Category "performance"

How to convert a nested for of loop into a custom iterator?

I have the following code: function* getPossibleCollidersWith(shape) { for (let square of retrieve(shape)) { for (let neighbor of square) { yield ne

MongoDB query optimizer keeps choosing the least efficient index for the query

I have a large collection (~20M records) with some moderate documents with ~20 indexed fields. All of those indexes are single field. This collection also has q

When using ASP.NET MVC, what is the best way to update multiple page sections with one HTML.Action() method?

I have a pretty big ASP.NET MVC site with 100 controllers and thousands of actions. Previously the header image that was defined on the Site.Master page was ha

timeit and its default_timer completely disagree

I benchmarked these two functions (they unzip pairs back into source lists, came from here): n = 10**7 a = list(range(n)) b = list(range(n)) pairs = list(zip(a,

Codewars execution timeout despite short execution time on other IDEs (Python)

I was solving a problem on CodeWars and my solution keeps getting execution timeouts. I know the code is correct and doesn't take long to execute, since when I

Docker running really slow on mac after PHP 7.4 > 8 update

We've recently updated our docker config from PHP7.4 to PHP8 running on Ubuntu 20.04. For most of the team this has been fine. For me and one other (both using

Android ViewPager and TabLayout are not working fast

There are nested fragments with TabLayout and ViewPager. Each fragment has listview inside it so they get call together and now I'm getting an issue of slow pro

Avoiding allocations but without allowing default zero values for value types

Value types in C# can't have a parameterless ctor, as the default behaviour for CLR when creating an instance without parameters is to just zero all the bits. A

Combining 2 Tables, Want to keep all Non 0 Bit on DUPLICATE KEY

I have a table with 1000 columns (yes its normalized), that is storing Biiig Daaata! I need to Insert Update new data as it becomes available overnight, and f

Can modern x86 implementations store-forward from more than one prior store?

In the case that a load overlaps two earlier stores (and the load is not fully contained in the oldest store), can modern Intel or AMD x86 implementations forwa

Why is a conditional move not vulnerable to Branch Prediction Failure?

After reading this post (answer on StackOverflow) (at the optimization section), I was wondering why conditional moves are not vulnerable for Branch Prediction

Why is XCHG reg, reg a 3 micro-op instruction on modern Intel architectures?

I'm doing micro-optimization on a performance critical part of my code and came across the sequence of instructions (in AT&T syntax): add %rax, %rbx mov %r

How to reduce CPU usage for Java 11 with G1GC on GCP

I have: the application multi thread, low latency OpenJDK 64-Bit Server VM version 11.0.7+10 configuration is Xms=6g Xmx=12g machine is 12CPU started in GCP (Go

Android method performance suddnely slow after upgrade from Marshmallow to Nougat

I have been developing a game, using a Samsung Galaxy S6 running Marshmallow as one of my development devices. After the phone upgraded itself to Nougat, a met

Android method performance suddnely slow after upgrade from Marshmallow to Nougat

I have been developing a game, using a Samsung Galaxy S6 running Marshmallow as one of my development devices. After the phone upgraded itself to Nougat, a met

Fast real valued random generator in java

java.util.Random.nextDouble() is slow for me and I need something really fast. I did some google search and I've found only integers based fast random generat

Fast hash function with collision possibility near SHA-1

I'm using SHA-1 to detect duplicates in a program handling files. It is not required to be cryptographic strong and may be reversible. I found this list of fast

python read zipfile into numpy-array efficiently

I want to read a zipfile into memory and extract its content into a numpy array (as numpy-datatypes). This needs to happen in an extremely efficient/fast manner

Why is processing a sorted array faster than processing an unsorted array?

Here is a piece of C++ code that shows some very peculiar behavior. For some strange reason, sorting the data (before the timed region) miraculously makes the l

Google Tag manager impact in web performance (load time)

I´m trying to improve the load time and performance of my website. To summarize this is the average loading time stats that I get without including Google