comparison rust/hg-core/src/revlog/index.rs @ 52177:1da6995835b4

rust-revlog: move non-persistent-nodemap rev lookup to the index

It only uses index features and does not need to be on the revlog. A later
patch will make use of this function from a different context.

52176:72bc29f01570

use bitvec::prelude::*;
use byteorder::{BigEndian, ByteOrder};
use bytes_cast::{unaligned, BytesCast};

use super::REVIDX_KNOWN_FLAGS;
use crate::errors::HgError;
use crate::node::{NODE_BYTES_LENGTH, NULL_NODE, STORED_NODE_ID_BYTES};
use crate::revlog::node::Node;
use crate::revlog::{Revision, NULL_REVISION};
use crate::{

                .expect("inline should have offsets")
                .len()
        } else {
            self.bytes.len() / INDEX_ENTRY_SIZE
        }
    }

    pub fn get_offsets(&self) -> RwLockReadGuard<Option<Vec<usize>>> {
        assert!(self.is_inline());
        {

52177:1da6995835b4

use bitvec::prelude::*;
use byteorder::{BigEndian, ByteOrder};
use bytes_cast::{unaligned, BytesCast};

use super::{NodePrefix, REVIDX_KNOWN_FLAGS};
use crate::errors::HgError;
use crate::node::{NODE_BYTES_LENGTH, NULL_NODE, STORED_NODE_ID_BYTES};
use crate::revlog::node::Node;
use crate::revlog::{Revision, NULL_REVISION};
use crate::{

                .expect("inline should have offsets")
                .len()
        } else {
            self.bytes.len() / INDEX_ENTRY_SIZE
        }
    }

    /// Same as `rev_from_node`, without using a persistent nodemap
    ///
    /// This is used as fallback when a persistent nodemap is not present.
    /// This happens when the persistent-nodemap experimental feature is not
    /// enabled, or for small revlogs.
    pub fn rev_from_node_no_persistent_nodemap(
        &self,
        node: NodePrefix,
    ) -> Result<Revision, RevlogError> {
        // Linear scan of the revlog
        // TODO: consider building a non-persistent nodemap in memory to
        // optimize these cases.
        let mut found_by_prefix = None;
        for rev in (-1..self.len() as BaseRevision).rev() {
            let rev = Revision(rev as BaseRevision);
            let candidate_node = if rev == Revision(-1) {
                NULL_NODE
            } else {
                let index_entry = self.get_entry(rev).ok_or_else(|| {
                    HgError::corrupted(
                        "revlog references a revision not in the index",
                    )
                })?;
                *index_entry.hash()
            };
            if node == candidate_node {
                return Ok(rev);
            }
            if node.is_prefix_of(&candidate_node) {
                if found_by_prefix.is_some() {
                    return Err(RevlogError::AmbiguousPrefix);
                }
                found_by_prefix = Some(rev)
            }
        }
        found_by_prefix
            .ok_or_else(|| RevlogError::InvalidRevision(format!("{:x}", node)))
    }

    pub fn get_offsets(&self) -> RwLockReadGuard<Option<Vec<usize>>> {
        assert!(self.is_inline());
        {