Create custom endpoint for aggregate

bigchaindb/tatau_backend/query.py

@@ -0,0 +1,8 @@
+"""Tatau Query implementation for MongoDB"""
+
+
+def aggregate(conn, pipeline, table='transactions'):
+    cursor = conn.run(
+        conn.collection(table).aggregate(pipeline))
+
+    return (obj for obj in cursor)

bigchaindb/web/routes.py

@@ -12,6 +12,7 @@ from bigchaindb.web.views import (
     transactions as tx,
     outputs,
     validators,
+    aggregate,
 )
 
 
@@ -40,8 +41,12 @@ ROUTES_API_V1 = [
     r('validators/', validators.ValidatorsApi),
 ]
 
+ROUTES_API_TATAU = [
+    r('aggregate/', aggregate.AggregateListApi),
+]
 
 API_SECTIONS = [
     (None, [r('/', info.RootIndex)]),
     ('/api/v1/', ROUTES_API_V1),
+    ('/api/tatau/', ROUTES_API_TATAU),
 ]

bigchaindb/web/views/aggregate.py

@@ -0,0 +1,59 @@
+# Tatau
+
+"""This module provides the blueprint for some basic API endpoints.
+
+For more information please refer to the documentation: http://bigchaindb.com/http-api
+"""
+import logging
+import types
+import json
+from bson import json_util
+
+from flask_restful import  Resource
+from flask import request, current_app
+
+from bigchaindb.backend.exceptions import OperationError
+from bigchaindb.web.views.base import make_error
+from bigchaindb.tatau_backend import query
+
+
+logger = logging.getLogger(__name__)
+
+
+class AggregateListApi(Resource):
+
+    def post(self):
+        """API endpoint to aggregate.
+
+        Args:
+            pipeline (str): Request of aggregate in body.
+
+        Return:
+            A list of aggregate the query.
+        """
+        table = request.args.get('table')
+        if not table:
+            table = 'transactions'
+            # return make_error(400, 'table cannot be empty')
+        try:
+            pipeline = request.get_json(force=True)
+
+        except Exception as e:
+            return make_error(400, 'Json required')
+
+        pool = current_app.config['bigchain_pool']
+
+        with pool() as bigchain:
+            def aggregate(obj, pipeline, table):
+                return query.aggregate(obj.connection, pipeline, table)
+
+            bigchain.aggregate = types.MethodType(aggregate, bigchain)
+            data = bigchain.aggregate(pipeline, table)
+
+        try:
+            return json.loads(json_util.dumps(data))
+        except OperationError as e:
+            return make_error(
+                400,
+                '({}): {}'.format(type(e).__name__, e)
+            )