Add scan_blocks api

Reviewed-on: #1

.cargo/config.toml

@@ -0,0 +1,5 @@
+[build]
+target = "wasm32-unknown-unknown"
+
+[target.wasm32-unknown-unknown]
+rustflags = ["--cfg", "web_sys_unstable_apis"]

Cargo.toml

@@ -9,6 +9,7 @@ crate-type = ["lib", "cdylib"]
 
 [dependencies]
 anyhow = "1.0"
+async-trait = "0.1"
 serde = { version = "1.0.188", features = ["derive"] }
 serde_json = "1.0"
 wasm-bindgen = "0.2.91"
@@ -16,9 +17,10 @@ getrandom = { version="0.2.12", features = ["js"] }
 wasm-logger = "0.2.0"
 rand = "0.8.5"
 tsify = { git = "https://github.com/Sosthene00/tsify", branch = "next" }
-# sdk_common = { path = "../sdk_common" }
-sdk_common = { git = "https://git.4nkweb.com/4nk/sdk_common.git", branch = "dev" }
+sdk_common = { git = "https://git.4nkweb.com/4nk/sdk_common.git", branch = "dev", features = ["blindbit-wasm"] }
 serde-wasm-bindgen = "0.6.5"
+futures-util = { version = "0.3.28", default-features = false, features = ["sink", "std"] }
+web-time = "1.1.0"
 
 [dev-dependencies]
 wasm-bindgen-test = "0.3"

src/api.rs

@@ -6,7 +6,7 @@ use std::ops::Index;
 use std::str::FromStr;
 use std::string::FromUtf8Error;
 use std::sync::{Mutex, MutexGuard, OnceLock, PoisonError};
-use std::time::{Duration, Instant};
+use web_time::{Duration, Instant};
 use std::u32;
 
 use rand::{thread_rng, Fill, Rng, RngCore};
@@ -15,6 +15,7 @@ use sdk_common::aes_gcm::aes::cipher::ArrayLength;
 use sdk_common::aes_gcm::Nonce;
 use sdk_common::hash::AnkPcdHash;
 use sdk_common::log::{self, debug, info, warn};
+use sdk_common::backend_blindbit_wasm::wasm_bindgen_futures;
 
 use anyhow::{anyhow, Context};
 use anyhow::Error as AnyhowError;
@@ -68,12 +69,12 @@ use sdk_common::pcd::{
     DataType, FileBlob, Member, Pcd, PcdCommitments, RoleDefinition, Roles, ValidationRule, PCD_VERSION, PcdSerializable
 };
 use sdk_common::prd::{AnkPrdHash, Prd, PrdType};
-use sdk_common::silentpayments::{create_transaction as internal_create_transaction, sign_transaction as internal_sign_tx, TsUnsignedTransaction};
+use sdk_common::silentpayments::{create_transaction as internal_create_transaction, sign_transaction as internal_sign_tx, SpWallet, TsUnsignedTransaction};
 use sdk_common::sp_client::{FeeRate, OutputSpendStatus, OwnedOutput, Recipient, RecipientAddress, SilentPaymentUnsignedTransaction, SpClient, SpendKey};
 use sdk_common::secrets::SecretsStore;
 
 use crate::user::{lock_local_device, set_new_device, LOCAL_DEVICE};
-use crate::wallet::{generate_sp_wallet, lock_freezed_utxos, scan_blocks};
+use crate::wallet::{generate_sp_wallet, lock_freezed_utxos};
 
 const EMPTYSTATEID: &str = "0000000000000000000000000000000000000000000000000000000000000000";
 
@@ -293,6 +294,19 @@ pub fn create_new_device(birthday: u32, network_str: String) -> ApiResult<String
     Ok(our_address)
 }
 
+#[wasm_bindgen]
+pub async fn scan_blocks(tip_height: u32, blindbit_url: String) -> ApiResult<()> {
+    let local_device = lock_local_device()?;
+
+    let sp_wallet = local_device.get_sp_wallet();
+
+    let last_scan = sp_wallet.get_last_scan();
+    let n_blocks_to_scan = tip_height - last_scan;
+    crate::wallet::scan_blocks(n_blocks_to_scan, &blindbit_url, sp_wallet, tip_height, last_scan).await?;
+
+    Ok(())
+}
+
 #[wasm_bindgen]
 pub fn is_paired() -> ApiResult<bool> {
     let local_device = lock_local_device()?;
@@ -456,6 +470,7 @@ pub fn get_opreturn(transaction: String) -> ApiResult<String> {
 #[wasm_bindgen]
 pub fn process_commit_new_state(mut process: Process, state_id: String, new_tip: String) -> ApiResult<Process> {
     let state_id_array: [u8; 32] = Vec::from_hex(&state_id)?.try_into().unwrap();
+    let new_tip = OutPoint::from_str(&new_tip)?;
     let new_state: ProcessState;
     if let Ok(commited_state) = process.get_state_for_id(&state_id_array) {
         new_state = commited_state.clone();
@@ -469,7 +484,7 @@ pub fn process_commit_new_state(mut process: Process, state_id: String, new_tip:
 
     process.remove_all_concurrent_states()?;
     process.insert_concurrent_state(new_state)?;
-    process.update_states_tip(OutPoint::from_str(&new_tip)?)?;
+    process.update_states_tip(new_tip)?;
     Ok(process)
 }
 

src/lib.rs

@@ -6,3 +6,6 @@ pub mod api;
 mod peers;
 mod user;
 mod wallet;
+mod scanner;
+
+const WITH_CUTTHROUGH: bool = true;

src/scanner.rs

@@ -0,0 +1,306 @@
+use std::{collections::{HashMap, HashSet}, sync::atomic::AtomicBool};
+use web_time::{Duration, Instant};
+
+use anyhow::{bail, Result};
+use futures_util::Stream;
+use sdk_common::{backend_blindbit_wasm::{ChainBackend, SpScanner}, log::{self, info}, sp_client::{bitcoin::{absolute::Height, bip158::BlockFilter, hashes::{sha256, Hash}, secp256k1::PublicKey, Amount, BlockHash, OutPoint}, BlockData, FilterData, OutputSpendStatus, OwnedOutput, SpClient, Updater}};
+
+pub struct WasmSpScanner<'a> {
+    updater: Box<dyn Updater + Sync>,
+    backend: Box<dyn ChainBackend + Sync>,
+    client: SpClient,
+    keep_scanning: &'a AtomicBool,      // used to interrupt scanning
+    owned_outpoints: HashSet<OutPoint>, // used to scan block inputs
+}
+
+impl<'a> WasmSpScanner<'a> {
+    pub fn new(
+        client: SpClient,
+        updater: Box<dyn Updater + Sync>,
+        backend: Box<dyn ChainBackend + Sync>,
+        owned_outpoints: HashSet<OutPoint>,
+        keep_scanning: &'a AtomicBool,
+    ) -> Self {
+        log::info!("Creating WasmSpScanner");
+        Self {
+            client,
+            updater,
+            backend,
+            owned_outpoints,
+            keep_scanning,
+        }
+    }
+
+    pub async fn process_blocks(
+        &mut self,
+        start: Height,
+        end: Height,
+        block_data_stream: impl Stream<Item = Result<BlockData>> + Unpin ,
+    ) -> Result<()> {
+        use futures_util::StreamExt;
+
+        let mut update_time = Instant::now();
+        let mut stream = block_data_stream;
+
+        while let Some(blockdata) = stream.next().await {
+            let blockdata = blockdata?;
+            let blkheight = blockdata.blkheight;
+            let blkhash = blockdata.blkhash;
+
+            // stop scanning and return if interrupted
+            if self.should_interrupt() {
+                self.save_state()?;
+                return Ok(());
+            }
+
+            let mut save_to_storage = false;
+
+            // always save on last block or after 30 seconds since last save
+            if blkheight == end || update_time.elapsed() > Duration::from_secs(30) {
+                save_to_storage = true;
+            }
+
+            let (found_outputs, found_inputs) = self.process_block(blockdata).await?;
+
+            if !found_outputs.is_empty() {
+                save_to_storage = true;
+                self.record_outputs(blkheight, blkhash, found_outputs)?;
+            }
+
+            if !found_inputs.is_empty() {
+                save_to_storage = true;
+                self.record_inputs(blkheight, blkhash, found_inputs)?;
+            }
+
+            // tell the updater we scanned this block
+            self.record_progress(start, blkheight, end)?;
+
+            if save_to_storage {
+                self.save_state()?;
+                update_time = Instant::now();
+            }
+        }
+
+        Ok(())
+    }
+}
+
+#[async_trait::async_trait(?Send)]
+impl<'a> SpScanner for WasmSpScanner<'a> {
+    async fn scan_blocks(
+        &mut self,
+        start: Height,
+        end: Height,
+        dust_limit: Amount,
+        with_cutthrough: bool,
+    ) -> Result<()> {
+        if start > end {
+            bail!("bigger start than end: {} > {}", start, end);
+        }
+
+        info!("start: {} end: {}", start, end);
+        let start_time= web_time::Instant::now();
+
+        // get block data stream
+        let range = start.to_consensus_u32()..=end.to_consensus_u32();
+        let block_data_stream = self.get_block_data_stream(range, dust_limit, with_cutthrough);
+
+        // process blocks using block data stream
+        self.process_blocks(start, end, block_data_stream).await?;
+
+        // time elapsed for the scan
+        info!(
+            "Blindbit scan complete in {} seconds",
+            start_time.elapsed().as_secs()
+        );
+
+        Ok(())
+    }
+
+    async fn process_block(
+        &mut self,
+        blockdata: BlockData,
+    ) -> Result<(HashMap<OutPoint, OwnedOutput>, HashSet<OutPoint>)> {
+        let BlockData {
+            blkheight,
+            tweaks,
+            new_utxo_filter,
+            spent_filter,
+            ..
+        } = blockdata;
+
+        let outs = self
+            .process_block_outputs(blkheight, tweaks, new_utxo_filter)
+            .await?;
+
+        // after processing outputs, we add the found outputs to our list
+        self.owned_outpoints.extend(outs.keys());
+
+        let ins = self.process_block_inputs(blkheight, spent_filter).await?;
+
+        // after processing inputs, we remove the found inputs
+        self.owned_outpoints.retain(|item| !ins.contains(item));
+
+        Ok((outs, ins))
+    }
+
+    async fn process_block_outputs(
+        &self,
+        blkheight: Height,
+        tweaks: Vec<PublicKey>,
+        new_utxo_filter: FilterData,
+    ) -> Result<HashMap<OutPoint, OwnedOutput>> {
+        let mut res = HashMap::new();
+
+        if !tweaks.is_empty() {
+            let secrets_map = self.client.get_script_to_secret_map(tweaks)?;
+
+            //last_scan = last_scan.max(n as u32);
+            let candidate_spks: Vec<&[u8; 34]> = secrets_map.keys().collect();
+
+            //get block gcs & check match
+            let blkfilter = BlockFilter::new(&new_utxo_filter.data);
+            let blkhash = new_utxo_filter.block_hash;
+
+            let matched_outputs = Self::check_block_outputs(blkfilter, blkhash, candidate_spks)?;
+
+            //if match: fetch and scan utxos
+            if matched_outputs {
+                info!("matched outputs on: {}", blkheight);
+                let found = self.scan_utxos(blkheight, secrets_map).await?;
+
+                if !found.is_empty() {
+                    for (label, utxo, tweak) in found {
+                        let outpoint = OutPoint {
+                            txid: utxo.txid,
+                            vout: utxo.vout,
+                        };
+
+                        let out = OwnedOutput {
+                            blockheight: blkheight,
+                            tweak: tweak.to_be_bytes(),
+                            amount: utxo.value,
+                            script: utxo.scriptpubkey,
+                            label,
+                            spend_status: OutputSpendStatus::Unspent,
+                        };
+
+                        res.insert(outpoint, out);
+                    }
+                }
+            }
+        }
+        Ok(res)
+    }
+
+    async fn process_block_inputs(
+        &self,
+        blkheight: Height,
+        spent_filter: FilterData,
+    ) -> Result<HashSet<OutPoint>> {
+        let mut res = HashSet::new();
+
+        let blkhash = spent_filter.block_hash;
+
+        // first get the 8-byte hashes used to construct the input filter
+        let input_hashes_map = self.get_input_hashes(blkhash)?;
+
+        // check against filter
+        let blkfilter = BlockFilter::new(&spent_filter.data);
+        let matched_inputs = self.check_block_inputs(
+            blkfilter,
+            blkhash,
+            input_hashes_map.keys().cloned().collect(),
+        )?;
+
+        // if match: download spent data, collect the outpoints that are spent
+        if matched_inputs {
+            info!("matched inputs on: {}", blkheight);
+            let spent = self.backend.spent_index(blkheight).await?.data;
+
+            for spent in spent {
+                let hex: &[u8] = spent.as_ref();
+
+                if let Some(outpoint) = input_hashes_map.get(hex) {
+                    res.insert(*outpoint);
+                }
+            }
+        }
+        Ok(res)
+    }
+
+    fn get_block_data_stream(
+        &self,
+        range: std::ops::RangeInclusive<u32>,
+        dust_limit: Amount,
+        with_cutthrough: bool,
+    ) -> std::pin::Pin<Box<dyn Stream<Item = Result<BlockData>>>> {
+        self.backend
+            .get_block_data_for_range(range, dust_limit, with_cutthrough)
+    }
+
+    fn should_interrupt(&self) -> bool {
+        !self
+            .keep_scanning
+            .load(std::sync::atomic::Ordering::Relaxed)
+    }
+
+    fn save_state(&mut self) -> Result<()> {
+        self.updater.save_to_persistent_storage()
+    }
+
+    fn record_outputs(
+        &mut self,
+        height: Height,
+        block_hash: BlockHash,
+        outputs: HashMap<OutPoint, OwnedOutput>,
+    ) -> Result<()> {
+        self.updater
+            .record_block_outputs(height, block_hash, outputs)
+    }
+
+    fn record_inputs(
+        &mut self,
+        height: Height,
+        block_hash: BlockHash,
+        inputs: HashSet<OutPoint>,
+    ) -> Result<()> {
+        self.updater.record_block_inputs(height, block_hash, inputs)
+    }
+
+    fn record_progress(&mut self, start: Height, current: Height, end: Height) -> Result<()> {
+        self.updater.record_scan_progress(start, current, end)
+    }
+
+    fn client(&self) -> &SpClient {
+        &self.client
+    }
+
+    fn backend(&self) -> &dyn ChainBackend {
+        self.backend.as_ref()
+    }
+
+    fn updater(&mut self) -> &mut dyn Updater {
+        self.updater.as_mut()
+    }
+
+    // Override the default get_input_hashes implementation to use owned_outpoints
+    fn get_input_hashes(&self, blkhash: BlockHash) -> Result<HashMap<[u8; 8], OutPoint>> {
+        let mut map: HashMap<[u8; 8], OutPoint> = HashMap::new();
+
+        for outpoint in &self.owned_outpoints {
+            let mut arr = [0u8; 68];
+            arr[..32].copy_from_slice(&outpoint.txid.to_raw_hash().to_byte_array());
+            arr[32..36].copy_from_slice(&outpoint.vout.to_le_bytes());
+            arr[36..].copy_from_slice(&blkhash.to_byte_array());
+            let hash = sha256::Hash::hash(&arr);
+
+            let mut res = [0u8; 8];
+            res.copy_from_slice(&hash[..8]);
+
+            map.insert(res, outpoint.clone());
+        }
+
+        Ok(map)
+    }
+}

src/wallet.rs

@@ -1,17 +1,18 @@
 use std::{
     collections::HashSet,
-    sync::{Mutex, MutexGuard, OnceLock},
+    sync::{atomic::AtomicBool, Arc, Mutex, MutexGuard, OnceLock},
 };
+use web_time::Instant;
 
 use anyhow::Error;
 use rand::Rng;
-use sdk_common::sp_client::{
-    bitcoin::{secp256k1::SecretKey, Network, OutPoint},
+use sdk_common::{backend_blindbit_wasm::{BlindbitBackend, SpScanner}, log, silentpayments::SpWallet, sp_client::{
+    bitcoin::{absolute::Height, secp256k1::SecretKey, Amount, Network, OutPoint},
     silentpayments::SilentPaymentAddress,
     SpClient, SpendKey,
-};
+}, updates::StateUpdater};
 
-use crate::MutexExt;
+use crate::{scanner::WasmSpScanner, MutexExt, WITH_CUTTHROUGH};
 
 pub static FREEZED_UTXOS: OnceLock<Mutex<HashSet<OutPoint>>> = OnceLock::new();
 
@@ -29,3 +30,59 @@ pub fn generate_sp_wallet(network: Network) -> anyhow::Result<SpClient> {
         network,
     )
 }
+
+pub async fn scan_blocks(mut n_blocks_to_scan: u32, blindbit_url: &str, sp_wallet: &SpWallet, tip_height: u32, scan_height: u32) -> anyhow::Result<()> {
+    log::info!("Starting a rescan");
+
+    // 0 means scan to tip
+    if n_blocks_to_scan == 0 {
+        n_blocks_to_scan = tip_height - scan_height;
+    }
+
+    let start = scan_height + 1;
+    let end = if scan_height + n_blocks_to_scan <= tip_height {
+        scan_height + n_blocks_to_scan
+    } else {
+        tip_height
+    };
+
+    if start > end {
+        return Ok(());
+    }
+
+    let updater = StateUpdater::new();
+    let backend = BlindbitBackend::new(blindbit_url.to_string())?;
+
+    let owned_outpoints = sp_wallet.get_unspent_outputs().keys().map(|o| *o).collect();
+
+    let keep_scanning = Arc::new(AtomicBool::new(true));
+
+    log::info!("start: {} end: {}", start, end);
+    let start_time = Instant::now();
+    log::info!("{:?}", start_time);
+    let mut scanner = WasmSpScanner::new(
+        sp_wallet.get_sp_client().clone(),
+        Box::new(updater),
+        Box::new(backend),
+        owned_outpoints,
+        &keep_scanning,
+    );
+
+    let dust_limit = Amount::from_sat(0); // We don't really have a dust limit for this use case
+    scanner
+        .scan_blocks(
+            Height::from_consensus(start)?,
+            Height::from_consensus(end)?,
+            dust_limit,
+            WITH_CUTTHROUGH,
+        )
+        .await?;
+
+    // time elapsed for the scan
+    log::info!(
+        "Scan complete in {} seconds",
+        start_time.elapsed().as_secs()
+    );
+
+    Ok(())
+}