From e457efc4d695014a2a8d1fd81c002fec8322ed4f Mon Sep 17 00:00:00 2001
From: Guillaume Endignoux <guillaumee@google.com>
Date: Thu, 25 Jun 2020 15:46:08 +0200
Subject: [PATCH] Add a heap visualization tool.

---
 run_desktop_tests.sh      |  2 +
 tools/heapviz/Cargo.toml  | 12 ++++++
 tools/heapviz/src/main.rs | 90 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 104 insertions(+)
 create mode 100644 tools/heapviz/Cargo.toml
 create mode 100644 tools/heapviz/src/main.rs

diff --git a/run_desktop_tests.sh b/run_desktop_tests.sh
index 07b652e..8bcd2d7 100755
--- a/run_desktop_tests.sh
+++ b/run_desktop_tests.sh
@@ -26,6 +26,8 @@ cd ../..
 
 echo "Building sha256sum tool..."
 cargo build --manifest-path third_party/tock/tools/sha256sum/Cargo.toml
+echo "Checking that heapviz tool builds properly..."
+cargo build --manifest-path tools/heapviz/Cargo.toml
 
 echo "Checking that CTAP2 builds properly..."
 cargo check --release --target=thumbv7em-none-eabi
diff --git a/tools/heapviz/Cargo.toml b/tools/heapviz/Cargo.toml
new file mode 100644
index 0000000..e173d17
--- /dev/null
+++ b/tools/heapviz/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "heapviz"
+version = "0.1.0"
+authors = [
+  "Guillaume Endignoux <guillaumee@google.com>",
+]
+license = "Apache-2.0"
+edition = "2018"
+
+[dependencies]
+ncurses = "5.99.0"
+regex = "1"
diff --git a/tools/heapviz/src/main.rs b/tools/heapviz/src/main.rs
new file mode 100644
index 0000000..82e07dd
--- /dev/null
+++ b/tools/heapviz/src/main.rs
@@ -0,0 +1,90 @@
+use regex::Regex;
+use std::io::{BufRead, Write};
+use std::thread::sleep;
+use std::time::Duration;
+
+struct Event {
+    is_alloc: bool,
+    start: usize,
+    len: usize,
+}
+
+fn main() {
+    let re = Regex::new(r"^(alloc|dealloc)\[(\d+), \d+\] = 0x([0-9a-f]+) \(\d+ ptrs, \d+ bytes\)$")
+        .unwrap();
+
+    let mut events = Vec::new();
+    for line in std::io::stdin().lock().lines() {
+        if let Some(caps) = re.captures(&line.unwrap()) {
+            let typ = caps.get(1).unwrap().as_str();
+            let len = caps.get(2).unwrap().as_str().parse::<usize>().unwrap();
+            let start = usize::from_str_radix(&caps.get(3).unwrap().as_str(), 16).unwrap();
+            events.push(Event {
+                is_alloc: typ == "alloc",
+                start,
+                len,
+            });
+        }
+    }
+
+    let count_alloc = events.iter().filter(|e| e.is_alloc).count();
+    let count_dealloc = events.len() - count_alloc;
+    let start = events.iter().map(|e| e.start).min().unwrap_or(0);
+    let end = events.iter().map(|e| e.start + e.len).max().unwrap_or(0);
+    let mut usage = 0;
+    let peak = events
+        .iter()
+        .map(|e| {
+            if e.is_alloc {
+                usage += e.len;
+            } else {
+                usage -= e.len;
+            }
+            usage
+        })
+        .max()
+        .unwrap_or(0);
+    let len = end - start;
+    println!(
+        "Observed {} allocations and {} deallocations",
+        count_alloc, count_dealloc
+    );
+    println!("Start address: {:08x}", start);
+    println!("End address: {:08x}", end);
+    println!("Peak usage: {0} = {0:08x} bytes", peak);
+    println!("Peak consumption: {0} = {0:08x} bytes", len);
+    println!("Fragmentation overhead: {0} = {0:08x} bytes", len - peak);
+
+    print!("\nLoading visualization");
+    for _ in 0..30 {
+        print!(".");
+        std::io::stdout().flush().unwrap();
+        sleep(Duration::from_millis(50));
+    }
+    println!();
+
+    let window = ncurses::initscr();
+    ncurses::cbreak();
+    ncurses::noecho();
+    ncurses::intrflush(window, false);
+    ncurses::curs_set(ncurses::CURSOR_VISIBILITY::CURSOR_INVISIBLE);
+
+    let width = ncurses::getmaxx(window) as usize;
+
+    for e in events.iter() {
+        let position = e.start - start;
+        ncurses::wmove(window, (position / width) as i32, (position % width) as i32);
+
+        let mut s = Vec::with_capacity(e.len);
+        if e.is_alloc {
+            s.resize(e.len, b'#');
+        } else {
+            s.resize(e.len, b'.');
+        }
+        ncurses::addstr(std::str::from_utf8(s.as_slice()).unwrap());
+        ncurses::refresh();
+        sleep(Duration::from_millis(50));
+    }
+
+    ncurses::endwin();
+}