##// END OF EJS Templates
debugmergestate: make templated...
debugmergestate: make templated Our IntelliJ team wants to be able to read the merge state in order to help the user resolve merge conflicts. They had so far been reading file contents from p1() and p2() and their merge base. That is not ideal for several reasons (merge base is not necessarily the "graft base", renames are not handled, commands like `hg update -m` is not handled). It will get especially bad as of my D7827. This patch makes the output s a templated. I haven't bothered to make it complete (e.g. merge driver states are not handled), but it's probably good enough as a start. I've done a web search for "debugmergestate" and I can't find any indication that any tools currently rely on its output. If it turns out that we get bug reports for it once this is released, I won't object to backing this patch out on the stable branch (and then perhaps replace it by a separate command, or put it behind a new flag). The changes in test-backout.t are interesting, in particular this: ``` - other path: foo (node not stored in v1 format) + other path: (node foo) ``` I wonder if that means that we actually read v1 format incorrectly. That seems to be an old format that was switched away from in 2014, so it doesn't matter now anyway. Differential Revision: https://phab.mercurial-scm.org/D8120

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parsers.rs
433 lines | 13.6 KiB | application/rls-services+xml | RustLexer
// Copyright 2019 Raphaël Gomès <rgomes@octobus.net>
//
// This software may be used and distributed according to the terms of the
// GNU General Public License version 2 or any later version.
use crate::utils::hg_path::HgPath;
use crate::{
dirstate::{CopyMap, EntryState, StateMap},
DirstateEntry, DirstatePackError, DirstateParents, DirstateParseError,
};
use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
use std::convert::{TryFrom, TryInto};
use std::io::Cursor;
use std::time::Duration;
/// Parents are stored in the dirstate as byte hashes.
pub const PARENT_SIZE: usize = 20;
/// Dirstate entries have a static part of 8 + 32 + 32 + 32 + 32 bits.
const MIN_ENTRY_SIZE: usize = 17;
// TODO parse/pack: is mutate-on-loop better for performance?
pub fn parse_dirstate(
state_map: &mut StateMap,
copy_map: &mut CopyMap,
contents: &[u8],
) -> Result<DirstateParents, DirstateParseError> {
if contents.len() < PARENT_SIZE * 2 {
return Err(DirstateParseError::TooLittleData);
}
let mut curr_pos = PARENT_SIZE * 2;
let parents = DirstateParents {
p1: contents[..PARENT_SIZE].try_into().unwrap(),
p2: contents[PARENT_SIZE..curr_pos].try_into().unwrap(),
};
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 = EntryState::try_from(cursor.read_u8()?)?;
let mode = cursor.read_i32::<BigEndian>()?;
let size = cursor.read_i32::<BigEndian>()?;
let mtime = cursor.read_i32::<BigEndian>()?;
let path_len = cursor.read_i32::<BigEndian>()? 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 {
copy_map.insert(
HgPath::new(path).to_owned(),
HgPath::new(copy_path).to_owned(),
);
};
state_map.insert(
HgPath::new(path).to_owned(),
DirstateEntry {
state,
mode,
size,
mtime,
},
);
curr_pos = curr_pos + MIN_ENTRY_SIZE + (path_len);
}
Ok(parents)
}
/// `now` is the duration in seconds since the Unix epoch
pub fn pack_dirstate(
state_map: &mut StateMap,
copy_map: &CopyMap,
parents: DirstateParents,
now: Duration,
) -> Result<Vec<u8>, DirstatePackError> {
// TODO move away from i32 before 2038.
let now: i32 = now.as_secs().try_into().expect("time overflow");
let expected_size: usize = state_map
.iter()
.map(|(filename, _)| {
let mut length = MIN_ENTRY_SIZE + filename.len();
if let Some(copy) = copy_map.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_state_map = vec![];
packed.extend(&parents.p1);
packed.extend(&parents.p2);
for (filename, entry) in state_map.iter() {
let new_filename = filename.to_owned();
let mut new_mtime: i32 = entry.mtime;
if entry.state == EntryState::Normal && entry.mtime == now {
// 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_state_map.push((
filename.to_owned(),
DirstateEntry {
mtime: new_mtime,
..*entry
},
));
}
let mut new_filename = new_filename.into_vec();
if let Some(copy) = copy_map.get(filename) {
new_filename.push('\0' as u8);
new_filename.extend(copy.bytes());
}
packed.write_u8(entry.state.into())?;
packed.write_i32::<BigEndian>(entry.mode)?;
packed.write_i32::<BigEndian>(entry.size)?;
packed.write_i32::<BigEndian>(new_mtime)?;
packed.write_i32::<BigEndian>(new_filename.len() as i32)?;
packed.extend(new_filename)
}
if packed.len() != expected_size {
return Err(DirstatePackError::BadSize(expected_size, packed.len()));
}
state_map.extend(new_state_map);
Ok(packed)
}
#[cfg(test)]
mod tests {
use super::*;
use crate::{utils::hg_path::HgPathBuf, FastHashMap};
#[test]
fn test_pack_dirstate_empty() {
let mut state_map: StateMap = FastHashMap::default();
let copymap = FastHashMap::default();
let parents = DirstateParents {
p1: *b"12345678910111213141",
p2: *b"00000000000000000000",
};
let now = Duration::new(15000000, 0);
let expected = b"1234567891011121314100000000000000000000".to_vec();
assert_eq!(
expected,
pack_dirstate(&mut state_map, &copymap, parents, now).unwrap()
);
assert!(state_map.is_empty())
}
#[test]
fn test_pack_dirstate_one_entry() {
let expected_state_map: StateMap = [(
HgPathBuf::from_bytes(b"f1"),
DirstateEntry {
state: EntryState::Normal,
mode: 0o644,
size: 0,
mtime: 791231220,
},
)]
.iter()
.cloned()
.collect();
let mut state_map = expected_state_map.clone();
let copymap = FastHashMap::default();
let parents = DirstateParents {
p1: *b"12345678910111213141",
p2: *b"00000000000000000000",
};
let now = Duration::new(15000000, 0);
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();
assert_eq!(
expected,
pack_dirstate(&mut state_map, &copymap, parents, now).unwrap()
);
assert_eq!(expected_state_map, state_map);
}
#[test]
fn test_pack_dirstate_one_entry_with_copy() {
let expected_state_map: StateMap = [(
HgPathBuf::from_bytes(b"f1"),
DirstateEntry {
state: EntryState::Normal,
mode: 0o644,
size: 0,
mtime: 791231220,
},
)]
.iter()
.cloned()
.collect();
let mut state_map = expected_state_map.clone();
let mut copymap = FastHashMap::default();
copymap.insert(
HgPathBuf::from_bytes(b"f1"),
HgPathBuf::from_bytes(b"copyname"),
);
let parents = DirstateParents {
p1: *b"12345678910111213141",
p2: *b"00000000000000000000",
};
let now = Duration::new(15000000, 0);
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();
assert_eq!(
expected,
pack_dirstate(&mut state_map, &copymap, parents, now).unwrap()
);
assert_eq!(expected_state_map, state_map);
}
#[test]
fn test_parse_pack_one_entry_with_copy() {
let mut state_map: StateMap = [(
HgPathBuf::from_bytes(b"f1"),
DirstateEntry {
state: EntryState::Normal,
mode: 0o644,
size: 0,
mtime: 791231220,
},
)]
.iter()
.cloned()
.collect();
let mut copymap = FastHashMap::default();
copymap.insert(
HgPathBuf::from_bytes(b"f1"),
HgPathBuf::from_bytes(b"copyname"),
);
let parents = DirstateParents {
p1: *b"12345678910111213141",
p2: *b"00000000000000000000",
};
let now = Duration::new(15000000, 0);
let result =
pack_dirstate(&mut state_map, &copymap, parents.clone(), now)
.unwrap();
let mut new_state_map: StateMap = FastHashMap::default();
let mut new_copy_map: CopyMap = FastHashMap::default();
let new_parents = parse_dirstate(
&mut new_state_map,
&mut new_copy_map,
result.as_slice(),
)
.unwrap();
assert_eq!(
(parents, state_map, copymap),
(new_parents, new_state_map, new_copy_map)
)
}
#[test]
fn test_parse_pack_multiple_entries_with_copy() {
let mut state_map: StateMap = [
(
HgPathBuf::from_bytes(b"f1"),
DirstateEntry {
state: EntryState::Normal,
mode: 0o644,
size: 0,
mtime: 791231220,
},
),
(
HgPathBuf::from_bytes(b"f2"),
DirstateEntry {
state: EntryState::Merged,
mode: 0o777,
size: 1000,
mtime: 791231220,
},
),
(
HgPathBuf::from_bytes(b"f3"),
DirstateEntry {
state: EntryState::Removed,
mode: 0o644,
size: 234553,
mtime: 791231220,
},
),
(
HgPathBuf::from_bytes(b"f4\xF6"),
DirstateEntry {
state: EntryState::Added,
mode: 0o644,
size: -1,
mtime: -1,
},
),
]
.iter()
.cloned()
.collect();
let mut copymap = FastHashMap::default();
copymap.insert(
HgPathBuf::from_bytes(b"f1"),
HgPathBuf::from_bytes(b"copyname"),
);
copymap.insert(
HgPathBuf::from_bytes(b"f4\xF6"),
HgPathBuf::from_bytes(b"copyname2"),
);
let parents = DirstateParents {
p1: *b"12345678910111213141",
p2: *b"00000000000000000000",
};
let now = Duration::new(15000000, 0);
let result =
pack_dirstate(&mut state_map, &copymap, parents.clone(), now)
.unwrap();
let mut new_state_map: StateMap = FastHashMap::default();
let mut new_copy_map: CopyMap = FastHashMap::default();
let new_parents = parse_dirstate(
&mut new_state_map,
&mut new_copy_map,
result.as_slice(),
)
.unwrap();
assert_eq!(
(parents, state_map, copymap),
(new_parents, new_state_map, new_copy_map)
)
}
#[test]
/// https://www.mercurial-scm.org/repo/hg/rev/af3f26b6bba4
fn test_parse_pack_one_entry_with_copy_and_time_conflict() {
let mut state_map: StateMap = [(
HgPathBuf::from_bytes(b"f1"),
DirstateEntry {
state: EntryState::Normal,
mode: 0o644,
size: 0,
mtime: 15000000,
},
)]
.iter()
.cloned()
.collect();
let mut copymap = FastHashMap::default();
copymap.insert(
HgPathBuf::from_bytes(b"f1"),
HgPathBuf::from_bytes(b"copyname"),
);
let parents = DirstateParents {
p1: *b"12345678910111213141",
p2: *b"00000000000000000000",
};
let now = Duration::new(15000000, 0);
let result =
pack_dirstate(&mut state_map, &copymap, parents.clone(), now)
.unwrap();
let mut new_state_map: StateMap = FastHashMap::default();
let mut new_copy_map: CopyMap = FastHashMap::default();
let new_parents = parse_dirstate(
&mut new_state_map,
&mut new_copy_map,
result.as_slice(),
)
.unwrap();
assert_eq!(
(
parents,
[(
HgPathBuf::from_bytes(b"f1"),
DirstateEntry {
state: EntryState::Normal,
mode: 0o644,
size: 0,
mtime: -1
}
)]
.iter()
.cloned()
.collect::<StateMap>(),
copymap,
),
(new_parents, new_state_map, new_copy_map)
)
}
}