( )⚙ D12545 rust-nodemap-docket: make unaware of `Repo`

This is an archive of the discontinued Mercurial Phabricator instance.

Differential D12545

rust-nodemap-docket: make unaware of `Repo`
AcceptedPublic

Authored by martinvonz on Wed, Apr 13, 9:10 AM.

Details

Reviewers
Alphare
Group Reviewers
hg-reviewers

Diff Detail

Repository
rHG Mercurial
Branch
default
Lint
No Linters Available
Unit
No Unit Test Coverage

Event Timeline

martinvonz created this revision.Wed, Apr 13, 9:10 AM
Alphare accepted this revision.Thu, Apr 14, 4:58 AM
This revision is now accepted and ready to land.Thu, Apr 14, 4:58 AM

Revision Contents
Changeset List

Diff 33183

rust/hg-core/src/revlog/nodemap_docket.rs

use crate::errors::{HgError, HgResultExt}; use crate::errors::{HgError, HgResultExt};
use bytes_cast::{unaligned, BytesCast}; use bytes_cast::{unaligned, BytesCast};
use memmap2::Mmap; use memmap2::Mmap;
use std::path::{Path, PathBuf}; use std::path::{Path, PathBuf};
use crate::repo::Repo;
use crate::utils::strip_suffix; use crate::utils::strip_suffix;
use crate::vfs::Vfs;
const ONDISK_VERSION: u8 = 1; const ONDISK_VERSION: u8 = 1;
pub(super) struct NodeMapDocket { pub(super) struct NodeMapDocket {
pub data_length: usize, pub data_length: usize,
// TODO: keep here more of the data from `parse()` when we need it // TODO: keep here more of the data from `parse()` when we need it
} }
/// ///
/// * This revlog does not have a `.n` docket file (it is not generated for /// * This revlog does not have a `.n` docket file (it is not generated for
/// small revlogs), or /// small revlogs), or
/// * The docket has an unsupported version number (repositories created by /// * The docket has an unsupported version number (repositories created by
/// later hg, maybe that should be a requirement instead?), or /// later hg, maybe that should be a requirement instead?), or
/// * The docket file points to a missing (likely deleted) data file (this /// * The docket file points to a missing (likely deleted) data file (this
/// can happen in a rare race condition). /// can happen in a rare race condition).
pub fn read_from_file( pub fn read_from_file(
repo: &Repo, store_vfs: &Vfs,
index_path: &Path, index_path: &Path,
) -> Result<Option<(Self, Mmap)>, HgError> { ) -> Result<Option<(Self, Mmap)>, HgError> {
let docket_path = index_path.with_extension("n"); let docket_path = index_path.with_extension("n");
let docket_bytes = if let Some(bytes) = let docket_bytes = if let Some(bytes) =
repo.store_vfs().read(&docket_path).io_not_found_as_none()? store_vfs.read(&docket_path).io_not_found_as_none()?
{ {
bytes bytes
} else { } else {
return Ok(None); return Ok(None);
}; };
let input = if let Some((&ONDISK_VERSION, rest)) = let input = if let Some((&ONDISK_VERSION, rest)) =
docket_bytes.split_first() docket_bytes.split_first()
let (_tip_node, _rest) = let (_tip_node, _rest) =
parse(u8::slice_from_bytes(rest, tip_node_size))?; parse(u8::slice_from_bytes(rest, tip_node_size))?;
let uid = parse(std::str::from_utf8(uid))?; let uid = parse(std::str::from_utf8(uid))?;
let docket = NodeMapDocket { data_length }; let docket = NodeMapDocket { data_length };
let data_path = rawdata_path(&docket_path, uid); let data_path = rawdata_path(&docket_path, uid);
// TODO: use `vfs.read()` here when the `persistent-nodemap.mmap` // TODO: use `vfs.read()` here when the `persistent-nodemap.mmap`
// config is false? // config is false?
if let Some(mmap) = repo if let Some(mmap) =
.store_vfs() store_vfs.mmap_open(&data_path).io_not_found_as_none()?
.mmap_open(&data_path)
.io_not_found_as_none()?
{ {
if mmap.len() >= data_length { if mmap.len() >= data_length {
Ok(Some((docket, mmap))) Ok(Some((docket, mmap)))
} else { } else {
Err(HgError::corrupted("persistent nodemap too short")) Err(HgError::corrupted("persistent nodemap too short"))
} }
} else { } else {
// Even if .hg/requires opted in, some revlogs are deemed small // Even if .hg/requires opted in, some revlogs are deemed small

rust/hg-core/src/revlog/revlog.rs

None None
} else if !repo } else if !repo
.requirements() .requirements()
.contains(requirements::NODEMAP_REQUIREMENT) .contains(requirements::NODEMAP_REQUIREMENT)
{ {
// If .hg/requires does not opt it, don’t try to open a nodemap // If .hg/requires does not opt it, don’t try to open a nodemap
None None
} else { } else {
NodeMapDocket::read_from_file(repo, index_path)?.map( NodeMapDocket::read_from_file(&repo.store_vfs(), index_path)?.map(
|(docket, data)| { |(docket, data)| {
nodemap::NodeTree::load_bytes( nodemap::NodeTree::load_bytes(
Box::new(data), Box::new(data),
docket.data_length, docket.data_length,
) )
}, },
) )
}; };