From d0d7cbb9eb78b3bbb1a0aa9606d1646766d53c97 Mon Sep 17 00:00:00 2001
From: Douglas Blank <doug.blank@gmail.com>
Date: Tue, 24 Jul 2018 16:38:53 -0400
Subject: [PATCH] SQLAlchemy working, but not fast; WIP: use indexes for
 queries

---
 activitypub/database/sqldb.py | 113 +++++++++++++++++++++++++---------
 1 file changed, 83 insertions(+), 30 deletions(-)

diff --git a/activitypub/database/sqldb.py b/activitypub/database/sqldb.py
index 04bd044..20dc57b 100644
--- a/activitypub/database/sqldb.py
+++ b/activitypub/database/sqldb.py
@@ -1,3 +1,6 @@
+from sqlalchemy import create_engine, inspect
+from sqlalchemy.orm import scoped_session, sessionmaker
+import logging
 import json
 
 from ..bson import ObjectId
@@ -102,28 +105,71 @@ class SQLList():
 class SQLTable(ListTable):
     def __init__(self, database, name):
         super().__init__(database, name)
-        if not self.table_exists(name):
-            self.build_table(name)
+        if not self.database.table_exists(name):
+            self.database.build_table(name)
         self.data = SQLList(database, name)
 
-    def table_exists(self, table):
-        result = self.database.execute("""SELECT COUNT(*) 
-                                           FROM sqlite_master 
-                                           WHERE type='table' AND name='%s';""" % table)
-        return result.fetchone()[0] != 0
+    def get_schema(self):
+        ins = inspect(self.database.engine)
+        return ins.get_columns(self.name)
 
-    def build_table(self, name):
-        try:
-            self.database.execute(
-                """CREATE TABLE %s (
-                    rowid INTEGER PRIMARY KEY ASC,
-                    oid CHAR(24),
-                    blob_data BLOB
-                )""" % name)
-            self.database.commit()
-        except:
-            self.database.rollback()
-            raise
+    def get_columns(self):
+        schema = self.get_schema()
+        return [d["name"] for d in schema]
+
+    def build_compare(self, lhs, rhs):
+        if isinstance(rhs, dict):
+            q = []
+            for item in rhs:
+                if item == "$regex":
+                    q.append("SQL regex") ## FIXME
+                elif item == "$lt":
+                    q.append("(%s < %s)" % (lhs, rhs[item]))
+                elif item == "$gt":
+                    q.append("(%s > %s)" % (lhs, rhs[item]))
+                elif item == "$in":
+                    if isinstance(lhs, list):
+                        q.append("(%s IN %s)" % (lhs, rhs)) ## FIXME?
+                    else:
+                        q.append("(%s IN %s)" % (lhs, rhs[item])) ## FIXME?
+                else:
+                    raise Exception("unknown operator: %s" % item)
+            return "(" + (" AND ".join(q)) + ")"
+        else:
+            if isinstance(lhs, list):
+                if isinstance(rhs, list):
+                    return "(%s = %s)" % (lhs, repr(rhs)) ## FIXME?
+                else:
+                    return "(%s IN %s)" % (rhs, lhs) ## FIXME?
+            else:
+                return "(%s = %s)" % (lhs, repr(rhs))
+
+    def build_query(self, query, limit=None):
+        q = []
+        for item in query:
+            if item == "$or":
+                expr = "(" + (" OR ".join([self.build_query(each) for each in query[item]])) + ")"
+            elif item == "$and":
+                expr = "(" + (" AND ".join([self.build_query(each) for each in query[item]])) + ")"
+            else:
+                expr = self.build_compare(item, query[item])
+            q.append(expr)
+        return "(" + (" AND ".join(q)) + ")"
+
+    def find(self, query=None, limit=None, enumerated=False):
+        ## if the query contains a SQL table field, then
+        ## use that portion
+        ## WIP: find portion of query that can be SQL selected
+        ## NOTE: limit can only be applied if full query applies
+        # logging.info("query: %s" % query)
+        # if query is not None or limit is not None:
+        #     q = self.build_query(query, limit)
+        #     logging.info("built q: %s" % q)
+        #     if False: ## TODO: handle query
+        #         results = self.database.execute(q)
+        #         return ListTable(data=results.fetchall()).find(query, enumerated=enumerated)
+        ## else, just go through all of the items
+        return super().find(query, limit, enumerated)
 
     def sort(self, sort_key, sort_order):
         # sort_key = "_id"
@@ -136,21 +182,12 @@ class SQLTable(ListTable):
 
 class SQLDatabase(Database):
     Table = SQLTable
-    
-    def __init__(self, *args, **kwargs):
-        from sqlalchemy import create_engine
-        from sqlalchemy.orm import scoped_session, sessionmaker
-        #from sqlalchemy.pool import StaticPool
-        #from sqlalchemy.pool import QueuePool
 
+    def __init__(self, *args, **kwargs):
         super().__init__()
         self.engine = create_engine(*args, **kwargs)
-        # poolclass=QueuePool,
-        # convert_unicode=True,
-        # connect_args={'check_same_thread':False},
-        # poolclass=StaticPool,
         self.session = scoped_session(sessionmaker(bind=self.engine))
-        
+
     def commit(self):
         self.session.commit()
 
@@ -160,3 +197,19 @@ class SQLDatabase(Database):
     def execute(self, *args, **kwargs):
         return self.session.execute(*args, **kwargs)
 
+    def table_exists(self, table):
+        ins = inspect(self.engine)
+        return table in ins.get_table_names()
+
+    def build_table(self, name):
+        try:
+            self.execute(
+                """CREATE TABLE %s (
+                    rowid INTEGER PRIMARY KEY ASC,
+                    oid CHAR(24),
+                    blob_data BLOB
+                )""" % name)
+            self.commit()
+        except:
+            self.rollback()
+            raise