Mercurial > hg
diff rust/hg-core/src/revlog/revlog.rs @ 45601:900b9b79b99c
hg-core: make `Index` owner of its bytes (D8958#inline-14994 followup 1/2)
Prevent building `Index` every time it is needed. It was a bad idea anyway.
When `Index::new` will return `Result` it will avoid things like `Revlog::len`
returning `Result<usize>` instead of `usize`.
[X] make `Index` owner of its bytes
[ ] make `Index::new` return an error if `offset != bytes.len()`
Differential Revision: https://phab.mercurial-scm.org/D9106
author | Antoine cezar<acezar@chwitlabs.fr> |
---|---|
date | Mon, 28 Sep 2020 15:13:51 +0200 |
parents | 497657895b54 |
children | 1cef583541c0 |
line wrap: on
line diff
--- a/rust/hg-core/src/revlog/revlog.rs Mon Sep 28 14:33:52 2020 +0200 +++ b/rust/hg-core/src/revlog/revlog.rs Mon Sep 28 15:13:51 2020 +0200 @@ -36,7 +36,7 @@ /// When index and data are not interleaved: bytes of the revlog index. /// When index and data are interleaved: bytes of the revlog index and /// data. - index_bytes: Box<dyn Deref<Target = [u8]> + Send>, + index: Index, /// When index and data are not interleaved: bytes of the revlog data data_bytes: Option<Box<dyn Deref<Target = [u8]> + Send>>, } @@ -56,15 +56,13 @@ return Err(RevlogError::UnsuportedVersion(version)); } - let is_inline = is_inline(&index_mmap); - - let index_bytes = Box::new(index_mmap); + let index = Index::new(Box::new(index_mmap)); // TODO load data only when needed // // type annotation required // won't recognize Mmap as Deref<Target = [u8]> let data_bytes: Option<Box<dyn Deref<Target = [u8]> + Send>> = - if is_inline { + if index.is_inline() { None } else { let data_path = index_path.with_extension("d"); @@ -73,31 +71,27 @@ Some(Box::new(data_mmap)) }; - Ok(Revlog { - index_bytes, - data_bytes, - }) + Ok(Revlog { index, data_bytes }) } /// Return number of entries of the `Revlog`. pub fn len(&self) -> usize { - self.index().len() + self.index.len() } /// Returns `true` if the `Revlog` has zero `entries`. pub fn is_empty(&self) -> bool { - self.index().is_empty() + self.index.is_empty() } /// Return the full data associated to a node. #[timed] pub fn get_node_rev(&self, node: &[u8]) -> Result<Revision, RevlogError> { - let index = self.index(); // This is brute force. But it is fast enough for now. // Optimization will come later. for rev in (0..self.len() as Revision).rev() { let index_entry = - index.get_entry(rev).ok_or(RevlogError::Corrupted)?; + self.index.get_entry(rev).ok_or(RevlogError::Corrupted)?; if node == index_entry.hash() { return Ok(rev); } @@ -123,9 +117,10 @@ } // TODO do not look twice in the index - let index = self.index(); - let index_entry = - index.get_entry(rev).ok_or(RevlogError::InvalidRevision)?; + let index_entry = self + .index + .get_entry(rev) + .ok_or(RevlogError::InvalidRevision)?; let data: Vec<u8> = if delta_chain.is_empty() { entry.data()?.into() @@ -153,13 +148,12 @@ expected: &[u8], data: &[u8], ) -> bool { - let index = self.index(); - let e1 = index.get_entry(p1); + let e1 = self.index.get_entry(p1); let h1 = match e1 { Some(ref entry) => entry.hash(), None => &NULL_NODE_ID, }; - let e2 = index.get_entry(p2); + let e2 = self.index.get_entry(p2); let h2 = match e2 { Some(ref entry) => entry.hash(), None => &NULL_NODE_ID, @@ -187,30 +181,32 @@ Ok(patch.apply(&snapshot)) } - /// Return the revlog index. - pub fn index(&self) -> Index { - let is_inline = self.data_bytes.is_none(); - Index::new(&self.index_bytes, is_inline) - } - /// Return the revlog data. fn data(&self) -> &[u8] { match self.data_bytes { Some(ref data_bytes) => &data_bytes, - None => &self.index_bytes, + None => panic!( + "forgot to load the data or trying to access inline data" + ), } } /// Get an entry of the revlog. fn get_entry(&self, rev: Revision) -> Result<RevlogEntry, RevlogError> { - let index = self.index(); - let index_entry = - index.get_entry(rev).ok_or(RevlogError::InvalidRevision)?; + let index_entry = self + .index + .get_entry(rev) + .ok_or(RevlogError::InvalidRevision)?; let start = index_entry.offset(); let end = start + index_entry.compressed_len(); + let data = if self.index.is_inline() { + self.index.data(start, end) + } else { + &self.data()[start..end] + }; let entry = RevlogEntry { rev, - bytes: &self.data()[start..end], + bytes: data, compressed_len: index_entry.compressed_len(), uncompressed_len: index_entry.uncompressed_len(), base_rev: if index_entry.base_revision() == rev { @@ -296,14 +292,6 @@ } } -/// Value of the inline flag. -pub fn is_inline(index_bytes: &[u8]) -> bool { - match &index_bytes[0..=1] { - [0, 0] | [0, 2] => false, - _ => true, - } -} - /// Format version of the revlog. pub fn get_version(index_bytes: &[u8]) -> u16 { BigEndian::read_u16(&index_bytes[2..=3]) @@ -332,113 +320,12 @@ use super::super::index::IndexEntryBuilder; - #[cfg(test)] - pub struct RevlogBuilder { - version: u16, - is_general_delta: bool, - is_inline: bool, - offset: usize, - index: Vec<Vec<u8>>, - data: Vec<Vec<u8>>, - } - - #[cfg(test)] - impl RevlogBuilder { - pub fn new() -> Self { - Self { - version: 2, - is_inline: false, - is_general_delta: true, - offset: 0, - index: vec![], - data: vec![], - } - } - - pub fn with_inline(&mut self, value: bool) -> &mut Self { - self.is_inline = value; - self - } - - pub fn with_general_delta(&mut self, value: bool) -> &mut Self { - self.is_general_delta = value; - self - } - - pub fn with_version(&mut self, value: u16) -> &mut Self { - self.version = value; - self - } - - pub fn push( - &mut self, - mut index: IndexEntryBuilder, - data: Vec<u8>, - ) -> &mut Self { - if self.index.is_empty() { - index.is_first(true); - index.with_general_delta(self.is_general_delta); - index.with_inline(self.is_inline); - index.with_version(self.version); - } else { - index.with_offset(self.offset); - } - self.index.push(index.build()); - self.offset += data.len(); - self.data.push(data); - self - } - - pub fn build_inline(&self) -> Vec<u8> { - let mut bytes = - Vec::with_capacity(self.index.len() + self.data.len()); - for (index, data) in self.index.iter().zip(self.data.iter()) { - bytes.extend(index); - bytes.extend(data); - } - bytes - } - } - - #[test] - fn is_not_inline_when_no_inline_flag_test() { - let bytes = RevlogBuilder::new() - .with_general_delta(false) - .with_inline(false) - .push(IndexEntryBuilder::new(), vec![]) - .build_inline(); - - assert_eq!(is_inline(&bytes), false) - } - - #[test] - fn is_inline_when_inline_flag_test() { - let bytes = RevlogBuilder::new() - .with_general_delta(false) - .with_inline(true) - .push(IndexEntryBuilder::new(), vec![]) - .build_inline(); - - assert_eq!(is_inline(&bytes), true) - } - - #[test] - fn is_inline_when_inline_and_generaldelta_flags_test() { - let bytes = RevlogBuilder::new() - .with_general_delta(true) - .with_inline(true) - .push(IndexEntryBuilder::new(), vec![]) - .build_inline(); - - assert_eq!(is_inline(&bytes), true) - } - #[test] fn version_test() { - let bytes = RevlogBuilder::new() + let bytes = IndexEntryBuilder::new() + .is_first(true) .with_version(1) - .push(IndexEntryBuilder::new(), vec![]) - .build_inline(); + .build(); assert_eq!(get_version(&bytes), 1) }