custom write and read are much slower than the default

[GalmWing]

I was trying to speed up the cache read/write, so I decided to store stuff in memory with node-cache, instead of in the filesystem (default behavior).

To my surprise, the build time is slower with in-memory cache than with filesystem, it's so slow even a build without cache-loader is faster.

node-cache has pretty much the same function signatures as the example provided in the docs here for Redis. so my implementation is basically carbon copy of that

const NodeCache = require( "node-cache" );
const myCache = new NodeCache();
const BUILD_CACHE_TIMEOUT = 24 * 3600; // 1 day
// Read data from database and parse them
function read(key, callback) {
  myCache.get(key, (err, result) => {
    if (err) {
      return callback(err);
    }

    if (!result) {
      return callback(new Error(`Key ${key} not found`));
    }

    try {
      let data = JSON.parse(result);
      callback(null, data);
    } catch (e) {
      callback(e);
    }
  });
}

// Write data to database under cacheKey
function write(key, data, callback) {
  myCache.set(key, JSON.stringify(data), BUILD_CACHE_TIMEOUT, callback);
}


...
module.exports = {
  // rest of config
  use: [
          {
            loader: "cache-loader",
            options: { read, write }
          },
          { loader: "babel-loader"},
          { loader: "ts-loader" }
        ]
}

My project is quite massive, hundreds of tsx files that need both babel and ts loaders (which is why I wanted to do caching).

Incremental build times:

• Without cache-loader: 30s
• With cache-loader and default read/write: 20s
• With cache-loader and custom read/write to memory: 50s

[alexander-akait]

Looks custom cache is more slow than original, what is problem?

[GalmWing]

The custom cache shouldn't be that slow. node-cache by itself (the module I'm using to cache in-memory) is very fast, and I'm not adding any overhead, cache-loader does also a json serialization with the default options. So I don't see why my custom read and write methods would make cache-loader be this slow

[alexander-akait]

@GalmWing Feel free to investigate what is problem, should be not difficult