Cost of computation/execution
The fee for the rebate. The portion of the storage rebate kept by the system.
Storage cost, it's the sum of all storage cost for all objects created or mutated.
The amount of storage cost refunded to the user for all objects deleted or mutated in the transaction.
Summary of the charges in a transaction. Storage is charged independently of computation. There are 3 parts to the storage charges:
storage_cost
: it is the charge of storage at the time the transaction is executed. The cost of storage is the number of bytes of the objects being mutated multiplied by a variable storage cost per bytestorage_rebate
: this is the amount a user gets back when manipulating an object. Thestorage_rebate
is thestorage_cost
for an object minus fees.non_refundable_storage_fee
: not all the value of the object storage cost is given back to user and there is a small fraction that is kept by the system. This value tracks that charge.When looking at a gas cost summary the amount charged to the user is
computation_cost + storage_cost - storage_rebate
and that is the amount that is deducted from the gas coins.non_refundable_storage_fee
is collected from the objects being mutated/deleted and it is tracked by the system in storage funds.Objects deleted, including the older versions of objects mutated, have the storage field on the objects added up to a pool of "potential rebate". This rebate then is reduced by the "nonrefundable rate" such that:
potential_rebate(storage cost of deleted/mutated objects) = storage_rebate + non_refundable_storage_fee