Only load jinja2 templates once

Instead of every time a new email pusher is created, as loading jinja2
templates is slow.

1 files changed, 54 insertions, 33 deletions

diff --git a/synapse/push/mailer.py b/synapse/push/mailer.py
index f83aa7625c..b5cd9b426a 100644
--- a/synapse/push/mailer.py
+++ b/synapse/push/mailer.py
@@ -78,23 +78,17 @@ ALLOWED_ATTRS = {
 
 
 class Mailer(object):
-    def __init__(self, hs, app_name):
+    def __init__(self, hs, app_name, notif_template_html, notif_template_text):
         self.hs = hs
+        self.notif_template_html = notif_template_html
+        self.notif_template_text = notif_template_text
+
         self.store = self.hs.get_datastore()
         self.macaroon_gen = self.hs.get_macaroon_generator()
         self.state_handler = self.hs.get_state_handler()
-        loader = jinja2.FileSystemLoader(self.hs.config.email_template_dir)
         self.app_name = app_name
+
         logger.info("Created Mailer for app_name %s" % app_name)
-        env = jinja2.Environment(loader=loader)
-        env.filters["format_ts"] = format_ts_filter
-        env.filters["mxc_to_http"] = self.mxc_to_http_filter
-        self.notif_template_html = env.get_template(
-            self.hs.config.email_notif_template_html
-        )
-        self.notif_template_text = env.get_template(
-            self.hs.config.email_notif_template_text
-        )
 
     @defer.inlineCallbacks
     def send_notification_mail(self, app_id, user_id, email_address,
@@ -481,28 +475,6 @@ class Mailer(object):
             urllib.urlencode(params),
         )
 
-    def mxc_to_http_filter(self, value, width, height, resize_method="crop"):
-        if value[0:6] != "mxc://":
-            return ""
-
-        serverAndMediaId = value[6:]
-        fragment = None
-        if '#' in serverAndMediaId:
-            (serverAndMediaId, fragment) = serverAndMediaId.split('#', 1)
-            fragment = "#" + fragment
-
-        params = {
-            "width": width,
-            "height": height,
-            "method": resize_method,
-        }
-        return "%s_matrix/media/v1/thumbnail/%s?%s%s" % (
-            self.hs.config.public_baseurl,
-            serverAndMediaId,
-            urllib.urlencode(params),
-            fragment or "",
-        )
-
 
 def safe_markup(raw_html):
     return jinja2.Markup(bleach.linkify(bleach.clean(
@@ -543,3 +515,52 @@ def string_ordinal_total(s):
 
 def format_ts_filter(value, format):
     return time.strftime(format, time.localtime(value / 1000))
+
+
+def load_jinja2_templates(config):
+    """Load the jinja2 email templates from disk
+
+    Returns:
+        (notif_template_html, notif_template_text)
+    """
+    logger.info("loading jinja2")
+
+    loader = jinja2.FileSystemLoader(config.email_template_dir)
+    env = jinja2.Environment(loader=loader)
+    env.filters["format_ts"] = format_ts_filter
+    env.filters["mxc_to_http"] = _create_mxc_to_http_filter(config)
+
+    notif_template_html = env.get_template(
+        config.email_notif_template_html
+    )
+    notif_template_text = env.get_template(
+        config.email_notif_template_text
+    )
+
+    return notif_template_html, notif_template_text
+
+
+def _create_mxc_to_http_filter(config):
+    def mxc_to_http_filter(value, width, height, resize_method="crop"):
+        if value[0:6] != "mxc://":
+            return ""
+
+        serverAndMediaId = value[6:]
+        fragment = None
+        if '#' in serverAndMediaId:
+            (serverAndMediaId, fragment) = serverAndMediaId.split('#', 1)
+            fragment = "#" + fragment
+
+        params = {
+            "width": width,
+            "height": height,
+            "method": resize_method,
+        }
+        return "%s_matrix/media/v1/thumbnail/%s?%s%s" % (
+            config.public_baseurl,
+            serverAndMediaId,
+            urllib.urlencode(params),
+            fragment or "",
+        )
+
+    return mxc_to_http_filter