DigixGlobal#70 WatchingTransaction::resend_transactions optimized

app/models/watching_transaction.rb

@@ -71,10 +71,11 @@ def resend(user, watching_transaction, attrs)
     end
 
     def resend_transactions
+      group_size = WatchingTransaction.group(:group_id).count
       WatchingTransaction.all.order('created_at ASC').each do |tx|
         ok_tx, data = EthereumApi.get_transaction_by_hash(tx.txhash)
         unless ok_tx == :ok && data
-          if WatchingTransaction.where(group_id: tx.group_id).count == 1
+          if group_size[tx.group_id] == 1
             ok_send, txhash = EthereumApi.send_raw_transaction(tx.signed_transaction)
             if ok_send == :ok
               Rails.logger.info "Resent transaction #{tx.txhash}, new hash is #{txhash}"
@@ -85,6 +86,7 @@ def resend_transactions
           else
             Rails.logger.info "Destroying dropped transaction #{tx.txhash}"
             tx.destroy
+            group_size[tx.group_id] -= 1
           end
           next
         end