From b91a19418453b902c4b066e30fd89194c069d6d2 Mon Sep 17 00:00:00 2001
From: Jarrod Johnson <jjohnson2@lenovo.com>
Date: Tue, 17 Oct 2023 16:29:30 -0400
Subject: [PATCH] Improve selfselfice performance with yaml

The yaml python default behavior is 'pure python' and is
tortuously slow.

As a test, yaml dump of a 17,000 element list took 70 seconds in default configuration.

Opting into the C functions, that time comes down to 10 seconds, a
nice and easy improvement for generic yaml.

For dumping a simple dumb list (e.g. the nodelist for ssh), a special
case yaml-looking result is done, which hits 0.4 seconds on that same
test. So this special case is added to nodelist, which can be very long
and very in demand at the same time.
---
 confluent_server/confluent/selfservice.py | 32 +++++++++++++++++++----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/confluent_server/confluent/selfservice.py b/confluent_server/confluent/selfservice.py
index 04030491..cd4180c7 100644
--- a/confluent_server/confluent/selfservice.py
+++ b/confluent_server/confluent/selfservice.py
@@ -19,6 +19,12 @@ import json
 import os
 import time
 import yaml
+try:
+    from yaml import CSafeDumper as SafeDumper
+    from yaml import CSafeLoader as SafeLoader
+except ImportError:
+    from yaml import SafeLoader
+    from yaml import SafeDumper
 import confluent.discovery.protocols.ssdp as ssdp
 import eventlet
 webclient = eventlet.import_patched('pyghmi.util.webclient')
@@ -31,7 +37,20 @@ currtzvintage = None
 
 
 def yamldump(input):
-    return yaml.safe_dump(input, default_flow_style=False)
+    return yaml.dump_all([input], Dumper=SafeDumper, default_flow_style=False)
+
+def yamlload(input):
+    return yaml.load(input, Loader=SafeLoader)
+
+def listdump(input):
+    # special case yaml for flat dumb list
+    # this is about 25x faster than doing full yaml dump even with CSafeDumper
+    # with a 17,000 element list
+    retval = ''
+    for entry in input:
+        retval += '- ' + entry + '\n'
+    return retval
+
 
 def get_extra_names(nodename, cfg, myip=None):
     names = set([])
@@ -402,10 +421,13 @@ def handle_request(env, start_response):
                 yield node + '\n'
         else:
             start_response('200 OK', (('Content-Type', retype),))
-            yield dumper(list(util.natural_sort(nodes)))
+            if retype == 'application/yaml':
+                yield listdump(list(util.natural_sort(nodes)))
+            else:
+                yield dumper(list(util.natural_sort(nodes)))
     elif env['PATH_INFO'] == '/self/remoteconfigbmc' and reqbody:
         try:
-            reqbody = yaml.safe_load(reqbody)
+            reqbody = yamlload(reqbody)
         except Exception:
             reqbody = None
         cfgmod = reqbody.get('configmod', 'unspecified')
@@ -419,7 +441,7 @@ def handle_request(env, start_response):
         start_response('200 Ok', ())
         yield 'complete'
     elif env['PATH_INFO'] == '/self/updatestatus' and reqbody:
-        update = yaml.safe_load(reqbody)
+        update = yamlload(reqbody)
         statusstr = update.get('state', None)
         statusdetail = update.get('state_detail', None)
         didstateupdate = False
@@ -522,7 +544,7 @@ def handle_request(env, start_response):
             '/var/lib/confluent/public/os/{0}/scripts/{1}')
         if slist:
             start_response('200 OK', (('Content-Type', 'application/yaml'),))
-            yield yaml.safe_dump(util.natural_sort(slist), default_flow_style=False)
+            yield yamldump(util.natural_sort(slist))
         else:
             start_response('200 OK', ())
             yield ''