The short version: Arrays are mostly faster than objects. But there is no 100% correct solution. Update 2017 – Test and Results var a1 = [{id: 29938, name: ‘name1’}, {id: 32994, name: ‘name1’}]; var a2 = []; a2[29938] = {id: 29938, name: ‘name1’}; a2[32994] = {id: 32994, name: ‘name1’}; var o = {}; o[‘29938’] = … Read more
An ANR happens when some long operation takes place in the “main” thread. This is the event loop thread, and if it is busy, Android cannot process any further GUI events in the application, and thus throws up an ANR dialog. Now, in the trace you posted, the main thread seems to be doing fine, … Read more
Here’s a solution using data.table’s := operator, building on Andrie and Ramnath’s answers. require(data.table) # v1.6.6 require(gdata) # v2.8.2 set.seed(1) dt1 = create_dt(2e5, 200, 0.1) dim(dt1) [1] 200000 200 # more columns than Ramnath’s answer which had 5 not 200 f_andrie = function(dt) remove_na(dt) f_gdata = function(dt, un = 0) gdata::NAToUnknown(dt, un) f_dowle = function(dt) … Read more
Since there seems to be some interest in this question still (judging by the views), I thought I might as well post an update. I ended up implementing an immediate-mode GUI as my master’s thesis, and have some numbers in on the performance. The gist is: It’s fine – quality of implementation dominates, not systematic … Read more
It depends on a lot of factors – but most crucially: complexity of calculations (prefer doing complex crunching on an app-server, since that scales out; rather than a db server, which scales up) volume of data (if you need to access/aggregate a lot of data, doing it at the db server will save bandwidth, and … Read more
from functools import reduce def factors(n): return set(reduce(list.__add__, ([i, n//i] for i in range(1, int(n**0.5) + 1) if n % i == 0))) This will return all of the factors, very quickly, of a number n. Why square root as the upper limit? sqrt(x) * sqrt(x) = x. So if the two factors are the … Read more
You are measuring the OSR (on-stack replacement) stub. OSR stub is a special version of compiled method intended specifically for transferring execution from interpreted mode to compiled code while the method is running. OSR stubs are not as optimized as regular methods, because they need a frame layout compatible with interpreted frame. I showed this … Read more
The best explanation I’ve seen is in Chapter 7 of the free Foundations of Programming e-book. Basically, in .NET a memory leak occurs when referenced objects are rooted and thus cannot be garbage collected. This occurs accidentally when you hold on to references beyond the intended scope. You’ll know that you have leaks when you … Read more
Modern Java is one of the fastest languages, even though it is still a memory hog. Java had a reputation for being slow because it used to take a long time for the VM to start up. If you still think Java is slow, see the benchmarks game results. Tightly optimized code written in a … Read more
First, using those multiple domains requires several DNS lookups. You’d be better off combining many of those images into a sprite instead of spreading the requests. Second, when I load your page, I see most of the blocking (~1.25s) on all.js. I see that begins with (an old version of) jQuery. You should reference that … Read more