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3
votes
1answer
89 views

How to get an evm reference inside go-ethereum GetBalance function?

In order to modify GetBalance function to fork go-ethereum, I find difficulties to get a reference of the running evm. The function has a reference for self *StateDB: func (self *StateDB) GetBalance(...
3
votes
2answers
48 views

Auction contract problem regarding highest bid display

I have an Auction contract which has a function like this: function bid() payable{ //calculate and store highest bid value } But because each transaction takes time to mine, so when a user bids ...
3
votes
0answers
198 views

parity initializing snapshot whole night

I have parity installed and synced. I went out of disk space. I moved the chain to bigger ssd. Then I started the parity service and let it run whole night. It did not finish. in log I can see ...
3
votes
0answers
71 views

Does Geth store trace data for later calls (after full-sync with pruning + reexec)?

The wisdom is that having a full node is enough to reconstruct all past information the archive nodes keeps readily constructured, hence available faster. I was reading the Geth IceBerg 1.8 release ...
3
votes
0answers
80 views

Invalid JSON RPC response on IOS build with Infura

I am developing a mobile DAPP using ionic frame work, everything was fine when I testing on the browser. However I try to build my app on IOS, and run it on my Iphone7, the web3 doesn't work(did't ...
3
votes
1answer
18 views

Create a slightly customized version of ethereum and run it as a node on a public ethereum blockchain

I might need a small modification to ethereum virtual machine but I still want to run it as a node on the public blockchain not private, if that makes sense. I assume its doable? Since I will not be ...
3
votes
0answers
99 views

VM revert on Scalar Multiplication in pre-compiled contracts

I tried to build a wrapper around the precompiled contracts as follows: https://gist.github.com/AlexXiong97/9c24bbd4541323a61fa63100860a5f89 If you paste it into Remix and deploy it, inputting any (...
3
votes
0answers
54 views

Block Timestamps vs. Received Timestamp

I've been logging local timestamps when I receive blocks on two separate geth nodes to see which (if any) is consistently faster. But I just stumbled across something that I don't understand - in my ...
3
votes
1answer
47 views

Order of evaluation: an example

In the Solidity documentation is stated that: The evaluation order of expressions is not specified (more formally, the order in which the children of one node in the expression tree are evaluated ...
3
votes
0answers
67 views

One-to-many mapping inside struct

I have two structs: struct A{ uint bid; mapping(uint => B[]) BMap; //bid - index for struct B } struct B{ uint cid; } mapping(uint => A[]) AMap; How can we push and fetch 'cid' ...
3
votes
0answers
230 views

The sendSignedTransaction function does not activate the on('receipt') event at an appropriate time

console.log(transacting...); web3.eth.sendSignedTransaction('0x' + serializedTx.toString('hex')).on('receipt', receipt => { log(receipt); log(`https://ropsten.etherscan.io/tx/${receipt....
3
votes
0answers
284 views

Header broke chain ancestry, Synchronisation failed, dropping peer & retrieved hash chain is invalid

System information Geth version: Geth Version: 1.8.22-stable Git Commit: 7fa3509e2eaf1a4ebc12344590e5699406690f15 Architecture: arm Protocol Versions: [63 62] Network Id: 1 Go Version: go1.11.5 ...
3
votes
0answers
71 views

Zero Knowledge Range Proofs

I am new to the world of Zero Knowledge Range Proofs. I read the following on GitHub: https://github.com/ing-bank/zkproofs The Zero Knowledge Range Proof allows the blockchain network to validate ...
3
votes
0answers
225 views

Why can't I fetch my Metamask account address with Next.js's getInitialProps?

I'm using Next.js to implement server-side rendering in my Ethereum app, however I can't fetch my Metamask address to display it in the top-right corner of the navigation bar in my index.js file. ...
3
votes
1answer
57 views

How to use enums for conditions on constructor?

I am learning to code with solidity. need help to solve this I have a membership system where users can have basic, gold, diamond membership types. Users can use coupons every 5 minutes and for basic ...
3
votes
2answers
198 views

Native mobile Dapp - Sign transactions with user wallet

I'm starting a new project that involves a mobile Dapp and I have a question regarding signing transactions. Every mobile Dapp post that I read about offered two solutions: Use a Dapp browser, such ...
3
votes
0answers
135 views

What is the position of Whisper and Swarm in the Ethereum 2.0 Roadmap

Back in 2015, Ethereum vision was to be a "World Computer" relying on three main complementary technologies: Ethereum for decentralized Logic Swarm for decentralized Storage Whisper for decentralized ...
3
votes
0answers
136 views

What filesystem should I use for geth and leveldb?

I used old LGA775 machine for running geth node. Its mobo has older sata 3gb/s (benchmark showed that ssd bottlenecked there) and only 4gb of DDR2, with windows installed. So syncing is a real pain ...
3
votes
1answer
34 views

Merkle Hash forest and MErkle DAG is it the same?

I'm wondering if a merkle hash forest is the same as a merkle dag? I need a reliable paper as reference I could cite in my paper. Thx for all your help!
3
votes
0answers
193 views

PoA network with half million blocks, sealers stopped

System information Geth Version: 1.8.17-stable Git Commit: 8bbe72075e4e16442c4e28d999edee12e294329e Architecture: amd64 Protocol Versions: [63 62] Network Id: 1 Go Version: go1.10.1 Operating System: ...
3
votes
0answers
201 views

Questions on MinterRole contract in openzeppelin

I am using the openzeppelin for creating the ICO contract. I am concerned about the MinterRole here. After I develop Token contract, I added the sale contract as a minter using "addMinter" function. ...
3
votes
1answer
276 views

how to use web3j over infura to find exact gas price used for a successful transaction

my goal is to compute the cost of gas for a successful tx. I get a callback when a transaction succeeds and i retrieve gasUsed with transactionReceipt.getGasUsed(). Now I need to know the exact gas ...
3
votes
0answers
166 views

Installing Truffle without npm

I'm a student trying to install a truffle test RPC client (just for simple contract deployment in small scale). I am using a remote Ubuntu machine in my university, and i don't root privileges. ...
3
votes
0answers
147 views

Truffle test of two transactions during the same block

I'm trying to test a solidity function that only allows it to be called once per block. E.g. (my desired functionality): Tx1 calls Fn during block #100, and when successful sets a boolean flag for ...
3
votes
2answers
90 views

is it possible to get events from transactions that are in the `txpool`?

Is it possible to see the events that will be emitted in the txpool, or is only the transaction information available? For example, can I search in either the queued or pending transactions and ...
3
votes
1answer
65 views

What is the default license for solidity code released to the blockchain?

What is the default license for solidity code released to the blockchain? Is there such a thing? I'm just wondering because i thought the idea of smart contracts is to release the source code, so ...
3
votes
1answer
51 views

Ethereum Merkle Patricia Tree Riddle

since I spend some time on diving into the data structures that ethereum is based on, I stumbled upon the following task from a stanford course which i included at the bottom. I am struggling ...
3
votes
1answer
34 views

What mathematical concepts do I need to master in order to understand the Aztec Procotol?

What mathematical concepts do I need to master in order to understand how privacy in the Aztec Protocol works? When I look at the white paper, I have no idea what is going on; however, I am confident ...
3
votes
2answers
77 views

Format of Event logs structure in Remix

I am running a simple contract in remix. I have an event in my contract which will be emitted just to check values of stateVariables. contract stateVariable{ uint stateVariable1=10; uint ...
3
votes
0answers
74 views

Why two contracts got same address?

I've been testing payments for shopping cart on a private chain. I create and deploy contracts to disburse payments among sellers. So if a shopper buys same items again the contracts for two carts ...
3
votes
2answers
797 views

Truffle Compile with Solidity 0.5.0

I just upgraded my code to Solidity 0.5 and am trying to use the truffle framework with it. I did update my code in Remix and it does seem to work. The problem I have is that I am unable to compile ...
3
votes
0answers
186 views

How to access txpool pending transactions using Netherum?

I want to get list of transactions which are in pending state & queued state in txpool. I can see these transactions in pool using txpool.inspect command. I tried code given in nethereum sample ...
3
votes
3answers
542 views

How to handle dynamic size string array in solidity?

I have a shop owner and a shop owner can have multiple products. I want to keep the products id in an array. Also, A public method can return all the product id list of a shop owner. I tried the ...
3
votes
0answers
115 views

Quorum :- metamask do not support privateFor feature of quorum

i got to know that metamask do not support privateFor because of which private transaction for quorum dapp was not behaving as expected. so, I can't use metamask for my quorum DApp to switch port and ...
3
votes
0answers
94 views

Miner accepting 0 price transactions

I am hosting a private blockchain and I am testing out the Geth functionality. I have deployed a Solidity contract based on the Greeter example. The functionality is not important, but suffice to say ...
3
votes
0answers
87 views

How the Ethereum Swarm connects nodes and several related questions

Read everything after https://swarm-guide.readthedocs.io/en/latest/usage.html and leave an article. Some questions about etherium swarm Where is the uploaded data stored? And how do you find it? I ...
3
votes
0answers
128 views

solc: [libevmasm/CMakeFiles/evmasm.dir/Assembly.cpp.o] Error 1

I am trying to install solc v0.4.25 through brew on a Mac. Please note that I was able to install its latest version solc v.0.5.0 using brew install solidity; but I am unable to install its previous ...
3
votes
1answer
45 views

Is it possible to check the Thrid party token ( USDT ) within my ERC223 contracts?

I want to check how many tokens are received in my contracts, so that I am able to allocate MY TOKENS to the TOKEN Sender. I tried several ways like approveAndCall, but its not working. I don't ...
3
votes
0answers
28 views

Reconstruct sender address from signature

I am using a service that wants me to verify that the data it returns to me is correct before I use it. The service returns something that looks like the following: { "signature": { "v": ...
3
votes
1answer
81 views

Signing a transaction with uport can't approve as the selected account can't change.How can i change in uport selected account?

I am developing a dapp with uport verifications but when I go for saving information into ropsten network, a uport signing transaction appears on my screen and I can't approved the transaction. I ...
3
votes
0answers
280 views

How to Catch Connection Issues to Web3 Provider using Web3.js

My node.js script is able to successfully connect to the Web3 provider when both the private key (using truffle-privatekey-provider) and the provider host URL are correct. let privateKey = ..., ...
3
votes
0answers
701 views

NetworkError when attempting to fetch resource. Resource URL: moz-extension://2…/contentscript.js Source Map URL: ../sourcemaps/contentscript.js.map

I get the following error message in Firefox Developer Tools Console following a successful sendTransaction: "Source map error: TypeError: NetworkError when attempting to fetch resource. ...
3
votes
1answer
222 views

Create Accounts Using Web3.js in Browser

TL;DR - Replicated Ethereum Blockchain. Running Local Node. Connecting Local Node to Web3.js in browser using RPC. Want to create addresses & send transactions Details - I have a blockchain that ...
3
votes
0answers
220 views

Where is the latest MetaMask hello world dapp example?

MetaMask recently added a new permissions check. I'd like a copy-pasteable hello world dapp that includes all best practices and can check the balance of the current user's ERC20 balance for some ...
3
votes
0answers
73 views

Spoofing of totalDifficulty variable

Péter Szilágyi, in his talk in Taipei, claims that totalDifficulty can be spoofed: https://www.youtube.com/watch?time_continue=575&v=qJA6J0mP73w How is that possible? Can the variable only be ...
3
votes
0answers
157 views

Bloom Filters - is the blockchain filtered block by block?

I understand that bloom filters are used to quickly scan for log topics and corresponding contract addresses. I also understand that an 2048-bit bloom filter is stored in the block header. Question: ...
3
votes
0answers
153 views

Difference between execution costs on remix an Ganache?

I created a contract on remix and then deployed it. when I call any function there is an execution cost in gas. I also deployed the same contract on Ganache for testing. I find the execution cost in ...
3
votes
2answers
487 views

IPFS. Add a directory recursively with an HTTP api

Is there an HTTP api equivalent of doing: ipfs add -r resources/public where resources/public is a directory with a static website (index.html in the root, css, js etc). Doing: curl -F file=...
3
votes
0answers
586 views

Verify Public Key from an RSA SHA256 signature

Given an RSA SHA256 signature (obtained from encrypting a hash using an RSA Private Key), I must assert whether a provided Public Key matches this signature or not. It is imperative that this ...
3
votes
0answers
51 views

Why does a full client need to store the DAG?

The yellow paper says that miners and full clients must store the DAG dataset, but light clients can verify block headers by generating only a few necessary pages from the DAG. It makes sense to me ...

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