Questions tagged [gas-refund]
The gas-refund tag has no usage guidance.
61
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How to Determine the Optimal Gas Limit for Maximum Gas Refund without Excess?
I'm optimizing the gasLimit for transactions to ensure the maximum possible gas refund without leaving any unused gas. Given most web3 network's have a maximum gas refund policy where a portion of the ...
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2
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Can a simple ether refund without storage checks be hackable(reentrancy attack, ...)?
As the title says, I am wondering if the following ether refund(using .call) can be hackable.
I am not entirely sure no reentrancy attack can be performed in it, but I think so since I am not updating ...
- 11
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Any alternatives to reducing msg.value without resorting to refunds?
In my contract, users are required to deposit a specific amount of Wei. I want to prevent users from overpaying and need to decrease the value of msg.value.
Currently, I'm refunding the difference, ...
- 808
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EVM Gas refund and total gas calculation
My understanding is that the total gas refund can never exceed 20% of the transaction total gas cost, which I guess means that the EVM will first add-up all the transaction gas cost then deduct the ...
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572
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Is it possible to reverse the gas used in case of using revert?
I try to refund gas to the minimum even after using revert with the following example.
uint A = IERC20(base).balanceOf(address(this));
IERC20(token).transfer(owner,1000000);
then I run swaps ...
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2
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172
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Gas Less ERC-20 Token Minting
How can I create ERC-20 token on Ethereum blockchain without paying gas fee using Remix.ethereum.org
Please provide code to help
I saw Zeroswap DEX allow us to trade without paying gas fee.
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115
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Is the all of Gas Fee refunded if the transaction fails?
function burn(uint256 _value) public returns (bool success) {
balances[msg.sender] = balances[msg.sender].sub(_value);
totalSupply = totalSupply.sub(_value);
Burn(msg.sender, _value);
...
- 455
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80
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Why does releasing a storage variable cost more gas than it saves?
I am experimenting on saving gas by releasing some storage on my smart contract.
In the smart contract there is a mapping, which i fill with data by calling the function setStorage. The other function ...
- 21
2
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1
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388
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What is the gas refund for clearing out storage via SSTORE?
There is a lot of conflicting information due to the change in the gas refund mechanism from EIP-3298.
According to evm.codes the user will still be charged net 200 gas for clearing out a storage slot....
- 21
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Maximum gas estimate
eth_estimateGas provides estimated final gas consumed by transaction and accounts for gas refund in the end of transaction. However, is there a way to estimate maximum gas the transaction may consume ...
- 131
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345
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Can you create and destroy a contract in a single transaction?
Is it possible to create and destroy a contract in a single transaction? Specifically could I:
deploy to a known address using CREATE2
call a function on that contract
destroy the contract and ...
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43
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Does it cost gas to cancel a transaction? Can I replace / speed up the transaction to just 1 gwei then cancel to reduce fees?
My transaction is stuck, but can I speed it up by replacing the fee with 1 gwei then cancel it to reduce the fees to cancel?
I tried to cancel and speed up but its still stuck. I check etherscan and ...
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122
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Is there still gas refund for SSTORE to 0 instructions?
I'm trying to optimize a contract and wondering if I can still rely on gas refunds to optimize for gas?
https://twitter.com/n2ckchong/status/1365843261567365121
I've read from this tweet that there ...
- 81
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What happens when creating contract but out of gas? [duplicate]
I am new to ethereum.
I have learned that all states will be rolled back if out of gas.
Assuming that there is a transaction with value field, but it runs out of gas. Will the value be back? (i know ...
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What would be the safest way to prevent paying unnecessary high gas fees for transferring USDT?
Bitfinex paid a seismic $23.7 million dollars in a gas fee for a comparatively nominal $100K transaction, link.
At 11:10 UTC on the 27th September a deposit transaction was made
using a hardware ...
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Something Weird Happening w/ Blockchain, Gas fee is hold and historical ETH balance is changed [duplicate]
I am trying to send ETH from Ledger to CoinMetro account. I tried 4 times, with slow, medium and fast options. Each time it failed due to "out of gas" error. The 4th one failed immediately. ...
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ETH Transaction Fails but My Funds are Not Delivered Back
I am trying to send ETH from Ledger to CoinMetro account. I tried three times so far, with slow, medium and fast options. Each time it failed due to "out of gas" error. I did some research ...
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Is the gas usage O(1) for this code?
Is the gas usage constant for this function regardless of mapping/array size (assuming non-zero array entries)?
items is an array, and presence is a mapping
function clear() public {
for (uint i = ...
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1k
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Do NFT bids, and refunds from being outbid, have the same transaction/gas fees?
If I bid on crypto art to the tun of $50 in transaction/gas fees,
can I expect the same amount of fees to incur if I am outbid on that item, and the NFT platform refunds me my bid? $50 fee there, and $...
- 1,486
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811
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How are gas refunds "payed"? [duplicate]
I have a doubt about the gas refund concept.
Imagine that I created a smart contract 1 month ago and now I want to call the SELFDESTRUCT
because I want to send the current balance to an address and ...
- 259
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64
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Make transactions free of charge for the user
I involved in a project that aims to create a token for public use (non blockchain familiar users).
User will have an ERC20 token, but I don't want they to have ETH to pay the gas.
One obvious ...
- 1,731
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341
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refund function in smart contract [closed]
I am looking to add a Refund function in my smart contract.
Like If User A deposited 1 ETH in the contract, and uses refund function, he gets 1 ETH - Gas Fee back.
I can do the transfer(address....
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62
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Do gas refunds apply in a fallback function? What is the limit for non matching function identifiers?
I know that a fallback function called with a .transfer only has gas limit of 2300. What happens if the fallback function deletes some storage variables in the fallback function? Would the fallback ...
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518
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Understanding gas tokens and create2
I am going through a sample gas token code on Ethereum. The token mints some dummy smart contracts using CREATE2 and then calculates the address. Later on it destroys them to get the gas refund.
...
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429
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Does self-destruct() delete contracts data from the storage as well?
Destroying two contracts: (1) contract A with 1 integer variable stored in it and (2) contract B with 100 integer variables stored in it, would result in the same amount of refund: 24000 gas.
So does ...
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2
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1k
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Gas refunds via “Self-destruct” prior to a revert()
In a transaction that eventually calls revert(), if prior to the revert we have SELFDESTRUCT some contracts and thus received a gas refund, does the gas refund also get reverted?
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2k
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is it possible to get gas refunded if a smart contract call fails to complete?
I am using trust wallet, and whilst using a number of exchanges (for example - uniswap, balancer liquidity pool) I have paid gas prices without the exchange actually taking place. Is it possible to ...
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75
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If gas is refunded, is it required to call? [duplicate]
Suppose a smart contract external function uses very much gas, but refunds (with .transfer()) the used gas to the caller.
Question: Can it be called with a small amount of gas despite it uses much?
...
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How to refund gas to the smart contract caller? (What is the number?)
I have this function:
function setAccount(BaseUBI _ubi, address _user, uint256 _startTime, uint _esiaID, bool _setToZero) external {
uint256 _refund = (gasleft() + 0/*FIXME*/) * tx....
- 1,744
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589
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Refund mechanism - How is it possible to have transactions with M$ fee?
As stated here, my current understanding is that an unused gas is refund when the transaction succeeds (otherwise it is fully consumed)
Lately I found an article about some fee mistakes that led to ...
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How can I measure the gas used in a block of code?
This answer explains well how to measure the gas used in a block of code.
I had actually been using this method before I found that answer:
pragma solidity 0.4.26;
import './IERC20Token.sol';
...
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Which are the operations providing gas refund available immediatly for the current running transaction?
Most of gas refund operation aren’t available immediately, but instead increase the refund counter (which if I understand correctly is refunded not after the end of contract creation or call by ...
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Does the 10,000 refund apply to booleans too?
I understand from this thread that you're refunded up to 10,000 gas when setting a value to 0.
Does this also apply to boolean values? That is, going from true to false?
- 17.3k
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2k
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Is there a drawback of setting a too high gas limit for a transaction?
Say, I want to send a transaction that consumes around ~40,000 gas. Could I just set the gas limit of the transaction to 1 million or is there some disadvantage and I should set a more realistic gas ...
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295
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Which `EVM` bytecode is actually used to "deposit" the transferred Ether?
A quick question. Which EVM opcode is actually used to "deposit" the transferred Ether into the contract? From the EVM opcode list, there are only two opcodes related to the fund transfer: balance and ...
- 257
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Is the refund gas paid up-front?
Excerpt from chapter 9 of the yellow paper, "Execution Model", describing the behaviour of the EMV when clearing storage:
This refund is effectively paid up-front since the initial usage of a ...
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287
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Gas usage higher when using the delete keyword
I'm currently working on a marketplace demo for the consensys bootcamp, you can find my entire code here.
Stores inside the marketplace (which are structs) are stored inside a mapping and the keys ...
- 1,279
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370
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Understanding the formal description of a transaction and its associated refunds
Excerpt from page 8 of the yellow paper:
I fully understand that contracts can self-destruct and, when that happens, according to this thread, all the balance is refunded to the address specified as ...
- 17.3k
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719
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How to use ETH GAS refund in contracts?
How can we use refunded GAS from a transaction in subsequent ETH transfers? In general, how is refunded GAS used? How can we check the status of the amount of refunded GAS?
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385
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How to use / see refunded gas in ETH blockchain?
I buy a GAStoken contract which requires say 21000 GAS at 1 Gwei and later when we delete/destroy the contract when the Gwei is around 50. I understand that we will get around 50% refund of GAS at the ...
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Is our smart contract required gas,every time it executes.
form my understandings, after the first execution of a smart contract, the network will return the remaining gas to the contract sender. if so, how will the contract obtain gas for future execution??...
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is there any way to have a permanent refund contract for ERC20 tokens?
Im a newbie when it comes to Ethereum but from what I gather, there is a type of crowdsale where if the goal is not met, the investors can send back their tokens and get a refund. However, this is ...
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390
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Paying for gas on behalf of users?
I'm exploring ways to enable contracts/dApp owners to pay for gas on behalf of users.
I know contact abstraction should enable this eventually, and the first step has been done with EIP208 which ...
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92
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storage gas refund, is gas only refunded when storage is completely deleted? What if a key / value in a mapping is deleted?
I have a which tracks ids for some structs for different users.
mapping (address => uint[]) usersStuff
This mapping for each user can grow or shrink.
If it happens to shrink to 0 for a single ...
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Refunding gas fomula in Ethereum yellow paper
After execution of the transaction by miner, the transactor is refunded a remaining gas. it is explained in section 6 of Ethereum's yellow paper.
When calculating the amount to be refunded gas, the ...
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371
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How can I claim a refund from a failed ICO (Watertech)
My questions is about claiming a refund from a failed ICO. The ICO in question is WaterTech and the token is WATR
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682
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Resetting storage slot increases gas usage although should decrease it
I have a simple contract that deletes the last element of the array:
pragma solidity^0.4.11;
contract GasRefundTest {
uint[] myArray = [1, 2];
function deleteLastElem() public returns(...
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ICO refund: "Insufficient funds...account you tried to send transaction from does not have enough funds" [duplicate]
EDIT: Please note that this concern revolves around the "Contracts" portion of MyEtherWallet. I'm not trying to send funds from my account, I'm trying to recover funds for a failed ICO using the ...
- 11
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790
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Can't claim EOS tokens. Problem with GAS amount when claim EOS tokens
To make story short,I participated in 167 EOS distribution period, so i've sent ETH amount to their account 0xd0a6E6C54DbC68Db5db3A091B171A77407Ff7ccf. Then i've registered my public EOS key and right ...
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ClaimRefund Process
One of the PreICO is cancelled so they are providing me refund of my ETH. They are asking me to enter their ABI/JSON and ClaimRefund through myether wallet under my login.
Can using the Claimrefund ...
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