badblocks/pkmntrade.club
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Greatly improve prefetching and reduce # of db calls for each trade_offer

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badblocks 2025-05-18 15:26:34 -07:00
parent b89025a7e0
commit 95d794d8b9
5 changed files with 89 additions and 67 deletions
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58
src/pkmntrade_club/trades/models.py
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@ -25,20 +25,46 @@ def generate_tradeacceptance_hash():
class TradeOfferManager(models.Manager):
def get_queryset(self):
qs = super().get_queryset().select_related(
"initiated_by",
"initiated_by__user",
qs = super().get_queryset()
# Prefetch for have_cards (through model: TradeOfferHaveCard)
# Ensures 'card' is select_related and 'Meta.ordering' is respected/applied.
prefetch_have_cards = Prefetch(
'trade_offer_have_cards',
queryset=TradeOfferHaveCard.objects.select_related('card').order_by('card__name')
)
# Prefetch for want_cards (through model: TradeOfferWantCard)
# Ensures 'card' is select_related and 'Meta.ordering' is respected/applied.
prefetch_want_cards = Prefetch(
'trade_offer_want_cards',
queryset=TradeOfferWantCard.objects.select_related('card').order_by('card__name')
)
# Prefetch for acceptances
# Ensures related 'accepted_by__user', 'requested_card', 'offered_card' are fetched.
prefetch_acceptances = Prefetch(
'acceptances',
queryset=TradeAcceptance.objects.select_related(
'accepted_by__user',
'requested_card',
'offered_card'
).order_by('-created_at') # Sensible default ordering for acceptances
)
qs = qs.select_related(
"initiated_by__user", # Fetches FriendCode and its related CustomUser
).prefetch_related(
"trade_offer_have_cards__card",
"trade_offer_want_cards__card",
"acceptances",
"acceptances__accepted_by",
"acceptances__requested_card",
"acceptances__offered_card",
"acceptances__accepted_by__user",
prefetch_have_cards,
prefetch_want_cards,
prefetch_acceptances,
# If direct access like offer.have_cards.all() (the M2M to Card, not through model)
# is heavily used AND causes N+1s (e.g. via __str__), uncomment these:
Prefetch('have_cards'),
Prefetch('want_cards'),
)
return qs.order_by("-updated_at")
return qs.order_by("-updated_at") # Default ordering for TradeOffer querysets
class TradeOffer(models.Model):
objects = TradeOfferManager()
@ -112,16 +138,6 @@ class TradeOffer(models.Model):
# Returns the list of want_cards (through objects) that still have available quantity.
return [item for item in self.trade_offer_want_cards.all() if item.quantity > item.qty_accepted]
@property
def have_cards_available_qs(self):
# Returns a queryset of TradeOfferHaveCard objects that still have available quantity
return self.trade_offer_have_cards.filter(quantity__gt=F("qty_accepted")).select_related("card")
@property
def want_cards_available_qs(self):
# Returns a queryset of TradeOfferWantCard objects that still have available quantity
return self.trade_offer_want_cards.filter(quantity__gt=F("qty_accepted")).select_related("card")
class TradeOfferHaveCard(models.Model):
"""
Through model for TradeOffer.have_cards.