As a gitcoin admin, I'd like the mailchimp syncing to be refactored, …

…so the load on the database is lowered and the site runs faster (#4798)

* sync mail perf

* comment

app/marketing/management/commands/sync_mail.py

@@ -23,22 +23,28 @@
 from marketing.models import EmailSubscriber
 from marketing.utils import get_or_save_email_subscriber as process_email
 
+hours_ago = 12 #if you change, this make sure you change the crontab file to ...
+# make it inclusive of all users since last run of this job
+
 
 def pull_to_db():
+    # setup
+    before_timestamp = timezone.now() - timezone.timedelta(hours=hours_ago)
+
     print('- pull_to_db')
     print("- profile")
     from dashboard.models import Profile
     # right now, we only take profiles that've given us an access token
-    profiles = Profile.objects.exclude(email='').all()
+    profiles = Profile.objects.exclude(email='').filter(modified_on__gt=before_timestamp).all()
     # in the future, though, we could take ALL github profiles in the system and use those
     # profiles = Profile.objects.exclude(email='').all()
-    for profile in profiles:
-        process_email(profile.email, 'profile_email')
+    for email in profiles.values_list('email', flat=True):
+        process_email(email, 'profile_email')
 
     print("- match")
     from marketing.models import Match
-    for match in Match.objects.all():
-        process_email(match.email, 'match')
+    for email in Match.objects.filter(modified_on__gt=before_timestamp).values_list('email', flat=True):
+        process_email(email, 'match')
 
     get_size = 50
     client = MailChimp(mc_api=settings.MAILCHIMP_API_KEY, mc_user=settings.MAILCHIMP_USER)
@@ -58,16 +64,15 @@ def pull_to_db():
     print('local')
     print("- dashboard_sub")
     from dashboard.models import Subscription
-    for sub in Subscription.objects.all():
-        email = sub.email
+    for email in Subscription.objects.filter(modified_on__gt=before_timestamp).values_list('email', flat=True):
         process_email(email, 'dashboard_subscription')
 
     print("- tip, Kudos")
     from dashboard.models import Tip
     from kudos.models import KudosTransfer
     objects = [Tip, KudosTransfer]
     for obj in objects:
-        for _this in obj.objects.all():
+        for _this in obj.objects.filter(modified_on__gt=before_timestamp):
             # do not add receive tip emails to the mailing list,
             # don't want to spam people at 4 diff email addresses
             # for email in tip.emails:
@@ -79,7 +84,7 @@ def pull_to_db():
 
     print("- bounty")
     from dashboard.models import Bounty
-    for b in Bounty.objects.prefetch_related('fulfillments').all():
+    for b in Bounty.objects.filter(modified_on__gt=before_timestamp).prefetch_related('fulfillments').all():
         email_list = []
         if b.bounty_owner_email:
             email_list.append(b.bounty_owner_email)
@@ -91,17 +96,18 @@ def pull_to_db():
 
     print("- tdi")
     from tdi.models import WhitepaperAccess, WhitepaperAccessRequest
-    for wa in WhitepaperAccess.objects.all():
-        process_email(wa.email, 'whitepaperaccess')
+    for email in WhitepaperAccess.objects.filter(modified_on__gt=before_timestamp).values_list('email', flat=True):
+        process_email(email, 'whitepaperaccess')
 
-    for wa in WhitepaperAccessRequest.objects.all():
-        process_email(wa.email, 'whitepaperaccessrequest')
+    for email in WhitepaperAccessRequest.objects.filter(modified_on__gt=before_timestamp).values_list('email', flat=True):
+        process_email(email, 'whitepaperaccessrequest')
 
     print('/pull_to_db')
 
 def sync_mailchimp_list(eses, list_id):
     print("- {} emails".format(eses.count()))
-    for es in eses:
+    client = MailChimp(mc_api=settings.MAILCHIMP_API_KEY, mc_user=settings.MAILCHIMP_USER)
+    for es in eses.values_list('email', flat=True):
         email = es.email
         print(email)
         try: