new utility: report-profile.ts

Author: cscheid

tools/profiler/lua-profiler-data-loader.ts

@@ -0,0 +1,85 @@
+import { LuaStack } from "./types.ts";
+
+export const loadProfilerData = (filename: string, frameSkip: number = 3): LuaStack[] => {
+  let longestCommonPrefix: string | undefined = undefined;
+  const file = Deno.readTextFileSync(filename);
+  // find the longest common prefix for source to trim
+  for (const fileLine of file.split("\n")) {
+    if (fileLine === "") 
+      continue;
+    const entries = fileLine.split(" ");
+    if (entries.length === 4) {
+      continue;
+    }
+    const [_name, source] = fileLine.split(" ");
+    if (source === "=[C]") continue;
+  
+    if (longestCommonPrefix === undefined) {
+      longestCommonPrefix = source;
+    } else {
+      // find the longest common prefix
+      let i = 0;
+      while (i < longestCommonPrefix.length && longestCommonPrefix[i] === source[i]) {
+        i++;
+      }
+      longestCommonPrefix = longestCommonPrefix.slice(0, i);
+    }
+  }
+  
+  if (longestCommonPrefix === undefined) {
+    throw new Error("Internal error: no common prefix found");
+  }
+  
+  type LuaStack = {
+    frames: LuaStackFrame[];
+    time: number;
+    line: number;
+    category: string;
+  }
+  
+  type LuaStackFrame = {
+    location: string;
+    // name: string;
+    // source: string;
+    // line: number;
+  }
+  
+  const stacks: LuaStack[] = [];
+  let stackNum = "";
+  let time = 0;
+  let thisStack: LuaStackFrame[] = [];
+  let category = "";
+  
+  for (const fileLine of file.split("\n")) {
+    if (fileLine === "") continue;
+    const entries = fileLine.split(" ");
+    if (entries.length === 4) {
+      category = entries[2];
+      if (stackNum !== entries[0]) {
+        if (thisStack.length) {
+          thisStack[0].location = `${thisStack[0].location}:${entries[3]}`;
+        }
+        stacks.push({
+          frames: thisStack,
+          time: Number(entries[1]),
+          line: Number(entries[3]),
+          category
+        });
+        thisStack = [];
+        stackNum = entries[0];
+      }
+      continue;
+    }
+    const [name, source, line] = fileLine.split(" ");
+    try {
+      const frame: LuaStackFrame = {
+        location: `${source.slice(longestCommonPrefix.length)}:${line}:${name}`,
+      };
+      thisStack.push(frame);
+    } catch (_e) {
+      throw new Error(`Error parsing line: ${fileLine}`);
+    }
+  }
+
+  return stacks;
+}

tools/profiler/report-profile.ts

@@ -0,0 +1,34 @@
+import { loadProfilerData } from "./lua-profiler-data-loader.ts";
+import { LuaStack } from "./types.ts";
+
+const filename = Deno.args[0];
+const frameSkip = Deno.args[1] === undefined ? 3 : Number(Deno.args[1]);
+const stacks = loadProfilerData(filename, frameSkip);
+
+const estimateSampleRate = (stacks: LuaStack[]) => {
+  return (stacks[stacks.length - 1].time - stacks[0].time) / (stacks.length - 1);
+}
+
+const totalTime = stacks[stacks.length - 1].time - stacks[0].time;
+const sampleRate = estimateSampleRate(stacks);
+
+const selfTimes = new Map<string, number>();
+
+for (const stack of stacks) {
+  const topFrame = stack.frames[0];
+  const location = topFrame.location;
+  if (!selfTimes.has(location)) {
+    selfTimes.set(location, 0);
+  }
+  selfTimes.set(location, selfTimes.get(location)! + sampleRate);
+}
+
+const roundToDigits = (num: number, digits: number) => {
+  const factor = 10 ** digits;
+  return Math.round(num * factor) / factor;
+}
+
+console.log(
+  Array.from(selfTimes.entries())
+    .sort((a, b) => b[1] - a[1])
+    .map(([location, time]) => `${roundToDigits(100 * time / totalTime, 1)}% (${roundToDigits(time, 3)}): ${location}`).join("\n"));

tools/profiler/types.ts

@@ -0,0 +1,13 @@
+export type LuaStack = {
+  frames: LuaStackFrame[];
+  time: number;
+  line: number;
+  category: string;
+}
+
+export type LuaStackFrame = {
+  location: string;
+  // name: string;
+  // source: string;
+  // line: number;
+}