Tag Archives: download server

Writing a download server. Part II: headers: Last-Modified, ETag and If-None-Match


via Writing a download server. Part II: headers: Last-Modified, ETag and If-None-Match | NoBlogDefFound.

Caching on the client side is one of the foundations of World Wide Web. Server should inform client about validity of resources and client should cache them as eagerly as possible. Without caching the web as we see it would be insanely slow. Just hit Ctrl + F5 on any website and compare it with ordinary F5 – the latter is much faster as it uses already cached resources. Caching is also important for downloading. If we already fetched several megabytes of data and they haven’t changed, pushing them through network is quite wasteful.