as-heap-analyzer

assemblyscript heap dump analysis tooling

How to use

• install as-heap-analyzer

npm i -D as-heap-analyzer

• Before you build assemblyscript to wasm, add --transform as-heap-analyzer/transform/addHeapAnalyzerInfo.mjs or add following line in asconfig.json

"transform": ["as-heap-analyzer/transform/addHeapAnalyzerInfo.mjs"]

for run assemblyscript in nodejs

• run code and use analysis function

import { memory } from "../build/debug.js";
import { readFileSync } from "fs";
import { analysis } from "as-heap-analyzer/dist/index.js";
import assert from "assert";

const wasm = readFileSync("build/debug.wasm");
const memoryUsage = analysis(memory, wasm);
memoryUsage.forEach((v, k) => console.log(`${k} use ${v} bytes`));

for run assemblyscript in browser

• run code and use analysis function

import { memory } from "./build/release.js";
import { analysis } from "as-heap-analyzer/dist/index.js";

const wasm = (await (await fetch(new URL("build/release.wasm", import.meta.url))).body.getReader().read()).value;
const memoryUsage = analysis(new Uint8Array(memory.buffer), wasm);
memoryUsage.forEach((v, k) => {
  document.body.innerText += `${k} use ${v} bytes\n`;
});

for run assemblyscript in other device (self-diagnosis)

• use self-diagnosis API in assemblyscript to trace memory information to log

import { dumpUsedMemoryDetail } from "as-heap-analyzer/assembly/index";

trace(dumpUsedMemoryDetail());

• run cli

npx as-heap-analyzer frame <transformed_wasm_module_path>

• copy and paste self-diagnosis result from log to cli

• the result should be:

total memory usage is 48300
  class ~lib/arraybuffer/ArrayBuffer use 544 bytes
  class assembly/index/A use 6400 bytes
  class ~lib/array/Array<assembly/index/A> use 48 bytes
  class assembly/index/B use 32 bytes