Work constants are incorrect #2103
Description
Work and Target have an inverse relationship, so min work should equal max target.
println!("{:?}", Target::MAX.to_work());
println!("{:?}", Work::MAINNET_MIN.to_target());
println!("{:?}", Target::MAX);
println!("{:?}", Work::MAINNET_MIN);
println!("{:?}", Work::MAINNET_MIN.to_target().to_compact_lossy().to_consensus());
println!("{:?}", Target::MAX.to_compact_lossy().to_consensus());Expected:
Work(0x0000000000000000000000000000000000000000000000000000000100010000)
Target(0x00000000ffff00000000ffff00000000ffff00000000ffff00000000fffeffff)
Target(0x00000000ffff0000000000000000000000000000000000000000000000000000)
Work(0x0000000000000000000000000000000000000000000000000000000100010000)
486604799
486604799
Got:
Work(0x0000000000000000000000000000000000000000000000000000000100010001)
Target(0x0000000000000000000000000000000000000000000000000000000100010001)
Target(0x00000000ffff0000000000000000000000000000000000000000000000000000)
Work(0x00000000ffff0000000000000000000000000000000000000000000000000000)
83951617
486604799
This diff is what got me from Got to Expected... without the fix to the inverse function, the Target was slightly off.
diff --git a/bitcoin/src/pow.rs b/bitcoin/src/pow.rs
index 99e50014..09eb9466 100644
--- a/bitcoin/src/pow.rs
+++ b/bitcoin/src/pow.rs
@@ -71,7 +71,7 @@ pub struct Work(U256);
impl Work {
/// Lowest possible work value for Mainnet. See comment on [`Params::pow_limit`] for more info.
- pub const MAINNET_MIN: Work = Work(U256(0x0000_0000_ffff_0000_0000_0000_0000_0000_u128, 0));
+ pub const MAINNET_MIN: Work = Work(U256(0, 0x100010000));
/// Lowest possible work value for Testnet. See comment on [`Params::pow_limit`] for more info.
pub const TESTNET_MIN: Work = Work(U256(0x0000_0000_ffff_0000_0000_0000_0000_0000_u128, 0));
@@ -382,8 +382,7 @@ impl U256 {
return U256::ONE;
}
- let ret = !*self / self.wrapping_inc();
- ret.wrapping_inc()
+ !*self / self.wrapping_inc()
}
#[cfg_attr(all(test, mutate), mutate)]I noticed this when making a fix PR for the next target PR.