moving files around after repository merger

1 files changed, 260 insertions, 0 deletions

diff --git a/src/server/neo4j_util.py b/src/server/neo4j_util.py
new file mode 100644
index 00000000..cf2f962e
--- /dev/null
+++ b/src/server/neo4j_util.py
@@ -0,0 +1,260 @@
+"""
+ Utility code in speaking the neo4j REST api
+"""
+
+import json
+import six
+from six.moves.urllib import request
+import six.moves.urllib_error as urllib_error
+import model
+import string
+import time
+
+from util import debug_log_duration
+
+class Neo4JException(Exception):
+    def __init__(self, error_set):
+        self.error_set = error_set
+
+    def __str__(self):
+        return 'neo4j error set: ' + str(self.error_set)
+
+class DB_row(object):
+    def __init__(self, data):
+        self.data = data
+
+    def __iter__(self):
+        for column_val in self.data:
+            yield column_val
+
+    def items(self):
+        return [x for x in self]
+
+class DB_result_set(object):
+    def __init__(self, data):
+        self.data = data
+
+    def __iter__(self):
+        for db_row_dict in self.data['data']:
+            # example: dict: {u'row': [{u'title': u'foo'}]}
+            assert None != db_row_dict['row']
+
+            yield DB_row(db_row_dict['row'])
+
+    def items(self):
+        return [x for x in self]
+
+class Cypher_String_Formatter(string.Formatter):
+    """
+    Despite parameter support in Cypher, we sometimes do engage in query string building
+    - as both Cypher & Python use brackets to wrap parameters, escaping them in Python makes
+    queries less readable. This customized formatter will simply ignore unavailable keyworded
+    formatting arguments, allowing the use of non-escaped parameter designation, eg:
+    q = cfmt("match (a:{type} {cypher_param})", type='Book')
+    """
+
+    def get_field(self, field_name, args, kwargs):
+        # ignore key not found, return bracket wrapped key
+        try:
+            val = super(Cypher_String_Formatter, self).get_field(field_name, args, kwargs)
+        except (KeyError, AttributeError):
+            val = "{" + field_name + "}", field_name
+        return val
+
+def cfmt(fmt_str, *args, **kwargs):
+    return Cypher_String_Formatter().format(fmt_str, *args, **kwargs)
+
+def post_neo4j(url, data):
+    """
+    @return dict object from the neo4j json POST response
+    """
+    ret = post(url, data)
+    ret_data = json.load(ret)
+
+    # [!] do not raise exception if ret_data['errors'] is not empty -
+    # this allows query-sets to partially succeed
+
+    return ret_data
+
+def post(url, data):
+    assert(isinstance(data, dict))  # make sure we're not handed json strings
+
+    post_data_json = json.dumps(data)
+
+    req = request.Request(url)
+    req.add_header('User-Agent', 'rhizi-server/0.1')
+    req.add_header('Accept', 'application/json; charset=UTF-8')
+    req.add_header('Content-Type', 'application/json')
+
+    req.add_header('X-Stream', 'true')  # enable neo4j JSON streaming
+
+    try:
+        ret = request.urlopen(req, post_data_json)
+    except urllib_error.HTTPError as e:
+        raise Exception('post request failed: code: {0}, reason: {1}'.format(e.code, e.reason))
+
+    return ret
+
+def statement_to_REST_form(query, parameters={}):
+    """
+    turn cypher query to neo4j json API format
+    """
+    assert isinstance(query, six.string_types)
+    if isinstance(parameters, list):
+        for v in parameters:
+            assert isinstance(v, dict)
+    else:
+        assert isinstance(parameters, dict)
+
+    return {'statement' : query, 'parameters': parameters}
+
+def statement_set_to_REST_form(statement_set):
+    assert isinstance(statement_set, list)
+
+    return {'statements': statement_set}
+
+def gen_clause_attr_filter_from_filter_attr_map(filter_attr_map, node_label="n"):
+    if not filter_attr_map:
+        return "{}"
+
+    __type_check_filter_attr_map(filter_attr_map)
+
+    filter_arr = []
+    for attr_name in filter_attr_map.keys():
+        # create a cypher query parameter place holder for each attr set
+        # eg. n.foo in {foo}, where foo is passed as a query parameter
+        f_attr = cfmt("{attr_name}: {{{attr}}}", attr_name=attr_name)
+        filter_arr.append(f_attr)
+
+    filter_str = "{{{0}}}".format(', '.join(filter_arr))
+    return filter_str
+
+def gen_clause_where_from_filter_attr_map(filter_attr_map, node_label="n"):
+    """
+    convert a filter attribute map to a parameterized Cypher where clause, eg.
+    in: { 'att_foo': [ 'a', 'b' ], 'att_goo': [1,2] }
+    out: {att_foo: {att_foo}, att_goo: {att_goo}, ...}
+
+    this function will essentially ignore all but the first value in the value list
+
+    @param filter_attr_map: may be None or empty
+    """
+    if not filter_attr_map:
+        return ""
+
+    __type_check_filter_attr_map(filter_attr_map)
+
+    filter_arr = []
+    for attr in filter_attr_map.keys():
+        # create a cypher query parameter place holder for each attr set
+        # eg. n.foo in {foo}, where foo is passed as a query parameter
+        f_attr = cfmt("{node_label}.{attr} in {{{attr}}}", node_label=node_label, attr=attr)
+        filter_arr.append(f_attr)
+    filter_str = "where {0}".format(' and '.join(filter_arr))
+    return filter_str
+
+def gen_query_create_from_node_map(node_map, input_to_DB_property_map=lambda _: _):
+    """
+    generate a set of node create queries
+
+    @param node_map: is a node-type to node map
+    @input_to_DB_property_map: optional function which takes a map of input properties and returns a map of DB properties - use to map input schemas to DB schemas
+
+    @return: a (query, query_parameteres) set of create queries
+    """
+    __type_check_link_or_node_map(node_map)
+
+    ret = []
+    for label, n_set in node_map.items():
+
+        assert len(label) > 2 and label[0].isupper() and label[1:].islower(), 'malformed label: ' + label
+
+        q_arr = ['create (n:%s {node_attr})' % (label),
+                 'return n.id'
+                 ]
+
+        q = ' '.join(q_arr)
+        q_params_set = []
+        for n_prop_set in n_set:
+
+            assert None != n_prop_set['id'], 'node create query: node id attribute not set'
+
+            q_params = input_to_DB_property_map(n_prop_set)
+            q_params_set.append(q_params)
+        ret.append((q, {'node_attr': q_params_set}))
+    return ret
+
+def gen_query_create_from_link_map(link_map, input_to_DB_property_map=lambda _: _):
+    """
+    generate a set of link create queries
+
+    @param link_map: is a link-type to link map - see model.link
+    """
+    __type_check_link_or_node_map(link_map)
+
+    ret = []
+    for l_type, l_set in link_map.items():
+        q = "match (src {id: {src}.id}),(dst {id: {dst}.id}) " + \
+            "create (src)-[r:%(__type)s {link_attr}]->(dst) " + \
+            "return id(r)"
+        q = q % {'__type':l_type}
+
+        for link in l_set:
+            __type_check_link(link)
+
+            src_id = link['__src_id']
+            dst_id = link['__dst_id']
+
+            # TODO: use object based link representation
+            prop_dict = link.copy()
+            del prop_dict['__dst_id']
+            del prop_dict['__src_id']
+
+            q_params = {'src': { 'id': src_id} ,
+                        'dst': { 'id': dst_id} ,
+                        'link_attr' : input_to_DB_property_map(prop_dict)}
+            ret.append((q, q_params))
+
+    return ret
+
+def meta_attr_list_to_meta_attr_map(e_set, meta_attr='__label_set'):
+    """
+    convert a list of maps each containing a meta_attr key into a
+    meta_attr-mapped collection of lists with the meta_attr removed - eg:
+
+        in: [{'id':0, '__type': 'T'}, {'id':1, '__type': 'T'}]
+        out: { 'T', [{'id':0}, {'id':1}] }
+    """
+    ret = {}
+    for v in e_set:
+        assert None != v[meta_attr], 'missing type meta-attribute'
+        assert 1 == len(v[meta_attr]), 'only single-type mapping currently suppoerted'
+
+        v_type = v[meta_attr][0]
+        if None == ret.get(v_type):  # init type list if necessary
+            ret[v_type] = []
+
+        v_no_meta = v.copy()
+        del v_no_meta[meta_attr]
+
+        ret[v_type].append(v_no_meta)
+
+    return ret
+
+def __type_check_link(link):
+    assert link.has_key('__src_id')
+    assert link.has_key('__dst_id')
+
+def __type_check_link_or_node_map(x_map):
+    for k, v in x_map.iteritems():  # do some type sanity checking
+        assert isinstance(k, six.string_types)
+        assert isinstance(v, list)
+
+def __type_check_filter_attr_map(filter_attr_map):
+    """
+    # type sanity check an attribute filter map
+    """
+    assert isinstance(filter_attr_map, dict)
+    for k, v in filter_attr_map.items():
+        assert isinstance(k, six.string_types)
+        assert isinstance(v, list)