Add some level of caching for speed-up

deploystream/__init__.py

@@ -4,6 +4,7 @@
 from os.path import join, dirname
 from flask import Flask
 
+
 APP_DIR = dirname(__file__)
 CONFIG_DIR = join(dirname(APP_DIR), 'config')
 STATIC_DIR = join(APP_DIR, 'static')
@@ -44,21 +45,26 @@
         }
     })
 
-from deploystream.lib import ensure_certifi_certs_installed
+from .lib import ensure_certifi_certs_installed
 ensure_certifi_certs_installed()
 
 # set the secret key. Dummy secret for flask. When using in real life, have
 # something that is actually a secret
 app.secret_key = 'mysecret'
 
 # Initialise the providers.
-from providers import init_providers
+from .providers import init_providers
 classes = init_providers(app.config['PROVIDERS'])
 
 # Configure additional routes needed for oauth
-from deploystream.apps.oauth.views import configure_oauth_routes
+from .apps.oauth.views import configure_oauth_routes
 configure_oauth_routes(classes)
 
 # Import any views we want to register here at the bottom of the file:
-import deploystream.views  # NOQA
-import deploystream.apps.feature.views  # NOQA
+from . import views  # NOQA
+from .apps.feature import views as feature_views  # NOQA
+
+# As this requests caching monkey patches requests.Session, it must be done
+# at the end, else the Jira provider fails
+from .lib import cache
+cache.activate_requests_caching()

deploystream/apps/feature/views.py

@@ -4,6 +4,7 @@
 
 from deploystream import app
 from deploystream.apps.feature.lib import get_feature_info, get_all_features
+from deploystream.lib import cache
 from deploystream.lib.transforms import nativify
 from deploystream.decorators import needs_providers
 
@@ -23,6 +24,7 @@ def _wrapped(*args, **kwargs):
 
 @app.route('/features', methods=['GET'])
 @needs_providers
+@cache.cached()
 @as_json
 def list_features(providers):
     features = get_all_features(providers)

deploystream/lib/cache.py

@@ -0,0 +1,39 @@
+from functools import wraps
+
+from flask import request
+from werkzeug.contrib.cache import SimpleCache
+
+
+cache = SimpleCache()
+EXPIRY_SECONDS = 5 * 60
+
+
+def cached(timeout=EXPIRY_SECONDS, key='view/%s'):
+    """
+    A decorator for caching views.
+
+    Source: http://flask.pocoo.org/docs/patterns/viewdecorators/
+
+    With a little additional work it could be made into a generic caching
+    decorator for other functions that return pickleable data.
+    """
+    def decorator(f):
+        @wraps(f)
+        def decorated_function(*args, **kwargs):
+            cache_key = key % request.path
+            rv = cache.get(cache_key)
+            if rv is not None:
+                return rv
+            rv = f(*args, **kwargs)
+            cache.set(cache_key, rv, timeout=timeout)
+            return rv
+        return decorated_function
+    return decorator
+
+
+def activate_requests_caching():
+    """
+    Call once to activate caching for all HTTP GET issued by 'requests'
+    """
+    import requests_cache
+    requests_cache.install_cache(expire_after=EXPIRY_SECONDS)

requirements/runtime.txt

@@ -7,3 +7,4 @@ zope.interface       # define and enforce interfaces
 certifi              # Module for Mozilla's CA bundle
 apitopy              # Required to implement the sprint.ly client
 jira-python>=0.13    # Required to access JIRA api
+requests-cache       # A transparent caching library for 'requests'