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Optimize extension performance

Optimize your extensions for production to reduce load times.

Combine multiple extensions​

Combining multiple extensions that share code or dependencies can reduce file size, speed up installation, and reduce load times on app launch.

A single extension's activate function can call multiple registration functions to add different features:

export function activate(extensionContext: ExtensionContext) {
  extensionContext.registerPanel({ name: "my-panel", initPanel: initCustomPanel });
  extensionContext.registerPanel({ name: "my-other-panel", initPanel: initAnotherCustomPanel });
  extensionContext.registerMessageConverter({
    fromSchemaName: "...",
    toSchemaName: "...",
    converter: (inputMessage: MyInputType, messageEvent: MessageEvent<MyInputType>) => {
      // ...
    },
  });
  extensionContext.registerTopicAliases((args) => {
    // ...
  });
}

Minimize WASM/host boundary crossings (data loaders)​

For data loaders, each call from your WASM module into the host (for example Reader::open) crosses the WASM/host boundary. These crossings can be costly.

To keep loaders fast:

  • Read in larger chunks rather than issuing many small reads.
  • Cache file metadata gathered during initialize so message iteration doesn't re-fetch it.
  • Profile by counting boundary crossings before optimizing decode logic.

If your file format doesn't have its own index, consider building one during initialize by scanning front-to-back and recording message offsets, channel boundaries, and chunk locations. Paying that indexing cost up front keeps seeks responsive; the pcap data loader prototype is a good reference.

Disable source maps​

By default, extensions are packaged with source maps to improve the debugging experience. However, source maps take up additional space and can slow down extension installation and loading.

If your extension grows, consider disabling source maps by adding a file named config.ts with the following contents:

module.exports = {
  webpack: (config) => {
    config.devtool = undefined; // disable source maps to reduce bundle size
    return config;
  },
};