers:
+            raise ValueError('Circular reference detected')
+        markers[markerid] = o
+
+        yield '{'
+        first = True
+        for k, v in dict_items(o):
+            if isinstance(k, string_types):
+                pass
+            elif (k is True or k is False or k is None or
+                  isinstance(k, integer_types) or isinstance(k, float)):
+                k = _encoder(k)
+            else:
+                raise TypeError('keys must be str, int, float, bool or None, '
+                                'not %s' % k.__class__.__name__)
+
+            if first:
+                first = False
+            else:
+                yield ','
+
+            yield _quote_string(_encoder(k))
+            yield ':'
+            for chunk in _iterencode(v):
+                yield chunk
+        yield '}'
+
+        del markers[markerid]
+
+    def _iterencode(o):
+        if isinstance(o, string_types):
+            yield _quote_string(_encoder(o))
+        elif isinstance(o, (list, tuple)):
+            for chunk in _iterencode_list(o):
+                yield chunk
+        elif isinstance(o, dict):
+            for chunk in _iterencode_dict(o):
+                yield chunk
+        else:
+            yield _encoder(o)
+
+    return _iterencode
+
+_default_encoder = PropertyEncoder()
+
+class Property(object):
+    def __init__(self, value):
+        self.value = value
+
+    def __conform__(self, proto):
+        if proto is ISQLQuote:
+            return self
+
+    def prepare(self, conn):
+        self._conn = conn
+
+    def getquoted(self):
+        return _default_encoder.encode(self.value)

tests/test_agensgraph.py

@@ -1,5 +1,5 @@
 '''
-Copyright (c) 2014-2017, Bitnine Inc.
+Copyright (c) 2014-2018, Bitnine Inc.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -124,5 +124,36 @@ def test_path(self):
                     (e.eid,))
             self.assertEqual(1, self.cur.fetchone()[0])
 
+class TestParam(TestConnection):
+    def setUp(self):
+        super(TestParam, self).setUp()
+        self.name = "'Agens\"Graph'"
+
+    def test_param_dict(self):
+        d = {'name': self.name, 'since': 2016}
+        p = agensgraph.Property(d)
+        self.cur.execute('CREATE (n %s) RETURN n', (p,))
+        self.conn.commit()
+
+        v = self.cur.fetchone()[0]
+        self.assertEqual(self.name, v.props['name'])
+        self.assertEqual(2016, v.props['since'])
+
+    def test_param_list_and_tuple(self):
+        a = [self.name, 2016]
+        t = (self.name, 2016)
+        pa = agensgraph.Property(a)
+        pt = agensgraph.Property(t)
+        self.cur.execute('CREATE (n {a: %s, t: %s}) RETURN n', (pa, pt))
+        self.conn.commit()
+
+        v = self.cur.fetchone()[0]
+        va = v.props['a']
+        self.assertEqual(self.name, va[0])
+        self.assertEqual(2016, va[1])
+        vt = v.props['t']
+        self.assertEqual(self.name, vt[0])
+        self.assertEqual(2016, vt[1])
+
 if __name__ == '__main__':
     unittest.main()

tests/test_property.py

@@ -0,0 +1,53 @@
+'''
+Copyright (c) 2014-2018, Bitnine Inc.
+
+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 unittest
+
+from agensgraph._property import Property
+
+from psycopg2.extensions import QuotedString, adapt
+
+class TestProperty(unittest.TestCase):
+    def test_string(self):
+        self.assertEqual(r"'\"'", Property('"').getquoted())
+        self.assertEqual(r"''''", Property("'").getquoted())
+
+    def test_number(self):
+        self.assertEqual('0', Property(0).getquoted())
+        self.assertEqual('-1', Property(-1).getquoted())
+        self.assertEqual('3.14159', Property(3.14159).getquoted())
+
+    def test_boolean(self):
+        self.assertEqual('true', Property(True).getquoted())
+        self.assertEqual('false', Property(False).getquoted())
+
+    def test_null(self):
+        self.assertEqual('null', Property(None).getquoted())
+
+    def test_array(self):
+        a = ["'\\\"'", 3.14159, True, None, (), {}]
+        e = "['''\\\\\\\"''',3.14159,true,null,[],{}]"
+        self.assertEqual(e, Property(a).getquoted())
+
+    def test_object(self):
+        self.assertEqual("{'\\\"':'\\\"'}", Property({'"': '"'}).getquoted())
+        self.assertEqual("{'3.14159':3.14159}",
+                         Property({3.14159: 3.14159}).getquoted())
+        self.assertEqual("{'true':false}", Property({True: False}).getquoted())
+        self.assertEqual("{'null':null}", Property({None: None}).getquoted())
+        self.assertEqual("{'a':[]}", Property({'a': []}).getquoted())
+        self.assertEqual("{'o':{}}", Property({'o': {}}).getquoted())
+        self.assertRaises(TypeError, Property({(): None}).getquoted)