Equivalent of eth_getLogs() in Solana?

Question

EVM based blockchains offer eth_getLogs() RPC call and provide filters (topics argument in eth_getLogs function call) to filter out the results.

Is there an equivalent in Solana RPC calls?

I am using getSignaturesForAddress() RPC call along with getTransactions() RPC to get all transaction info related to an address.

I want to filter transactions based upon which instruction handler is called from the Solana program.

Answer 1

There is no way to filter transactions based upon which function is called on a given program. The best you can do is to subscribe to logs involving a program, then to filter the logs for any mention of your target instruction.

const PROGRAM_ADDRESS = '...';
const FOREIGN_PROGRAM_INVOKE_LOG_REGEX = new RegExp(
  `^Program ((?!${PROGRAM_ADDRESS})\\w)+ invoke \\[\\d+\\]$`,
);
const TARGET_PROGRAM_INVOKE_LOG_REGEX = new RegExp(
  `^Program ${PROGRAM_ADDRESS} invoke \\[\\d+\\]$`,
);
connection.onLogs(new PublicKey(PROGRAM_ADDRESS), ({logs}) => {
  let inTargetProgramLogSection = false;
  for (const line in logs) {
    if (inTargetProgramLogSection) {
      if (FOREIGN_PROGRAM_INVOKE_LOG_REGEX.test(line)) {
        inTargetProgramLogSection = false;
      } else if (line === 'Program log: Instruction: MyInstruction') {
        // Found the target instruction. Run your code here.
        break;
      }
    } else if (TARGET_PROGRAM_INVOKE_LOG_REGEX.test(line)) {
      inTargetProgramLogSection === true;
    }
  }
});

Note that this is predicated upon the program outputting a log when your target instruction is invoked.