From bd9ede0ec9fb76c8cc0b572ef0405811e1cb666e Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Sat, 25 Apr 2020 21:04:04 +0200
Subject: [PATCH] Extract messy tree handling out of profiling code
---
Cargo.lock | 1 +
crates/ra_arena/src/lib.rs | 3 +
crates/ra_prof/Cargo.toml | 1 +
crates/ra_prof/src/hprof.rs | 179 ++++++------------------------------
crates/ra_prof/src/lib.rs | 1 +
crates/ra_prof/src/tree.rs | 84 +++++++++++++++++
6 files changed, 119 insertions(+), 150 deletions(-)
create mode 100644 crates/ra_prof/src/tree.rs
diff --git a/Cargo.lock b/Cargo.lock
index 20e6cd54030..367ff3f8281 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1139,6 +1139,7 @@ dependencies = [
"jemalloc-ctl",
"jemallocator",
"once_cell",
+ "ra_arena",
]
[[package]]
diff --git a/crates/ra_arena/src/lib.rs b/crates/ra_arena/src/lib.rs
index ea98d54441a..441fbb3cbef 100644
--- a/crates/ra_arena/src/lib.rs
+++ b/crates/ra_arena/src/lib.rs
@@ -96,6 +96,9 @@ impl<T> Arena<T> {
pub const fn new() -> Arena<T> {
Arena { data: Vec::new() }
}
+ pub fn clear(&mut self) {
+ self.data.clear();
+ }
pub fn len(&self) -> usize {
self.data.len()
diff --git a/crates/ra_prof/Cargo.toml b/crates/ra_prof/Cargo.toml
index d15b089925c..c33b5121ae2 100644
--- a/crates/ra_prof/Cargo.toml
+++ b/crates/ra_prof/Cargo.toml
@@ -9,6 +9,7 @@ publish = false
doctest = false
[dependencies]
+ra_arena = { path = "../ra_arena" }
once_cell = "1.3.1"
backtrace = { version = "0.3.44", optional = true }
diff --git a/crates/ra_prof/src/hprof.rs b/crates/ra_prof/src/hprof.rs
index 4bbe5cb12d2..2b8a903636c 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<Instant>,
- messages: Vec<Message>,
filter: Filter,
+ messages: Tree<Message>,
}
+#[derive(Default)]
struct Message {
- level: usize,
duration: Duration,
label: Label,
detail: Option<String>,
@@ -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<usize>],
- msgs: &[Message],
+fn print(
+ tree: &Tree<Message>,
+ curr: Idx<Message>,
+ 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<Vec<usize>> {
- // 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<usize>> = 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<_>>(),
- 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<_>>(),
- 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 e6d672ef558..89df7f04b7f 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 00000000000..9ea5b5db8e1
--- /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<T> {
+ nodes: Arena<Node<T>>,
+ current_path: Vec<(Idx<T>, Option<Idx<T>>)>,
+}
+
+pub type Idx<T> = ra_arena::Idx<Node<T>>;
+
+impl<T> Tree<T> {
+ 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<Idx<T>> {
+ self.nodes.iter().next().map(|(idx, _)| idx)
+ }
+
+ pub fn children(&self, idx: Idx<T>) -> impl Iterator<Item = Idx<T>> + '_ {
+ NodeIter { nodes: &self.nodes, next: self.nodes[idx].first_child }
+ }
+ pub fn clear(&mut self) {
+ self.nodes.clear();
+ self.current_path.clear();
+ }
+}
+
+impl<T> ops::Index<Idx<T>> for Tree<T> {
+ type Output = T;
+ fn index(&self, index: Idx<T>) -> &T {
+ &self.nodes[index].data
+ }
+}
+
+pub struct Node<T> {
+ data: T,
+ first_child: Option<Idx<T>>,
+ next_sibling: Option<Idx<T>>,
+}
+
+impl<T> Node<T> {
+ fn new(data: T) -> Node<T> {
+ Node { data, first_child: None, next_sibling: None }
+ }
+}
+
+struct NodeIter<'a, T> {
+ nodes: &'a Arena<Node<T>>,
+ next: Option<Idx<T>>,
+}
+
+impl<'a, T> Iterator for NodeIter<'a, T> {
+ type Item = Idx<T>;
+
+ fn next(&mut self) -> Option<Idx<T>> {
+ self.next.map(|next| {
+ self.next = self.nodes[next].next_sibling;
+ next
+ })
+ }
+}