rustfs-mimalloc 0.5.2

//! Stats, options, version, and process information APIs.

use crate::MiMalloc;
use core::ffi::c_void;
use core::ptr::NonNull;

/// Mark the current thread as part of a thread pool for mimalloc.
///
/// This is a safe wrapper around mimalloc V3's `mi_thread_set_in_threadpool`.
/// The upstream API takes no pointers, only updates the current thread's
/// mimalloc thread-local state, and is intended to be called by custom
/// thread-pool worker threads. Repeated calls keep the same threadpool marker.
#[inline]
pub fn set_current_thread_in_threadpool() {
    unsafe { rustfs_mimalloc_sys::mi_thread_set_in_threadpool() }
}

/// Process memory information returned by [`MiMalloc::process_info`].
#[derive(Debug, Clone, Copy, Default)]
pub struct ProcessInfo {
    pub elapsed_msecs: usize,
    pub user_msecs: usize,
    pub system_msecs: usize,
    pub current_rss: usize,
    pub peak_rss: usize,
    pub current_commit: usize,
    pub peak_commit: usize,
    pub page_faults: usize,
}

impl MiMalloc {
    /// mimalloc version as `major * 10000 + minor * 100 + patch`.
    #[inline]
    pub fn version() -> i32 {
        unsafe { rustfs_mimalloc_sys::mi_version() }
    }

    /// Force garbage collection.
    #[inline]
    pub fn collect(force: bool) {
        unsafe { rustfs_mimalloc_sys::mi_collect(force) }
    }

    /// Usable size of an allocated block (may be larger than requested).
    ///
    /// # Safety
    /// `ptr` must have been allocated by mimalloc.
    #[inline]
    pub unsafe fn usable_size(ptr: *const u8) -> usize {
        unsafe { rustfs_mimalloc_sys::mi_usable_size(ptr as *const c_void) }
    }

    /// Free a mimalloc block when the allocation size is known.
    ///
    /// For small sizes this uses mimalloc's small-free fast path.
    ///
    /// # Safety
    /// `ptr` must be null or a valid mimalloc allocation, and `size` must be
    /// the allocation size used for the corresponding allocation.
    #[inline]
    pub unsafe fn free_csize(ptr: *mut u8, size: usize) {
        unsafe { rustfs_mimalloc_sys::mi_free_csize(ptr as *mut c_void, size) }
    }

    /// Free a non-null mimalloc block when the allocation size is known.
    ///
    /// For small sizes this uses mimalloc's non-null small-free fast path.
    ///
    /// # Safety
    /// `ptr` must be a valid mimalloc allocation, and `size` must be the
    /// allocation size used for the corresponding allocation.
    #[inline]
    pub unsafe fn free_csize_nonnull(ptr: NonNull<u8>, size: usize) {
        unsafe { rustfs_mimalloc_sys::mi_free_csize_nonnull(ptr.as_ptr() as *mut c_void, size) }
    }

    /// Free a small mimalloc block.
    ///
    /// # Safety
    /// `ptr` must be null or a valid mimalloc allocation whose allocation size
    /// is less than or equal to [`crate::MI_SMALL_SIZE_MAX`].
    #[inline]
    pub unsafe fn free_small(ptr: *mut u8) {
        unsafe { rustfs_mimalloc_sys::mi_free_small(ptr as *mut c_void) }
    }

    /// Free a non-null small mimalloc block.
    ///
    /// # Safety
    /// `ptr` must be a valid mimalloc allocation whose allocation size is less
    /// than or equal to [`crate::MI_SMALL_SIZE_MAX`].
    #[inline]
    pub unsafe fn free_small_nonnull(ptr: NonNull<u8>) {
        unsafe { rustfs_mimalloc_sys::mi_free_small_nonnull(ptr.as_ptr() as *mut c_void) }
    }

    /// Process memory information.
    pub fn process_info() -> ProcessInfo {
        let mut info = ProcessInfo::default();
        unsafe {
            rustfs_mimalloc_sys::mi_process_info(
                &mut info.elapsed_msecs,
                &mut info.user_msecs,
                &mut info.system_msecs,
                &mut info.current_rss,
                &mut info.peak_rss,
                &mut info.current_commit,
                &mut info.peak_commit,
                &mut info.page_faults,
            );
        }
        info
    }

    // ── Stats ───────────────────────────────────────────────────────────────

    /// Allocation statistics as JSON. Returns empty string on failure.
    pub fn stats_json() -> String {
        unsafe {
            crate::ffi::owned_mimalloc_string(rustfs_mimalloc_sys::mi_stats_get_json(
                0,
                core::ptr::null_mut(),
            ))
        }
    }

    /// Allocation statistics in mimalloc's human-readable text format.
    pub fn stats_print() -> String {
        crate::ffi::collect_mimalloc_output(|out, arg| unsafe {
            rustfs_mimalloc_sys::mi_stats_print_out(out, arg);
        })
    }

    /// Reset accumulated mimalloc allocation statistics.
    #[inline]
    pub fn stats_reset() {
        unsafe { rustfs_mimalloc_sys::mi_stats_reset() }
    }

    /// Process memory information in mimalloc's human-readable text format.
    pub fn process_info_print() -> String {
        crate::ffi::collect_mimalloc_output(|out, arg| unsafe {
            rustfs_mimalloc_sys::mi_process_info_print_out(out, arg);
        })
    }

    // ── Options ─────────────────────────────────────────────────────────────

    /// Check if an option is enabled.
    #[inline]
    pub fn option_is_enabled(option: rustfs_mimalloc_sys::mi_option_t) -> bool {
        unsafe { rustfs_mimalloc_sys::mi_option_is_enabled(option) }
    }

    /// Get an option value.
    #[inline]
    pub fn option_get(option: rustfs_mimalloc_sys::mi_option_t) -> rustfs_mimalloc_sys::c_long {
        unsafe { rustfs_mimalloc_sys::mi_option_get(option) }
    }

    /// Get an option value as size (bytes).
    #[inline]
    pub fn option_get_size(option: rustfs_mimalloc_sys::mi_option_t) -> usize {
        unsafe { rustfs_mimalloc_sys::mi_option_get_size(option) }
    }

    /// Set an option value.
    ///
    /// ```rust
    /// use rustfs_mimalloc::MiMalloc;
    /// use rustfs_mimalloc_sys::mi_option_t;
    ///
    /// // Return memory to OS immediately
    /// MiMalloc::option_set(mi_option_t::mi_option_purge_delay, 0);
    /// ```
    #[inline]
    pub fn option_set(
        option: rustfs_mimalloc_sys::mi_option_t,
        value: rustfs_mimalloc_sys::c_long,
    ) {
        unsafe { rustfs_mimalloc_sys::mi_option_set(option, value) }
    }

    /// Enable an option.
    #[inline]
    pub fn option_enable(option: rustfs_mimalloc_sys::mi_option_t) {
        unsafe { rustfs_mimalloc_sys::mi_option_enable(option) }
    }

    /// Disable an option.
    #[inline]
    pub fn option_disable(option: rustfs_mimalloc_sys::mi_option_t) {
        unsafe { rustfs_mimalloc_sys::mi_option_disable(option) }
    }
}

// ── Tests ───────────────────────────────────────────────────────────────────

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

    #[test]
    fn version_is_v3() {
        assert!(MiMalloc::version() >= 30501, "expected >= V3.5.1");
    }

    #[test]
    fn stats_json_not_empty() {
        let json = MiMalloc::stats_json();
        assert!(!json.is_empty());
    }

    #[test]
    fn stats_print_not_empty() {
        let stats = MiMalloc::stats_print();
        assert!(!stats.is_empty());
    }

    #[test]
    fn stats_reset_smoke() {
        MiMalloc::stats_reset();
    }

    #[test]
    fn process_info_print_not_empty() {
        let info = MiMalloc::process_info_print();
        assert!(!info.is_empty());
    }

    #[test]
    fn option_roundtrip() {
        // Just verify no panic
        let _ = MiMalloc::option_get(mi_option_t::mi_option_purge_delay);
        let _ = MiMalloc::option_is_enabled(mi_option_t::mi_option_show_errors);
    }

    #[test]
    fn process_info_smoke() {
        let info = MiMalloc::process_info();
        let _ = info;
    }

    #[test]
    fn set_current_thread_in_threadpool_smoke() {
        set_current_thread_in_threadpool();
        set_current_thread_in_threadpool();
    }

    #[test]
    fn usable_size_at_least_requested() {
        unsafe {
            let ptr = rustfs_mimalloc_sys::mi_malloc(64);
            assert!(MiMalloc::usable_size(ptr as *const u8) >= 64);
            rustfs_mimalloc_sys::mi_free(ptr);
        }
    }

    #[test]
    fn free_small_nonnull_smoke() {
        unsafe {
            let ptr = rustfs_mimalloc_sys::mi_malloc_small(64);
            let ptr = NonNull::new(ptr as *mut u8).expect("mi_malloc_small returned null");
            MiMalloc::free_small_nonnull(ptr);
        }
    }

    #[test]
    fn free_csize_routes_small_and_large() {
        unsafe {
            let small = rustfs_mimalloc_sys::mi_malloc_small(64);
            MiMalloc::free_csize(small as *mut u8, 64);

            let large_size = rustfs_mimalloc_sys::MI_SMALL_SIZE_MAX + 64;
            let large = rustfs_mimalloc_sys::mi_malloc(large_size);
            let large = NonNull::new(large as *mut u8).expect("mi_malloc returned null");
            MiMalloc::free_csize_nonnull(large, large_size);
        }
    }
}