runtime

runtime of using indexing in mongodb

由 爱⌒轻易说出口 提交于 2019-12-06 07:59:52
问题 Based on mongodb documentation The ensureIndex() function only creates the index if it does not exist. Once a collection is indexed on a key, random access on query expressions which match the specified key are fast. Without the index, MongoDB has to go through each document checking the value of specified key in the query: db.things.find({j:2}); // fast - uses index db.things.find({x:3}); // slow - has to check all because 'x' isn't Does that mean the 1st line of code runtime is big_theta =

OSGi Declarative services filter references at runtime

由 自古美人都是妖i 提交于 2019-12-06 07:50:51
I've been trying some examples with OSGi Declarative Services (among other things, such as Blueprint) on Karaf. The problem I am trying to solve now, is how to get references to certain services at runtime (so annotations and/or XML are not really an option here) I will explain my use case: I am trying to design (so far only in my head, that's why I am still only experimenting with OSGi :) ) a system to control certain automation processes in industry. To communicate with devices, a special set of protocols is being used. To make the components as reusable as possible, I designed a

How can I add a jar to an APK & make the APK refer to it without Eclipse?

由 瘦欲@ 提交于 2019-12-06 07:41:43
This may seem a bit weird, but I need to implement it. I have an APK & I dont have its source code. Now I can break the apk , modify & repack it, but while doing so, I need to add my custom jar to it & make the app/apk refer this library/jar at run time. If I just create a folder libs inside the apk & put my jar inside, I get a NoClassDefFound error. Any idea how to implement it using ANT or any other tool ? Thanx in advance The Jar(s) you attach in your android project, are not copied into APK. What happens is that, The code of your Jar(s) file becomes part of your Android code. That means

Any way to extract underlying Xaml?

由 試著忘記壹切 提交于 2019-12-06 06:29:20
Is there anyway to extract the underlying xaml from a control. IE. I have a textbox named fooBox. Can I get xaml back from the textbox at runtime that represents the textbox? This shows you the full lifecycle (from control to XAML back to control). As you can see, string s = XamlWriter.Save(value); is the interesting part you might care about. /// <summary> /// Clones a given UIElement. Please note that any events, animations, etc /// on the source item may not carry over to the cloned object. /// </summary> /// <param name="value">UIElement to clone.</param> /// <returns>A shallow clone of

Add Routes at Runtime (ExpressJs)

由 最后都变了- 提交于 2019-12-06 06:14:26
问题 I would like to add routes at run time. I read that its possible but I am not so sure how. Currently I using the following code: var app = express(); function CreateRoute(route){ app.use(route, require('./routes/customchat.js')); } And customchat looks like var express = require('express'); var router = express.Router(); router.route('/').get(function (req, res) { var url = req.baseUrl; var roomname = url.substring(url.lastIndexOf('_') + 1); res.render('chat', { name: roomname , year: new

Does golang depend on c runtime?

由 空扰寡人 提交于 2019-12-06 05:46:29
问题 I can't find info does golang depend on c runtime? If it's depend on it is it's statically compiled in go-binary to make Go-app work everywhere without dependences? Here is topic about what C-runtime is 回答1: If you're talking about executable files provided by a Go compiler, then the answer is "yes or no—it depends": In most cases, the resulting executable program does not depend on a C run-time library. However, on some platforms under certain circumstances the C runtime library gets

Write a custom syntax interpreter in java?

由 。_饼干妹妹 提交于 2019-12-06 05:46:15
问题 I am about to begin coding a demo program for a lecture I'm about to give. I want to let each student in the class download this application, then be able to create instances of objects (and their graphical representations) interactively via a command line. I decided to write in java, not because it's the language I'm most familiar with, but because it's got easy graphics classes and I can be pretty sure that the jar is going to run on their computers. Intro over. Now the question: What is a

Communicating to a C++ program from java

由 和自甴很熟 提交于 2019-12-06 05:29:27
问题 I want to execute a external .exe program from within java. The .exe is a CLI application which takes input in runtime( scanf() ) and outputs depending on the input. I can call the program to execute from java using Process p = Runtime.getRuntime().exec("cmd /c start a.exe"); instead of Process p = Runtime.getRuntime().exec("cmd /c start a.exe"); But I think it is also possible to call a program from within java. I have my whole program written in C++ just need a GUI which is written in java.

Speed comparison of sapply with a composite function

由 寵の児 提交于 2019-12-06 05:20:55
问题 > system.time(sapply(rnorm(1000000,0,1), function (x) round(x,2))) user system elapsed 2.78 0.11 2.89 > system.time(round(rnorm(1000000,0,1),2)) user system elapsed 0.29 0.00 0.30 I was trying this out after reading the answers to the R tips question. I did not expect sapply to be order of magnitude slower than the equivalent composite function in the above case. Does anyone know why this is the case? If i understand correctly sapply will vectorize and be near optimally fast. 回答1: There's

Java - start another class' main in a different process

由 ↘锁芯ラ 提交于 2019-12-06 04:58:14
问题 I need a clean way to start many instances of a Java program with a GUI, and I want to do it programmatically. The "program" i want to run is just a .class file (a compiled .java file with a main method), it should show a GUI and run independently from the others (as its own process). I also need to pass that program some arguments. Check EDIT5 for the complete working solution code. Here's the class that's supposed to start the many processes package startothermain; import java.io
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