comparison rust/hg-core/src/revlog/index.rs @ 51260:c4f1a790bda8

rust-index: use a `BitVec` instead of plain `Vec` for heads computation

The `Vec` method uses one byte per revision, this uses 1 per 8 revisions,
which improves our memory footprint. For large graphs (10+ millions), this
can make a measurable difference server-side.

I have seen no measurable impact on execution speed.

51259:ed6683d4cb29

use std::collections::{HashMap, HashSet};
use std::fmt::Debug;
use std::ops::Deref;
use std::sync::{RwLock, RwLockReadGuard, RwLockWriteGuard};

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

use super::REVIDX_KNOWN_FLAGS;
use crate::errors::HgError;

        }

        let as_vec = if self.is_empty() {
            vec![NULL_REVISION]
        } else {
            let mut not_heads = vec![false; self.len()];
            dagops::retain_heads_fast(self, &mut not_heads, filtered_revs)?;
            not_heads
                .into_iter()
                .enumerate()
                .filter_map(|(idx, is_not_head)| {
                    if is_not_head {

51260:c4f1a790bda8

use std::collections::{HashMap, HashSet};
use std::fmt::Debug;
use std::ops::Deref;
use std::sync::{RwLock, RwLockReadGuard, RwLockWriteGuard};

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

use super::REVIDX_KNOWN_FLAGS;
use crate::errors::HgError;

        }

        let as_vec = if self.is_empty() {
            vec![NULL_REVISION]
        } else {
            let mut not_heads = bitvec![0; self.len()];
            dagops::retain_heads_fast(
                self,
                not_heads.as_mut_bitslice(),
                filtered_revs,
            )?;
            not_heads
                .into_iter()
                .enumerate()
                .filter_map(|(idx, is_not_head)| {
                    if is_not_head {