jay-compositor 1.15.0

The Jay compositor
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#![allow(dead_code)]

const SEG_SIZE: usize = usize::BITS as usize;

#[derive(Default)]
pub struct Bitfield {
    vals: Vec<usize>,
}

impl Bitfield {
    pub fn take(&mut self, val: u32) {
        let idx = val as usize / SEG_SIZE;
        let pos = val as usize % SEG_SIZE;
        while self.vals.len() <= idx {
            self.vals.push(!0);
        }
        self.vals[idx] &= !(1 << pos);
    }

    pub fn acquire(&mut self) -> u32 {
        for (idx, n) in self.vals.iter_mut().enumerate() {
            if *n != 0 {
                let pos = n.trailing_zeros();
                *n &= !(1 << pos);
                return (idx * SEG_SIZE) as u32 + pos;
            }
        }
        self.vals.push(!1);
        ((self.vals.len() - 1) * SEG_SIZE) as u32
    }

    pub fn acquire64(&mut self) -> u64 {
        self.acquire() as u64
    }

    pub fn release(&mut self, val: u32) {
        let idx = val as usize / SEG_SIZE;
        let pos = val as usize % SEG_SIZE;
        self.vals[idx] |= 1 << pos;
    }

    pub fn release64(&mut self, val: u64) {
        if val <= u32::MAX as u64 {
            self.release(val as u32);
        }
    }
}