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Logs

The logs of a transaction are contained in the TransactionReceipt model.
There is also a helper method in the Block object (block.logs()), which retrieves all the logs for the block.
EVM-compatible Protobuf Structure - Logs
Retrieving the Logs of a Transaction
Given a TransactionTrace:
1.Get TransactionReceipt (receipt property)
2.Get logs from TransactionReceipt (receipt.logs property)
use substreams::Hex;
use substreams_ethereum::pb::eth::v2::TransactionTrace;
​
struct Log {
    address: String,
    topics: Vec<String>,
    tx_hash: String
}
​
fn transaction_logs(transaction: &TransactionTrace) -> Vec<Log> {
    return transaction.receipt.unwrap().logs
        .iter()
        .map(|log| Log {
            address: Hex::encode(log.address),
            topics: log.topics.into_iter().map(Hex::encode).collect(),
            tx_hash: Hex::encode(&transaction.hash),
        })
        .collect();
}
Retrieving the Logs of a Smart Contract
Given a Block and a smart contract address (String):
1.Use the logs() method to get all the logs for the corresponding block.
2.Filter every log by its address (address property).
use substreams::Hex;
use substreams_ethereum::pb::eth::v2::Block;
​
struct ContractLog {
    address: String,
    topics: Vec<String>,
    tx_hash: String
}
​
fn get_contract_logs(contract_address: String, blk: Block) -> Vec<ContractLog> {
    let events: Vec<ContractLog> = blk
        .logs()
        .filter(|log| log.address().to_vec() == Hex::decode(&contract_address).unwrap())
        .map(|log| ContractLog {
            address: Hex::encode(log.address()),
            topics: log.topics().into_iter().map(Hex::encode).collect(),
            tx_hash: Hex::encode(&log.receipt.transaction.hash),
        })
        .collect();
​
    return events;
}

Transactions

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Last modified 2mo ago