Mercurial > public > mercurial-scm > hg-stable
view rust/hg-core/src/lib.rs @ 44420:6329ce04c69f
rust-nodemap: accounting for dead blocks
By the very append-only nature of the `NodeTree`, inserting
new blocks has the effect of making some of the older ones
useless as they become unreachable.
Therefore some automatic housekeeping will need to be provided.
This is standard procedure in the word of databases, under names
such as "repack" or "vacuum".
The new `masked_readonly_blocks()` will provide callers with
useful information to decide if the nodetree is ripe for
repacking, but all the `NodeTree` can provide is how many
blocks have been masked in the currently mutable part. Analysing
the readonly part would be way too long to do it for each
transaction and defeat the whole purpose of nodemap persistence.
Serializing callers (from the Python layer) will get this figure
before each extraction and maintain an aggregate counter of
unreachable blocks separately.
Note: at this point, the most efficient repacking is just to restart
afresh with a full rescan.
Differential Revision: https://phab.mercurial-scm.org/D8097
author | Georges Racinet <georges.racinet@octobus.net> |
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date | Tue, 18 Feb 2020 19:11:17 +0100 |
parents | d8d4fa9a7f18 |
children | 52d40f8fb82d |
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// Copyright 2018-2020 Georges Racinet <georges.racinet@octobus.net> // and Mercurial contributors // // This software may be used and distributed according to the terms of the // GNU General Public License version 2 or any later version. mod ancestors; pub mod dagops; pub use ancestors::{AncestorsIterator, LazyAncestors, MissingAncestors}; mod dirstate; pub mod discovery; pub mod testing; // unconditionally built, for use from integration tests pub use dirstate::{ dirs_multiset::{DirsMultiset, DirsMultisetIter}, dirstate_map::DirstateMap, parsers::{pack_dirstate, parse_dirstate, PARENT_SIZE}, status::{status, StatusResult}, CopyMap, CopyMapIter, DirstateEntry, DirstateParents, EntryState, StateMap, StateMapIter, }; mod filepatterns; pub mod matchers; pub mod revlog; pub use revlog::*; #[cfg(feature = "with-re2")] pub mod re2; pub mod utils; use crate::utils::hg_path::{HgPathBuf, HgPathError}; pub use filepatterns::{ parse_pattern_syntax, read_pattern_file, IgnorePattern, PatternFileWarning, PatternSyntax, }; use std::collections::HashMap; use twox_hash::RandomXxHashBuilder64; pub type LineNumber = usize; /// Rust's default hasher is too slow because it tries to prevent collision /// attacks. We are not concerned about those: if an ill-minded person has /// write access to your repository, you have other issues. pub type FastHashMap<K, V> = HashMap<K, V, RandomXxHashBuilder64>; #[derive(Clone, Debug, PartialEq)] pub enum DirstateParseError { TooLittleData, Overflow, CorruptedEntry(String), Damaged, } impl From<std::io::Error> for DirstateParseError { fn from(e: std::io::Error) -> Self { DirstateParseError::CorruptedEntry(e.to_string()) } } impl ToString for DirstateParseError { fn to_string(&self) -> String { use crate::DirstateParseError::*; match self { TooLittleData => "Too little data for dirstate.".to_string(), Overflow => "Overflow in dirstate.".to_string(), CorruptedEntry(e) => format!("Corrupted entry: {:?}.", e), Damaged => "Dirstate appears to be damaged.".to_string(), } } } #[derive(Debug, PartialEq)] pub enum DirstatePackError { CorruptedEntry(String), CorruptedParent, BadSize(usize, usize), } impl From<std::io::Error> for DirstatePackError { fn from(e: std::io::Error) -> Self { DirstatePackError::CorruptedEntry(e.to_string()) } } #[derive(Debug, PartialEq)] pub enum DirstateMapError { PathNotFound(HgPathBuf), EmptyPath, InvalidPath(HgPathError), } impl ToString for DirstateMapError { fn to_string(&self) -> String { match self { DirstateMapError::PathNotFound(_) => { "expected a value, found none".to_string() } DirstateMapError::EmptyPath => "Overflow in dirstate.".to_string(), DirstateMapError::InvalidPath(e) => e.to_string(), } } } pub enum DirstateError { Parse(DirstateParseError), Pack(DirstatePackError), Map(DirstateMapError), IO(std::io::Error), } impl From<DirstateParseError> for DirstateError { fn from(e: DirstateParseError) -> Self { DirstateError::Parse(e) } } impl From<DirstatePackError> for DirstateError { fn from(e: DirstatePackError) -> Self { DirstateError::Pack(e) } } #[derive(Debug)] pub enum PatternError { Path(HgPathError), UnsupportedSyntax(String), UnsupportedSyntaxInFile(String, String, usize), TooLong(usize), IO(std::io::Error), /// Needed a pattern that can be turned into a regex but got one that /// can't. This should only happen through programmer error. NonRegexPattern(IgnorePattern), } impl ToString for PatternError { fn to_string(&self) -> String { match self { PatternError::UnsupportedSyntax(syntax) => { format!("Unsupported syntax {}", syntax) } PatternError::UnsupportedSyntaxInFile(syntax, file_path, line) => { format!( "{}:{}: unsupported syntax {}", file_path, line, syntax ) } PatternError::TooLong(size) => { format!("matcher pattern is too long ({} bytes)", size) } PatternError::IO(e) => e.to_string(), PatternError::Path(e) => e.to_string(), PatternError::NonRegexPattern(pattern) => { format!("'{:?}' cannot be turned into a regex", pattern) } } } } impl From<DirstateMapError> for DirstateError { fn from(e: DirstateMapError) -> Self { DirstateError::Map(e) } } impl From<std::io::Error> for DirstateError { fn from(e: std::io::Error) -> Self { DirstateError::IO(e) } } impl From<std::io::Error> for PatternError { fn from(e: std::io::Error) -> Self { PatternError::IO(e) } } impl From<HgPathError> for PatternError { fn from(e: HgPathError) -> Self { PatternError::Path(e) } }