Merge branch 'master' of https://github.com/bitcoindevkit/bdk into rpc-pruned

Author: kjain1810

CHANGELOG.md

@@ -5,7 +5,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
-
+- Add `descriptor::checksum::get_checksum_bytes` method.
+- Add `Excess` enum to handle remaining amount after coin selection.
+- Move change creation from `Wallet::create_tx` to `CoinSelectionAlgorithm::coin_select`.
+- Change the interface of `SqliteDatabase::new` to accept any type that implement AsRef<Path>
 
 ## [v0.20.0] - [v0.19.0]
 

README.md

@@ -95,6 +95,7 @@ use bdk::blockchain::ElectrumBlockchain;
 use bdk::electrum_client::Client;
 use bdk::wallet::AddressIndex::New;
 
+use bitcoin::base64;
 use bitcoin::consensus::serialize;
 
 fn main() -> Result<(), bdk::Error> {
@@ -131,6 +132,7 @@ fn main() -> Result<(), bdk::Error> {
 ```rust,no_run
 use bdk::{Wallet, SignOptions, database::MemoryDatabase};
 
+use bitcoin::base64;
 use bitcoin::consensus::deserialize;
 
 fn main() -> Result<(), bdk::Error> {
@@ -154,15 +156,15 @@ fn main() -> Result<(), bdk::Error> {
 
 ### Unit testing
 
-```
+```bash
 cargo test
 ```
 
 ### Integration testing
 
 Integration testing require testing features, for example:
 
-```
+```bash
 cargo test --features test-electrum
 ```
 

src/blockchain/esplora/reqwest.rs

@@ -213,7 +213,6 @@ impl WalletSync for EsploraBlockchain {
         };
 
         database.commit_batch(batch_update)?;
-
         Ok(())
     }
 }

src/blockchain/script_sync.rs

@@ -5,6 +5,7 @@ returns associated transactions i.e. electrum.
 #![allow(dead_code)]
 use crate::{
     database::{BatchDatabase, BatchOperations, DatabaseUtils},
+    error::MissingCachedScripts,
     wallet::time::Instant,
     BlockTime, Error, KeychainKind, LocalUtxo, TransactionDetails,
 };
@@ -34,11 +35,12 @@ pub fn start<D: BatchDatabase>(db: &D, stop_gap: usize) -> Result<Request<'_, D>
     let scripts_needed = db
         .iter_script_pubkeys(Some(keychain))?
         .into_iter()
-        .collect();
+        .collect::<VecDeque<_>>();
     let state = State::new(db);
 
     Ok(Request::Script(ScriptReq {
         state,
+        initial_scripts_needed: scripts_needed.len(),
         scripts_needed,
         script_index: 0,
         stop_gap,
@@ -50,6 +52,7 @@ pub fn start<D: BatchDatabase>(db: &D, stop_gap: usize) -> Result<Request<'_, D>
 pub struct ScriptReq<'a, D: BatchDatabase> {
     state: State<'a, D>,
     script_index: usize,
+    initial_scripts_needed: usize, // if this is 1, we assume the descriptor is not derivable
     scripts_needed: VecDeque<Script>,
     stop_gap: usize,
     keychain: KeychainKind,
@@ -113,43 +116,71 @@ impl<'a, D: BatchDatabase> ScriptReq<'a, D> {
             self.script_index += 1;
         }
 
-        for _ in txids {
-            self.scripts_needed.pop_front();
-        }
+        self.scripts_needed.drain(..txids.len());
 
-        let last_active_index = self
+        // last active index: 0 => No last active
+        let last = self
             .state
             .last_active_index
             .get(&self.keychain)
-            .map(|x| x + 1)
-            .unwrap_or(0); // so no addresses active maps to 0
-
-        Ok(
-            if self.script_index > last_active_index + self.stop_gap
-                || self.scripts_needed.is_empty()
-            {
-                debug!(
-                    "finished scanning for transactions for keychain {:?} at index {}",
-                    self.keychain, last_active_index
-                );
-                // we're done here -- check if we need to do the next keychain
-                if let Some(keychain) = self.next_keychains.pop() {
-                    self.keychain = keychain;
-                    self.script_index = 0;
-                    self.scripts_needed = self
-                        .state
-                        .db
-                        .iter_script_pubkeys(Some(keychain))?
-                        .into_iter()
-                        .collect();
-                    Request::Script(self)
-                } else {
-                    Request::Tx(TxReq { state: self.state })
-                }
-            } else {
-                Request::Script(self)
-            },
-        )
+            .map(|&l| l + 1)
+            .unwrap_or(0);
+        // remaining scripts left to check
+        let remaining = self.scripts_needed.len();
+        // difference between current index and last active index
+        let current_gap = self.script_index - last;
+
+        // this is a hack to check whether the scripts are coming from a derivable descriptor
+        // we assume for non-derivable descriptors, the initial script count is always 1
+        let is_derivable = self.initial_scripts_needed > 1;
+
+        debug!(
+            "sync: last={}, remaining={}, diff={}, stop_gap={}",
+            last, remaining, current_gap, self.stop_gap
+        );
+
+        if is_derivable {
+            if remaining > 0 {
+                // we still have scriptPubKeys to do requests for
+                return Ok(Request::Script(self));
+            }
+
+            if last > 0 && current_gap < self.stop_gap {
+                // current gap is not large enough to stop, but we are unable to keep checking since
+                // we have exhausted cached scriptPubKeys, so return error
+                let err = MissingCachedScripts {
+                    last_count: self.script_index,
+                    missing_count: self.stop_gap - current_gap,
+                };
+                return Err(Error::MissingCachedScripts(err));
+            }
+
+            // we have exhausted cached scriptPubKeys and found no txs, continue
+        }
+
+        debug!(
+            "finished scanning for txs of keychain {:?} at index {:?}",
+            self.keychain, last
+        );
+
+        if let Some(keychain) = self.next_keychains.pop() {
+            // we still have another keychain to request txs with
+            let scripts_needed = self
+                .state
+                .db
+                .iter_script_pubkeys(Some(keychain))?
+                .into_iter()
+                .collect::<VecDeque<_>>();
+
+            self.keychain = keychain;
+            self.script_index = 0;
+            self.initial_scripts_needed = scripts_needed.len();
+            self.scripts_needed = scripts_needed;
+            return Ok(Request::Script(self));
+        }
+
+        // We have finished requesting txids, let's get the actual txs.
+        Ok(Request::Tx(TxReq { state: self.state }))
     }
 }
 
@@ -294,6 +325,8 @@ struct State<'a, D> {
     tx_missing_conftime: BTreeMap<Txid, TransactionDetails>,
     /// The start of the sync
     start_time: Instant,
+    /// Missing number of scripts to cache per keychain
+    missing_script_counts: HashMap<KeychainKind, usize>,
 }
 
 impl<'a, D: BatchDatabase> State<'a, D> {
@@ -305,6 +338,7 @@ impl<'a, D: BatchDatabase> State<'a, D> {
             tx_needed: BTreeSet::default(),
             tx_missing_conftime: BTreeMap::default(),
             start_time: Instant::new(),
+            missing_script_counts: HashMap::default(),
         }
     }
     fn into_db_update(self) -> Result<D::Batch, Error> {

src/database/sqlite.rs

@@ -8,6 +8,8 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
 // You may not use this file except in accordance with one or both of these
 // licenses.
+use std::path::Path;
+use std::path::PathBuf;
 
 use bitcoin::consensus::encode::{deserialize, serialize};
 use bitcoin::hash_types::Txid;
@@ -60,17 +62,20 @@ static MIGRATIONS: &[&str] = &[
 #[derive(Debug)]
 pub struct SqliteDatabase {
     /// Path on the local filesystem to store the sqlite file
-    pub path: String,
+    pub path: PathBuf,
     /// A rusqlite connection object to the sqlite database
     pub connection: Connection,
 }
 
 impl SqliteDatabase {
     /// Instantiate a new SqliteDatabase instance by creating a connection
     /// to the database stored at path
-    pub fn new(path: String) -> Self {
+    pub fn new<T: AsRef<Path>>(path: T) -> Self {
         let connection = get_connection(&path).unwrap();
-        SqliteDatabase { path, connection }
+        SqliteDatabase {
+            path: PathBuf::from(path.as_ref()),
+            connection,
+        }
     }
     fn insert_script_pubkey(
         &self,
@@ -908,7 +913,7 @@ impl BatchDatabase for SqliteDatabase {
     }
 }
 
-pub fn get_connection(path: &str) -> Result<Connection, Error> {
+pub fn get_connection<T: AsRef<Path>>(path: &T) -> Result<Connection, Error> {
     let connection = Connection::open(path)?;
     migrate(&connection)?;
     Ok(connection)

src/descriptor/checksum.rs

@@ -14,12 +14,10 @@
 //! This module contains a re-implementation of the function used by Bitcoin Core to calculate the
 //! checksum of a descriptor
 
-use std::iter::FromIterator;
-
 use crate::descriptor::DescriptorError;
 
-const INPUT_CHARSET: &str =  "0123456789()[],'/*abcdefgh@:$%{}IJKLMNOPQRSTUVWXYZ&+-.;<=>?!^_|~ijklmnopqrstuvwxyzABCDEFGH`#\"\\ ";
-const CHECKSUM_CHARSET: &str = "qpzry9x8gf2tvdw0s3jn54khce6mua7l";
+const INPUT_CHARSET: &[u8] = b"0123456789()[],'/*abcdefgh@:$%{}IJKLMNOPQRSTUVWXYZ&+-.;<=>?!^_|~ijklmnopqrstuvwxyzABCDEFGH`#\"\\ ";
+const CHECKSUM_CHARSET: &[u8] = b"qpzry9x8gf2tvdw0s3jn54khce6mua7l";
 
 fn poly_mod(mut c: u64, val: u64) -> u64 {
     let c0 = c >> 35;
@@ -43,15 +41,17 @@ fn poly_mod(mut c: u64, val: u64) -> u64 {
     c
 }
 
-/// Compute the checksum of a descriptor
-pub fn get_checksum(desc: &str) -> Result<String, DescriptorError> {
+/// Computes the checksum bytes of a descriptor
+pub fn get_checksum_bytes(desc: &str) -> Result<[u8; 8], DescriptorError> {
     let mut c = 1;
     let mut cls = 0;
     let mut clscount = 0;
-    for ch in desc.chars() {
+
+    for ch in desc.as_bytes() {
         let pos = INPUT_CHARSET
-            .find(ch)
-            .ok_or(DescriptorError::InvalidDescriptorCharacter(ch))? as u64;
+            .iter()
+            .position(|b| b == ch)
+            .ok_or(DescriptorError::InvalidDescriptorCharacter(*ch))? as u64;
         c = poly_mod(c, pos & 31);
         cls = cls * 3 + (pos >> 5);
         clscount += 1;
@@ -67,17 +67,18 @@ pub fn get_checksum(desc: &str) -> Result<String, DescriptorError> {
     (0..8).for_each(|_| c = poly_mod(c, 0));
     c ^= 1;
 
-    let mut chars = Vec::with_capacity(8);
+    let mut checksum = [0_u8; 8];
     for j in 0..8 {
-        chars.push(
-            CHECKSUM_CHARSET
-                .chars()
-                .nth(((c >> (5 * (7 - j))) & 31) as usize)
-                .unwrap(),
-        );
+        checksum[j] = CHECKSUM_CHARSET[((c >> (5 * (7 - j))) & 31) as usize];
     }
 
-    Ok(String::from_iter(chars))
+    Ok(checksum)
+}
+
+/// Compute the checksum of a descriptor
+pub fn get_checksum(desc: &str) -> Result<String, DescriptorError> {
+    // unsafe is okay here as the checksum only uses bytes in `CHECKSUM_CHARSET`
+    get_checksum_bytes(desc).map(|b| unsafe { String::from_utf8_unchecked(b.to_vec()) })
 }
 
 #[cfg(test)]
@@ -97,17 +98,12 @@ mod test {
 
     #[test]
     fn test_get_checksum_invalid_character() {
-        let sparkle_heart = vec![240, 159, 146, 150];
-        let sparkle_heart = std::str::from_utf8(&sparkle_heart)
-            .unwrap()
-            .chars()
-            .next()
-            .unwrap();
+        let sparkle_heart = unsafe { std::str::from_utf8_unchecked(&[240, 159, 146, 150]) };
         let invalid_desc = format!("wpkh(tprv8ZgxMBicQKsPdpkqS7Eair4YxjcuuvDPNYmKX3sCniCf16tHEVrjjiSXEkFRnUH77yXc6ZcwHHcL{}fjdi5qUvw3VDfgYiH5mNsj5izuiu2N/1/2/*)", sparkle_heart);
 
         assert!(matches!(
             get_checksum(&invalid_desc).err(),
-            Some(DescriptorError::InvalidDescriptorCharacter(invalid_char)) if invalid_char == sparkle_heart
+            Some(DescriptorError::InvalidDescriptorCharacter(invalid_char)) if invalid_char == sparkle_heart.as_bytes()[0]
         ));
     }
 }

src/descriptor/error.rs

@@ -28,8 +28,8 @@ pub enum Error {
     /// Error while extracting and manipulating policies
     Policy(crate::descriptor::policy::PolicyError),
 
-    /// Invalid character found in the descriptor checksum
-    InvalidDescriptorCharacter(char),
+    /// Invalid byte found in the descriptor checksum
+    InvalidDescriptorCharacter(u8),
 
     /// BIP32 error
     Bip32(bitcoin::util::bip32::Error),

src/doctest.rs

@@ -9,6 +9,6 @@
 // You may not use this file except in accordance with one or both of these
 // licenses.
 
-#[doc(include = "../README.md")]
+#[doc = include_str!("../README.md")]
 #[cfg(doctest)]
 pub struct ReadmeDoctests;

src/error.rs

@@ -13,7 +13,7 @@ use std::fmt;
 
 use crate::bitcoin::Network;
 use crate::{descriptor, wallet, wallet::address_validator};
-use bitcoin::OutPoint;
+use bitcoin::{OutPoint, Txid};
 
 /// Errors that can be thrown by the [`Wallet`](crate::wallet::Wallet)
 #[derive(Debug)]
@@ -125,6 +125,10 @@ pub enum Error {
     //DifferentDescriptorStructure,
     //Uncapable(crate::blockchain::Capability),
     //MissingCachedAddresses,
+    /// [`crate::blockchain::WalletSync`] sync attempt failed due to missing scripts in cache which
+    /// are needed to satisfy `stop_gap`.
+    MissingCachedScripts(MissingCachedScripts),
+
     #[cfg(feature = "electrum")]
     /// Electrum client error
     Electrum(electrum_client::Error),
@@ -145,6 +149,16 @@ pub enum Error {
     Rusqlite(rusqlite::Error),
 }
 
+/// Represents the last failed [`crate::blockchain::WalletSync`] sync attempt in which we were short
+/// on cached `scriptPubKey`s.
+#[derive(Debug)]
+pub struct MissingCachedScripts {
+    /// Number of scripts in which txs were requested during last request.
+    pub last_count: usize,
+    /// Minimum number of scripts to cache more of in order to satisfy `stop_gap`.
+    pub missing_count: usize,
+}
+
 impl fmt::Display for Error {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "{:?}", self)

src/testutils/blockchain_tests.rs

@@ -743,7 +743,6 @@ macro_rules! bdk_blockchain_tests {
 
                 blockchain.broadcast(&tx1).expect("broadcasting first");
                 blockchain.broadcast(&tx2).expect("broadcasting replacement");
-
                 receiver_wallet.sync(&blockchain, SyncOptions::default()).expect("syncing receiver");
                 assert_eq!(receiver_wallet.get_balance().expect("balance"), 49_000, "should have received coins once and only once");
             }