use Inferno to generate flamegraphs

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## Unreleased
+### Added
+- `flamegraph`: new tool that uses the `inferno` crate to generate flamegraph svg files ([GH-73])
+
 ## [0.4.0] - 2019-10-24
 ### Added
 - `measureme`: Added RAII-based API for recording events ([GH-70])
@@ -37,3 +41,4 @@
 [GH-59]: https://github.com/rust-lang/measureme/pull/59
 [GH-60]: https://github.com/rust-lang/measureme/pull/60
 [GH-70]: https://github.com/rust-lang/measureme/pull/70
+[GH-73]: https://github.com/rust-lang/measureme/pull/73

Cargo.toml

@@ -6,4 +6,6 @@ members = [
     "mmview",
     "stack_collapse",
     "summarize",
+    "tools_lib",
+    "flamegraph",
 ]

README.md

@@ -29,6 +29,12 @@ It contains two main modes:
 
 [Learn more](./stack_collapse/README.md)
 
+### flamegraph
+
+`flamegraph` reads `measureme` profiling data and outputs [Flame Graph](https://github.com/brendangregg/FlameGraph).
+
+[Learn more](./flamegraph/README.md)
+
 ### crox
 
 `crox` turns `measureme` profiling data into files that can be visualized by the Chromium performance tools.

flamegraph/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "flamegraph"
+version = "0.1.0"
+authors = ["Wesley Wiser <wwiser@gmail.com>", "Michael Woerister <michaelwoerister@posteo>"]
+edition = "2018"
+license = "MIT OR Apache-2.0"
+
+[dependencies]
+measureme = { path = "../measureme" }
+tools_lib = { path = "../tools_lib" }
+structopt = "0.2"
+inferno = { version="0.9.1", default-features = false }

flamegraph/README.md

@@ -0,0 +1,17 @@
+# flamegraph
+
+flamegraph is a tool to produce [Flame Graph](https://github.com/brendangregg/FlameGraph) from `measureme` data.
+
+## Example
+
+```bash
+$ git clone https://github.com/rust-lang/regex.git
+
+$ cd regex
+
+$ cargo rustc -- -Z self-profile
+
+$ flamegraph pid-{pid}
+
+$ open rustc.svg
+```

flamegraph/src/main.rs

@@ -0,0 +1,53 @@
+use std::error::Error;
+use std::fs::File;
+use std::io::BufWriter;
+use std::path::PathBuf;
+use std::time::Duration;
+
+use measureme::ProfilingData;
+
+use structopt::StructOpt;
+
+use tools_lib::stack_collapse::collapse_stacks;
+
+use inferno::flamegraph::{from_lines, Options as FlamegraphOptions};
+
+#[derive(StructOpt, Debug)]
+struct Opt {
+    file_prefix: PathBuf,
+
+    /// The sampling interval in milliseconds
+    #[structopt(short = "i", long = "interval", default_value = "1")]
+    interval: u64,
+}
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let opt = Opt::from_args();
+
+    let profiling_data = ProfilingData::new(&opt.file_prefix)?;
+
+    let first_event_time = {
+        let current_time = profiling_data.iter().next().unwrap().timestamp;
+        current_time + Duration::from_millis(opt.interval)
+    };
+
+    let recorded_stacks = collapse_stacks(profiling_data.iter(), first_event_time, opt.interval)
+        .iter()
+        .map(|(unique_stack, count)| format!("{} {}", unique_stack, count))
+        .collect::<Vec<_>>();
+
+    let file = BufWriter::new(File::create("rustc.svg")?);
+    let mut flamegraph_options = FlamegraphOptions::default();
+
+    from_lines(
+        &mut flamegraph_options,
+        recorded_stacks.iter().map(|s| s.as_ref()),
+        file,
+    )
+    .expect(
+        "unable to generate a flamegraph \
+         from the collapsed stack data",
+    );
+
+    Ok(())
+}

stack_collapse/Cargo.toml

@@ -7,4 +7,5 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 measureme = { path = "../measureme" }
+tools_lib = { path = "../tools_lib" }
 structopt = "0.2"

stack_collapse/src/main.rs

@@ -8,9 +8,7 @@ use measureme::ProfilingData;
 
 use structopt::StructOpt;
 
-mod stack_collapse;
-
-use stack_collapse::collapse_stacks;
+use tools_lib::stack_collapse::collapse_stacks;
 
 #[derive(StructOpt, Debug)]
 struct Opt {

tools_lib/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "tools_lib"
+version = "0.1.0"
+authors = ["Wesley Wiser <wwiser@gmail.com>", "Michael Woerister <michaelwoerister@posteo>"]
+edition = "2018"
+license = "MIT OR Apache-2.0"
+
+[dependencies]
+measureme = { path = "../measureme" }

tools_lib/src/lib.rs

@@ -0,0 +1 @@
+pub mod stack_collapse;