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Average case performance of a Modified Merkle Patricia Trie

I recently read this specification of a merkle-patricia Trie by Parity, which states that the performance of the Merkle Patricia Trie used in Ethereum is: [Merkle-Patricia Trees] provide the holy ...
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1answer
14 views

How the contract address being decide when deploy it in another contract?

According to How is the address of an Ethereum contract computed?, I know a contract address is decided by the hash of deployer address and nonce. How about the contract is deployed through another ...
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0answers
21 views

What does “Time” in the Geth VM Trace Transaction refer to?

I'm new to Ethereum world, and I need some declaration, I used "Rinkeby network" and just found Geth VM Trace Transaction { "type": "CALL", "from": "0x6f1e5fc933898859686a4d39f4430316be589f5e", ...
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1answer
13 views

Type Error: send and transfer are only available for objects of type “address payable ” not address

pragma solidity ^0.6.0; contract Campaign { Request[] public requests; address public manager; uint public minimumConstribution; mapping(address => bool ) public approvers; ...
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0answers
25 views

Web3.js Batch Request Limit?

I'm trying out Batch Request provided by web3.js. In the example below I want to test making 300 transactions but i get the error log displayed below. I'm trying to figure out the error log but it ...
0
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1answer
28 views

Number of state entries needed before geth node is synced up with Ropsten

I am currently syncing a Geth node with the Ropsten network. Currently the download in the terminal show a neverending stream of Imported new state entries. I understand that I have to wait for all of ...
0
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1answer
33 views

Metamask not returning the current address

I am using web3.eth.getcoinbase() function to get the address of the current account but instead, it returns null. Can someone help me with this? This is the code web3.eth.getCoinbase(function(err, ...
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1answer
18 views

web3 does not find metamask accounts

I have a very strange bug in the code. When loading a page with a code, the current account in metamask should be determined. but this only happens on one local domain. in other domaines accounts are ...
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0answers
10 views

How can I get all updates for a given transaction hash via websockets?

Given an Ethereum public key, "0x7B10c5AaFa65B8AEd953bE6D593D3D29391592D7", how can I get all available data for transactions sent from the afore mentioned public key after they have been included in ...
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0answers
8 views

How to duplicate a Geth server?

I have a Geth server which is fully synced, but the second server I have lunched cannot being synced after 2 weeks! I don't know why is this happening, but I decided to test another way. I setup a new ...
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1answer
18 views

Someone Can Help Me With This Warning Error! It Stuck My code

I'm trying to create an ERC20 token and if someone sends ether to this contract, contract will send equivalent tokens to the calling address. Code::: pragma solidity ^0.6.6; import "./new1ERC20.sol"...
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1answer
12 views

How to find private key on build.secondstate

I'm a beginner in ethereum application developing. Actually I started some days ago with a book and now I tried to build my first smart contract using BUIDL, actually at this site: https://buidl....
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0answers
17 views

Best way to avoid transactions that create a new smart contract before submitting it

We are creating a permissioned network (using Besu) where anyone can create and submit transactions. In this context, the writer nodes need to verify that these transactions are not creating new ...
1
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1answer
37 views

How to send ethers from multiple accounts to a single recipient?

I want to transfer 1 ETH distributed to three addresses to a single recipient address. How can I achieve this in ethers.js
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1answer
28 views

Truffle Deployment Error: Invalid number of parameters for “undefined”. Got 1 expected 0!

I am trying to deploy my smart contract. When I run truffle compile everything works however when I run truffle migrate, I get this occurring error message: Error: * Deployment Failed * "...
0
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1answer
35 views

Error when sending multiple transactions

I'm having a weird issue with the code below in that sometimes it works and sometimes it doesn't. It seems more apparent when TRANSACTIONS is set to a larger number. I have had it fail AND pass with ...
0
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1answer
12 views

What does instance refer to in solidity/JavaScript

DToken.deployed().then(function(instance){ token = instance; }) This code I saw in truffle test. Can someone please tell what does this "instance" parameter refer to?
1
vote
1answer
23 views

Which Mobile Wallet support *data* field?

Referring to this link ERC: Standard URI scheme with metadata, value and byte code #67 Since it was proposed in 2016, may I know if there is any mobile wallet that can scan QR code with these 4 ...
1
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0answers
12 views

Simple way to balance web3j connections between nodes

Context: I have a client that can connect to 3 local-network nodes to distribute query-loads and be more resilient to network/software issues. I have managed to create a -simple- watch-dog with a ...
0
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0answers
13 views

Can I check whether any deployed contract has implemented some particular interface or not?

My concern is whether I can do interface detection with my own interface,,, Like suppose, i have implemented some interface say loyalty interface in my one contract and I have deployed that contract ,...
0
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1answer
14 views

Can't unlock address when using ganache-cli

I want to unlock an address and fund it with ETH in ganache that I don't have its private key. So I run this: ./node_modules/.bin/ganache-cli --hardfork istanbul --port 8545 --gasLimit 8000000 --fork ...
1
vote
1answer
28 views

can anyone explain why call, delegateCall, staticCall functions in solidity are called low level functions?

As i have read at many resources, that these functions are low level functions. I want to know, should i use these methods to interact with already deployed contracts or not ?
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0answers
20 views

Transaction receipt was not generated after 600 seconds for contract transaction

I use SimpleMultiSig to generate java code with web3j. When I call the execute() function after 600s throw the error org.web3j.protocol.exceptions.TransactionException: Transaction receipt was not ...
0
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0answers
12 views

Rinkeby Chaindata location

Hi I need to know where is the location of the folder who contains the rinkeby chaindata on Windows10 normally it's under ~/AppData/Roaming/Ethereum but the problem is that I can't find Ethereum ...
0
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0answers
13 views

Geth returns tx hash but blockchain

I have a Geth server on light mode, and implemented sending transactions based on web3.php project. Everything works well, except sending transactions. The code I am using sends from, to, and value ...
0
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0answers
16 views

Document version control

Version control systems are used to track record of changes to files. the files are contained in a repository or database, and it contains all the history versions of the files. My question is : Is ...
0
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0answers
69 views

How is etherscan calculating block size (bytes) from gas used?

https://etherscan.io/block/9980912 It says "The block size is actually determined by the block's gas limit". Not sure how to convert gas used to bytes and geth doesn't provide the block size in bytes....
0
votes
1answer
14 views

How to add values to array within a struct in Solidity?

First of all, sorry for my English as a Google Translate I wanted to add values to the list inside the struct, but with the code below the following error appears: UnimplementedFeatureError: Copying ...
1
vote
1answer
26 views

Spending funds before the block is mined

Suppose I have an application that receives funds from users and instantly moves them into an associated cold storage account. If one of our nodes detects a transaction broadcast to one of our ...
0
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1answer
19 views

Having a problem compiling a ERC20 token smart contract - Code inside

Basically i'm using a cut and paste erc20 token code from this site: https://hashnode.com/post/how-to-build-your-own-ethereum-based-erc20-token-and-launch-an-ico-in-next-20-minutes-...
1
vote
1answer
23 views

How to make an API call in solidity using Chainlink?

I am following the documentation from the Chainlink site, and I am attempting to make an API call. The main issue is I'm not sure what "address" is referring too. I am using remix in solidity v0.6 ...
0
votes
1answer
18 views

got response data to nonsencical eth_call request. What is that response?

When I call a seemingly nonsensical transaction on mainnet and rinkeby. ethereum.send('eth_call', [{'from':'0x0000000000000000000000000000000000000000', 'to':'...
0
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0answers
41 views

sending request with curl returns that method does not exist

I try to make call with curl curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"eth_accounts","params":[],"id":67}' http://localhost:8545 and it returns this: {"...
0
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1answer
23 views

Time period in contract

there I have a contract that I want to work just in a specific period and then stop working I wrote these two function but they didn't seem correct, this contract is called multiple times and I just ...
0
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2answers
21 views

How can I test someone else‘s ETH contract with only bytecode and ABI? [duplicate]

If I just have someone else's ETH contract bytecod an ABI, how can I test it's function?
0
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0answers
13 views

Convert X509 ECDSA public key into Ehtereum Address

I have been given an X509 ECDSA public key that I want to use to assosicate data with. However, when I use Base64.getDecoder().decode(X509PublicKey) I end up with 88 bytes. What do I do to ...
0
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0answers
15 views

Memory Arrays Should Have Push() And Pop()

Dynamic memory arrays currently cannot be resized. This is true for Solang and solc solidity. However, Solang uses a heap, and has a realloc() function. Thus it is is possible for Solang to support ...
0
votes
1answer
25 views

Receive ERC20 token as value in function of smart contract

I want to receive an erc20 token as value for a function. Basically, the function caller defines an amount which will then be transferred from their balance to the smart contract. Which transfer ...
0
votes
3answers
32 views

Can i know by any method whether the particular address is contract address or simple ethereum address?

Here is the problem I am facing. I am calling some function of already deployed contract using its contract address. Below are the lines of code :- function registerYourBrand(string memory brand, ...
1
vote
0answers
20 views

Possibilities of ERC721 image generation [closed]

What image generation techniques could you suggest for a DApp game that utilizes ERC721? I know that CrypoKitties has a unique DNA sequence and different pieces of the sequence correspond to the ...
0
votes
2answers
16 views

How to specify custom test directory path in truffle-config.js

How do I specify a custom test directory path in truffle-config.js? My test directory is not present at the same level as truffle-config.js, it is residing in a different directory. Truffle has ...
0
votes
1answer
24 views

How to resolve the function payable issue in ERC20?

pragma solidity ^0.6.6; import "./ERCI20.sol"; import "./newERC20.sol"; contract timeLock is ERCI20, newERC20 { address payable sender = msg.sender; address payable benificiary = ...
0
votes
1answer
22 views

Why 'Out of gas' error when there is still a lot of gas?

Gas limit was set to 6,000,000 Tx consumed just 1,943,125 Yet is still failed with Out of gas error. If it makes any difference, this is my contract which calls other contracts with raw_call (in ...
1
vote
1answer
20 views

Scam: Sent ETH to HEX Contract - Where is it?

I sent ETH to the HEX contract, waited for 24 hours to transform and was ready to click "exit" at the end but it just disappeared?
1
vote
1answer
26 views

Receiving error while getting state variable value after using selfdestruct method “Error: Returned values aren't valid, did it run Out of Gas?”

I am using selfdestruct method and passing the payable address to it but receiving the following error when trying to get the value of a state variable : "Error: Returned values aren't valid, did it ...
0
votes
1answer
12 views

Nethereum C# FilterInput.GetAllChanges always empty

I use Nethereum in my project to get all pending transactions on a specific smartcontract address. To do that based on the existing docs and Nethereum playground I try the following: private async ...
0
votes
0answers
41 views

can't verify contract on etherscan (But we were unable to locate a matching bytecode (err_code_2))

so i'm trying to verify a contract on rinkeby and ropsten... getting the same error of "Compiler debug log: Error! Unable to generate Contract ByteCode and ABI Found the following ContractName(s) ...
0
votes
1answer
13 views

web3.eth.defaultChain returns undefined

Hi I am trying to make a call to the Dai contract in the Kovan testnet using web3.js and have to set the value of web3.eth.defaultChain to 'kovan'. The docs state that the default value for web3.eth....
0
votes
1answer
23 views

Can I change state of mapping variable in deployed contract from another contract?

I am calling addCoin and subCoin function of my AirToken contract and Hotel contract. This is function defination of addCoin and subCoin in AirToken contract and Hotel contract function addCoin(...
5
votes
2answers
45 views

Can anyone explain how bytes memory can be converted to address type in solidity

when I am using below function to convert bytes memory to address, this is working fine. Suppose input to the function is 0X0000000000000000000000004af3246b4fff356261136f113411cb187134D675 I am ...

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