Merge pull request #2427 from TheBlueMatt/2023-07-cut-116

[rust-lightning] / lightning-block-sync / src / poll.rs

diff --git a/lightning-block-sync/src/poll.rs b/lightning-block-sync/src/poll.rs
index d45e900bad0b3733da3335cd9415001bd4c9a558..e7171cf3656138036d50385691c96e419db29bcd 100644 (file)
--- a/lightning-block-sync/src/poll.rs
+++ b/lightning-block-sync/src/poll.rs
@@ -4,6 +4,7 @@ use crate::{AsyncBlockSourceResult, BlockData, BlockHeaderData, BlockSource, Blo
 
 use bitcoin::hash_types::BlockHash;
 use bitcoin::network::constants::Network;
+use lightning::chain::BestBlock;
 
 use std::ops::Deref;
 
@@ -60,7 +61,7 @@ impl Validate for BlockHeaderData {
        fn validate(self, block_hash: BlockHash) -> BlockSourceResult<Self::T> {
                let pow_valid_block_hash = self.header
                        .validate_pow(&self.header.target())
-                       .or_else(|e| Err(BlockSourceError::persistent(e)))?;
+                       .map_err(BlockSourceError::persistent)?;
 
                if pow_valid_block_hash != block_hash {
                        return Err(BlockSourceError::persistent("invalid block hash"));
@@ -81,7 +82,7 @@ impl Validate for BlockData {
 
                let pow_valid_block_hash = header
                        .validate_pow(&header.target())
-                       .or_else(|e| Err(BlockSourceError::persistent(e)))?;
+                       .map_err(BlockSourceError::persistent)?;
 
                if pow_valid_block_hash != block_hash {
                        return Err(BlockSourceError::persistent("invalid block hash"));
@@ -135,8 +136,11 @@ impl ValidatedBlockHeader {
 
                if let Network::Bitcoin = network {
                        if self.height % 2016 == 0 {
-                               let previous_work = previous_header.header.work();
-                               if work > (previous_work << 2) || work < (previous_work >> 2) {
+                               let target = self.header.target();
+                               let previous_target = previous_header.header.target();
+                               let min_target = previous_target >> 2;
+                               let max_target = previous_target << 2;
+                               if target > max_target || target < min_target {
                                        return Err(BlockSourceError::persistent("invalid difficulty transition"))
                                }
                        } else if self.header.bits != previous_header.header.bits {
@@ -146,6 +150,19 @@ impl ValidatedBlockHeader {
 
                Ok(())
        }
+
+    /// Returns the [`BestBlock`] corresponding to this validated block header, which can be passed
+    /// into [`ChannelManager::new`] as part of its [`ChainParameters`]. Useful for ensuring that
+    /// the [`SpvClient`] and [`ChannelManager`] are initialized to the same block during a fresh
+    /// start.
+    ///
+    /// [`SpvClient`]: crate::SpvClient
+    /// [`ChainParameters`]: lightning::ln::channelmanager::ChainParameters
+    /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
+    /// [`ChannelManager::new`]: lightning::ln::channelmanager::ChannelManager::new
+    pub fn to_best_block(&self) -> BestBlock {
+        BestBlock::new(self.block_hash, self.inner.height)
+    }
 }
 
 /// A block with validated data against its transaction list and corresponding block hash.