Questions tagged [smart-contract]
Anything related to decentralized application (dApp) development, concepts, and possibilities with smart contracts, or technical questions for the development of smart contracts.
618
questions
3
votes
1
answer
73
views
How to pass specific eosio-cpp/eosio-ld options via cmake
I'm typically using CMake to compile my contracts, like described here.
How can I pass specific eosio-cpp/eosio-ld options (specifically -stack-size) described here?
- 1,929
0
votes
1
answer
159
views
How to Define and use Array of Strings in Struct?
My Sample Struct and its method
// Department Table
struct [[eosio::table]] department_info {
uint32_t ID;
std::string deptname;
std::string deptcode;
std::...
- 11
1
vote
1
answer
78
views
Difference between _self and get_Authorization and RAM optimization
I have build a Smart Contract with 14-15 Tables for I/O.
It will be used to store important data of our platform.
I have used require_auth(_self) as this contract will not be used by 3rd person.
It ...
- 11
2
votes
1
answer
58
views
how to find greatest common divisor inside smart contract?
I need the greatest common divisor between two numbers in the smart contract. I tried:
int gcd = __gcd(num1, num2);
num1 and num2 are two numbers. When the smart contract is compiled, its generating ...
- 307
0
votes
1
answer
92
views
Generate random numbers in the smart contract
I am writing smart contract and stucked on this line :
int p = 0;
p = (rand() % 997);
This is giving error
error: use of undeclared identifier 'rand'
I do search and got some reference links but ...
- 307
1
vote
1
answer
53
views
Is it possible to get the initiating contract name from a token transfer?
When an external account transfers tokens to my account (which has a contract with an "on_notify" action for incoming transfers), is there any way I can get the name of the contract that ...
- 11
2
votes
1
answer
37
views
cleos push action is not working on multihost peer node
I have a setup of multinode, one genesis node and another host node inita connected to the genesis node. Nodeos is running on both hosts. Genesis node is producing blocks and inita is receiving them. ...
- 307
0
votes
1
answer
75
views
What does 'datastream<const char*>' mean in this code?
From this tutorial
addressbook(name receiver, name code, datastream<const char*> ds):
contract(receiver, code, ds)
I'm not familiar with 'datastream' and Googling isn't turning up any precise ...
user4272
0
votes
1
answer
142
views
Calling external action with 'action_wrapper' and 'action'
In contract we have two way to call another action:
Use 'action'
action(permission_level{get_self(), eosio::name{"active"}},
eosio::name{"eosio"},
...
- 125
1
vote
1
answer
27
views
Does the size of a contract affect CPU consumption
Does the size of a contract increase CPU consumption in general?
To my knowledge, there may be several secondary factors that slow down the processing of transactions.
For example, a memcpy command ...
- 1,929
0
votes
1
answer
133
views
How can I change quantity in transfer
Good Day!!
I want to change add_balance in transfer
How can change quantity value in add_balance?
Ex) invalid operands to binary expression
('eosio::asset' and 'int')
add_balance( to, quantity - 100 , ...
- 1
0
votes
1
answer
207
views
EOS Blockchain How to free up RAM or optimize Smartcontract
We have developed a small program that uses the EOS blockchain and we are storing some of our data in an EOS smart contract. Together with a UUID we are storing the object status. Our goal is to have ...
1
vote
1
answer
81
views
Smart contract compiling loop
When I try to compile the contract the process creates an infinite loop. Here is my code, please help!
kjnjrwsyxszg.cpp
#include "kjnjrwsyxszg.hpp"
void kjnjrwsyxszg::create(const name owner,...
- 11
1
vote
0
answers
76
views
Multiple transaction hash collisions on mainnet
There are currently multiple transaction hash collisions in consecutive blocks in EOS as noted below:
7dcdcdb558028c7703faddee96e1aa48e9bbe7cd3a07cd0a74513a3599185b40 at block 10712420 and 10712421
...
- 111
0
votes
1
answer
308
views
Convert type string to type checksum256
fist off let me get this strait, yes I know the dangers of memo parsing, yes I am aware of the vulnerabilities that can be created from doing such a process, so please there is no need to lecture me ...
1
vote
0
answers
9
views
is there a service that creates EOS or TRX div tokens?
is there a service that creates EOS or TRX div tokens? Or can someone point me in the right direction?
Thank you
- 11
-1
votes
1
answer
72
views
What's the max speed of EOSIO contract?
I try to do performance testing about EOS contract. I built private EOS network with 6 nodes.
I use apache bench to formulate http requests, and post to EOS service http://127.0.0.1:8888/v1/chain/...
- 1
1
vote
1
answer
131
views
Dispatcher in smart contract
I want to implement dispatcher in a smart contract. I research about this and understand theoretically but I am not getting practically. Exactly why the dispatcher is to be used? The basic thing I got ...
- 307
0
votes
1
answer
49
views
EOSlime TypeError: Contract.actionname is not a function
This is my test file:
const assert = require('assert');
const TOKEN_WASM_PATH = './contracts/group/group.wasm';
const TOKEN_ABI_PATH = './contracts/group/group.abi';
describe("EOSIO Group", ...
- 307
0
votes
1
answer
52
views
eoslime test not saving data in table
This is my first experience with eoslime as I want to do unit testing for smart contracts. Not much experienced with nodejs .I am following eoslime documentation: https://docs.eoslime.limechain.tech/...
- 307
0
votes
2
answers
191
views
how to define a vector with fixed size?
I want to define a vector of strings with a fixed size 3 in the multi-index table of smart contract. I search and tried different ways which I found for CPP vector like:
std::vector<string> abc(...
- 307
0
votes
1
answer
51
views
Wrong table name in scope response
My contract has two tables mcat and mcatmig.
Problem: scope request return wrong table name mcat........1 instead of mcatmig:
% cleos get scope teresacode
{
"rows": [{
"code": "teresacode",
"...
- 125
0
votes
0
answers
83
views
How to generate unique string id from given array of strings in smart contract?
I am writing an EOS smart contract in which need to write the action to generate a unique id from the given array. Array consisting of n number of string elements (UUID). Suppose I pass 10 strings to ...
- 307
0
votes
0
answers
111
views
How to set vector type field as a secondary index in smart contract?
I want to set a group vector as a secondary index in the user smart contract. group is the list of groups.
Following is the changes I am doing:
struct [[eosio::table]] usertable {
...
- 307
0
votes
1
answer
311
views
Multiple smart contracts with single account
I have three smart contracts (A, B, C) and one account (X). As the requirement is I just need only one authority (administrator) who is going to manage all these smart contracts data. So I deployed ...
- 307
0
votes
1
answer
120
views
How to check authorization for a particular account in EOS smart contract?
I want to write an EOS smart contract to manage users data. I need that only some admin account will able to add, update and delete users and the particular user can only update data. Can I check ...
- 307
0
votes
1
answer
77
views
Complex smart contract for rule based auction in multiple currencies
The imagined application allows users to participate in an auction and make bids in cryptocurrencies. There are several behavioral rules that control the execution of the auction and determine the ...
- 103
0
votes
1
answer
38
views
Take output from GetActions and send to database using eossharp
I am using eos-sharp to get data from the eos smart contract. I am trying to get actions data by using:
var resultaction = await eos.GetActions("dqzmember", 0, 30);
I need information from ...
- 307
0
votes
1
answer
99
views
how to save data in mongodb from eos smart contract?
I am getting the actions log data using an action constructor in a smart contract. I need to save this data in MongoDB from the smart contract. How can I do this? I didn't get exactly my required ...
- 307
0
votes
1
answer
31
views
How to access and manipulate tables when using native unit tests?
I am trying to write unit tests for functions in a smart contract that require access to tables within the smart contract. I tried to set this up using the hello_test.cpp code as a base and when I get ...
- 4,744
0
votes
1
answer
105
views
How do I record LOG in eosio smart contract?
I deployed and tested eosio smart contract. I want to record the logs of a smart contract using the web API. How can I do this? I searched but didn't get any satisfying answer. I tried to get logs by ...
- 307
0
votes
1
answer
36
views
Question cost while using token contract
I am sorry to bother you, I am a little confused about the cost while using a token contract:
the contract provider will pay all the utilities if a user using the contract including the CPU, NET and ...
- 1
1
vote
1
answer
129
views
cleos data getting inserted and deleted but table shows empty record
I have written one smart contract for insert, update and delete data. The smart contract is compiled and deployed to the two accounts. I insert data using calling the action upsert, this transaction ...
- 307
0
votes
1
answer
59
views
make inline transfer contract and using it on jungle testnet
hello everyone i am faceing a problem on jungle testnet i am trying to make a inline transfer
but i got this error after i work with the api_endpoint
the code is
#include <eosio/eosio.hpp>
#...
- 11
3
votes
1
answer
67
views
Where is the smart contract is stored
I would like to know where the smart contract is stored after the copilation and deployment.
Thanks
- 53
4
votes
1
answer
70
views
Trying to execute a smartcontract action using a multisig account, but it shows executed even when the transc fails due to smartcontract constraints
I'm proposing a transaction to execute an action of some smartcontract, the transaction is showing executed irrespective of failure or success of the smartcontract action(say transferFunds), this is ...
- 235
1
vote
1
answer
46
views
Eos-sharp jungle Error 3090003 when trying to call external smart contract
I’m trying to achieve something quite simple.
I try to call eosio.token transfer from one of my smartContract (lomtaxjungle dopurchase), but after severals days i still don’t manage to do it.
From ...
0
votes
0
answers
22
views
Make a trade contract between two tokens like (EOS) & (SYS)
hello everyone i made a small contract that trade between two tokens using eosio.token but if i wasn't work on local test how can i have access to EOS tokens or SYS in the main net and how can i do ...
- 11
0
votes
1
answer
63
views
Declare custom structs
I am trying to create a custom struct called Student in a contract. Where do I declare or define the struct? I tried to define it in the abi file, but the file was over written when I compile the ...
0
votes
1
answer
134
views
Check public keys on contract level
Is it meanwhile possible to check the public key of an account name on contract level? (Not with Cleos)
Example: The contract contains some public keys (not the account names).
If a user performs a ...
- 3
1
vote
1
answer
238
views
What is the difference between std::string and eosio::string?
Why should I use eosio::string over std::string? What are the use cases where it would make a difference?
- 4,744
1
vote
1
answer
81
views
I have doubts about intercontract communication
I have read that:
In order to call an inline action, that is to call an action of contract A from contract B, there is a need to set some special permission. In this case, the Ram payer for the ...
- 43
1
vote
1
answer
97
views
Contract transaction cannot be found after i get result of pushSignedTransaction
I've send a contract trans on mainnet use eosjs@20, and i've tried for 4 times, every time i get a trans result, but all of them seemed been drop, i cannot find them on explorer or on chain, can any ...
- 11
0
votes
1
answer
178
views
Strange checksum256->uint64_t casting
I'm trying to cast checksum256 to uint64_t
Here is conversion code:
uint64_t checksum_to_uint64(const eosio::checksum256 & digest) {
auto checksum_bytes = digest.extract_as_byte_array()....
1
vote
1
answer
49
views
Profiling EOS.IO smart contract code
What's the best way for profiling the code of an EOS.IO smart contract?
I'd like to know what percentage of the CPU time is spent on executing each function\line (including multi index table function ...
0
votes
1
answer
97
views
Trouble using EOSIO built in crypto library (can't resolve headers)
I ran eosio-init on the newest CDT (1.7) and made a -bare project.
newtest.cpp
#include "newtest.hpp"
ACTION newtest::hi( name nm ) {
/* fill in action body */
print_f("Name : %\n",nm);
}
...
- 33
0
votes
1
answer
128
views
Is there way to retrieve auto incremented primary key after submission of transaction?
I'm working on sample dApp application to understand the working of multi_index table in EOS smart contract.
I have defined two multi_index table. The primary key of table1 is auto incremented using "...
- 1
0
votes
1
answer
89
views
How to check in my contract the incomming amount?
I would like to check in my contract the incomming amount.
I tried these:
void mycontract(name from, name to, eosio::asset quantity, std::string memo){
check( quantity.amount > 50, "must ...
- 1
0
votes
2
answers
246
views
Use UUID as primary key in multi_index
How can I use a uuid as the primary.
struct [[eosio::table]] blackboxdata {
name user;
std::string uuid;
std::string hash;
std::string sqlrequest;
uint64_t ...
- 15
0
votes
1
answer
120
views
Is it possible to see the RAM delta of a multi_index table operation, or see who is currently paying for a row in a table
My question is in the context of smart contract development, so I'm looking for solutions that work within smart contracts:
1st: Is is possible to see the RAM delta of either an individual ...
