Trustgraph initial code drop

trustgraph/trustgraph.py

@@ -0,0 +1,108 @@
+
+from cassandra.cluster import Cluster
+from cassandra.auth import PlainTextAuthProvider
+
+class TrustGraph:
+
+    def __init__(self, hosts=None):
+
+        if hosts is None:
+            hosts = ["localhost"]
+            
+        self.cluster = Cluster(hosts)
+        self.session = self.cluster.connect()
+
+        self.init()
+
+    def clear(self):
+
+        self.session.execute("""
+            drop keyspace if exists trustgraph;
+        """);
+
+        self.init()
+
+    def init(self):
+
+        self.session.execute("""
+            create keyspace if not exists trustgraph
+                with replication = { 
+                   'class' : 'SimpleStrategy', 
+                   'replication_factor' : 1 
+                };
+        """);
+
+        self.session.set_keyspace('trustgraph')
+
+        self.session.execute("""
+            create table if not exists triples (
+                s text,
+                p text,
+                o text,
+                PRIMARY KEY (s, p)
+            );
+        """);
+
+        self.session.execute("""
+            create index if not exists triples_p
+                ON triples (p);
+        """);
+
+        self.session.execute("""
+            create index if not exists triples_o
+                ON triples (o);
+        """);
+
+    def insert(self, s, p, o):
+    
+        self.session.execute(
+            "insert into triples (s, p, o) values (%s, %s, %s)",
+            (s, p, o)
+        )
+
+    def get_all(self, limit=50):
+        return self.session.execute(
+            f"select s, p, o from triples limit {limit}"
+        )
+
+    def get_s(self, s, limit=10):
+        return self.session.execute(
+            f"select p, o from triples where s = %s",
+            (s,)
+        )
+
+    def get_p(self, p, limit=10):
+        return self.session.execute(
+            f"select s, o from triples where p = %s limit {limit}",
+            (p,)
+        )
+
+    def get_o(self, o, limit=10):
+        return self.session.execute(
+            f"select s, p from triples where o = %s limit {limit}",
+            (o,)
+        )
+
+    def get_sp(self, s, p, limit=10):
+        return self.session.execute(
+            f"select o from triples where s = %s and p = %s limit {limit}",
+            (s, p)
+        )
+
+    def get_po(self, p, o, limit=10):
+        return self.session.execute(
+            f"select s from triples where p = %s and o = %s allow filtering limit {limit}",
+            (p, o)
+        )
+
+    def get_os(self, o, s, limit=10):
+        return self.session.execute(
+            f"select s from triples where o = %s and s = %s limit {limit}",
+            (o, s)
+        )
+
+    def get_spo(self, s, p, o, limit=10):
+        return self.session.execute(
+            f"""select s as x from triples where s = %s and p = %s and o = %s limit {limit}""",
+            (s, p, o)
+        )