Class: SpreeCmCommissioner::InventoryItems::AdjustAvailableQuantity

Inherits:
Object
  • Object
show all
Extended by:
ServiceModuleThrowable
Includes:
Spree::ServiceModule::Base
Defined in:
app/services/spree_cm_commissioner/inventory_items/adjust_available_quantity.rb

Overview

Moves quantity_available on a single inventory item, in the database and in Redis, without touching max_capacity.

Used by seat locking: locking a seat deducts 1, unlocking returns 1. max_capacity is left alone because it is the physical vehicle capacity and InventoryItems::Reset recomputes it from variant.total_on_hand — folding locks into it would be silently wiped by any later reset.

No defensive clamping: locking a date whose quantity_available is already 0 must raise ActiveRecord::RecordInvalid (the model validates >= 0) so the caller can report it as a skip, rather than silently losing the deduction.

Instance Method Summary collapse

Methods included from ServiceModuleThrowable

call!

Instance Method Details

#call(inventory_item:, delta:, caller_source: nil, lock: true, warm_redis: true) ⇒ Object

lock: pass false ONLY when the caller already holds this row's lock (Seats::LockBlocks and UnlockBlocks both wrap each pair in item.with_lock). Nesting a second with_lock on the same row costs a SAVEPOINT + a redundant SELECT ... FOR UPDATE + a RELEASE per call — about a third of all queries in a bulk lock. Defaults to true so a standalone caller is still safe.

warm_redis: pass false when the caller has already warmed this item's key in a batch. Warming is SET-NX, so doing it once up front is equivalent to doing it per call and saves one Redis round-trip per seat-date.



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# File 'app/services/spree_cm_commissioner/inventory_items/adjust_available_quantity.rb', line 25

def call(inventory_item:, delta:, caller_source: nil, lock: true, warm_redis: true)
  return success(inventory_item) if delta.zero?

  # CRITICAL: warm the Redis key before adjusting it.
  #
  # adjust_quantity_in_redis runs `GET key or 0` then applies the delta and clamps at 0. Against a
  # key that does not exist yet, a -1 becomes `0 + (-1) = -1` -> clamped to 0 -> SET 0 with a
  # one-year TTL. The date would then advertise 0 available while the database says 38, and
  # AvailabilityChecker reads only Redis — so locking one seat on a not-yet-cached date would
  # silently take the whole departure off sale.
  #
  # CachedInventoryItemsBuilder SET-NXs the database value into a cold key, which is the same
  # thing RedisStock::Unstock and InventoryHolds::Convert do before their own Lua scripts.
  warm_redis_key!(inventory_item) if warm_redis

  apply = lambda do
    before = inventory_item.quantity_available
    after = before + delta

    inventory_item.update!(quantity_available: after)
    inventory_item.adjust_quantity_in_redis(delta)

    CmAppLogger.log(
      label: "#{self.class.name}#call",
      data: {
        caller_source: caller_source,
        inventory_item_id: inventory_item.id,
        quantity_available_before: before,
        delta: delta,
        quantity_available_after: after
      }
    )
  end

  lock ? inventory_item.with_lock(&apply) : apply.call

  success(inventory_item)
rescue ActiveRecord::RecordInvalid => e
  CmAppLogger.error(
    label: "#{self.class.name}#call failed",
    data: {
      caller_source: caller_source,
      inventory_item_id: inventory_item.id,
      quantity_available_current: inventory_item.quantity_available,
      delta: delta,
      errors: inventory_item.errors.full_messages
    }
  )
  raise e
end