adds tracing for instrumenting non-async functions (#44147)

Tracing code is not included in normal release builds
Documents how to use them in our performance docs
Only the maps and cursors are instrumented atm

# Compile times:
current main: fresh release build (cargo clean then build --release)
377.34 secs
current main: fresh debug build (cargo clean then build )
89.31 secs

tracing tracy: fresh release build (cargo clean then build --release)
374.84 secs
tracing tracy: fresh debug build (cargo clean then build )
88.95 secs

tracing tracy: fresh release build with timings (cargo clean then build
--release --features tracing)
375.77 secs
tracing tracy: fresh debug build with timings (cargo clean then build
--features tracing)
90.03 secs


Release Notes:

- N/A

---------

Co-authored-by: localcc <work@localcc.cc>

crates/sum_tree/src/cursor.rs

@@ -1,6 +1,7 @@
 use super::*;
 use arrayvec::ArrayVec;
 use std::{cmp::Ordering, mem, sync::Arc};
+use ztracing::instrument;
 
 #[derive(Clone)]
 struct StackEntry<'a, T: Item, D> {
@@ -211,6 +212,7 @@ where
     }
 
     #[track_caller]
+    #[instrument(skip_all)]
     pub fn prev(&mut self) {
         self.search_backward(|_| true)
     }
@@ -394,6 +396,7 @@ where
 {
     /// Returns whether we found the item you were seeking for.
     #[track_caller]
+    #[instrument(skip_all)]
     pub fn seek<Target>(&mut self, pos: &Target, bias: Bias) -> bool
     where
         Target: SeekTarget<'a, T::Summary, D>,
@@ -408,6 +411,7 @@ where
     ///
     /// If we did not seek before, use seek instead in that case.
     #[track_caller]
+    #[instrument(skip_all)]
     pub fn seek_forward<Target>(&mut self, pos: &Target, bias: Bias) -> bool
     where
         Target: SeekTarget<'a, T::Summary, D>,
@@ -449,6 +453,7 @@ where
 
     /// Returns whether we found the item you were seeking for.
     #[track_caller]
+    #[instrument(skip_all)]
     fn seek_internal(
         &mut self,
         target: &dyn SeekTarget<'a, T::Summary, D>,

crates/sum_tree/src/sum_tree.rs

@@ -8,6 +8,7 @@ use std::marker::PhantomData;
 use std::mem;
 use std::{cmp::Ordering, fmt, iter::FromIterator, sync::Arc};
 pub use tree_map::{MapSeekTarget, TreeMap, TreeSet};
+use ztracing::instrument;
 
 #[cfg(test)]
 pub const TREE_BASE: usize = 2;
@@ -379,6 +380,7 @@ impl<T: Item> SumTree<T> {
     /// A more efficient version of `Cursor::new()` + `Cursor::seek()` + `Cursor::item()`.
     ///
     /// Only returns the item that exactly has the target match.
+    #[instrument(skip_all)]
     pub fn find_exact<'a, 'slf, D, Target>(
         &'slf self,
         cx: <T::Summary as Summary>::Context<'a>,
@@ -404,6 +406,7 @@ impl<T: Item> SumTree<T> {
     }
 
     /// A more efficient version of `Cursor::new()` + `Cursor::seek()` + `Cursor::item()`
+    #[instrument(skip_all)]
     pub fn find<'a, 'slf, D, Target>(
         &'slf self,
         cx: <T::Summary as Summary>::Context<'a>,