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Merge rust-bitcoin/rust-bitcoin#6867: consensus_encoding: Flatten remaining error constructors
Public commit record
91/100 · Strong
What the developer wrote
Authored by Andrew Poelstra
Merge rust-bitcoin/rust-bitcoin#6867: consensus_encoding: Flatten remaining error constructors
234f39fd8de288bd607a47ed34ee8377f31f0351 consensus_encoding: Flatten remaining error constructors (Gaurav Chaudhary)
Pull request description:
Contributes to #6539.
Follow up on #6546 by flattening 14 remaining nested error constructions in consensus_encoding. Chained map_err calls make each conversion read from the leaf error outward, improving readability while preserving behavior and public APIs.
Crate tests, feature checks, and repository lint pass.
ACKs for top commit:
apoelstra:
ACK 234f39fd8de288bd607a47ed34ee8377f31f0351; successfully ran local tests
Tree-SHA512: 54e2b0421412c07fe2a60a4557b790f3e010897bec9d0a878e1e8b48674b2525c6ceafdb2751e9d6f4d867f30ec9e4b1f7ded65e07bea5cc28074288ed6291c6
✓ Specific, descriptive subject✓ Names a concrete action or component✓ Provides detailed explanatory context✓ Mentions testing or verification✓ Links an issue, advisory, or supporting reference
What changed, and why it matters
This commit is a pure code-style refactor. It rewrites how error values are constructed in the consensus encoding/decoding code, replacing direct nested constructor calls with chained `map_err` calls. The pull request explicitly states the goal is readability, and the behavior and public APIs are preserved. There is no security-relevant change.
Recommended action
No action required. This is a routine refactoring commit with no security implications.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The change flattens 14 nested error constructor expressions into Err(...).map_err(...) chains across compact_size.rs, decode/decoders.rs, and decode/mod.rs. This is a non-functional refactor: error types, variants, conversion logic, and public API surfaces remain identical. No bounds checks, validation logic, or control flow were altered.
Changed components
consensus_encoding/src/compact_size.rsconsensus_encoding/src/decode/decoders.rsconsensus_encoding/src/decode/mod.rsInspect captured patch +18 / −19
### consensus_encoding/src/compact_size.rs
@@ -175,10 +175,9 @@ impl Decoder for CompactSizeDecoder {
match usize::try_from(dec_value) {
Ok(nsize) if nsize <= self.limit => Ok(nsize),
- _ => Err(CompactSizeDecoderError(E::ValueExceedsLimit(LengthPrefixExceedsMaxError {
- limit: self.limit,
- value: dec_value,
- }))),
+ _ => Err(LengthPrefixExceedsMaxError { limit: self.limit, value: dec_value })
+ .map_err(E::ValueExceedsLimit)
+ .map_err(CompactSizeDecoderError),
}
}
@@ -293,23 +292,23 @@ fn compact_size_decode_u64(buf: &ArrayVec<u8, 9>) -> Result<u64, CompactSizeDeco
PREFIX_U64 => {
let x = u64::from_le_bytes(arr(payload)?);
if x < 0x100_000_000 {
- Err(CompactSizeDecoderError(E::NonMinimal { value: x }))
+ Err(E::NonMinimal { value: x }).map_err(CompactSizeDecoderError)
} else {
Ok(x)
}
}
PREFIX_U32 => {
let x = u32::from_le_bytes(arr(payload)?);
if x < 0x10000 {
- Err(CompactSizeDecoderError(E::NonMinimal { value: x.into() }))
+ Err(E::NonMinimal { value: x.into() }).map_err(CompactSizeDecoderError)
} else {
Ok(x.into())
}
}
PREFIX_U16 => {
let x = u16::from_le_bytes(arr(payload)?);
if x < 0xFD {
- Err(CompactSizeDecoderError(E::NonMinimal { value: x.into() }))
+ Err(E::NonMinimal { value: x.into() }).map_err(CompactSizeDecoderError)
} else {
Ok(x.into())
}
### consensus_encoding/src/decode/decoders.rs
@@ -91,12 +91,12 @@ impl Decoder for ByteVecDecoder {
use ByteVecDecoderErrorInner as Inner;
if let Some(mut decoder) = self.prefix_decoder.take() {
- if decoder.push_bytes(bytes).map_err(|e| E(Inner::LengthPrefixDecode(e)))?.needs_more()
+ if decoder.push_bytes(bytes).map_err(Inner::LengthPrefixDecode).map_err(E)?.needs_more()
{
self.prefix_decoder = Some(decoder);
return Ok(DecoderStatus::NeedsMore);
}
- self.bytes_expected = decoder.end().map_err(|e| E(Inner::LengthPrefixDecode(e)))?;
+ self.bytes_expected = decoder.end().map_err(Inner::LengthPrefixDecode).map_err(E)?;
self.prefix_decoder = None;
// For DoS prevention, let's not allocate all memory upfront.
@@ -131,7 +131,7 @@ impl Decoder for ByteVecDecoder {
return Ok(self.buffer);
};
- Err(E(Inner::UnexpectedEof(UnexpectedEofError { missing })))
+ Err(UnexpectedEofError { missing }).map_err(Inner::UnexpectedEof).map_err(E)
}
fn read_limit(&self) -> usize {
@@ -222,11 +222,11 @@ impl<D: Decoder + Default> Decoder for ExactVecDecoderWith<D> {
self.reserve();
let mut decoder = self.decoder.take().unwrap_or_default();
- if decoder.push_bytes(bytes).map_err(|e| E(Inner::Item(e)))?.needs_more() {
+ if decoder.push_bytes(bytes).map_err(Inner::Item).map_err(E)?.needs_more() {
self.decoder = Some(decoder);
return Ok(DecoderStatus::NeedsMore);
}
- let item = decoder.end().map_err(|e| E(Inner::Item(e)))?;
+ let item = decoder.end().map_err(Inner::Item).map_err(E)?;
self.buffer.push(item);
if self.buffer.len() == self.length {
@@ -250,7 +250,7 @@ impl<D: Decoder + Default> Decoder for ExactVecDecoderWith<D> {
}
let missing = self.length - len;
- Err(VecDecoderError(E::UnexpectedEof(UnexpectedEofError { missing })))
+ Err(UnexpectedEofError { missing }).map_err(E::UnexpectedEof).map_err(VecDecoderError)
}
fn read_limit(&self) -> usize {
@@ -327,11 +327,11 @@ impl<D: Decoder + Default> Decoder for VecDecoderWith<D> {
use VecDecoderErrorInner as Inner;
if let Some(mut pd) = self.prefix_decoder.take() {
- if pd.push_bytes(bytes).map_err(|e| E(Inner::LengthPrefixDecode(e)))?.needs_more() {
+ if pd.push_bytes(bytes).map_err(Inner::LengthPrefixDecode).map_err(E)?.needs_more() {
self.prefix_decoder = Some(pd);
return Ok(DecoderStatus::NeedsMore);
}
- let count = pd.end().map_err(|e| E(Inner::LengthPrefixDecode(e)))?;
+ let count = pd.end().map_err(Inner::LengthPrefixDecode).map_err(E)?;
self.items = ExactVecDecoderWith::new(count);
}
@@ -342,9 +342,9 @@ impl<D: Decoder + Default> Decoder for VecDecoderWith<D> {
use VecDecoderErrorInner as Inner;
if let Some(pd) = self.prefix_decoder {
- return Err(VecDecoderError(Inner::UnexpectedEof(UnexpectedEofError {
- missing: pd.read_limit(),
- })));
+ return Err(UnexpectedEofError { missing: pd.read_limit() })
+ .map_err(Inner::UnexpectedEof)
+ .map_err(VecDecoderError);
}
self.items.end()
### consensus_encoding/src/decode/mod.rs
@@ -272,7 +272,7 @@ fn decode_from_slice_internal<D: Decoder>(
if remaining.is_empty() {
Ok(data)
} else {
- Err(DecodeError::Unconsumed(UnconsumedError()))
+ Err(UnconsumedError()).map_err(DecodeError::Unconsumed)
}
}
Risk score
Our methodology →Why this scored 15/100
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