There’s a great deal of research on this. Here’s a quick summary. Response Times: The 3 Important Limits by Jakob Nielsen on January 1, 1993 Summary: There are 3 main time limits (which are determined by human perceptual abilities) to keep in mind when optimizing web and application performance. Excerpt from Chapter 5 in my … Read more
The most fundamental thing here probably is that you don’t want to transmit static images but only changes to the images, which essentially is analogous to video stream. My best guess is some very efficient (and heavily specialized and optimized) motion compensation algorithm, because most of the actual change in generic desktop usage is linear … Read more
It’s about accumulation, not queue efficiency. Fastpass works because it makes the individual items in the queue more efficient in “consuming” something. It’s not so much a queue like a processor waiting for instructions to execute as it is people waiting in line for food. In the case of people at Disneyland, it allows them … Read more
Stop using LinkedList for anything but heavy removing from the middle of the list using iterator. Stop writing benchmarking code by hand, use JMH. Proper benchmarks: @OutputTimeUnit(TimeUnit.NANOSECONDS) @BenchmarkMode(Mode.AverageTime) @OperationsPerInvocation(StreamVsVanilla.N) public class StreamVsVanilla { public static final int N = 10000; static List<Integer> sourceList = new ArrayList<>(); static { for (int i = 0; i < … Read more
Nested weights are bad for performance because: Layout weights require a widget to be measured twice. When a LinearLayout with non-zero weights is nested inside another LinearLayout with non-zero weights, then the number of measurements increase exponentially. It’s better to use RelativeLayouts and adjust your view according to the places of other views without using … Read more
2017 update: First, for readers coming today – here is a version that works with Node 7 (4+): function enforceFastProperties(o) { function Sub() {} Sub.prototype = o; var receiver = new Sub(); // create an instance function ic() { return typeof receiver.foo; } // perform access ic(); ic(); return o; eval(“o” + o); // ensure … Read more
Build a new list with a list comprehension: new_items = [x if x % 2 else None for x in items] You can modify the original list in-place if you want, but it doesn’t actually save time: items = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10] for index, item in enumerate(items): … Read more
This is taken from the scala mailing list and gives implementation details of lazy in terms of Java code (rather than bytecode): class LazyTest { lazy val msg = “Lazy” } is compiled to something equivalent to the following Java code: class LazyTest { public int bitmap$0; private String msg; public String msg() { if … Read more
Optimum buffer size is related to a number of things: file system block size, CPU cache size and cache latency. Most file systems are configured to use block sizes of 4096 or 8192. In theory, if you configure your buffer size so you are reading a few bytes more than the disk block, the operations … Read more