diff --git a/rust/hg-core/Cargo.toml b/rust/hg-core/Cargo.toml --- a/rust/hg-core/Cargo.toml +++ b/rust/hg-core/Cargo.toml @@ -10,3 +10,7 @@ [dev-dependencies] rand = "*" rand_pcg = "*" + +[dependencies] +memchr = "2.2.0" +byteorder = "1.3.1" \ No newline at end of file diff --git a/rust/hg-core/src/dirstate.rs b/rust/hg-core/src/dirstate.rs new file mode 100644 --- /dev/null +++ b/rust/hg-core/src/dirstate.rs @@ -0,0 +1,409 @@ +// Copyright 2019 Raphaël Gomès +// +// This software may be used and distributed according to the terms of the +// GNU General Public License version 2 or any later version. + +use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt}; +use std::collections::HashMap; +use std::io::Cursor; +use {DirstatePackError, DirstateParseError}; + +#[derive(Debug, PartialEq, Copy, Clone)] +pub struct DirstateParents<'a> { + pub p1: &'a [u8], + pub p2: &'a [u8], +} +/// The C implementation uses all signed types. This will be an issue +/// either when 4GB+ source files are commonplace or in 2038, whichever +/// comes first. +#[derive(Debug, PartialEq)] +pub struct DirstateEntry { + pub state: i8, + pub mode: i32, + pub mtime: i32, + pub size: i32, +} +pub type DirstateVec = Vec<(Vec, DirstateEntry)>; + +#[derive(Debug, PartialEq)] +pub struct CopyVecEntry<'a> { + pub path: &'a [u8], + pub copy_path: &'a [u8], +} +pub type CopyVec<'a> = Vec>; + +/// Parents are stored in the dirstate as byte hashes. +const PARENT_SIZE: usize = 20; +/// Dirstate entries have a static part of 8 + 32 + 32 + 32 + 32 bits. +const MIN_ENTRY_SIZE: usize = 17; + +pub fn parse_dirstate( + contents: &[u8], +) -> Result<(DirstateParents, DirstateVec, CopyVec), DirstateParseError> { + if contents.len() < PARENT_SIZE * 2 { + return Err(DirstateParseError::TooLittleData); + } + + let mut dirstate_vec = vec![]; + let mut copies = vec![]; + let mut curr_pos = PARENT_SIZE * 2; + let parents = DirstateParents { + p1: &contents[..PARENT_SIZE], + p2: &contents[PARENT_SIZE..curr_pos], + }; + + while curr_pos < contents.len() { + if curr_pos + MIN_ENTRY_SIZE > contents.len() { + return Err(DirstateParseError::Overflow); + } + let entry_bytes = &contents[curr_pos..]; + + let mut cursor = Cursor::new(entry_bytes); + let state = cursor.read_i8()?; + let mode = cursor.read_i32::()?; + let size = cursor.read_i32::()?; + let mtime = cursor.read_i32::()?; + let path_len = cursor.read_i32::()? as usize; + + if path_len > contents.len() - curr_pos { + return Err(DirstateParseError::Overflow); + } + + // Slice instead of allocating a Vec needed for `read_exact` + let path = &entry_bytes[MIN_ENTRY_SIZE..MIN_ENTRY_SIZE + (path_len)]; + + let (path, copy) = match memchr::memchr(0, path) { + None => (path, None), + Some(i) => (&path[..i], Some(&path[(i + 1)..])), + }; + + if let Some(copy_path) = copy { + copies.push(CopyVecEntry { path, copy_path }); + }; + dirstate_vec.push(( + path.to_owned(), + DirstateEntry { + state, + mode, + size, + mtime, + }, + )); + curr_pos = curr_pos + MIN_ENTRY_SIZE + (path_len); + } + + Ok((parents, dirstate_vec, copies)) +} + +pub fn pack_dirstate( + dirstate_vec: &DirstateVec, + copymap: &HashMap, Vec>, + parents: DirstateParents, + now: i32, +) -> Result<(Vec, DirstateVec), DirstatePackError> { + if parents.p1.len() != PARENT_SIZE || parents.p2.len() != PARENT_SIZE { + return Err(DirstatePackError::CorruptedParent); + } + + let expected_size: usize = dirstate_vec + .iter() + .map(|(ref filename, _)| { + let mut length = MIN_ENTRY_SIZE + filename.len(); + if let Some(ref copy) = copymap.get(filename) { + length += copy.len() + 1; + } + length + }) + .sum(); + let expected_size = expected_size + PARENT_SIZE * 2; + + let mut packed = Vec::with_capacity(expected_size); + let mut new_dirstate_vec = vec![]; + + packed.extend(parents.p1); + packed.extend(parents.p2); + + for (ref filename, entry) in dirstate_vec { + let mut new_filename: Vec = filename.to_owned(); + let mut new_mtime: i32 = entry.mtime; + if entry.state == 'n' as i8 && entry.mtime == now.into() { + // The file was last modified "simultaneously" with the current + // write to dirstate (i.e. within the same second for file- + // systems with a granularity of 1 sec). This commonly happens + // for at least a couple of files on 'update'. + // The user could change the file without changing its size + // within the same second. Invalidate the file's mtime in + // dirstate, forcing future 'status' calls to compare the + // contents of the file if the size is the same. This prevents + // mistakenly treating such files as clean. + new_mtime = -1; + new_dirstate_vec.push(( + filename.to_owned(), + DirstateEntry { + mtime: new_mtime, + ..*entry + }, + )); + } + + if let Some(copy) = copymap.get(filename) { + new_filename.push('\0' as u8); + new_filename.extend(copy); + } + + packed.write_i8(entry.state)?; + packed.write_i32::(entry.mode)?; + packed.write_i32::(entry.size)?; + packed.write_i32::(new_mtime)?; + packed.write_i32::(new_filename.len() as i32)?; + packed.extend(new_filename) + } + + if packed.len() != expected_size { + return Err(DirstatePackError::BadSize(expected_size, packed.len())); + } + + Ok((packed, new_dirstate_vec)) +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn test_pack_dirstate_empty() { + let dirstate_vec: DirstateVec = vec![]; + let copymap = HashMap::new(); + let parents = DirstateParents { + p1: b"12345678910111213141", + p2: b"00000000000000000000", + }; + let now: i32 = 15000000; + let expected = + (b"1234567891011121314100000000000000000000".to_vec(), vec![]); + + assert_eq!( + expected, + pack_dirstate(&dirstate_vec, ©map, parents, now).unwrap() + ); + } + #[test] + fn test_pack_dirstate_one_entry() { + let dirstate_vec: DirstateVec = vec![( + vec!['f' as u8, '1' as u8], + DirstateEntry { + state: 'n' as i8, + mode: 0o644, + size: 0, + mtime: 791231220, + }, + )]; + let copymap = HashMap::new(); + let parents = DirstateParents { + p1: b"12345678910111213141", + p2: b"00000000000000000000", + }; + let now: i32 = 15000000; + let expected = ( + [ + 49, 50, 51, 52, 53, 54, 55, 56, 57, 49, 48, 49, 49, 49, 50, + 49, 51, 49, 52, 49, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, + 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 110, 0, 0, 1, 164, 0, + 0, 0, 0, 47, 41, 58, 244, 0, 0, 0, 2, 102, 49, + ] + .to_vec(), + vec![], + ); + + assert_eq!( + expected, + pack_dirstate(&dirstate_vec, ©map, parents, now).unwrap() + ); + } + #[test] + fn test_pack_dirstate_one_entry_with_copy() { + let dirstate_vec: DirstateVec = vec![( + b"f1".to_vec(), + DirstateEntry { + state: 'n' as i8, + mode: 0o644, + size: 0, + mtime: 791231220, + }, + )]; + let mut copymap = HashMap::new(); + copymap.insert(b"f1".to_vec(), b"copyname".to_vec()); + let parents = DirstateParents { + p1: b"12345678910111213141", + p2: b"00000000000000000000", + }; + let now: i32 = 15000000; + let expected = ( + [ + 49, 50, 51, 52, 53, 54, 55, 56, 57, 49, 48, 49, 49, 49, 50, + 49, 51, 49, 52, 49, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, + 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 110, 0, 0, 1, 164, 0, + 0, 0, 0, 47, 41, 58, 244, 0, 0, 0, 11, 102, 49, 0, 99, 111, + 112, 121, 110, 97, 109, 101, + ] + .to_vec(), + vec![], + ); + + assert_eq!( + expected, + pack_dirstate(&dirstate_vec, ©map, parents, now).unwrap() + ); + } + + #[test] + fn test_parse_pack_one_entry_with_copy() { + let dirstate_vec: DirstateVec = vec![( + b"f1".to_vec(), + DirstateEntry { + state: 'n' as i8, + mode: 0o644, + size: 0, + mtime: 791231220, + }, + )]; + let mut copymap = HashMap::new(); + copymap.insert(b"f1".to_vec(), b"copyname".to_vec()); + let parents = DirstateParents { + p1: b"12345678910111213141", + p2: b"00000000000000000000", + }; + let now: i32 = 15000000; + let result = + pack_dirstate(&dirstate_vec, ©map, parents, now).unwrap(); + + assert_eq!( + ( + parents, + dirstate_vec, + copymap + .iter() + .map(|(k, v)| CopyVecEntry { + path: k.as_slice(), + copy_path: v.as_slice() + }) + .collect() + ), + parse_dirstate(result.0.as_slice()).unwrap() + ) + } + + #[test] + fn test_parse_pack_multiple_entries_with_copy() { + let dirstate_vec: DirstateVec = vec![ + ( + b"f1".to_vec(), + DirstateEntry { + state: 'n' as i8, + mode: 0o644, + size: 0, + mtime: 791231220, + }, + ), + ( + b"f2".to_vec(), + DirstateEntry { + state: 'm' as i8, + mode: 0o777, + size: 1000, + mtime: 791231220, + }, + ), + ( + b"f3".to_vec(), + DirstateEntry { + state: 'r' as i8, + mode: 0o644, + size: 234553, + mtime: 791231220, + }, + ), + ( + b"f4\xF6".to_vec(), + DirstateEntry { + state: 'a' as i8, + mode: 0o644, + size: -1, + mtime: -1, + }, + ), + ]; + let mut copymap = HashMap::new(); + copymap.insert(b"f1".to_vec(), b"copyname".to_vec()); + copymap.insert(b"f4\xF6".to_vec(), b"copyname2".to_vec()); + let parents = DirstateParents { + p1: b"12345678910111213141", + p2: b"00000000000000000000", + }; + let now: i32 = 15000000; + let result = + pack_dirstate(&dirstate_vec, ©map, parents, now).unwrap(); + + assert_eq!( + (parents, dirstate_vec, copymap), + parse_dirstate(result.0.as_slice()) + .and_then(|(p, dvec, cvec)| Ok(( + p, + dvec, + cvec.iter() + .map(|entry| ( + entry.path.to_vec(), + entry.copy_path.to_vec() + )) + .collect() + ))) + .unwrap() + ) + } + + #[test] + /// https://www.mercurial-scm.org/repo/hg/rev/af3f26b6bba4 + fn test_parse_pack_one_entry_with_copy_and_time_conflict() { + let dirstate_vec: DirstateVec = vec![( + b"f1".to_vec(), + DirstateEntry { + state: 'n' as i8, + mode: 0o644, + size: 0, + mtime: 15000000, + }, + )]; + let mut copymap = HashMap::new(); + copymap.insert(b"f1".to_vec(), b"copyname".to_vec()); + let parents = DirstateParents { + p1: b"12345678910111213141", + p2: b"00000000000000000000", + }; + let now: i32 = 15000000; + let result = + pack_dirstate(&dirstate_vec, ©map, parents, now).unwrap(); + + assert_eq!( + ( + parents, + vec![( + b"f1".to_vec(), + DirstateEntry { + state: 'n' as i8, + mode: 0o644, + size: 0, + mtime: -1 + } + )], + copymap + .iter() + .map(|(k, v)| CopyVecEntry { + path: k.as_slice(), + copy_path: v.as_slice() + }) + .collect() + ), + parse_dirstate(result.0.as_slice()).unwrap() + ) + } +} diff --git a/rust/hg-core/src/lib.rs b/rust/hg-core/src/lib.rs --- a/rust/hg-core/src/lib.rs +++ b/rust/hg-core/src/lib.rs @@ -2,6 +2,9 @@ // // This software may be used and distributed according to the terms of the // GNU General Public License version 2 or any later version. +extern crate byteorder; +extern crate memchr; + mod ancestors; pub mod dagops; pub use ancestors::{AncestorsIterator, LazyAncestors, MissingAncestors}; @@ -40,3 +43,29 @@ ParentOutOfRange(Revision), WorkingDirectoryUnsupported, } + +#[derive(Clone, Debug, PartialEq)] +pub enum DirstateParseError { + TooLittleData, + Overflow, + CorruptedEntry(String), +} + +#[derive(Debug, PartialEq)] +pub enum DirstatePackError { + CorruptedEntry(String), + CorruptedParent, + BadSize(usize, usize), +} + +impl From for DirstatePackError { + fn from(e: std::io::Error) -> Self { + DirstatePackError::CorruptedEntry(e.to_string()) + } +} + +impl From for DirstateParseError { + fn from(e: std::io::Error) -> Self { + DirstateParseError::CorruptedEntry(e.to_string()) + } +}