From bd9ede0ec9fb76c8cc0b572ef0405811e1cb666e Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Sat, 25 Apr 2020 21:04:04 +0200 Subject: Extract messy tree handling out of profiling code --- crates/ra_prof/src/hprof.rs | 179 +++++++------------------------------------- crates/ra_prof/src/lib.rs | 1 + crates/ra_prof/src/tree.rs | 84 +++++++++++++++++++++ 3 files changed, 114 insertions(+), 150 deletions(-) create mode 100644 crates/ra_prof/src/tree.rs (limited to 'crates/ra_prof/src') diff --git a/crates/ra_prof/src/hprof.rs b/crates/ra_prof/src/hprof.rs index 4bbe5cb12..2b8a90363 100644 --- a/crates/ra_prof/src/hprof.rs +++ b/crates/ra_prof/src/hprof.rs @@ -1,4 +1,5 @@ //! Simple hierarchical profiler +use once_cell::sync::Lazy; use std::{ cell::RefCell, collections::{BTreeMap, HashSet}, @@ -10,7 +11,7 @@ use std::{ time::{Duration, Instant}, }; -use once_cell::sync::Lazy; +use crate::tree::{Idx, Tree}; /// Filtering syntax /// env RA_PROFILE=* // dump everything @@ -138,12 +139,12 @@ impl Filter { struct ProfileStack { starts: Vec, - messages: Vec, filter: Filter, + messages: Tree, } +#[derive(Default)] struct Message { - level: usize, duration: Duration, label: Label, detail: Option, @@ -151,7 +152,7 @@ struct Message { impl ProfileStack { fn new() -> ProfileStack { - ProfileStack { starts: Vec::new(), messages: Vec::new(), filter: Default::default() } + ProfileStack { starts: Vec::new(), messages: Tree::default(), filter: Default::default() } } fn push(&mut self, label: Label) -> bool { @@ -171,6 +172,7 @@ impl ProfileStack { } self.starts.push(Instant::now()); + self.messages.start(); true } @@ -178,7 +180,7 @@ impl ProfileStack { let start = self.starts.pop().unwrap(); let duration = start.elapsed(); let level = self.starts.len(); - self.messages.push(Message { level, duration, label, detail }); + self.messages.finish(Message { duration, label, detail }); if level == 0 { let longer_than = self.filter.longer_than; // Convert to millis for comparison to avoid problems with rounding @@ -186,7 +188,9 @@ impl ProfileStack { // `duration` is just a few nanos). if duration.as_millis() > longer_than.as_millis() { let stderr = stderr(); - print(&self.messages, longer_than, &mut stderr.lock()); + if let Some(root) = self.messages.root() { + print(&self.messages, root, 0, longer_than, &mut stderr.lock()); + } } self.messages.clear(); assert!(self.starts.is_empty()) @@ -194,50 +198,38 @@ impl ProfileStack { } } -fn print(msgs: &[Message], longer_than: Duration, out: &mut impl Write) { - if msgs.is_empty() { - return; - } - let children_map = idx_to_children(msgs); - let root_idx = msgs.len() - 1; - print_for_idx(root_idx, &children_map, msgs, longer_than, out); -} - -fn print_for_idx( - current_idx: usize, - children_map: &[Vec], - msgs: &[Message], +fn print( + tree: &Tree, + curr: Idx, + level: u32, longer_than: Duration, out: &mut impl Write, ) { - let current = &msgs[current_idx]; - let current_indent = " ".repeat(current.level); - let detail = current.detail.as_ref().map(|it| format!(" @ {}", it)).unwrap_or_default(); + let current_indent = " ".repeat(level as usize); + let detail = tree[curr].detail.as_ref().map(|it| format!(" @ {}", it)).unwrap_or_default(); writeln!( out, "{}{:5}ms - {}{}", current_indent, - current.duration.as_millis(), - current.label, + tree[curr].duration.as_millis(), + tree[curr].label, detail, ) .expect("printing profiling info"); - let longer_than_millis = longer_than.as_millis(); - let children_indices = &children_map[current_idx]; let mut accounted_for = Duration::default(); let mut short_children = BTreeMap::new(); // Use `BTreeMap` to get deterministic output. + for child in tree.children(curr) { + accounted_for += tree[child].duration; - for child_idx in children_indices.iter() { - let child = &msgs[*child_idx]; - if child.duration.as_millis() > longer_than_millis { - print_for_idx(*child_idx, children_map, msgs, longer_than, out); + if tree[child].duration.as_millis() > longer_than.as_millis() { + print(tree, child, level + 1, longer_than, out) } else { - let pair = short_children.entry(child.label).or_insert((Duration::default(), 0)); - pair.0 += child.duration; - pair.1 += 1; + let (total_duration, cnt) = + short_children.entry(tree[child].label).or_insert((Duration::default(), 0)); + *total_duration += tree[child].duration; + *cnt += 1; } - accounted_for += child.duration; } for (child_msg, (duration, count)) in short_children.iter() { @@ -246,122 +238,9 @@ fn print_for_idx( .expect("printing profiling info"); } - let unaccounted_millis = (current.duration - accounted_for).as_millis(); - if !children_indices.is_empty() - && unaccounted_millis > 0 - && unaccounted_millis > longer_than_millis - { - writeln!(out, " {}{:5}ms - ???", current_indent, unaccounted_millis) + let unaccounted = tree[curr].duration - accounted_for; + if tree.children(curr).next().is_some() && unaccounted > longer_than { + writeln!(out, " {}{:5}ms - ???", current_indent, unaccounted.as_millis()) .expect("printing profiling info"); } } - -/// Returns a mapping from an index in the `msgs` to the vector with the indices of its children. -/// -/// This assumes that the entries in `msgs` are in the order of when the calls to `profile` finish. -/// In other words, a postorder of the call graph. In particular, the root is the last element of -/// `msgs`. -fn idx_to_children(msgs: &[Message]) -> Vec> { - // Initialize with the index of the root; `msgs` and `ancestors` should be never empty. - assert!(!msgs.is_empty()); - let mut ancestors = vec![msgs.len() - 1]; - let mut result: Vec> = vec![vec![]; msgs.len()]; - for (idx, msg) in msgs[..msgs.len() - 1].iter().enumerate().rev() { - // We need to find the parent of the current message, i.e., the last ancestor that has a - // level lower than the current message. - while msgs[*ancestors.last().unwrap()].level >= msg.level { - ancestors.pop(); - } - result[*ancestors.last().unwrap()].push(idx); - ancestors.push(idx); - } - // Note that above we visited all children from the last to the first one. Let's reverse vectors - // to get the more natural order where the first element is the first child. - for vec in result.iter_mut() { - vec.reverse(); - } - result -} - -#[cfg(test)] -mod tests { - use super::*; - - #[test] - fn test_basic_profile() { - let s = vec!["profile1".to_string(), "profile2".to_string()]; - let f = Filter::new(2, s, Duration::new(0, 0)); - set_filter(f); - profiling_function1(); - } - - fn profiling_function1() { - let _p = profile("profile1"); - profiling_function2(); - } - - fn profiling_function2() { - let _p = profile("profile2"); - } - - #[test] - fn test_longer_than() { - let mut result = vec![]; - let msgs = vec![ - Message { level: 1, duration: Duration::from_nanos(3), label: "bar", detail: None }, - Message { level: 1, duration: Duration::from_nanos(2), label: "bar", detail: None }, - Message { level: 0, duration: Duration::from_millis(1), label: "foo", detail: None }, - ]; - print(&msgs, Duration::from_millis(0), &mut result); - // The calls to `bar` are so short that they'll be rounded to 0ms and should get collapsed - // when printing. - assert_eq!( - std::str::from_utf8(&result).unwrap(), - " 1ms - foo\n 0ms - bar (2 calls)\n" - ); - } - - #[test] - fn test_unaccounted_for_topmost() { - let mut result = vec![]; - let msgs = vec![ - Message { level: 1, duration: Duration::from_millis(2), label: "bar", detail: None }, - Message { level: 0, duration: Duration::from_millis(5), label: "foo", detail: None }, - ]; - print(&msgs, Duration::from_millis(0), &mut result); - assert_eq!( - std::str::from_utf8(&result).unwrap().lines().collect::>(), - vec![ - " 5ms - foo", - " 2ms - bar", - " 3ms - ???", - // Dummy comment to improve formatting - ] - ); - } - - #[test] - fn test_unaccounted_for_multiple_levels() { - let mut result = vec![]; - let msgs = vec![ - Message { level: 2, duration: Duration::from_millis(3), label: "baz", detail: None }, - Message { level: 1, duration: Duration::from_millis(5), label: "bar", detail: None }, - Message { level: 2, duration: Duration::from_millis(2), label: "baz", detail: None }, - Message { level: 1, duration: Duration::from_millis(4), label: "bar", detail: None }, - Message { level: 0, duration: Duration::from_millis(9), label: "foo", detail: None }, - ]; - print(&msgs, Duration::from_millis(0), &mut result); - assert_eq!( - std::str::from_utf8(&result).unwrap().lines().collect::>(), - vec![ - " 9ms - foo", - " 5ms - bar", - " 3ms - baz", - " 2ms - ???", - " 4ms - bar", - " 2ms - baz", - " 2ms - ???", - ] - ); - } -} diff --git a/crates/ra_prof/src/lib.rs b/crates/ra_prof/src/lib.rs index e6d672ef5..89df7f04b 100644 --- a/crates/ra_prof/src/lib.rs +++ b/crates/ra_prof/src/lib.rs @@ -4,6 +4,7 @@ mod memory_usage; #[cfg(feature = "cpu_profiler")] mod google_cpu_profiler; mod hprof; +mod tree; use std::cell::RefCell; diff --git a/crates/ra_prof/src/tree.rs b/crates/ra_prof/src/tree.rs new file mode 100644 index 000000000..9ea5b5db8 --- /dev/null +++ b/crates/ra_prof/src/tree.rs @@ -0,0 +1,84 @@ +//! A simple tree implementation which tries to not allocate all over the place. +use std::ops; + +use ra_arena::Arena; + +#[derive(Default)] +pub struct Tree { + nodes: Arena>, + current_path: Vec<(Idx, Option>)>, +} + +pub type Idx = ra_arena::Idx>; + +impl Tree { + pub fn start(&mut self) + where + T: Default, + { + let me = self.nodes.alloc(Node::new(T::default())); + if let Some((parent, last_child)) = self.current_path.last_mut() { + let slot = match *last_child { + Some(last_child) => &mut self.nodes[last_child].next_sibling, + None => &mut self.nodes[*parent].first_child, + }; + let prev = slot.replace(me); + assert!(prev.is_none()); + *last_child = Some(me); + } + + self.current_path.push((me, None)); + } + + pub fn finish(&mut self, data: T) { + let (me, _last_child) = self.current_path.pop().unwrap(); + self.nodes[me].data = data; + } + + pub fn root(&self) -> Option> { + self.nodes.iter().next().map(|(idx, _)| idx) + } + + pub fn children(&self, idx: Idx) -> impl Iterator> + '_ { + NodeIter { nodes: &self.nodes, next: self.nodes[idx].first_child } + } + pub fn clear(&mut self) { + self.nodes.clear(); + self.current_path.clear(); + } +} + +impl ops::Index> for Tree { + type Output = T; + fn index(&self, index: Idx) -> &T { + &self.nodes[index].data + } +} + +pub struct Node { + data: T, + first_child: Option>, + next_sibling: Option>, +} + +impl Node { + fn new(data: T) -> Node { + Node { data, first_child: None, next_sibling: None } + } +} + +struct NodeIter<'a, T> { + nodes: &'a Arena>, + next: Option>, +} + +impl<'a, T> Iterator for NodeIter<'a, T> { + type Item = Idx; + + fn next(&mut self) -> Option> { + self.next.map(|next| { + self.next = self.nodes[next].next_sibling; + next + }) + } +} -- cgit v1.2.3