I am looking to use Berkeley DB to create a simple key-value storage system. The keys will be SHA-1 hashes, so they are in 160-bit address space. I have a simple server working, that was easy enough thanks to the fairly well written documentation from Berkeley DB website. However, I have some questions about how best to set up such a sys...
My application is a network application. Its job is to receive streams of packets (QByteArray) in which I would like to emit them as signals. Would doing so be inefficient? I'm concerned with copying of large buffers. ...
I want to measure the running times of selected loops in a C program so as to see what percentage of the total time for executing the program (on linux) is spent in these loops. I should be able to specify the loops for which the performance should be measured. I have tried out several tools (vtune, hpctoolkit, oprofile) in the last few ...
I'm trying to take a CGImage and copy its data into a buffer for later processing. The code below is what I have so far, but there's one thing I don't like about it - it's copying the image data twice. Once for CGDataProviderCopyData() and once for the :getBytes:length call on imgData. I haven't been able to find a way to copy the ima...
I'm working with an oracle DB trying to tune some queries and I'm having trouble understanding why working a particular clause in a particular way has such a drastic impact on the query performance. Here is a performant version of the query I'm doing select * from ( select a.*, rownum rn from ( select * fro...
Probably just watch this video: http://screencast.com/t/OWE1OWVkO As you see, the delay between a connection being initiated (via telnet or firefox) and my program first getting word of it. Here's the code that waits for the connection public IDLServer(System.Net.IPAddress addr,int port) { Listener = new TcpLis...
Can anyone comment on which is more scalable between RoR and PHP? I have heard that RoR is less scalable than PHP since RoR has a little more overhead with its MVC framework while PHP is more low level and lighter. This is a bit vague - can anyone explain better? ...
I am running an application server on Linux 64bit with 8 core CPUs and 6 GB memory. The server must be highly responsive. After some inspection I found that the application running on the server creates rather a huge amount of short-lived objects, and has only about 200~400 MB long-lived objects(as long as there is no memory leak) Aft...
Hello ! I am building graphs. A graph consists of nodes linked each other with links (indeed my dear). In order to assign a given behavior to each node, I implemented the strategy pattern. class Node { public BaseNodeBehavior Behavior {get; set;} } As a result, in many parts of the application, I am extensively using type reflect...
Hi guys! Right now I'm thinking about adding a private constructor to a class that only holds some String constants. public class MyStrings { // I want to add this: private MyString() {} public static final String ONE = "something"; public static final String TWO = "another"; ... } Is there any performance or memory overhe...
When i request a page using browser / AJAX request i see lot of spaces and newlines which i think must be adding some overhead for retrieving the response as they too belong to characters means bytes and size. right ? Is there some way it can be removed while sending from the server ? how ? (I am using IIS and asp.net for development) ...
I'm running that method in quick succession as fast as I can, and the faster the better, so obviously if CGDataProviderCopyData() is actually copying the data byte-for-byte, then I think there must be a faster way to directly access that data...it's just bytes in memory. Anyone know for sure if CGDataProviderCopyData() actually copies t...
any concrete suggestions for computing application/System reliability ? ...
Why would one use one over the other: d = dict() ~0.208 usec d = {} ~0.06 usec ...
Simple question, but tricky answer I guess. Does using Generic Interfaces hurts performance? Example: public interface Stuff<T> { void hello(T var); } vs public interface Stuff { void hello(Integer var); <---- Integer used just as an example } My first thought is that it doesn't. Generics are just part of the language ...
Hi, I am new to WMI and System.Diagnostics etc. I need to write something (a service?) that monitors several processes for CPU Usage %. When I am in Task Manager, the CPU column is the one that I want (i.e. the percentage). I need to be able to run this on a remote machine, and have it check the CPU Usage every second or so. When the us...
I do understand that querying a non-existent key in a defaultdict the way I do will add items to the defaultdict. That is why it is fair to compare my 2nd code snippet to my first one in terms of performance. import numpy as num from collections import defaultdict topKeys = range(16384) keys = range(8192) table = dict((k,defaultdict(i...
I have an existing asp.net web application I am redesigning to use a service architecture. I have the beginnings of an WCF service which I am able to call and perform functions with no problems. As far as updating data, it all makes sense. For example, I have a button that says Submit Order, it sends the data to the service, which does t...
I'm currently designing a object structure for a game, and the most natural organization in my case became a tree. Being a great fan of smart pointers I use shared_ptr's exclusively. However, in this case, the children in the tree will need access to it's parent (example -- beings on map need to be able to access map data -- ergo the dat...
Here is 3 css file (one is only for IE) <link rel="stylesheet" href="css/blueprint/screen.css" type="text/css" media="screen, projection"> <link rel="stylesheet" href="css/blueprint/print.css" type="text/css" media="print"> <!--[if lt IE 8]><link rel="stylesheet" href="css/blueprint/ie.css" type="text/css" media="screen, projection"...