ok/jj
1
0
Fork 0
forked from mirrors/jj
Code Pull requests Activity

index: transparently reindex if the index is corrupt

Browse source 
I'm about to change the index format (to remove predecessor
information), which will break the format. Let's prepare for that by
having `IndexStore` reindex the repo if it fails to read the index..
This commit is contained in:
Martin von Zweigbergk 2021-10-16 23:57:59 -07:00
parent 6722a79e27
commit 0354b8721b
2 changed files with 35 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

24
lib/src/index.rs
View file

@ -29,6 +29,7 @@ use blake2::{Blake2b, Digest};
use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
use itertools::Itertools;
use tempfile::NamedTempFile;
use thiserror::Error;
use crate::backend::{ChangeId, CommitId};
use crate::commit::Commit;
@ -219,6 +220,14 @@ impl CommitLookupEntry<'_> {
}
}
#[derive(Error, Debug)]
pub enum IndexLoadError {
#[error("Index file '{0}' is corrupt.")]
IndexCorrupt(String),
#[error("I/O error while loading index file: {0}")]
IoError(#[from] io::Error),
}
// File format:
// u32: number of entries
// u32: number of parent overflow entries
@ -612,7 +621,14 @@ impl MutableIndex {
persist_content_addressed_temp_file(temp_file, &index_file_path)?;
let mut cursor = Cursor::new(&buf);
ReadonlyIndex::load_from(&mut cursor, dir, index_file_id_hex, hash_length)
ReadonlyIndex::load_from(&mut cursor, dir, index_file_id_hex, hash_length).map_err(|err| {
match err {
IndexLoadError::IndexCorrupt(err) => {
panic!("Just-created index file is corrupt: {}", err)
}
IndexLoadError::IoError(err) => err,
}
})
}
pub fn num_commits(&self) -> u32 {
@ -1389,7 +1405,7 @@ impl ReadonlyIndex {
dir: PathBuf,
name: String,
hash_length: usize,
) -> io::Result<Arc<ReadonlyIndex>> {
) -> Result<Arc<ReadonlyIndex>, IndexLoadError> {
let parent_filename_len = file.read_u32::<LittleEndian>()?;
let num_parent_commits;
let maybe_parent_file;
@ -1420,7 +1436,9 @@ impl ReadonlyIndex {
let predecessor_overflow_size = (num_predecessor_overflow_entries as usize) * 4;
let expected_size =
graph_size + lookup_size + parent_overflow_size + predecessor_overflow_size;
assert_eq!(data.len(), expected_size);
if data.len() != expected_size {
return Err(IndexLoadError::IndexCorrupt(name));
}
let overflow_predecessor = data.split_off(graph_size + lookup_size + parent_overflow_size);
let overflow_parent = data.split_off(graph_size + lookup_size);
let lookup = data.split_off(graph_size);

18
lib/src/index_store.rs
View file

@ -26,7 +26,7 @@ use crate::backend::CommitId;
use crate::commit::Commit;
use crate::dag_walk;
use crate::file_util::persist_content_addressed_temp_file;
use crate::index::{MutableIndex, ReadonlyIndex};
use crate::index::{IndexLoadError, MutableIndex, ReadonlyIndex};
use crate::op_store::OperationId;
use crate::operation::Operation;
use crate::store::Store;
@ -54,8 +54,18 @@ impl IndexStore {
let op_id_hex = op.id().hex();
let op_id_file = self.dir.join("operations").join(&op_id_hex);
if op_id_file.exists() {
self.load_index_at_operation(store.hash_length(), op.id())
.unwrap()
match self.load_index_at_operation(store.hash_length(), op.id()) {
Err(IndexLoadError::IndexCorrupt(_)) => {
// If the index was corrupt (maybe it was written in a different format),
// we just reindex.
// TODO: Move this message to a callback or something.
println!("The index was corrupt (maybe the format has changed). Reindexing...");
std::fs::remove_dir_all(self.dir.join("operations")).unwrap();
std::fs::create_dir(self.dir.join("operations")).unwrap();
self.index_at_operation(store, op).unwrap()
}
result => result.unwrap(),
}
} else {
self.index_at_operation(store, op).unwrap()
}
@ -69,7 +79,7 @@ impl IndexStore {
&self,
hash_length: usize,
op_id: &OperationId,
) -> io::Result<Arc<ReadonlyIndex>> {
) -> Result<Arc<ReadonlyIndex>, IndexLoadError> {
let op_id_file = self.dir.join("operations").join(op_id.hex());
let mut buf = vec![];
File::open(op_id_file)