best way to convert `account_index` to address using rust rpc-client and JSON RPC response

Question

When using the solana-rpc-client in Rust to retrieve a transaction, the output is EncodedTransactionWithStatusMeta.

The metadata includes the following struct:

pub struct UiTransactionTokenBalance {
    pub account_index: u8,
    pub mint: String,
    pub ui_token_amount: UiTokenAmount,
    pub owner: OptionSerializer<String>,
    pub program_id: OptionSerializer<String>,
}

I'm wondering how to convert the account_index field (see UiTransactionTokenBalance into an address. Is this possible using just the transaction metadata, for example, by using loaded_addresses (refer to UiTransactionStatusMeta), or is it necessary to decode the transaction data?

Additionally, is there a way to obtain TransactionWithStatusMeta using the JSON RPC API or another protocol? What would be much pleasant to use.

Answer 1

If you want the account index, you'll need to dig into the EncodedTransaction, since none of the fields in the meta will give you the right thing. The loaded_addresses refer to addresses that were loaded from an address-lookup-table https://solana.com/docs/advanced/lookup-tables

So to get the addresses from the encoded JSON parsed tx, you'll need to do:

let accounts = match tx.encoded_transaction {
    EncodedTransaction::Json(ui_transaction) => match ui_transaction.message {
        UiMessage::Parsed(parsed_message) => parsed_message.account_keys.map(|k| k.pubkey).collect::<Vec<_>>(),
        UiMessage::Raw(raw_message) => raw_message.account_keys
    }
    _ => panic!()
};