poppable/src/lib.rs

use std::u16;

use anyhow::{Ok, Result};

//pub type BytesRef = AsRef<u8>;

pub trait Pushable {
    fn push_u8(&mut self, byte: &u8) -> Result<()>;
    fn push_vec(&mut self, bytes: Vec<u8>) -> Result<()>;
    fn push_slice(&mut self, bytes: &[u8]) -> Result<()>;
}
impl Pushable for Vec<u8> {
    fn push_u8(&mut self, byte: &u8) -> Result<()> {
        // TODO: push can panic. Return Err instead of panicing.
        self.push(byte.to_owned());
        Ok(())
    }

    fn push_vec(&mut self, mut bytes: Vec<u8>) -> Result<()> {
        // TODO: append can panic. Return Err instead of panicing.
        self.append(&mut bytes);
        Ok(())
    }

    fn push_slice(&mut self, bytes: &[u8]) -> Result<()> {
        // TODO: extend can also panic. Return Err instead of panicing.
        // https://doc.rust-lang.org/src/alloc/vec/mod.rs.html#2970 rustdoc 1.77.1 (7cf61ebde 2024-03-27)
        // http://web.archive.org/web/20240324062202/doc.rust-lang.org/src/alloc/vec/mod.rs.html#2970
        self.extend(bytes);
        Ok(())
    }
}

pub trait Poppable {
    fn try_pop_be<T: PopFromBE>(&mut self) -> Result<T>;
    fn try_pop_le<T: PopFromLE>(&mut self) -> Result<T>;
    fn try_pop_ne<T: PopFromNE>(&mut self) -> Result<T>;
}
impl Poppable for &[u8] {
    fn try_pop_be<T: PopFromBE>(&mut self) -> Result<T> {
        Ok(T::pop_be_from(self)?)
    }

    fn try_pop_le<T: PopFromLE>(&mut self) -> Result<T> {
        Ok(T::pop_le_from(self)?)
    }

    fn try_pop_ne<T: PopFromNE>(&mut self) -> Result<T> {
        Ok(T::pop_ne_from(self)?)
    }
}

pub trait PopFromBE {
    fn pop_be_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized;
    fn push_be_into<T: Pushable>(&self, dest: &mut T) -> Result<()>;
}
pub trait PopFromLE {
    fn pop_le_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized;
    fn push_le_into<T: Pushable>(&self, dest: &mut T) -> Result<()>;
}

pub trait PopFromNE {
    fn pop_ne_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized;
    fn push_ne_into<T: Pushable>(&self, dest: &mut T) -> Result<()>;
}

//
// Impl PopFromNE, PopFromLE, PopFromBE for core primitive types
// TODO: Create macro(s) for impls. Most of these impls are the same except for the the type name.
// TODO: Impl for u128 and i128
// TODO: Impl for usize and isize
//

impl PopFromNE for u8 {
    fn pop_ne_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        const SIZE: usize = std::mem::size_of::<u8>();
        if source.len() < SIZE {
            anyhow::bail!("Buffer too small to pop u8");
        }

        let value = source[0];
        *source = &source[SIZE..];
        Ok(value)
    }

    fn push_ne_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_u8(self)
    }
}
impl PopFromLE for u8 {
    fn pop_le_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        u8::pop_ne_from(source)
    }

    fn push_le_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_u8(self)
    }
}
impl PopFromBE for u8 {
    fn pop_be_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        u8::pop_ne_from(source)
    }

    fn push_be_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_u8(self)
    }
}

// Impls for u16
impl PopFromNE for u16 {
    fn pop_ne_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        const SIZE: usize = std::mem::size_of::<u16>();
        if source.len() < SIZE {
            anyhow::bail!("Buffer too small to pop u16");
        }
        let value = u16::from_be_bytes(source[..SIZE].try_into()?);
        *source = &source[SIZE..];
        Ok(value)
    }

    fn push_ne_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_ne_bytes())
    }
}
impl PopFromLE for u16 {
    fn pop_le_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        Ok(Self::from_le(Self::pop_ne_from(source)?))
    }

    fn push_le_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_le_bytes())
    }
}
impl PopFromBE for u16 {
    fn pop_be_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        Ok(Self::from_be(Self::pop_ne_from(source)?))
    }

    fn push_be_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_be_bytes())
    }
}

//Impls for u32
impl PopFromNE for u32 {
    fn pop_ne_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        const SIZE: usize = std::mem::size_of::<u32>();
        if source.len() < SIZE {
            anyhow::bail!("Buffer too small to pop u32");
        }
        let value = u32::from_be_bytes(source[..SIZE].try_into()?);
        *source = &source[SIZE..];
        Ok(value)
    }

    fn push_ne_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_ne_bytes())
    }
}
impl PopFromLE for u32 {
    fn pop_le_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        Ok(Self::from_le(Self::pop_ne_from(source)?))
    }

    fn push_le_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_le_bytes())
    }
}
impl PopFromBE for u32 {
    fn pop_be_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        Ok(Self::from_be(Self::pop_ne_from(source)?))
    }

    fn push_be_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_be_bytes())
    }
}

//Impls for u64
impl PopFromNE for u64 {
    fn pop_ne_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        const SIZE: usize = std::mem::size_of::<u64>();
        if source.len() < SIZE {
            anyhow::bail!("Buffer too small to pop u64");
        }
        let value = u64::from_be_bytes(source[..SIZE].try_into()?);
        *source = &source[SIZE..];
        Ok(value)
    }

    fn push_ne_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_ne_bytes())
    }
}
impl PopFromLE for u64 {
    fn pop_le_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        Ok(Self::from_le(Self::pop_ne_from(source)?))
    }

    fn push_le_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_le_bytes())
    }
}
impl PopFromBE for u64 {
    fn pop_be_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        Ok(Self::from_be(Self::pop_ne_from(source)?))
    }

    fn push_be_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_be_bytes())
    }
}

impl PopFromNE for i8 {
    fn pop_ne_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        const SIZE: usize = std::mem::size_of::<i8>();
        if source.len() < SIZE {
            anyhow::bail!("Buffer too small to pop i8");
        }

        let value = source[0] as i8;
        *source = &source[SIZE..];
        Ok(value)
    }

    fn push_ne_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_u8(&(*self as u8))
    }
}
impl PopFromLE for i8 {
    fn pop_le_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        i8::pop_ne_from(source)
    }

    fn push_le_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        self.push_ne_into(dest)
    }
}
impl PopFromBE for i8 {
    fn pop_be_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        i8::pop_ne_from(source)
    }

    fn push_be_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        self.push_ne_into(dest)
    }
}

impl PopFromNE for i16 {
    fn pop_ne_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        const SIZE: usize = std::mem::size_of::<i16>();
        if source.len() < SIZE {
            anyhow::bail!("Buffer too small to pop i16");
        }

        let value = i16::from_be_bytes(source[..SIZE].try_into()?);
        *source = &source[SIZE..];
        Ok(value)
    }

    fn push_ne_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_ne_bytes())
    }
}
impl PopFromNE for i32 {
    fn pop_ne_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        const SIZE: usize = std::mem::size_of::<i32>();
        if source.len() < SIZE {
            anyhow::bail!("Buffer too small to pop i32");
        }

        let value = i32::from_be_bytes(source[..SIZE].try_into()?);
        *source = &source[SIZE..];
        Ok(value)
    }

    fn push_ne_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_ne_bytes())
    }
}
impl PopFromNE for i64 {
    fn pop_ne_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        const SIZE: usize = std::mem::size_of::<i64>();
        if source.len() < SIZE {
            anyhow::bail!("Buffer too small to pop i64");
        }

        let value = i64::from_be_bytes(source[..SIZE].try_into()?);
        *source = &source[SIZE..];
        Ok(value)
    }

    fn push_ne_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_ne_bytes())
    }
}

impl PopFromLE for i16 {
    fn pop_le_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        Ok(Self::from_le(Self::pop_ne_from(source)?))
    }

    fn push_le_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_le_bytes())
    }
}
impl PopFromLE for i32 {
    fn pop_le_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        Ok(Self::from_le(Self::pop_ne_from(source)?))
    }

    fn push_le_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_le_bytes())
    }
}
impl PopFromLE for i64 {
    fn pop_le_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        Ok(Self::from_le(Self::pop_ne_from(source)?))
    }

    fn push_le_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_le_bytes())
    }
}

impl PopFromBE for i16 {
    fn pop_be_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        Ok(Self::from_be(Self::pop_ne_from(source)?))
    }

    fn push_be_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_be_bytes())
    }
}
impl PopFromBE for i32 {
    fn pop_be_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        Ok(Self::from_be(Self::pop_ne_from(source)?))
    }

    fn push_be_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_be_bytes())
    }
}
impl PopFromBE for i64 {
    fn pop_be_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        Ok(Self::from_be(Self::pop_ne_from(source)?))
    }

    fn push_be_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_be_bytes())
    }
}

//
// Floating Point
//
impl PopFromNE for f32 {
    fn pop_ne_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        const SIZE: usize = std::mem::size_of::<f32>();
        if source.len() < SIZE {
            anyhow::bail!("Buffer to small to pop f32");
        }
        let value = f32::from_ne_bytes(source[..SIZE].try_into()?);
        *source = &source[SIZE..];
        Ok(value)
    }

    fn push_ne_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_ne_bytes())
    }
}
impl PopFromLE for f32 {
    fn pop_le_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        const SIZE: usize = std::mem::size_of::<f32>();
        if source.len() < SIZE {
            anyhow::bail!("Buffer to small to pop f32");
        }
        let value = f32::from_le_bytes(source[..SIZE].try_into()?);
        *source = &source[SIZE..];
        Ok(value)
    }

    fn push_le_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_le_bytes())
    }
}
impl PopFromBE for f32 {
    fn pop_be_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        const SIZE: usize = std::mem::size_of::<f32>();
        if source.len() < SIZE {
            anyhow::bail!("Buffer to small to pop f32");
        }
        let value = f32::from_be_bytes(source[..SIZE].try_into()?);
        *source = &source[SIZE..];
        Ok(value)
    }

    fn push_be_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_be_bytes())
    }
}

impl PopFromNE for f64 {
    fn pop_ne_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        const SIZE: usize = std::mem::size_of::<f64>();
        if source.len() < SIZE {
            anyhow::bail!("Buffer to small to pop f64");
        }
        let value = f64::from_ne_bytes(source[..SIZE].try_into()?);
        *source = &source[SIZE..];
        Ok(value)
    }

    fn push_ne_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_ne_bytes())
    }
}
impl PopFromLE for f64 {
    fn pop_le_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        const SIZE: usize = std::mem::size_of::<f64>();
        if source.len() < SIZE {
            anyhow::bail!("Buffer to small to pop f64");
        }
        let value = f64::from_le_bytes(source[..SIZE].try_into()?);
        *source = &source[SIZE..];
        Ok(value)
    }

    fn push_le_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_le_bytes())
    }
}
impl PopFromBE for f64 {
    fn pop_be_from(source: &mut &[u8]) -> Result<Self>
    where
        Self: Sized,
    {
        const SIZE: usize = std::mem::size_of::<f64>();
        if source.len() < SIZE {
            anyhow::bail!("Buffer to small to pop f64");
        }
        let value = f64::from_be_bytes(source[..SIZE].try_into()?);
        *source = &source[SIZE..];
        Ok(value)
    }

    fn push_be_into<T: Pushable>(&self, dest: &mut T) -> Result<()> {
        dest.push_slice(&self.to_be_bytes())
    }
}