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/* 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
/// Object handle
///
/// Handles opaque `u64` values used to pass objects across the FFI, both for objects implemented in
/// Rust and ones implemented in the foreign language.
///
/// Rust handles are generated by leaking a raw pointer
/// Foreign handles are generated with a handle map that only generates odd values.
/// For all currently supported architectures and hopefully any ones we add in the future:
/// * 0 is an invalid value.
/// * The lowest bit will always be set for foreign handles and never set for Rust ones (since the
/// leaked pointer will be aligned to `size_of::<Arc<T>>()` == `size_of::<*const T>()`).
///
/// Rust handles are mainly managed is through the [crate::HandleAlloc] trait.
#[derive(Copy, Clone, Default, Debug, PartialEq, Eq)]
#[repr(transparent)]
pub struct Handle(u64);
impl Handle {
pub fn from_pointer<T>(ptr: *const T) -> Self {
Self(ptr as u64)
}
pub fn as_pointer<T>(&self) -> *const T {
self.0 as *const T
}
/// # Safety
/// The raw value must be a valid handle as described above.
pub unsafe fn from_raw(raw: u64) -> Option<Self> {
if raw == 0 {
None
} else {
Some(Self(raw))
}
}
pub fn from_raw_unchecked(raw: u64) -> Self {
Self(raw)
}
pub fn as_raw(&self) -> u64 {
self.0
}
}