feat(rpc)!: FilterIter API redesign

The API now consists of the methods `new` and `next`.

The local checkpoint and SPK inventory are provided to
the constructor. `next` is now responsible for locating
the point of agreement.

The next filter to fetch is determined by the `next_block_hash`
field of `GetBlockHeaderResult`. If the next header has negative
confirmations due to a reorg, we rewind the internal state until
we find a header still in the best chain.

Matched block events contain the most up to date checkpoint, so it
can be applied directly to the local chain as events are processed.

Added `Tip` variant to `Event` enum for emitting the tip
checkpoint when all blocks have been scanned.

Removed `EventInner`.

Author: ValuedMammal

crates/bitcoind_rpc/examples/filter_iter.rs

@@ -1,29 +1,28 @@
-#![allow(clippy::print_stdout)]
+#![allow(clippy::print_stdout, clippy::print_stderr)]
 use std::time::Instant;
 
 use anyhow::Context;
-use bdk_bitcoind_rpc::bip158::{Event, EventInner, FilterIter};
+use bdk_bitcoind_rpc::bip158::{Event, 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 EXTERNAL: &str = "tr([83737d5e/86'/1'/0']tpubDDR5GgtoxS8fJyjjvdahN4VzV5DV6jtbcyvVXhEKq2XtpxjxBXmxH3r8QrNbQqHg4bJM1EGkxi7Pjfkgnui9jQWqS7kxHvX6rhUeriLDKxz/0/*)";
+const INTERNAL: &str = "tr([83737d5e/86'/1'/0']tpubDDR5GgtoxS8fJyjjvdahN4VzV5DV6jtbcyvVXhEKq2XtpxjxBXmxH3r8QrNbQqHg4bJM1EGkxi7Pjfkgnui9jQWqS7kxHvX6rhUeriLDKxz/1/*)";
 const SPK_COUNT: u32 = 25;
 const NETWORK: Network = Network::Signet;
 
-const START_HEIGHT: u32 = 170_000;
-const START_HASH: &str = "00000041c812a89f084f633e4cf47e819a2f6b1c0a15162355a930410522c99d";
+const START_HEIGHT: u32 = 205_000;
+const START_HASH: &str = "0000002bd0f82f8c0c0f1e19128f84c938763641dba85c44bdb6aed1678d16cb";
 
 fn main() -> anyhow::Result<()> {
     // Setup receiving chain and graph structures.
@@ -52,38 +51,31 @@ fn main() -> anyhow::Result<()> {
     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);
+    // Initialize `FilterIter`
+    let mut spks = vec![];
     for (_, desc) in graph.index.keychains() {
-        let spks = SpkIterator::new_with_range(desc, 0..SPK_COUNT).map(|(_, spk)| spk);
-        emitter.add_spks(spks);
+        spks.extend(SpkIterator::new_with_range(desc, 0..SPK_COUNT).map(|(_, s)| s));
     }
+    let iter = FilterIter::new(&rpc_client, chain.tip(), 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 {
+    for res in iter {
+        let event = res?;
+        match event {
+            Event::NoMatch { .. } => {}
+            Event::Block { cp, ref block } => {
+                // Apply relevant tx data
+                let height = cp.height();
                 let _ = graph.apply_block_relevant(block, height);
-                println!("Matched block {curr}");
+                // Update chain tip
+                let _ = chain.apply_update(cp)?;
+                println!("Matched block {height}");
             }
-            if curr % 1000 == 0 {
-                let progress = (curr - start_height) as f32 / blocks_to_scan as f32;
-                println!("[{:.2}%]", progress * 100.0);
+            Event::Tip { cp } => {
+                let _ = chain.apply_update(cp)?;
             }
         }
-        // update chain
-        if let Some(cp) = emitter.chain_update() {
-            let _ = chain.apply_update(cp)?;
-        }
     }
 
     println!("\ntook: {}s", start.elapsed().as_secs());
@@ -105,9 +97,18 @@ fn main() -> anyhow::Result<()> {
         }
     }
 
-    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}");
+    for canon_tx in graph.graph().list_canonical_txs(
+        &chain,
+        chain.tip().block_id(),
+        bdk_chain::CanonicalizationParams::default(),
+    ) {
+        if !canon_tx.chain_position.is_confirmed() {
+            eprintln!(
+                "ERROR: canonical tx should be confirmed {}",
+                canon_tx.tx_node.txid
+            );
+        }
+    }
 
     Ok(())
 }