tycho_util/

lib.rs

use std::collections::{HashMap, HashSet};
use std::path::PathBuf;
use std::process::Command;

pub mod compression;
pub mod io;
pub mod progress_bar;
pub mod serde_helpers;
pub mod time;
pub mod tl;

pub mod futures {
    pub use self::box_future_or_noop::BoxFutureOrNoop;
    pub use self::join_task::JoinTask;
    pub use self::shared::{Shared, WeakShared};

    mod box_future_or_noop;
    mod join_task;
    mod shared;
}

pub mod sync {
    pub use self::once_take::*;
    pub use self::priority_semaphore::{AcquireError, PrioritySemaphore, TryAcquireError};
    pub use self::rayon::{rayon_run, rayon_run_fifo};
    pub use self::task::yield_on_complex;

    mod once_take;
    mod priority_semaphore;
    mod rayon;
    mod task;
}

#[cfg(any(test, feature = "test"))]
pub mod test {
    pub use self::logger::init_logger;

    mod logger;
}

pub mod metrics {
    pub use self::gauge_guard::GaugeGuard;
    pub use self::histogram_guard::{HistogramGuard, HistogramGuardWithLabels};
    pub use self::metrics_loop::spawn_metrics_loop;

    mod gauge_guard;
    mod histogram_guard;
    mod metrics_loop;
}

mod util {
    pub(crate) mod linked_list;
    pub(crate) mod wake_list;
}

#[cfg(feature = "cli")]
pub mod cli;

pub use dashmap::mapref::entry::Entry as DashMapEntry;

pub type FastDashMap<K, V> = dashmap::DashMap<K, V, ahash::RandomState>;
pub type FastDashSet<K> = dashmap::DashSet<K, ahash::RandomState>;
pub type FastHashMap<K, V> = HashMap<K, V, ahash::RandomState>;
pub type FastHashSet<K> = HashSet<K, ahash::RandomState>;
pub type FastHasherState = ahash::RandomState;

/// # Example
///
/// ```rust
/// # use tycho_util::realloc_box_enum;
/// enum Value {
///     One(BigValue1),
///     Two(BigValue2),
/// }
///
/// struct BigValue1([u32; 10]);
///
/// struct BigValue2([u32; 7]);
///
/// fn convert_to_one(value: Box<Value>) -> Option<Box<BigValue1>> {
///     realloc_box_enum!(value, {
///         Value::One(value) => Box::new(value) => Some(value),
///         _ => None,
///     })
/// }
/// ```
#[macro_export]
macro_rules! realloc_box_enum {
    ($value:expr, {
        $target_variant:pat => Box::new($extracted:ident) => $target:expr,
        $other_variant:pat => $other:expr,
    }) => {{
        let value: ::std::boxed::Box<_> = $value;
        match ::core::convert::AsRef::as_ref(&value) {
            #[allow(unused_variables)]
            $target_variant => {
                let $extracted = unsafe {
                    $crate::__internal::realloc_box(value, |value| match value {
                        $target_variant => $extracted,
                        _ => unreachable!(),
                    })
                };
                $target
            }
            $other_variant => $other,
        }
    }};
}

#[doc(hidden)]
pub mod __internal {
    /// # Safety
    /// The following must be true:
    /// - `T` must have the same layout as `R`
    /// - `f` must not panic
    pub unsafe fn realloc_box<T, F, R>(value: Box<T>, f: F) -> Box<R>
    where
        F: FnOnce(T) -> R,
    {
        assert!(std::mem::align_of::<T>() == std::mem::align_of::<R>());

        let ptr = Box::into_raw(value);
        let value = std::ptr::read(ptr);

        let ptr = std::alloc::realloc(
            ptr.cast::<u8>(),
            std::alloc::Layout::new::<T>(),
            std::mem::size_of::<R>(),
        )
        .cast::<R>();

        if ptr.is_null() {
            std::alloc::handle_alloc_error(std::alloc::Layout::new::<R>());
        }

        // NOTE: in case of panic, the memory will be leaked
        std::ptr::write(ptr, f(value));

        Box::from_raw(ptr)
    }
}

pub fn project_root() -> Result<PathBuf, anyhow::Error> {
    use anyhow::Context;

    let project_root = Command::new("git")
        .arg("rev-parse")
        .arg("--show-toplevel")
        .output()?
        .stdout;
    // won't work on windows but we don't care
    let project_root = PathBuf::from(
        String::from_utf8(project_root)
            .context("invalid project root")?
            .trim(),
    );
    Ok(project_root)
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    #[allow(dead_code)]
    fn realloc_enum() {
        enum Value {
            One(BigValue1),
            Two(BigValue2),
        }

        #[derive(Clone)]
        struct BigValue1([u32; 10]);

        #[derive(Clone)]
        struct BigValue2([u32; 7]);

        fn convert_to_one(value: Box<Value>) -> Option<Box<BigValue1>> {
            realloc_box_enum!(value, {
                Value::One(value) => Box::new(value) => Some(value),
                _ => None,
            })
        }

        let value = BigValue1([123; 10]);
        let one = convert_to_one(Box::new(Value::One(value.clone())));
        assert_eq!(one.unwrap().0, value.0);
    }
}