allocative 0.3.4

/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under both the MIT license found in the
 * LICENSE-MIT file in the root directory of this source tree and the Apache
 * License, Version 2.0 found in the LICENSE-APACHE file in the root directory
 * of this source tree.
 */

use std::collections::VecDeque;
use std::convert::Infallible;
use std::ffi::OsStr;
use std::marker::PhantomData;
use std::mem;
use std::num::NonZeroI16;
use std::num::NonZeroI32;
use std::num::NonZeroI64;
use std::num::NonZeroI8;
use std::num::NonZeroIsize;
use std::num::NonZeroU16;
use std::num::NonZeroU32;
use std::num::NonZeroU64;
use std::num::NonZeroU8;
use std::num::NonZeroUsize;
use std::path::PathBuf;

use crate::allocative_trait::Allocative;
use crate::impls::common::DATA_NAME;
use crate::impls::common::PTR_NAME;
use crate::impls::common::UNUSED_CAPACITY_NAME;
use crate::key::Key;
use crate::visitor::Visitor;

impl<T: Allocative + ?Sized> Allocative for &'static T {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        let _ = visitor;
    }
}

impl Allocative for str {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        visitor.visit_simple(Key::new("str"), self.len());
    }
}

impl Allocative for OsStr {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        visitor.visit_simple(Key::new("OsStr"), self.len());
    }
}

impl<T: Allocative + ?Sized> Allocative for Box<T> {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        let mut visitor = visitor.enter_self_sized::<Self>();
        {
            let mut visitor = visitor.enter_unique(PTR_NAME, mem::size_of::<*const T>());
            (**self).visit(&mut visitor);
        }
        visitor.exit();
    }
}

impl<T: Allocative, E: Allocative> Allocative for Result<T, E> {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        let mut visitor = visitor.enter_self_sized::<Self>();
        match self {
            Ok(v) => visitor.visit_field(Key::new("Ok"), v),
            Err(e) => visitor.visit_field(Key::new("Err"), e),
        }
    }
}

impl<T: Allocative> Allocative for Option<T> {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        let mut visitor = visitor.enter_self_sized::<Self>();
        if let Some(value) = self {
            visitor.visit_field(Key::new("Some"), value);
        }
    }
}

impl<T: Allocative> Allocative for Vec<T> {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        let mut visitor = visitor.enter_self_sized::<Self>();
        if self.capacity() != 0 && mem::size_of::<T>() != 0 {
            let mut visitor = visitor.enter_unique(PTR_NAME, mem::size_of::<*const T>());
            visitor.visit_slice(self.as_slice());
            visitor.visit_simple(
                UNUSED_CAPACITY_NAME,
                (self.capacity() - self.len()) * mem::size_of::<T>(),
            );
        }
        visitor.exit();
    }
}

impl<T: Allocative> Allocative for VecDeque<T> {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        let mut visitor = visitor.enter_self_sized::<Self>();
        if self.capacity() != 0 && mem::size_of::<T>() != 0 {
            let mut visitor = visitor.enter_unique(PTR_NAME, mem::size_of::<*const T>());
            visitor.visit_slice(self.as_slices().0);
            visitor.visit_slice(self.as_slices().1);
            visitor.visit_simple(
                UNUSED_CAPACITY_NAME,
                (self.capacity() - self.len()) * mem::size_of::<T>(),
            );
        }
        visitor.exit();
    }
}

impl Allocative for String {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        let mut visitor = visitor.enter_self_sized::<Self>();
        {
            let mut visitor = visitor.enter_unique(PTR_NAME, mem::size_of::<*const u8>());
            visitor.visit_vec_like_body(self.as_bytes(), self.capacity());
            visitor.exit();
        }
        visitor.exit();
    }
}

impl Allocative for PathBuf {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        let mut visitor = visitor.enter_self_sized::<Self>();
        if self.capacity() != 0 {
            let mut visitor = visitor.enter_unique(PTR_NAME, mem::size_of::<*const u8>());
            visitor.visit_simple(Key::new("path"), self.as_os_str().len());
            visitor.visit_simple(
                UNUSED_CAPACITY_NAME,
                self.capacity() - self.as_os_str().len(),
            );
        }
        visitor.exit();
    }
}

impl Allocative for NonZeroU64 {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        visitor.visit_simple_sized::<Self>();
    }
}

impl Allocative for NonZeroU32 {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        visitor.visit_simple_sized::<Self>();
    }
}

impl Allocative for NonZeroU16 {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        visitor.visit_simple_sized::<Self>();
    }
}

impl Allocative for NonZeroU8 {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        visitor.visit_simple_sized::<Self>();
    }
}

impl Allocative for NonZeroI64 {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        visitor.visit_simple_sized::<Self>();
    }
}

impl Allocative for NonZeroI32 {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        visitor.visit_simple_sized::<Self>();
    }
}

impl Allocative for NonZeroI16 {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        visitor.visit_simple_sized::<Self>();
    }
}

impl Allocative for NonZeroI8 {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        visitor.visit_simple_sized::<Self>();
    }
}

impl Allocative for NonZeroUsize {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        visitor.visit_simple_sized::<Self>();
    }
}

impl Allocative for NonZeroIsize {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        visitor.visit_simple_sized::<Self>();
    }
}

impl<T: ?Sized> Allocative for PhantomData<T> {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        let _ = visitor;
    }
}

impl Allocative for Infallible {
    fn visit<'a, 'b: 'a>(&self, _visitor: &'a mut Visitor<'b>) {
        match *self {}
    }
}

#[cfg(rust_nightly)]
impl Allocative for ! {
    fn visit<'a, 'b: 'a>(&self, _visitor: &'a mut Visitor<'b>) {
        match *self {}
    }
}

impl<T: Allocative> Allocative for [T] {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        let mut visitor = visitor.enter(Key::for_type_name::<T>(), mem::size_of_val::<[T]>(self));
        for item in self {
            // TODO(nga): faster for primitive.
            visitor.visit_field(DATA_NAME, item);
        }
        visitor.exit();
    }
}

impl<T: Allocative, const N: usize> Allocative for [T; N] {
    fn visit<'a, 'b: 'a>(&self, visitor: &'a mut Visitor<'b>) {
        self.as_slice().visit(visitor);
    }
}