performance

问题 I wanted to compare the performance characteristics of immutable.Map and mutable.Map in Scala for a similar operation (namely, merging many maps into a single one. See this question). I have what appear to be similar implementations for both mutable and immutable maps (see below). As a test, I generated a List containing 1,000,000 single-item Map[Int, Int] and passed this list into the functions I was testing. With sufficient memory, the results were unsurprising: ~1200ms for mutable.Map,

问题 I have 2 entities: Components & SurveyReadingWeb that have a one-to-many relationship. I have saved Components data in core data database; but while saving SurveyReadingWeb -- in a for loop -- I have to fetch Components data entity by passing component id and setting the surveyreadings isComponentexists relationship, like in the code below for 8000 records. This process is taking too much time, nearly 7 minutes. How can I reduce the time? for item in items { autoIncrementId = autoIncrementId

问题 I'm trying to optimalize web for speed and wanna ask about Eliminating render-blocking CSS and JS. by JS 'm only using async attr. - lets say, throwin' it at plugins like flexslider, lightbox.. but should I also use this with the base scripts like ?: <script src="https://cdnjs.cloudflare.com/.../4.5.3/js/bootstrap.min.js" async></script> <script src="js/script.js" async></script> Whenever i add async on some script and test it, that .js script won't just operate - as if not linked. What am I

问题 I had two loops (one nested in the other one) and I was wondering if there is any difference in how I nest these loops. Results of Code 1 and Code 2 are the same (100,000x4 = 4x100,000 = 400,000) but jsPerf shows that Code 2 is roughly 50% faster than Code 1. I'd like to kindly ask for your advice, I don't understand the difference between the two. Thank you very much. var tt = function () { // do some stuff // for example: return (3); }; Test code 1: for (var i = 0; i < 100000; i++) { for

问题 I had two loops (one nested in the other one) and I was wondering if there is any difference in how I nest these loops. Results of Code 1 and Code 2 are the same (100,000x4 = 4x100,000 = 400,000) but jsPerf shows that Code 2 is roughly 50% faster than Code 1. I'd like to kindly ask for your advice, I don't understand the difference between the two. Thank you very much. var tt = function () { // do some stuff // for example: return (3); }; Test code 1: for (var i = 0; i < 100000; i++) { for

问题 I have the following processes , I try to make ProcessB very low latency so I use tight loop all the time and isolate cpu core 2 . global var in shared memory : int bDOIT ; typedef struct XYZ_ { int field1 ; int field2 ; ..... int field20; } XYZ; XYZ glbXYZ ; static void escape(void* p) { asm volatile("" : : "g"(p) : "memory"); } ProcessA (in core 1 ) while(1){ nonblocking_recv(fd,&iret); if( errno == EAGAIN) continue ; if( iret == 1 ) bDOIT = 1 ; else bDOIT = 0 ; } // while ProcessB ( in

问题 Existing ways of adding content to an S3 file using methods in AmazonS3 class are by putObject with an InputStream Creating a local file with content and uploading it to S3. Is there a way an OutputStream can be created for an existing S3 object to which values from a list can be written into? I see there are no APIs for doing so. 回答1: It's possible to create an S3OutputStream which wraps the AmazonS3 client. See this gist for the implementation: https://gist.github.com/blagerweij

问题 I find it hard to understand the differences between the local and global miss rate and how to calculate the average time for a memory access and would just like to give an example of a problem that I have tried to solve. I would appreciate if someone could tell me if I'm on the right track, or if I'm wrong what I have missed. Consider the following multilevel cache hierarchy with their seek times and miss rates: L1-cache, 0.5 ns, 20% L2-cache, 1.8 ns, 5% L3-cache, 4.2 ns, 1.5% Main memory,

问题 Closed . This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed 5 years ago . Improve this question What's the best performance of these two different code solution: class Meme { private int[] a = new int[100]; private int[] b = new int[100]; private int[] c = new int[100]; } vs class Meme { private MemeProp[] prop = new MemeProp[100]; class MemeProp {

问题 using (StreamWriter writer = File.CreateText(FinishedFile)) { int lineNum = 0; while (lineNum < FilesLineCount.Min()) { for (int i = 0; i <= FilesToMerge.Count() - 1; i++) { if (i != FilesToMerge.Count() - 1) { var CurrentFile = File.ReadLines(FilesToMerge[i]).Skip(lineNum).Take(1); string CurrentLine = string.Join("", CurrentFile); writer.Write(CurrentLine + ","); } else { var CurrentFile = File.ReadLines(FilesToMerge[i]).Skip(lineNum).Take(1); string CurrentLine = string.Join("",