Merge rust-bitcoin/rust-bitcoin#2010: Use weight type for stripped_size

55e94b5dea Remove test from test names for Weight type (yancy)
142dde64c3 Use Weight type for stripped_size (yancy)
cb76f3ec43 Add scale_by_witness_factor to Weight type (yancy)
38c9e9947e Add witness scale factor to the Weight type (yancy)
77552987ab Add from_wu_usize to Weight type (yancy)
1a88c887f5 Rename strippedsize to stripped_size (yancy)
3369257c75 Fix grammar (yancy)

Pull request description:

  Return Weight type for the strippedize function.

ACKs for top commit:
  apoelstra:
    ACK 55e94b5dea
  tcharding:
    ACK 55e94b5dea

Tree-SHA512: ad3e4bc29380f22e20a6302c1b24c201c772be759c655c62ba4717840a01fcaa36f0f8442c9a3ba71c6400d6af47a9a815e6d90877b5f14c6883fb950b9669fd

bitcoin/src/blockdata/block.rs

@@ -287,9 +287,16 @@ impl Block {
     }
 
     /// Returns the stripped size of the block.
-    pub fn strippedsize(&self) -> usize {
-        let txs_size: usize = self.txdata.iter().map(Transaction::strippedsize).sum();
-        self.base_size() + txs_size
+    #[deprecated(
+        since = "0.31.0",
+        note = "Truncates on 32-bit machines, Use Block::stripped_size() instead"
+    )]
+    pub fn strippedsize(&self) -> usize { Self::stripped_size(self).to_wu() as usize }
+
+    /// Returns the stripped size of the block.
+    pub fn stripped_size(&self) -> Weight {
+        let txs_size: Weight = self.txdata.iter().map(Transaction::stripped_size).sum();
+        Weight::from_wu_usize(self.base_size()) + txs_size
     }
 
     /// Returns the weight of the block.
@@ -481,7 +488,7 @@ mod tests {
         // [test] TODO: check the transaction data
 
         assert_eq!(real_decode.size(), some_block.len());
-        assert_eq!(real_decode.strippedsize(), some_block.len());
+        assert_eq!(real_decode.stripped_size(), Weight::from_wu_usize(some_block.len()));
         assert_eq!(
             real_decode.weight(),
             Weight::from_non_witness_data_size(some_block.len() as u64)
@@ -523,7 +530,7 @@ mod tests {
         // [test] TODO: check the transaction data
 
         assert_eq!(real_decode.size(), segwit_block.len());
-        assert_eq!(real_decode.strippedsize(), 4283);
+        assert_eq!(real_decode.stripped_size(), Weight::from_wu(4283));
         assert_eq!(real_decode.weight(), Weight::from_wu(17168));
 
         assert!(real_decode.check_witness_commitment());

bitcoin/src/blockdata/transaction.rs

@@ -711,28 +711,32 @@ impl Transaction {
     }
 
     /// Returns the size of this transaction excluding the witness data.
-    pub fn strippedsize(&self) -> usize {
-        let mut input_size = 0;
+    #[deprecated(since = "0.31.0", note = "Use Transaction::stripped_size() instead")]
+    pub fn strippedsize(&self) -> usize { Self::stripped_size(self).to_wu() as usize }
+
+    /// Returns the size of this transaction excluding the witness data.
+    pub fn stripped_size(&self) -> Weight {
+        let mut input_size: Weight = Weight::ZERO;
         for input in &self.input {
-            input_size += TxIn::BASE_WEIGHT.to_wu() as usize
-                + VarInt(input.script_sig.len() as u64).len()
-                + input.script_sig.len();
+            input_size += TxIn::BASE_WEIGHT
+                + Weight::from_wu_usize(VarInt(input.script_sig.len() as u64).len())
+                + Weight::from_wu_usize(input.script_sig.len());
         }
-        let mut output_size = 0;
+        let mut output_size = Weight::ZERO;
         for output in &self.output {
-            output_size += 8 + // value
-                VarInt(output.script_pubkey.len() as u64).len() +
-                output.script_pubkey.len();
+            output_size += Weight::from_wu(8)+ // value
+                Weight::from_wu_usize(VarInt(output.script_pubkey.len() as u64).len()) +
+                Weight::from_wu_usize(output.script_pubkey.len());
         }
-        let non_input_size =
+        let non_input_size: Weight =
         // version:
-        4 +
+        Weight::from_wu(4)+
         // count varints:
-        VarInt(self.input.len() as u64).len() +
-        VarInt(self.output.len() as u64).len() +
+        Weight::from_wu_usize(VarInt(self.input.len() as u64).len()) +
+        Weight::from_wu_usize(VarInt(self.output.len() as u64).len()) +
         output_size +
         // lock_time
-        4;
+        Weight::from_wu(4);
         non_input_size + input_size
     }
 
@@ -1392,7 +1396,7 @@ mod tests {
         assert_eq!(realtx.weight().to_wu() as usize, tx_bytes.len() * WITNESS_SCALE_FACTOR);
         assert_eq!(realtx.size(), tx_bytes.len());
         assert_eq!(realtx.vsize(), tx_bytes.len());
-        assert_eq!(realtx.strippedsize(), tx_bytes.len());
+        assert_eq!(realtx.stripped_size(), Weight::from_wu_usize(tx_bytes.len()));
     }
 
     #[test]
@@ -1438,19 +1442,21 @@ mod tests {
         //     weight = WITNESS_SCALE_FACTOR * stripped_size + witness_size
         // then,
         //     stripped_size = (weight - size) / (WITNESS_SCALE_FACTOR - 1)
-        let expected_strippedsize =
-            (EXPECTED_WEIGHT.to_wu() as usize - tx_bytes.len()) / (WITNESS_SCALE_FACTOR - 1);
-        assert_eq!(realtx.strippedsize(), expected_strippedsize);
+        let expected_strippedsize: Weight = Weight::from_wu(
+            (EXPECTED_WEIGHT - Weight::from_wu_usize(tx_bytes.len()))
+                / (Weight::from_wu_usize(WITNESS_SCALE_FACTOR - 1)),
+        );
+        assert_eq!(realtx.stripped_size(), expected_strippedsize);
         // Construct a transaction without the witness data.
         let mut tx_without_witness = realtx;
         tx_without_witness.input.iter_mut().for_each(|input| input.witness.clear());
         assert_eq!(
-            tx_without_witness.weight().to_wu() as usize,
-            expected_strippedsize * WITNESS_SCALE_FACTOR
+            tx_without_witness.weight(),
+            expected_strippedsize.scale_by_witness_factor().unwrap()
         );
-        assert_eq!(tx_without_witness.size(), expected_strippedsize);
-        assert_eq!(tx_without_witness.vsize(), expected_strippedsize);
-        assert_eq!(tx_without_witness.strippedsize(), expected_strippedsize);
+        assert_eq!(Weight::from_wu_usize(tx_without_witness.size()), expected_strippedsize);
+        assert_eq!(Weight::from_wu_usize(tx_without_witness.vsize()), expected_strippedsize);
+        assert_eq!(tx_without_witness.stripped_size(), expected_strippedsize);
     }
 
     // We temporarily abuse `Transaction` for testing consensus serde adapter.

bitcoin/src/blockdata/weight.rs

@@ -31,22 +31,30 @@ impl Weight {
     /// Maximum possible value.
     pub const MAX: Weight = Weight(u64::MAX);
 
+    /// The factor that non-witness serialization data is multiplied by during weight calculation.
+    pub const WITNESS_SCALE_FACTOR: u64 = crate::blockdata::constants::WITNESS_SCALE_FACTOR as u64;
+
     /// The maximum allowed weight for a block, see BIP 141 (network rule).
     pub const MAX_BLOCK: Weight = Weight(4_000_000);
 
     /// The minimum transaction weight for a valid serialized transaction.
-    pub const MIN_TRANSACTION: Weight = Weight(4 * 60);
+    pub const MIN_TRANSACTION: Weight = Weight(Self::WITNESS_SCALE_FACTOR * 60);
 
     /// Directly constructs `Weight` from weight units.
     pub const fn from_wu(wu: u64) -> Self { Weight(wu) }
 
-    /// Constructs `Weight` from kilo weight units returning `None` if overflow occurred.
+    /// Directly constructs `Weight` from usize weight units.
+    pub const fn from_wu_usize(wu: usize) -> Self { Weight(wu as u64) }
+
+    /// Constructs `Weight` from kilo weight units returning `None` if an overflow occurred.
     pub fn from_kwu(wu: u64) -> Option<Self> { wu.checked_mul(1000).map(Weight) }
 
     /// Constructs `Weight` from virtual bytes, returning `None` on overflow.
-    pub fn from_vb(vb: u64) -> Option<Self> { vb.checked_mul(4).map(Weight::from_wu) }
+    pub fn from_vb(vb: u64) -> Option<Self> {
+        vb.checked_mul(Self::WITNESS_SCALE_FACTOR).map(Weight::from_wu)
+    }
 
-    /// Constructs `Weight` from virtual bytes without overflow check.
+    /// Constructs `Weight` from virtual bytes without an overflow check.
     pub const fn from_vb_unchecked(vb: u64) -> Self { Weight::from_wu(vb * 4) }
 
     /// Constructs `Weight` from witness size.
@@ -54,7 +62,7 @@ impl Weight {
 
     /// Constructs `Weight` from non-witness size.
     pub const fn from_non_witness_data_size(non_witness_size: u64) -> Self {
-        Weight(non_witness_size * 4)
+        Weight(non_witness_size * Self::WITNESS_SCALE_FACTOR)
     }
 
     /// Returns raw weight units.
@@ -66,30 +74,39 @@ impl Weight {
     pub const fn to_kwu_floor(self) -> u64 { self.0 / 1000 }
 
     /// Converts to vB rounding down.
-    pub const fn to_vbytes_floor(self) -> u64 { self.0 / 4 }
+    pub const fn to_vbytes_floor(self) -> u64 { self.0 / Self::WITNESS_SCALE_FACTOR }
 
     /// Converts to vB rounding up.
-    pub const fn to_vbytes_ceil(self) -> u64 { (self.0 + 3) / 4 }
+    pub const fn to_vbytes_ceil(self) -> u64 {
+        (self.0 + Self::WITNESS_SCALE_FACTOR - 1) / Self::WITNESS_SCALE_FACTOR
+    }
 
     /// Checked addition.
     ///
-    /// Computes `self + rhs` returning `None` if overflow occurred.
+    /// Computes `self + rhs` returning `None` if an overflow occurred.
     pub fn checked_add(self, rhs: Self) -> Option<Self> { self.0.checked_add(rhs.0).map(Self) }
 
     /// Checked subtraction.
     ///
-    /// Computes `self - rhs` returning `None` if overflow occurred.
+    /// Computes `self - rhs` returning `None` if an overflow occurred.
     pub fn checked_sub(self, rhs: Self) -> Option<Self> { self.0.checked_sub(rhs.0).map(Self) }
 
     /// Checked multiplication.
     ///
-    /// Computes `self * rhs` returning `None` if overflow occurred.
+    /// Computes `self * rhs` returning `None` if an overflow occurred.
     pub fn checked_mul(self, rhs: u64) -> Option<Self> { self.0.checked_mul(rhs).map(Self) }
 
     /// Checked division.
     ///
     /// Computes `self / rhs` returning `None` if `rhs == 0`.
     pub fn checked_div(self, rhs: u64) -> Option<Self> { self.0.checked_div(rhs).map(Self) }
+
+    /// Scale by witness factor.
+    ///
+    /// Computes `self * WITNESS_SCALE_FACTOR` returning `None` if an overflow occurred.
+    pub fn scale_by_witness_factor(self) -> Option<Self> {
+        Self::checked_mul(self, Self::WITNESS_SCALE_FACTOR)
+    }
 }
 
 /// Alternative will display the unit.
@@ -108,23 +125,24 @@ mod tests {
     use super::*;
 
     #[test]
-    fn weight_constructor_test() {
+    fn weight_constructor() {
         assert_eq!(Weight::ZERO, Weight::from_wu(0));
+        assert_eq!(Weight::ZERO, Weight::from_wu_usize(0_usize));
     }
 
     #[test]
-    fn kilo_weight_constructor_test() {
+    fn kilo_weight_constructor() {
         assert_eq!(Weight(1_000), Weight::from_kwu(1).expect("expected weight unit"));
     }
 
     #[test]
     #[should_panic]
-    fn kilo_weight_constructor_panic_test() {
+    fn kilo_weight_constructor_panic() {
         Weight::from_kwu(u64::MAX).expect("expected weight unit");
     }
 
     #[test]
-    fn from_vb_test() {
+    fn from_vb() {
         let vb = Weight::from_vb(1).expect("expected weight unit");
         assert_eq!(Weight(4), vb);
 
@@ -133,45 +151,45 @@ mod tests {
     }
 
     #[test]
-    fn from_vb_unchecked_test() {
+    fn from_vb_unchecked() {
         let vb = Weight::from_vb_unchecked(1);
         assert_eq!(Weight(4), vb);
     }
 
     #[test]
     #[should_panic]
-    fn from_vb_unchecked_panic_test() { Weight::from_vb_unchecked(u64::MAX); }
+    fn from_vb_unchecked_panic() { Weight::from_vb_unchecked(u64::MAX); }
 
     #[test]
-    fn from_witness_data_size_test() {
+    fn from_witness_data_size() {
         let witness_data_size = 1;
         assert_eq!(Weight(witness_data_size), Weight::from_witness_data_size(witness_data_size));
     }
 
     #[test]
-    fn from_non_witness_data_size_test() {
+    fn from_non_witness_data_size() {
         assert_eq!(Weight(4), Weight::from_non_witness_data_size(1));
     }
 
     #[test]
-    fn to_kwu_floor_test() {
+    fn to_kwu_floor() {
         assert_eq!(1, Weight(1_000).to_kwu_floor());
     }
 
     #[test]
-    fn to_vb_floor_test() {
+    fn to_vb_floor() {
         assert_eq!(1, Weight(4).to_vbytes_floor());
         assert_eq!(1, Weight(5).to_vbytes_floor());
     }
 
     #[test]
-    fn to_vb_ceil_test() {
+    fn to_vb_ceil() {
         assert_eq!(1, Weight(4).to_vbytes_ceil());
         assert_eq!(2, Weight(5).to_vbytes_ceil());
     }
 
     #[test]
-    fn checked_add_test() {
+    fn checked_add() {
         let result = Weight(1).checked_add(Weight(1)).expect("expected weight unit");
         assert_eq!(Weight(2), result);
 
@@ -180,7 +198,7 @@ mod tests {
     }
 
     #[test]
-    fn checked_sub_test() {
+    fn checked_sub() {
         let result = Weight(1).checked_sub(Weight(1)).expect("expected weight unit");
         assert_eq!(Weight::ZERO, result);
 
@@ -189,7 +207,7 @@ mod tests {
     }
 
     #[test]
-    fn checked_mul_test() {
+    fn checked_mul() {
         let result = Weight(2).checked_mul(2).expect("expected weight unit");
         assert_eq!(Weight(4), result);
 
@@ -198,13 +216,22 @@ mod tests {
     }
 
     #[test]
-    fn checked_div_test() {
+    fn checked_div() {
         let result = Weight(2).checked_div(2).expect("expected weight unit");
         assert_eq!(Weight(1), result);
 
         let result = Weight(2).checked_div(0);
         assert_eq!(None, result);
     }
+
+    #[test]
+    fn scale_by_witness_factor() {
+        let result = Weight(1).scale_by_witness_factor().expect("expected weight unit");
+        assert_eq!(Weight(4), result);
+
+        let result = Weight::MAX.scale_by_witness_factor();
+        assert_eq!(None, result);
+    }
 }
 
 impl From<Weight> for u64 {