cache power reports

Check version

• I'm running the latest version of Path of Building and I've verified this by checking the changelog

Check for duplicates

• I've checked for duplicate issues by using the search function of the issue tracker

Is your feature request related to a problem?

Power reports are extremely slow to generate, and they are often switched between even without modifying anything.

Describe the solution you'd like

A very simple cache would wok wonders for many use cases. You don't even need to be smart about caching sub-graph, just invalidate on modification. You could also keep a map of the build code to results for when edits are done and reverted often. I do that a lot, but I'm not sure how others use it. These are both pretty low impact changes I would think.

Describe alternatives you've considered

Rewrite in c++ probably isn't a great solution.

Additional context

Also, some progress indicator in a window footer for how much computation still needs to be done would be nice.

この issue では、ファイル、テスト、エントリーポイントが指定されていません。まず power-report の生成フローを特定し、build の変更がどのように検出されるかを確認します。その後、キャッシュと要求されている進捗インジケーターを個別に評価します。変更されていないレポートを繰り返し生成する際に不要な計算が回避され、残りの作業が適切な検証でカバーされれば完了です。