listen to mempool txs using zmq

mempool-listen.rs

extern crate zmq;
extern crate bitcoin;

use bitcoin::consensus::encode::deserialize;
use bitcoin::Transaction;

fn main() {
    // Initialize a new ZeroMQ context
    let context = zmq::Context::new();

    // Create a subscriber socket
    let subscriber = context.socket(zmq::SUB).expect("Failed to create subscriber socket");

    // Connect to the ZMQ publisher
    subscriber.connect("tcp://127.0.0.1:28332").expect("Failed to connect to the ZMQ publisher");

    // Subscribe to the raw transaction topic
    subscriber.set_subscribe(b"rawtx").expect("Failed to subscribe to the rawtx topic");

    println!("Listening for raw transactions...");

    // Infinite loop to continuously listen for new messages
    loop {
        // Receive the topic
        let topic = subscriber.recv_string(0).expect("Failed to receive topic").unwrap();
        
        // Ensure we are processing the correct topic
        if topic != "rawtx" {
            continue;
        }

        // Receive the message from the publisher
        let msg = subscriber.recv_bytes(0).expect("Failed to receive message");

        // Deserialize the raw transaction bytes
        match deserialize::<Transaction>(&msg) {
            Ok(tx) => {
                // println!("Received raw transaction: {:#?}", tx);
                // Print transaction details
                print_transaction(&tx);
            }
            Err(e) => {
                println!("Failed to deserialize transaction: {}", e);
            }
        }
    }
}

fn print_transaction(tx: &Transaction) {
    println!("Transaction ID: {}", tx.txid());
    // println!("Version: {}", tx.version);
    // println!("Lock Time: {}", tx.lock_time);
    // println!("Inputs:");
    // for input in &tx.input {
    //     println!("  Previous Output: {}", input.previous_output);
    //     println!("  Script Sig: {:?}", input.script_sig);
    //     println!("  Sequence: {}", input.sequence);
    // }
    // println!("Outputs:");
    // for output in &tx.output {
    //     println!("  Value: {}", output.value);
    //     println!("  Script PubKey: {:?}", output.script_pubkey);
    // }
}

Cargo.toml

[dependencies]
zmq = "0.9"
bitcoin = "0.28.0"

bitcoin.conf

zmqpubrawtx=tcp://127.0.0.1:28332