feat(sys): reimplement ngx_event_t macros and inline methods

Bindgen does not support functional macros or inline functions, so we
have to maintain a copy of the implementation for any such item we need
to use.

Author: bavshin-f5

nginx-sys/src/event.rs

@@ -0,0 +1,83 @@
+use core::ptr;
+
+use crate::{
+    ngx_current_msec, ngx_event_t, ngx_event_timer_rbtree, ngx_msec_t, ngx_queue_insert_before, ngx_queue_remove,
+    ngx_queue_t, ngx_rbtree_delete, ngx_rbtree_insert, NGX_TIMER_LAZY_DELAY,
+};
+
+/// Sets a timeout for an event.
+///
+/// # Safety
+///
+///`ev` must be a valid pointer to an `ngx_event_t`.
+#[inline]
+pub unsafe fn ngx_add_timer(ev: *mut ngx_event_t, timer: ngx_msec_t) {
+    let key: ngx_msec_t = ngx_current_msec.wrapping_add(timer);
+
+    if (*ev).timer_set() != 0 {
+        /*
+         * Use a previous timer value if difference between it and a new
+         * value is less than NGX_TIMER_LAZY_DELAY milliseconds: this allows
+         * to minimize the rbtree operations for fast connections.
+         */
+        if key.abs_diff((*ev).timer.key) < NGX_TIMER_LAZY_DELAY as _ {
+            return;
+        }
+
+        ngx_del_timer(ev);
+    }
+
+    (*ev).timer.key = key;
+
+    ngx_rbtree_insert(
+        ptr::addr_of_mut!(ngx_event_timer_rbtree),
+        ptr::addr_of_mut!((*ev).timer),
+    );
+
+    (*ev).set_timer_set(1);
+}
+
+/// Deletes a previously set timeout.
+///
+/// # Safety
+///
+/// `ev` must be a valid pointer to an `ngx_event_t`, previously armed with [ngx_add_timer].
+#[inline]
+pub unsafe fn ngx_del_timer(ev: *mut ngx_event_t) {
+    ngx_rbtree_delete(
+        ptr::addr_of_mut!(ngx_event_timer_rbtree),
+        ptr::addr_of_mut!((*ev).timer),
+    );
+
+    (*ev).timer.left = ptr::null_mut();
+    (*ev).timer.right = ptr::null_mut();
+    (*ev).timer.parent = ptr::null_mut();
+
+    (*ev).set_timer_set(0);
+}
+
+/// Post the event `ev` to the post queue `q`.
+///
+/// # Safety
+///
+/// `ev` must be a valid pointer to an `ngx_event_t`.
+/// `q` is a valid pointer to a queue head.
+#[inline]
+pub unsafe fn ngx_post_event(ev: *mut ngx_event_t, q: *mut ngx_queue_t) {
+    if (*ev).posted() == 0 {
+        (*ev).set_posted(1);
+        ngx_queue_insert_before(q, ptr::addr_of_mut!((*ev).queue));
+    }
+}
+
+/// Deletes the event `ev` from the queue it's currently posted in.
+///
+/// # Safety
+///
+/// `ev` must be a valid pointer to an `ngx_event_t`.
+/// `ev.queue` is initialized with `ngx_queue_init`.
+#[inline]
+pub unsafe fn ngx_delete_posted_event(ev: *mut ngx_event_t) {
+    (*ev).set_posted(0);
+    ngx_queue_remove(ptr::addr_of_mut!((*ev).queue));
+}

nginx-sys/src/lib.rs

@@ -2,6 +2,7 @@
 #![warn(missing_docs)]
 #![no_std]
 
+mod event;
 mod queue;
 
 use core::fmt;
@@ -24,6 +25,7 @@ mod bindings {
 #[doc(no_inline)]
 pub use bindings::*;
 
+pub use event::*;
 pub use queue::*;
 
 /// The offset of the `main_conf` field in the `ngx_http_conf_ctx_t` struct.