From 667b30e5e8cf01628ce0d8242eaa5864f7c987ea Mon Sep 17 00:00:00 2001
From: vrde <agranzot@gmail.com>
Date: Fri, 15 Apr 2016 16:08:08 +0200
Subject: [PATCH] Add connection pool to web views

---
 bigchaindb/web/server.py | 11 ++++++-----
 bigchaindb/web/views.py  | 29 +++++++++++++++--------------
 tests/web/conftest.py    |  2 +-
 3 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/bigchaindb/web/server.py b/bigchaindb/web/server.py
index 021ceab4..3001cb21 100644
--- a/bigchaindb/web/server.py
+++ b/bigchaindb/web/server.py
@@ -8,6 +8,7 @@ import multiprocessing
 
 from flask import Flask
 
+from bigchaindb import util
 from bigchaindb import Bigchain
 from bigchaindb.web import views
 import gunicorn.app.base
@@ -45,7 +46,7 @@ class StandaloneApplication(gunicorn.app.base.BaseApplication):
         return self.application
 
 
-def create_app(debug=False):
+def create_app(settings):
     """Return an instance of the Flask application.
 
     Args:
@@ -54,8 +55,8 @@ def create_app(debug=False):
     """
 
     app = Flask(__name__)
-    app.debug = debug
-    app.config['bigchain'] = Bigchain()
+    app.debug = settings.get('debug', False)
+    app.config['bigchain_pool'] = util.pool(Bigchain, size=settings.get('threads', 4))
     app.register_blueprint(views.basic_views, url_prefix='/api/v1')
     return app
 
@@ -79,8 +80,8 @@ def create_server(settings):
     if not settings.get('threads'):
         settings['threads'] = (multiprocessing.cpu_count() * 2) + 1
 
-    debug = settings.pop('debug', False)
-    app = create_app(debug)
+    app = create_app(settings)
+    settings.pop('debug', False)
     standalone = StandaloneApplication(app, settings)
     return standalone
 
diff --git a/bigchaindb/web/views.py b/bigchaindb/web/views.py
index 53db6f66..cf618fff 100644
--- a/bigchaindb/web/views.py
+++ b/bigchaindb/web/views.py
@@ -15,12 +15,11 @@ basic_views = Blueprint('basic_views', __name__)
 
 @basic_views.record
 def get_bigchain(state):
-    bigchain = state.app.config.get('bigchain')
+    bigchain_pool = state.app.config.get('bigchain_pool')
 
-    if bigchain is None:
+    if bigchain_pool is None:
         raise Exception('This blueprint expects you to provide '
-                        'database access through `bigchain`')
-
+                        'a pool of Bigchain instances called `bigchain_pool`')
 
 
 @basic_views.route('/transactions/<tx_id>')
@@ -34,9 +33,11 @@ def get_transaction(tx_id):
         A JSON string containing the data about the transaction.
     """
 
-    bigchain = current_app.config['bigchain']
+    pool = current_app.config['bigchain_pool']
+
+    with pool() as bigchain:
+        tx = bigchain.get_transaction(tx_id)
 
-    tx = bigchain.get_transaction(tx_id)
     return flask.jsonify(**tx)
 
 
@@ -47,7 +48,7 @@ def create_transaction():
     Return:
         A JSON string containing the data about the transaction.
     """
-    bigchain = current_app.config['bigchain']
+    pool = current_app.config['bigchain_pool']
 
     val = {}
 
@@ -55,15 +56,15 @@ def create_transaction():
     # set to `application/json`
     tx = request.get_json(force=True)
 
-    if tx['transaction']['operation'] == 'CREATE':
-        tx = util.transform_create(tx)
-        tx = bigchain.consensus.sign_transaction(
-            tx, private_key=bigchain.me_private)
+    with pool() as bigchain:
+        if tx['transaction']['operation'] == 'CREATE':
+            tx = util.transform_create(tx)
+            tx = bigchain.consensus.sign_transaction(tx, private_key=bigchain.me_private)
 
-    if not bigchain.consensus.verify_signature(tx):
-        val['error'] = 'Invalid transaction signature'
+        if not bigchain.consensus.verify_signature(tx):
+            val['error'] = 'Invalid transaction signature'
 
-    val = bigchain.write_transaction(tx)
+        val = bigchain.write_transaction(tx)
 
     return flask.jsonify(**tx)
 
diff --git a/tests/web/conftest.py b/tests/web/conftest.py
index 099f2fd3..bf1dd697 100644
--- a/tests/web/conftest.py
+++ b/tests/web/conftest.py
@@ -25,7 +25,7 @@ def app(request, node_config):
     restore_config(request, node_config)
 
     from bigchaindb.web import server
-    app = server.create_app(debug=True)
+    app = server.create_app({'debug': True})
     return app