1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148

// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

// Every codebase needs a `util` module.

use std::cmp::Ordering;
use std::ops::{Bound, IndexMut, Range, RangeBounds};
use std::ptr;

#[cfg(feature = "pool")]
pub(crate) use refpool::{PoolClone, PoolDefault};

// The `Ref` type is an alias for either `Rc` or `Arc`, user's choice.

// `Arc` without refpool
#[cfg(all(threadsafe, not(feature = "pool")))]
pub(crate) use crate::fakepool::{Arc as PoolRef, Pool, PoolClone, PoolDefault};

// `Arc` with refpool
#[cfg(all(threadsafe, feature = "pool"))]
pub(crate) type PoolRef<A> = refpool::PoolRef<A, refpool::PoolSync>;
#[cfg(all(threadsafe, feature = "pool"))]
pub(crate) type Pool<A> = refpool::Pool<A, refpool::PoolSync>;

// `Ref` == `Arc` when threadsafe
#[cfg(threadsafe)]
pub(crate) type Ref<A> = std::sync::Arc<A>;

// `Rc` without refpool
#[cfg(all(not(threadsafe), not(feature = "pool")))]
pub(crate) use crate::fakepool::{Pool, PoolClone, PoolDefault, Rc as PoolRef};

// `Rc` with refpool
#[cfg(all(not(threadsafe), feature = "pool"))]
pub(crate) type PoolRef<A> = refpool::PoolRef<A, refpool::PoolUnsync>;
#[cfg(all(not(threadsafe), feature = "pool"))]
pub(crate) type Pool<A> = refpool::Pool<A, refpool::PoolUnsync>;

// `Ref` == `Rc` when not threadsafe
#[cfg(not(threadsafe))]
pub(crate) type Ref<A> = std::rc::Rc<A>;

pub(crate) fn clone_ref<A>(r: Ref<A>) -> A
where
    A: Clone,
{
    Ref::try_unwrap(r).unwrap_or_else(|r| (*r).clone())
}

#[derive(Clone, Copy, PartialEq, Eq, Debug)]
pub(crate) enum Side {
    Left,
    Right,
}

/// Swap two values of anything implementing `IndexMut`.
///
/// Like `slice::swap`, but more generic.
#[allow(unsafe_code)]
pub(crate) fn swap_indices<V>(vector: &mut V, a: usize, b: usize)
where
    V: IndexMut<usize>,
    V::Output: Sized,
{
    if a == b {
        return;
    }
    // so sorry, but there's no implementation for this in std that's
    // sufficiently generic
    let pa: *mut V::Output = &mut vector[a];
    let pb: *mut V::Output = &mut vector[b];
    unsafe {
        ptr::swap(pa, pb);
    }
}

#[allow(dead_code)]
pub(crate) fn linear_search_by<'a, A, I, F>(iterable: I, mut cmp: F) -> Result<usize, usize>
where
    A: 'a,
    I: IntoIterator<Item = &'a A>,
    F: FnMut(&A) -> Ordering,
{
    let mut pos = 0;
    for value in iterable {
        match cmp(value) {
            Ordering::Equal => return Ok(pos),
            Ordering::Greater => return Err(pos),
            Ordering::Less => {}
        }
        pos += 1;
    }
    Err(pos)
}

pub(crate) fn to_range<R>(range: &R, right_unbounded: usize) -> Range<usize>
where
    R: RangeBounds<usize>,
{
    let start_index = match range.start_bound() {
        Bound::Included(i) => *i,
        Bound::Excluded(i) => *i + 1,
        Bound::Unbounded => 0,
    };
    let end_index = match range.end_bound() {
        Bound::Included(i) => *i + 1,
        Bound::Excluded(i) => *i,
        Bound::Unbounded => right_unbounded,
    };
    start_index..end_index
}

macro_rules! def_pool {
    ($name:ident<$($arg:tt),*>, $pooltype:ty) => {
        /// A memory pool for the appropriate node type.
        pub struct $name<$($arg,)*>(Pool<$pooltype>);

        impl<$($arg,)*> $name<$($arg,)*> {
            /// Create a new pool with the given size.
            pub fn new(size: usize) -> Self {
                Self(Pool::new(size))
            }

            /// Fill the pool with preallocated chunks.
            pub fn fill(&self) {
                self.0.fill();
            }

            ///Get the current size of the pool.
            pub fn pool_size(&self) -> usize {
                self.0.get_pool_size()
            }
        }

        impl<$($arg,)*> Default for $name<$($arg,)*> {
            fn default() -> Self {
                Self::new($crate::config::POOL_SIZE)
            }
        }

        impl<$($arg,)*> Clone for $name<$($arg,)*> {
            fn clone(&self) -> Self {
                Self(self.0.clone())
            }
        }
    };
}