feat(rpc): introduce FilterIter

crates/bitcoind_rpc/Cargo.toml

@@ -21,10 +21,15 @@ bitcoincore-rpc = { version = "0.19.0" }
 bdk_core = { path = "../core", version = "0.4.1", default-features = false }
 
 [dev-dependencies]
+bdk_bitcoind_rpc = { path = "." }
 bdk_testenv = { path = "../testenv" }
 bdk_chain = { path = "../chain" }
 
 [features]
 default = ["std"]
 std = ["bitcoin/std", "bdk_core/std"]
 serde = ["bitcoin/serde", "bdk_core/serde"]
+
+[[example]]
+name = "filter_iter"
+required-features = ["std"]

crates/bitcoind_rpc/examples/README.md

@@ -0,0 +1,21 @@
+# Example bitcoind RPC sync
+
+### Simple Signet Test with FilterIter
+
+1. Start local signet bitcoind. (~8 GB space required)
+   ```
+    mkdir -p /tmp/signet/bitcoind
+    bitcoind -signet -server -fallbackfee=0.0002 -blockfilterindex -datadir=/tmp/signet/bitcoind -daemon
+    tail -f /tmp/signet/bitcoind/signet/debug.log
+   ```
+   Watch debug.log and wait for bitcoind to finish syncing.
+
+2. Set bitcoind env variables.
+   ```
+   export RPC_URL=127.0.0.1:38332
+   export RPC_COOKIE=/tmp/signet/bitcoind/signet/.cookie
+   ```
+3. Run `filter_iter` example.
+   ```
+   cargo run -p bdk_bitcoind_rpc --example filter_iter
+   ```

crates/bitcoind_rpc/examples/filter_iter.rs

@@ -0,0 +1,111 @@
+#![allow(clippy::print_stdout)]
+use std::time::Instant;
+
+use anyhow::Context;
+use bdk_bitcoind_rpc::bip158::{Event, EventInner, FilterIter};
+use bdk_chain::bitcoin::{constants::genesis_block, secp256k1::Secp256k1, Network};
+use bdk_chain::indexer::keychain_txout::KeychainTxOutIndex;
+use bdk_chain::local_chain::LocalChain;
+use bdk_chain::miniscript::Descriptor;
+use bdk_chain::{BlockId, ConfirmationBlockTime, IndexedTxGraph, SpkIterator};
+use bdk_testenv::anyhow;
+use bitcoin::Address;
+
+// This example shows how BDK chain and tx-graph structures are updated using compact
+// filters syncing. Assumes a connection can be made to a bitcoin node via environment
+// variables `RPC_URL` and `RPC_COOKIE`.
+
+// Usage: `cargo run -p bdk_bitcoind_rpc --example filter_iter`
+
+const EXTERNAL: &str = "tr([7d94197e]tprv8ZgxMBicQKsPe1chHGzaa84k1inY2nAXUL8iPSyWESPrEst4E5oCFXhPATqj5fvw34LDknJz7rtXyEC4fKoXryUdc9q87pTTzfQyv61cKdE/86'/1'/0'/0/*)#uswl2jj7";
+const INTERNAL: &str = "tr([7d94197e]tprv8ZgxMBicQKsPe1chHGzaa84k1inY2nAXUL8iPSyWESPrEst4E5oCFXhPATqj5fvw34LDknJz7rtXyEC4fKoXryUdc9q87pTTzfQyv61cKdE/86'/1'/0'/1/*)#dyt7h8zx";
+const SPK_COUNT: u32 = 25;
+const NETWORK: Network = Network::Signet;
+
+const START_HEIGHT: u32 = 170_000;
+const START_HASH: &str = "00000041c812a89f084f633e4cf47e819a2f6b1c0a15162355a930410522c99d";
+
+fn main() -> anyhow::Result<()> {
+    // Setup receiving chain and graph structures.
+    let secp = Secp256k1::new();
+    let (descriptor, _) = Descriptor::parse_descriptor(&secp, EXTERNAL)?;
+    let (change_descriptor, _) = Descriptor::parse_descriptor(&secp, INTERNAL)?;
+    let (mut chain, _) = LocalChain::from_genesis_hash(genesis_block(NETWORK).block_hash());
+    let mut graph = IndexedTxGraph::<ConfirmationBlockTime, KeychainTxOutIndex<&str>>::new({
+        let mut index = KeychainTxOutIndex::default();
+        index.insert_descriptor("external", descriptor.clone())?;
+        index.insert_descriptor("internal", change_descriptor.clone())?;
+        index
+    });
+
+    // Assume a minimum birthday height
+    let block = BlockId {
+        height: START_HEIGHT,
+        hash: START_HASH.parse()?,
+    };
+    let _ = chain.insert_block(block)?;
+
+    // Configure RPC client
+    let url = std::env::var("RPC_URL").context("must set RPC_URL")?;
+    let cookie = std::env::var("RPC_COOKIE").context("must set RPC_COOKIE")?;
+    let rpc_client =
+        bitcoincore_rpc::Client::new(&url, bitcoincore_rpc::Auth::CookieFile(cookie.into()))?;
+
+    // Initialize block emitter
+    let cp = chain.tip();
+    let start_height = cp.height();
+    let mut emitter = FilterIter::new_with_checkpoint(&rpc_client, cp);
+    for (_, desc) in graph.index.keychains() {
+        let spks = SpkIterator::new_with_range(desc, 0..SPK_COUNT).map(|(_, spk)| spk);
+        emitter.add_spks(spks);
+    }
+
+    let start = Instant::now();
+
+    // Sync
+    if let Some(tip) = emitter.get_tip()? {
+        let blocks_to_scan = tip.height - start_height;
+
+        for event in emitter.by_ref() {
+            let event = event?;
+            let curr = event.height();
+            // apply relevant blocks
+            if let Event::Block(EventInner { height, ref block }) = event {
+                let _ = graph.apply_block_relevant(block, height);
+                println!("Matched block {}", curr);
+            }
+            if curr % 1000 == 0 {
+                let progress = (curr - start_height) as f32 / blocks_to_scan as f32;
+                println!("[{:.2}%]", progress * 100.0);
+            }
+        }
+        // update chain
+        if let Some(cp) = emitter.chain_update() {
+            let _ = chain.apply_update(cp)?;
+        }
+    }
+
+    println!("\ntook: {}s", start.elapsed().as_secs());
+    println!("Local tip: {}", chain.tip().height());
+    let unspent: Vec<_> = graph
+        .graph()
+        .filter_chain_unspents(
+            &chain,
+            chain.tip().block_id(),
+            graph.index.outpoints().clone(),
+        )
+        .collect();
+    if !unspent.is_empty() {
+        println!("\nUnspent");
+        for (index, utxo) in unspent {
+            // (k, index) | value | outpoint |
+            println!("{:?} | {} | {}", index, utxo.txout.value, utxo.outpoint);
+        }
+    }
+
+    let unused_spk = graph.index.reveal_next_spk("external").unwrap().0 .1;
+    let unused_address = Address::from_script(&unused_spk, NETWORK)?;
+    println!("Next external address: {}", unused_address);
+
+    Ok(())
+}