Mercurial > public > mercurial-scm > hg-stable
diff rust/hg-core/src/revlog/nodemap.rs @ 50990:4c5f6e95df84
rust: make `Revision` a newtype
This change is the one we've been building towards during this series.
The aim is to make `Revision` mean more than a simple integer, holding
the information that it is valid for a given revlog index.
While this still allows for programmer error, since creating a revision
directly and querying a different index with a "checked" revision are
still possible, the friction created by the newtype will hopefully make
us think twice about which type to use.
Enough of the Rust ecosystem relies on the newtype pattern to be
efficiently optimized away (even compiler in codegen tests?), so I'm not
worried about this being a fundamental problem.
[1] https://github.com/rust-lang/rust/blob/7a70647f195f6b0a0f1ebd72b1542ba91a32f43a/tests/codegen/vec-in-place.rs#L47
| author | Rapha?l Gom?s <rgomes@octobus.net> |
|---|---|
| date | Fri, 18 Aug 2023 14:34:29 +0200 |
| parents | 1928b770e3e7 |
| children | 12c308c55e53 |
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--- a/rust/hg-core/src/revlog/nodemap.rs Thu Aug 10 11:01:07 2023 +0200 +++ b/rust/hg-core/src/revlog/nodemap.rs Fri Aug 18 14:34:29 2023 +0200 @@ -474,9 +474,12 @@ self.mutable_block(deepest.block_idx); if let Element::Rev(old_rev) = deepest.element { - let old_node = index.node(old_rev).ok_or_else(|| { - NodeMapError::RevisionNotInIndex(old_rev.into()) - })?; + let old_node = index + .check_revision(old_rev.into()) + .and_then(|rev| index.node(rev)) + .ok_or_else(|| { + NodeMapError::RevisionNotInIndex(old_rev.into()) + })?; if old_node == node { return Ok(()); // avoid creating lots of useless blocks } @@ -500,14 +503,14 @@ } else { let mut new_block = Block::new(); new_block.set(old_nybble, Element::Rev(old_rev)); - new_block.set(new_nybble, Element::Rev(rev)); + new_block.set(new_nybble, Element::Rev(rev.0)); self.growable.push(new_block); break; } } } else { // Free slot in the deepest block: no splitting has to be done - block.set(deepest.nybble, Element::Rev(rev)); + block.set(deepest.nybble, Element::Rev(rev.0)); } // Backtrack over visit steps to update references @@ -707,6 +710,13 @@ ) } + /// Shorthand to reduce boilerplate when creating [`Revision`] for testing + macro_rules! R { + ($revision:literal) => { + Revision($revision) + }; + } + #[test] fn test_block_debug() { let mut block = Block::new(); @@ -755,7 +765,7 @@ } fn check_revision(&self, rev: UncheckedRevision) -> Option<Revision> { - self.get(&rev).map(|_| rev.0) + self.get(&rev).map(|_| Revision(rev.0)) } } @@ -800,17 +810,20 @@ #[test] fn test_immutable_find_simplest() -> Result<(), NodeMapError> { let mut idx: TestIndex = HashMap::new(); - pad_insert(&mut idx, 1, "1234deadcafe"); + pad_insert(&mut idx, R!(1), "1234deadcafe"); let nt = NodeTree::from(vec![block! {1: Rev(1)}]); - assert_eq!(nt.find_bin(&idx, hex("1"))?, Some(1)); - assert_eq!(nt.find_bin(&idx, hex("12"))?, Some(1)); - assert_eq!(nt.find_bin(&idx, hex("1234de"))?, Some(1)); + assert_eq!(nt.find_bin(&idx, hex("1"))?, Some(R!(1))); + assert_eq!(nt.find_bin(&idx, hex("12"))?, Some(R!(1))); + assert_eq!(nt.find_bin(&idx, hex("1234de"))?, Some(R!(1))); assert_eq!(nt.find_bin(&idx, hex("1a"))?, None); assert_eq!(nt.find_bin(&idx, hex("ab"))?, None); // and with full binary Nodes - assert_eq!(nt.find_node(&idx, idx.get(&1.into()).unwrap())?, Some(1)); + assert_eq!( + nt.find_node(&idx, idx.get(&1.into()).unwrap())?, + Some(R!(1)) + ); let unknown = Node::from_hex(&hex_pad_right("3d")).unwrap(); assert_eq!(nt.find_node(&idx, &unknown)?, None); Ok(()) @@ -819,15 +832,15 @@ #[test] fn test_immutable_find_one_jump() { let mut idx = TestIndex::new(); - pad_insert(&mut idx, 9, "012"); - pad_insert(&mut idx, 0, "00a"); + pad_insert(&mut idx, R!(9), "012"); + pad_insert(&mut idx, R!(0), "00a"); let nt = sample_nodetree(); assert_eq!(nt.find_bin(&idx, hex("0")), Err(MultipleResults)); - assert_eq!(nt.find_bin(&idx, hex("01")), Ok(Some(9))); + assert_eq!(nt.find_bin(&idx, hex("01")), Ok(Some(R!(9)))); assert_eq!(nt.find_bin(&idx, hex("00")), Err(MultipleResults)); - assert_eq!(nt.find_bin(&idx, hex("00a")), Ok(Some(0))); + assert_eq!(nt.find_bin(&idx, hex("00a")), Ok(Some(R!(0)))); assert_eq!(nt.unique_prefix_len_bin(&idx, hex("00a")), Ok(Some(3))); assert_eq!(nt.find_bin(&idx, hex("000")), Ok(Some(NULL_REVISION))); } @@ -835,11 +848,11 @@ #[test] fn test_mutated_find() -> Result<(), NodeMapError> { let mut idx = TestIndex::new(); - pad_insert(&mut idx, 9, "012"); - pad_insert(&mut idx, 0, "00a"); - pad_insert(&mut idx, 2, "cafe"); - pad_insert(&mut idx, 3, "15"); - pad_insert(&mut idx, 1, "10"); + pad_insert(&mut idx, R!(9), "012"); + pad_insert(&mut idx, R!(0), "00a"); + pad_insert(&mut idx, R!(2), "cafe"); + pad_insert(&mut idx, R!(3), "15"); + pad_insert(&mut idx, R!(1), "10"); let nt = NodeTree { readonly: sample_nodetree().readonly, @@ -847,13 +860,13 @@ root: block![0: Block(1), 1:Block(3), 12: Rev(2)], masked_inner_blocks: 1, }; - assert_eq!(nt.find_bin(&idx, hex("10"))?, Some(1)); - assert_eq!(nt.find_bin(&idx, hex("c"))?, Some(2)); + assert_eq!(nt.find_bin(&idx, hex("10"))?, Some(R!(1))); + assert_eq!(nt.find_bin(&idx, hex("c"))?, Some(R!(2))); assert_eq!(nt.unique_prefix_len_bin(&idx, hex("c"))?, Some(1)); assert_eq!(nt.find_bin(&idx, hex("00")), Err(MultipleResults)); assert_eq!(nt.find_bin(&idx, hex("000"))?, Some(NULL_REVISION)); assert_eq!(nt.unique_prefix_len_bin(&idx, hex("000"))?, Some(3)); - assert_eq!(nt.find_bin(&idx, hex("01"))?, Some(9)); + assert_eq!(nt.find_bin(&idx, hex("01"))?, Some(R!(9))); assert_eq!(nt.masked_readonly_blocks(), 2); Ok(()) } @@ -915,34 +928,34 @@ fn test_insert_full_mutable() -> Result<(), NodeMapError> { let mut idx = TestNtIndex::new(); idx.insert(0, "1234")?; - assert_eq!(idx.find_hex("1")?, Some(0)); - assert_eq!(idx.find_hex("12")?, Some(0)); + assert_eq!(idx.find_hex("1")?, Some(R!(0))); + assert_eq!(idx.find_hex("12")?, Some(R!(0))); // let's trigger a simple split idx.insert(1, "1a34")?; assert_eq!(idx.nt.growable.len(), 1); - assert_eq!(idx.find_hex("12")?, Some(0)); - assert_eq!(idx.find_hex("1a")?, Some(1)); + assert_eq!(idx.find_hex("12")?, Some(R!(0))); + assert_eq!(idx.find_hex("1a")?, Some(R!(1))); // reinserting is a no_op idx.insert(1, "1a34")?; assert_eq!(idx.nt.growable.len(), 1); - assert_eq!(idx.find_hex("12")?, Some(0)); - assert_eq!(idx.find_hex("1a")?, Some(1)); + assert_eq!(idx.find_hex("12")?, Some(R!(0))); + assert_eq!(idx.find_hex("1a")?, Some(R!(1))); idx.insert(2, "1a01")?; assert_eq!(idx.nt.growable.len(), 2); assert_eq!(idx.find_hex("1a"), Err(NodeMapError::MultipleResults)); - assert_eq!(idx.find_hex("12")?, Some(0)); - assert_eq!(idx.find_hex("1a3")?, Some(1)); - assert_eq!(idx.find_hex("1a0")?, Some(2)); + assert_eq!(idx.find_hex("12")?, Some(R!(0))); + assert_eq!(idx.find_hex("1a3")?, Some(R!(1))); + assert_eq!(idx.find_hex("1a0")?, Some(R!(2))); assert_eq!(idx.find_hex("1a12")?, None); // now let's make it split and create more than one additional block idx.insert(3, "1a345")?; assert_eq!(idx.nt.growable.len(), 4); - assert_eq!(idx.find_hex("1a340")?, Some(1)); - assert_eq!(idx.find_hex("1a345")?, Some(3)); + assert_eq!(idx.find_hex("1a340")?, Some(R!(1))); + assert_eq!(idx.find_hex("1a345")?, Some(R!(3))); assert_eq!(idx.find_hex("1a341")?, None); // there's no readonly block to mask @@ -987,12 +1000,12 @@ let node1 = Node::from_hex(&node1_hex).unwrap(); idx.insert(0.into(), node0); - nt.insert(idx, &node0, 0)?; + nt.insert(idx, &node0, R!(0))?; idx.insert(1.into(), node1); - nt.insert(idx, &node1, 1)?; + nt.insert(idx, &node1, R!(1))?; - assert_eq!(nt.find_bin(idx, (&node0).into())?, Some(0)); - assert_eq!(nt.find_bin(idx, (&node1).into())?, Some(1)); + assert_eq!(nt.find_bin(idx, (&node0).into())?, Some(R!(0))); + assert_eq!(nt.find_bin(idx, (&node1).into())?, Some(R!(1))); Ok(()) } @@ -1004,28 +1017,28 @@ idx.insert(2, "131")?; idx.insert(3, "cafe")?; let mut idx = idx.commit(); - assert_eq!(idx.find_hex("1234")?, Some(0)); - assert_eq!(idx.find_hex("1235")?, Some(1)); - assert_eq!(idx.find_hex("131")?, Some(2)); - assert_eq!(idx.find_hex("cafe")?, Some(3)); + assert_eq!(idx.find_hex("1234")?, Some(R!(0))); + assert_eq!(idx.find_hex("1235")?, Some(R!(1))); + assert_eq!(idx.find_hex("131")?, Some(R!(2))); + assert_eq!(idx.find_hex("cafe")?, Some(R!(3))); // we did not add anything since init from readonly assert_eq!(idx.nt.masked_readonly_blocks(), 0); idx.insert(4, "123A")?; - assert_eq!(idx.find_hex("1234")?, Some(0)); - assert_eq!(idx.find_hex("1235")?, Some(1)); - assert_eq!(idx.find_hex("131")?, Some(2)); - assert_eq!(idx.find_hex("cafe")?, Some(3)); - assert_eq!(idx.find_hex("123A")?, Some(4)); + assert_eq!(idx.find_hex("1234")?, Some(R!(0))); + assert_eq!(idx.find_hex("1235")?, Some(R!(1))); + assert_eq!(idx.find_hex("131")?, Some(R!(2))); + assert_eq!(idx.find_hex("cafe")?, Some(R!(3))); + assert_eq!(idx.find_hex("123A")?, Some(R!(4))); // we masked blocks for all prefixes of "123", including the root assert_eq!(idx.nt.masked_readonly_blocks(), 4); eprintln!("{:?}", idx.nt); idx.insert(5, "c0")?; - assert_eq!(idx.find_hex("cafe")?, Some(3)); - assert_eq!(idx.find_hex("c0")?, Some(5)); + assert_eq!(idx.find_hex("cafe")?, Some(R!(3))); + assert_eq!(idx.find_hex("c0")?, Some(R!(5))); assert_eq!(idx.find_hex("c1")?, None); - assert_eq!(idx.find_hex("1234")?, Some(0)); + assert_eq!(idx.find_hex("1234")?, Some(R!(0))); // inserting "c0" is just splitting the 'c' slot of the mutable root, // it doesn't mask anything assert_eq!(idx.nt.masked_readonly_blocks(), 4);