Add Neo4j support (#9)

- Add triples-write-neo4j and triples-query-neo4j to interact with neo4j
- Add docker-compose-openai-neo4j to demo Neo4j working

trustgraph/storage/triples/neo4j/__init__.py

@@ -0,0 +1,3 @@
+
+from . write import *
+

trustgraph/storage/triples/neo4j/__main__.py

@@ -0,0 +1,7 @@
+#!/usr/bin/env python3
+
+from . write import run
+
+if __name__ == '__main__':
+    run()
+

trustgraph/storage/triples/neo4j/write.py

@@ -0,0 +1,156 @@
+
+"""
+Graph writer.  Input is graph edge.  Writes edges to Cassandra graph.
+"""
+
+import pulsar
+import base64
+import os
+import argparse
+import time
+
+from neo4j import GraphDatabase
+
+from .... schema import Triple
+from .... schema import triples_store_queue
+from .... log_level import LogLevel
+from .... base import Consumer
+
+module = ".".join(__name__.split(".")[1:-1])
+
+default_input_queue = triples_store_queue
+default_subscriber = module
+
+default_graph_host = 'bolt://neo4j:7687'
+default_username = 'neo4j'
+default_password = 'password'
+
+class Processor(Consumer):
+
+    def __init__(self, **params):
+        
+        input_queue = params.get("input_queue", default_input_queue)
+        subscriber = params.get("subscriber", default_subscriber)
+        graph_host = params.get("graph_host", default_graph_host)
+        username = params.get("username", default_username)
+        password = params.get("passowrd", default_password)
+
+        super(Processor, self).__init__(
+            **params | {
+                "input_queue": input_queue,
+                "subscriber": subscriber,
+                "input_schema": Triple,
+                "graph_host": graph_host,
+            }
+        )
+
+        self.db = "neo4j"
+
+        self.io = GraphDatabase.driver(graph_host, auth=(username, password))
+
+    def create_node(self, uri):
+
+        print("Create node", uri)
+
+        summary = self.io.execute_query(
+            "MERGE (n:Node {uri: $uri})",
+            uri=uri,
+            database_=self.db,
+        ).summary
+
+        print("Created {nodes_created} nodes in {time} ms.".format(
+            nodes_created=summary.counters.nodes_created,
+            time=summary.result_available_after
+        ))
+
+    def create_literal(self, value):
+
+        print("Create literal", value)
+
+        summary = self.io.execute_query(
+            "MERGE (n:Literal {value: $value})",
+            value=value,
+            database_=self.db,
+        ).summary
+
+        print("Created {nodes_created} nodes in {time} ms.".format(
+            nodes_created=summary.counters.nodes_created,
+            time=summary.result_available_after
+        ))
+
+    def relate_node(self, src, uri, dest):
+
+        print("Create node rel", src, uri, dest)
+
+        summary = self.io.execute_query(
+            "MATCH (src:Node {uri: $src}) "
+            "MATCH (dest:Node {uri: $dest}) "
+            "MERGE (src)-[:Rel {uri: $uri}]->(dest)",
+            src=src, dest=dest, uri=uri,
+            database_=self.db,
+        ).summary
+
+        print("Created {nodes_created} nodes in {time} ms.".format(
+            nodes_created=summary.counters.nodes_created,
+            time=summary.result_available_after
+        ))
+
+    def relate_literal(self, src, uri, dest):
+
+        print("Create literal rel", src, uri, dest)
+
+        summary = self.io.execute_query(
+            "MATCH (src:Node {uri: $src}) "
+            "MATCH (dest:Literal {value: $dest}) "
+            "MERGE (src)-[:Rel {uri: $uri}]->(dest)",
+            src=src, dest=dest, uri=uri,
+            database_=self.db,
+        ).summary
+
+        print("Created {nodes_created} nodes in {time} ms.".format(
+            nodes_created=summary.counters.nodes_created,
+            time=summary.result_available_after
+        ))
+
+    def handle(self, msg):
+
+        v = msg.value()
+
+        self.create_node(v.s.value)
+
+        if v.o.is_uri:
+            self.create_node(v.o.value)
+            self.relate_node(v.s.value, v.p.value, v.o.value)
+        else:
+            self.create_literal(v.o.value)
+            self.relate_literal(v.s.value, v.p.value, v.o.value)
+
+    @staticmethod
+    def add_args(parser):
+
+        Consumer.add_args(
+            parser, default_input_queue, default_subscriber,
+        )
+
+        parser.add_argument(
+            '-g', '--graph_host',
+            default=default_graph_host,
+            help=f'Graph host (default: {default_graph_host})'
+        )
+
+        parser.add_argument(
+            '--username',
+            default=default_username,
+            help=f'Neo4j username (default: {default_username})'
+        )
+
+        parser.add_argument(
+            '--password',
+            default=default_password,
+            help=f'Neo4j password (default: {default_password})'
+        )
+
+def run():
+
+    Processor.start(module, __doc__)
+