Search Results

Search found 59286 results on 2372 pages for 'i question things deeply'.

Page 54/2372 | < Previous Page | 50 51 52 53 54 55 56 57 58 59 60 61  | Next Page >

  • C++ design question, container of instances and pointers

    - by Tom
    Hi all, Im wondering something. I have class Polygon, which composes a vector of Line (another class here) class Polygon { std::vector<Line> lines; public: const_iterator begin() const; const_iterator end() const; } On the other hand, I have a function, that calculates a vector of pointers to lines, and based on those lines, should return a pointer to a Polygon. Polygon* foo(Polygon& p){ std::vector<Line> lines = bar (p.begin(),p.end()); return new Polygon(lines); } Here's the question: I can always add a Polygon (vector Is there a better way that dereferencing each element of the vector and assigning it to the existing vector container? //for line in vector<Line*> v //vcopy is an instance of vector<Line> vcopy.push_back(*(v.at(i)) I think not, but I dont really like that approach. Hopefully, I will be able to convince the author of the class to change it, but I cant base my coding right now to that fact (and i'm scared of a performance hit). Thanks in advance.

    Read the article

  • string in c++,question

    - by user189364
    Hi, I created a program in C++ that remove commas (') from a given integer. i.e. 2,00,00 would return 20000. I am not using any new space. Here is the program i created void removeCommas(string& str1,int len) { int j=0; for(int i=0;i<len;i++) { if(str1[i] == ',') continue; else { str1[j] =str1[i]; j++; } } str1[j] = '\0'; } void main() { string str1; getline(cin,str1); int i = str1.length(); removeCommas(str1,i); cout<<"the new string "<<str1<<endl; } Here is the result i get : Input : 2,000,00 String length =8 Output = 200000 0 Length = 8 My question is that why does it show the length has 8 in output and shows the rest of string when i did put a null character. It should show output as 200000 and length has 6.

    Read the article

  • opengl: question about glutMainLoop()

    - by lego69
    can somebody explain how does glutMainLoop work? and second question, why glClearColor(0.0f, 0.0f, 1.0f, 1.0f); defined after glutDisplayFunc(RenderScene); cause firstly we call glClear(GL_COLOR_BUFFER_BIT); and only then define glClearColor(0.0f, 0.0f, 1.0f, 1.0f); int main(int argc, char* argv[]) { glutInit(&argc, argv); glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); glutInitWindowSize(800, 00); glutInitWindowPosition(300,50); glutCreateWindow("GLRect"); glutDisplayFunc(RenderScene); glutReshapeFunc(ChangeSize); glClearColor(0.0f, 0.0f, 1.0f, 1.0f); <-- glutMainLoop(); return 0; } void RenderScene(void) { // Clear the window with current clearing color glClear(GL_COLOR_BUFFER_BIT); // Set current drawing color to red // R G B glColor3f(1.0f, 0.0f, 1.0f); // Draw a filled rectangle with current color glRectf(0.0f, 0.0f, 50.0f, -50.0f); // Flush drawing commands glFlush(); }

    Read the article

  • StringBufferInputStream Question in Java

    - by JJG
    I want to read an input string and return it as a UTF8 encoded string. SO I found an example on the Oracle/Sun website that used FileInputStream. I didn't want to read a file, but a string, so I changed it to StringBufferInputStream and used the code below. The method parameter jtext, is some Japanese text. Actually this method works great. The question is about the deprecated code. I had to put @SuppressWarnings because StringBufferInputStream is deprecated. I want to know is there a better way to get a string input stream? Is it ok just to leave it as is? I've spent so long trying to fix this problem that I don't want to change anything now I seem to have cracked it. @SuppressWarnings("deprecation") private String readInput(String jtext) { StringBuffer buffer = new StringBuffer(); try { StringBufferInputStream sbis = new StringBufferInputStream (jtext); InputStreamReader isr = new InputStreamReader(sbis, "UTF8"); Reader in = new BufferedReader(isr); int ch; while ((ch = in.read()) > -1) { buffer.append((char)ch); } in.close(); return buffer.toString(); } catch (IOException e) { e.printStackTrace(); return null; } }

    Read the article

  • Redirection Still not working (updated on earlier question)

    - by NoviceCoding
    So earlier I asked this question: JQuery Login Redirect. Code Included The php file is sending the following: $return['error'] = false; $return['msg'] = 'You have successfully logged in!!'; I've tried all the suggestions, quoting the error on php and ajax end, 2 equals instead of 3, I've also tried DNE true which should be the same as an else statement: $(document).ready(function(){ $('#submit').click(function() { $('#waiting').show(500); $('#empty').show(500); $('#reg').hide(0); $('#message').hide(0); $.ajax({ type : 'POST', url : 'logina.php', dataType : 'json', data: { type : $('#typeof').val(), login : $('#login').val(), pass : $('#pass').val(), }, success : function(data){ $('#waiting').hide(500); $('#empty').show(500); $('#message').removeClass().addClass((data.error === true) ? 'error' : 'success') .text(data.msg).show(500) if(data.error != true) window.location.replace("http://blahblah.com/usercp.php"); if (data.error === true) $('#reg').show(500); $('#empty').hide() }, error : function(XMLHttpRequest, textStatus, errorThrown) { $('#waiting').hide(500); $('#message').removeClass().addClass('error') .text("There was an Error. Please try again.").show(500); $('#reg').show(500); $('#empty').hide(); Recaptcha.reload(); } }); return false; }); And it still wont work. Any ideas on how to make a redirection work if login is successful and error returns false? Also while I am asking, can I put a .delay(3000) 3s at the end of window.location.replace("http://blahblah.com/usercp.php")?

    Read the article

  • Python to C/C++ const char question

    - by tsukemonoki
    I am extending Python with some C++ code. One of the functions I'm using has the following signature: int PyArg_ParseTupleAndKeywords(PyObject *arg, PyObject *kwdict, char *format, char **kwlist, ...); (link: http://docs.python.org/release/1.5.2p2/ext/parseTupleAndKeywords.html) The parameter of interest is kwlist. In the link above, examples on how to use this function are given. In the examples, kwlist looks like: static char *kwlist[] = {"voltage", "state", "action", "type", NULL}; When I compile this using g++, I get the warning: warning: deprecated conversion from string constant to ‘char*’ So, I can change the static char* to a static const char*. Unfortunately, I can't change the Python code. So with this change, I get a different compilation error (can't convert char** to const char**). Based on what I've read here, I can turn on compiler flags to ignore the warning or I can cast each of the constant strings in the definition of kwlist to char *. Currently, I'm doing the latter. What are other solutions? Sorry if this question has been asked before. I'm new.

    Read the article

  • To NOLOCK or NOT to NOLOCK, that is the question

    - by Limey
    Hi all, This is really more of a discussion than a specific question about nolock. I took over an app recently that almost every query (and there are lots of them) has the nolock option on them. Now I am pretty new to SQL server (used Oracle for 10 years) but yet I find this pretty disturbing. So this weekend I was talking with one of my friends who runs a rather large ecommerce site (name will be withheld to protect the guilty) and he says he has to do this with all of his SQL servers cause he will always end in deadlocks. Is this just a huge short fall with SQL server? Is this just a failure in the DB design (mine is not 3rd level, but its close) Is anybody out there running an SQL server app without nolocks? These are issues that Oracle handles better with more grandulare recordlocks. Is SQL server just not able to handle big loads? Is there some better workaround than reading uncommited data? I would love to hear what people think. Thanks

    Read the article

  • Grid related UI design question

    - by younevertell
    Grid related UI design question I want some 16-grid (4 rows and 4 columns) user interface, and fill the grid with some round shapes. I also want to use the MouseOver, mouse left button down, and Mouse Left Button Up events to set the state of grids as selected or not selected. My questions: 1. How fill the grid with some round shapes? by SetColumn and SetRow? 2. How to make the grids respond to the mouse please? Thanks <Grid.ColumnDefinitions> <ColumnDefinition /> <ColumnDefinition /> <ColumnDefinition /> <ColumnDefinition /> </Grid.ColumnDefinitions> <Grid.RowDefinitions> <RowDefinition /> <RowDefinition /> <RowDefinition /> <RowDefinition /> </Grid.RowDefinitions>

    Read the article

  • A stupid question about wordpress and php

    - by bubdada
    It may seem stupid question, but i've a serious problem... if you could check out orcik.net the thumbnail images does not appear. I figured out the reason but I don't know how to solve.. http://orcik.net/projects/thumb/orcikthumb.php?src=http://orcik.net/wp-content/uploads/2010/05/mac-safari-search-cache.png If you go to the above link you will get page not found error. However, if you go to the link below you'll get the thumbnail version of the image... http://orcik.net/projects/thumb/orcikthumb.php?src=/wp-content/uploads/2010/05/mac-safari-search-cache.png I'm using this piece of code on wordpress and the line appears like <a href="<?php the_permalink() ?>" rel="bookmark"> <img src="<?php bloginfo('template_directory'); ?>/includes/orcikthumb.php?src=<?php get_thumbnail($post->ID, 'full'); ?>&amp;h=<?php echo get_theme_mod($height); ?>&amp;w=<?php echo get_theme_mod($width); ?>&amp;zc=1" alt="<?php the_title(); ?>" /> </a> Thus, I believe I can't change the directory of image. But I could not figure out why I am getting page not found error. Is that might be CHMOD'es??? or something else?? Thanks

    Read the article

  • Yet another question about C++ books..

    - by suicideducky
    Intro rant Hey all, so after just over a year of browsing I decided it's time to ask a question for myself, it's sadly similar to many that have been asked before. I'm 18, am studying towards a BSc in Comp SCi and have been programming 'on and off' for about 6 years now, after wrestling with C++ for a bit then stumbling upon (and reading cover to cover) "Programming: Principles and Practice Using C++" by the great man himself I feel pretty comfortable with C++, I am almost finished writing my first open source program in C++ (a mediawiki parser, http://code.google.com/p/apertium-mediawiki/). I have decided I want to really get to know the power of C++, get familiar with some of its 'darker' corners and also delve into game programming, at this point I am rather keen on the book "Essential 3D Game Programming: with C++ and OpenGL" (released 24 may '10), I would also like to get 1 or 2 other books on 'general C++' that I can read cover to cover during my spare time. At this point I am pretty open to suggestions I would like something in the intermediate/advanced zone, some books I am rather keen on include: The C++ Standard Library: A tutorial and reference, C++ Template, the complete guide, and Modern C++ Design: Generic Programming and Design Patterns Applied Thanks in advance.

    Read the article

  • C# Generic Generics (A Serious Question)

    - by tahirhassan
    In C# I am trying to write code where I would be creating a Func delegate which is in itself generic. For example the following (non-Generic) delegate is returning an arbitrary string: Func<string> getString = () => "Hello!"; I on the other hand want to create a generic which acts similarly to generic methods. For example if I want a generic Func to return default(T) for a type T. I would imagine that I write code as follows: Func<T><T> getDefaultObject = <T>() => default(T); Then I would use it as getDefaultObject<string>() which would return null and if I were to write getDefaultObject<int>() would return 0. This question is not merely an academic excercise. I have found numerous places where I could have used this but I cannot get the syntax right. Is this possible? Are there any libraries which provide this sort of functionality?

    Read the article

  • Unit Tests Architecture Question

    - by Tom Tresansky
    So I've started to layout unit tests for the following bit of code: public interface MyInterface { void MyInterfaceMethod1(); void MyInterfaceMethod2(); } public class MyImplementation1 implements MyInterface { void MyInterfaceMethod1() { // do something } void MyInterfaceMethod2() { // do something else } void SubRoutineP() { // other functionality specific to this implementation } } public class MyImplementation2 implements MyInterface { void MyInterfaceMethod1() { // do a 3rd thing } void MyInterfaceMethod2() { // do something completely different } void SubRoutineQ() { // other functionality specific to this implementation } } with several implementations and the expectation of more to come. My initial thought was to save myself time re-writing unit tests with something like this: public abstract class MyInterfaceTester { protected MyInterface m_object; @Setup public void setUp() { m_object = getTestedImplementation(); } public abstract MyInterface getTestedImplementation(); @Test public void testMyInterfaceMethod1() { // use m_object to run tests } @Test public void testMyInterfaceMethod2() { // use m_object to run tests } } which I could then subclass easily to test the implementation specific additional methods like so: public class MyImplementation1Tester extends MyInterfaceTester { public MyInterface getTestedImplementation() { return new MyImplementation1(); } @Test public void testSubRoutineP() { // use m_object to run tests } } and likewise for implmentation 2 onwards. So my question really is: is there any reason not to do this? JUnit seems to like it just fine, and it serves my needs, but I haven't really seen anything like it in any of the unit testing books and examples I've been reading. Is there some best practice I'm unwittingly violating? Am I setting myself up for heartache down the road? Is there simply a much better way out there I haven't considered? Thanks for any help.

    Read the article

  • question about partition

    - by davit-datuashvili
    i have question about hoare partition method here is code and also pseudo code please if something is wrong correct pseudo code HOARE-PARTITION ( A, p, r) 1 x ? A[ p] 2 i ? p-1 3 j ? r +1 4 while TRUE 5 do repeat j ? j - 1 6 until A[ j ] = x 7 do repeat i ? i + 1 8 until A[i] = x 9 if i < j 10 then exchange A[i] ? A[ j ] 11 else return j and my code public class Hoare { public static int partition(int a[],int p,int r) { int x=a[p]; int i=p-1; int j=r+1; while (true) { do { j=j-1; } while(a[j]>=x); do { i=i+1; } while(a[i]<=x); if (i<j) { int t=a[i]; a[i]=a[j]; a[j]=t; } else { return j; } } } public static void main(String[]args){ int a[]=new int[]{13,19,9,5,12,8,7,4,11,2,6,21}; partition(a,0,a.length-1); } } and mistake is this error: Class names, 'Hoare', are only accepted if annotation processing is explicitly requested 1 error any ideas

    Read the article

  • Simple javascript/jquery append, remove question

    - by Scarface
    Hey guys, quick question. I have a div that on click will execute a jquery function onclick, and then replace the div with its opposite div which onclick will replace back to the first div just like the favorite function on this site. I am having a simple problem I hope someone can spot or explain to me it is not possible. The function works with the initial two divs that are served directly, but when I click on either of the original two divs, and the function executes and replaces the div with the corresponding div the replacement div does not execute the function. I have to refresh the page to get the original div, which is identical to execute the function. Is the div actually replaced on the page with append, or does it just visually show it? Any advice appreciated. original div <div class="unfavorite"><img id="unfavorite_img" src="images/favorite2.png" /></div> javascript div replacement $(".favorite").remove(); $(".favoriteholder").append('<div class="unfavorite"><img id="unfavorite_img" src="images/favorite2.png" /></div>');

    Read the article

  • question about permut-by-sorting

    - by davit-datuashvili
    hi i have following question from book introduction in algorithms second edition there is such problem suppose we have some array A int a[]={1,2,3,4} and we have some random priorities array P={36,3,97,19} we shoud permut array a randomly using this priorities array here is pseudo code P ERMUTE -B Y-S ORTING ( A) 1 n ? length[A] 2 for i ? 1 to n do P[i] = R ANDOM(1, n 3 ) 3 4 sort A, using P as sort keys 5 return A and result will be permuted array B={2, 4, 1, 3}; please help any ideas i have done this code and need aideas how continue import java.util.*; public class Permut { public static void main(String[]args){ Random r=new Random(); int a[]=new int[]{1,2,3,4}; int n=a.length; int b[]=new int[a.length]; int p[]=new int[a.length]; for (int i=0;i<p.length;i++){ p[i]=r.nextInt(n*n*n)+1; } // for (int i=0;i<p.length;i++){ // System.out.println(p[i]); //} } } please help

    Read the article

  • determining the starting speed for an accelerated animation (in flash/actionscript but it's a math question)

    - by vulkanino
    This question burns my brain. I have an object on a plane, but for the sake of simplicity let's work just on a single dimension, thus the object has a starting position xs. I know the ending position xe. The object has to move from starting to ending position with an accelerated (acceleration=a) movement. I know the velocity the object has to have at the ending position (=ve). In my special case the ending speed is zero, but of course I need a general formula. The only unknown is the starting velocity vs. The objects starts with vs in xs and ends with ve in xe, moving along a space x with an acceleration a in a time t. Since I'm working with flash, space is expressed in pixels, time is expressed in frames (but you can reason in terms of seconds, it's easy to convert knowing the frames-per-second). In the animation loop (think onEnterFrame) I compute the new velocity and the new position with (a=0.4 for example): vx *= a (same for vy) x += vx (same for y) I want the entire animation to last, say, 2 seconds, which at 30 fps is 60 frames. Now you know that in 60 frames my object has to move from xs to xe with a constant deceleration so that the ending speed is 0. How do I compute the starting speed vs? Maybe there's a simpler way to do this in Flash, but I am now interested in the math/physics behind this.

    Read the article

  • SQL Table design question

    - by Projapati
    Please ignore this question if it sounds stupid to you. I have SQL table (SQL Server) for photo albums and it has 20+ columns & it will hold millions of albums. I need to designate some albums as Promoted and some as Featured every week. I also need a very efficient way to get these albums (page by page) when I show it to users. How should I design this? option 1: I can create another table just to store the ids of the promoted and featured albums like this and then join the main albums table to get the set of columns I need. table designated_albums: album_id promoted_featured 1 1 5 0 7 1 15 0 The query for promoted will return 1, 7 The query for featured will return 5, 15 Option 2: I can add 1 column store 1 if promoted and 0 if featured. Otherwise it is null I can then query to check for 1 in that column for promoted albums & 0 for featured. Option 3: I can add 2 bit columns: one for promoted (0/1) and one for featured(0/1) Which way would perform better? EDIT: The design should be efficient in SQL 2008 as well. Right now I have SQL 2005.

    Read the article

  • (again) i improve my question [closed]

    - by gcc
    Possible Duplicate: realizing number …how?? i hold input like that A is char pointer A[0]=n A[1]=j A[2]=n // i take (one number)+special char(s)+command(s) (like $ or #) from user A[3]=d // the input order can be changed like char(s)+number+command . // there is one number in A[] . // and every A[i] is important for me because what will i do in next step . // is determined by that input in A[h] or A[n] . // example . // when you see $ go before array do something . // when you see number go farad equation and use it in there A[j]=$ // (number can be pozitif or negatif . A[i]=14(any number) . . int func(int temp) { if(temp=='n') //..do something then return 10; if(temp=='j') return 11; if(temp=='d') return 12; if(/*........*/) // when temp find/realize number ,i wanna return 13; // in if statement, (instead of .....) what code should i write } how i can do } NOTE::please ,dont close my question ,when you close icannot edit it

    Read the article

  • Basic C question, concerning memory allocation and value assignment

    - by VHristov
    Hi there, I have recently started working on my master thesis in C that I haven't used in quite a long time. Being used to Java, I'm now facing all kinds of problems all the time. I hope someone can help me with the following one, since I've been struggling with it for the past two days. So I have a really basic model of a database: tables, tuples, attributes and I'm trying to load some data into this structure. Following are the definitions: typedef struct attribute { int type; char * name; void * value; } attribute; typedef struct tuple { int tuple_id; int attribute_count; attribute * attributes; } tuple; typedef struct table { char * name; int row_count; tuple * tuples; } table; Data is coming from a file with inserts (generated for the Wisconsin benchmark), which I'm parsing. I have only integer or string values. A sample row would look like: insert into table values (9205, 541, 1, 1, 5, 5, 5, 5, 0, 1, 9205, 10, 11, 'HHHHHHH', 'HHHHHHH', 'HHHHHHH'); I've "managed" to load and parse the data and also to assign it. However, the assignment bit is buggy, since all values point to the same memory location, i.e. all rows look identical after I've loaded the data. Here is what I do: char value[10]; // assuming no value is longer than 10 chars int i, j, k; table * data = (table*) malloc(sizeof(data)); data->name = "table"; data->row_count = number_of_lines; data->tuples = (tuple*) malloc(number_of_lines*sizeof(tuple)); tuple* current_tuple; for(i=0; i<number_of_lines; i++) { current_tuple = &data->tuples[i]; current_tuple->tuple_id = i; current_tuple->attribute_count = 16; // static in our system current_tuple->attributes = (attribute*) malloc(16*sizeof(attribute)); for(k = 0; k < 16; k++) { current_tuple->attributes[k].name = attribute_names[k]; // for int values: current_tuple->attributes[k].type = DB_ATT_TYPE_INT; // write data into value-field int v = atoi(value); current_tuple->attributes[k].value = &v; // for string values: current_tuple->attributes[k].type = DB_ATT_TYPE_STRING; current_tuple->attributes[k].value = value; } // ... } While I am perfectly aware, why this is not working, I can't figure out how to get it working. I've tried following things, none of which worked: memcpy(current_tuple->attributes[k].value, &v, sizeof(int)); This results in a bad access error. Same for the following code (since I'm not quite sure which one would be the correct usage): memcpy(current_tuple->attributes[k].value, &v, 1); Not even sure if memcpy is what I need here... Also I've tried allocating memory, by doing something like: current_tuple->attributes[k].value = (int *) malloc(sizeof(int)); only to get "malloc: * error for object 0x100108e98: incorrect checksum for freed object - object was probably modified after being freed." As far as I understand this error, memory has already been allocated for this object, but I don't see where this happened. Doesn't the malloc(sizeof(attribute)) only allocate the memory needed to store an integer and two pointers (i.e. not the memory those pointers point to)? Any help would be greatly appreciated! Regards, Vassil

    Read the article

  • MSBuild: Items + Batching + CreateItem + Transforms Question

    - by KeithCS
    I have this bit of an msbuild project that is making me wonder why it the outcome is the way it is. Not that it is causing an issue or anything of the sort, but I would like to try and better my understanding of it. <?xml version="1.0" encoding="utf-8" ?> <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="TestTarget1;TestTarget2" ToolsVersion="3.5"> <ItemGroup> <PathDir Include="C:\RootDir\UniqueDir1"/> <PathDir Include="C:\RootDir\UniqueDir2" /> </ItemGroup> <Target Name="TestTarget1" Outputs="%(PathDir.Identity)"> <PropertyGroup> <RootPath>%(PathDir.Identity)</RootPath> </PropertyGroup> <ItemGroup> <SubDirectory Include="Common1"/> <SubDirectory Include="Common2"/> </ItemGroup> <CreateItem Include="@(SubDirectory->'$(RootPath)\%(Identity)')"> <Output TaskParameter="Include" ItemName="FullPath"/> </CreateItem> <Message Text="@(FullPath)"/> </Target> <Target Name="TestTarget2"> <Message Text="@(FullPath)"/> </Target> </Project> So I have two main paths that are unique, and within each I have two directories with the same names in each of the unique paths. In target1, I am batching against the identity of the items in PathDir, and then performing a transform on item SubDirectory, which contains the common folder names found in the unique directories, to create a new item containing the full paths. So anyways, after that, the output for the targets is as follows: Target 1: C:\RootDir\UniqueDir1\Common1;C:\RootDir\UniqueDir1\Common2 C:\RootDir\UniqueDir2\Common1;C:\RootDir\UniqueDir2\Common2 Target 2: C:\RootDir\UniqueDir1\Common1;C:\RootDir\UniqueDir1\Common2;C:\RootDir\UniqueDir2\Common1;C:\RootDir\UniqueDir2\Common2 So my question I guess is ... why does target1 only display the directories containing the directory it is batching against? I know it probably has to do with batching, but thats all I know.

    Read the article

  • architecture python question

    - by tom smith
    hi. creating a distributed crawling python app. it consists of a master server, and associated client apps that will run on client servers. the purpose of the client app is to run across a targeted site, to extract specific data. the clients need to go "deep" within the site, behind multiple levels of forms, so each client is specifically geared towards a given site. each client app looks something like main: parse initial url call function level1 (data1) function level1 (data) parse the url, for data1 use the required xpath to get the dom elements call the next function call level2 (data) function level2 (data2) parse the url, for data2 use the required xpath to get the dom elements call the next function call level3 function level3 (dat3) parse the url, for data3 use the required xpath to get the dom elements call the next function call level4 function level4 (data) parse the url, for data4 use the required xpath to get the dom elements at the final function.. --all the data output, and eventually returned to the server --at this point the data has elements from each function... my question: given that the number of calls that is made to the child function by the current function varies, i'm trying to figure out the best approach. each function essentialy fetches a page of content, and then parses the page using a number of different XPath expressions, combined with different regex expressions depending on the site/page. if i run a client on a single box, as a sequential process, it'll take awhile, but the load on the box is rather small. i've thought of attempting to implement the child functions as threads from the current function, but that could be a nightmare, as well as quickly bring the "box" to its knees! i've thought of breaking the app up in a manner that would allow the master to essentially pass packets to the client boxes, in a way to allow each client/function to be run directly from the master. this process requires a bit of rewrite, but it has a number of advantages. a bunch of redundancy, and speed. it would detect if a section of the process was crashing and restart from that point. but not sure if it would be any faster... i'm writing the parsing scripts in python.. so... any thoughts/comments would be appreciated... i can get into a great deal more detail, but didn't want to bore anyone!! thanks! tom

    Read the article

  • Implementation question involving implementing an interface

    - by Vivin Paliath
    I'm writing a set of collection classes for different types of Trees. I'm doing this as a learning exercise and I'm also hoping it turns out to be something useful. I really want to do this the right way and so I've been reading Effective Java and I've also been looking at the way Joshua Bloch implemented the collection classes by looking at the source. I seem to have a fair idea of what is being done, but I still have a few things to sort out. I have a Node<T> interface and an AbstractNode<T> class that implements the Node interface. I then created a GenericNode<T> (a node that can have 0 to n children, and that is part of an n-ary tree) class that extends AbstractNode<T> and implements Node<T>. This part was easy. Next, I created a Tree<T> interface and an AbstractTree<T> class that implements the Tree<T> interface. After that, I started writing a GenericTree<T> class that extends AbstractTree<T> and implements Tree<T>. This is where I started having problems. As far as the design is concerned, a GenericTree<T> can only consist of nodes of type GenericTreeNode<T>. This includes the root. In my Tree<T> interface I have: public interface Tree<T> { void setRoot(Node<T> root); Node<T> getRoot(); List<Node<T>> postOrder(); ... rest omitted ... } And, AbstractTree<T> implements this interface: public abstract class AbstractTree<T> implements Tree<T> { protected Node<T> root; protected AbstractTree() { } protected AbstractTree(Node<T> root) { this.root = root; } public void setRoot(Node<T> root) { this.root = root; } public Node<T> getRoot() { return this.root; } ... rest omitted ... } In GenericTree<T>, I can have: public GenericTree(Node<T> root) { super(root); } But what this means is that you can create a generic tree using any subtype of Node<T>. You can also set the root of a tree to any subtype of Node<T>. I want to be able to restrict the type of the node to the type of the tree that it can represent. To fix this, I can do this: public GenericTree(GenericNode<T> root) { super(root); } However, setRoot still accepts a parameter of type Node<T>. Which means a user can still create a tree with the wrong type of root node. How do I enforce this constraint? The only way I can think of doing is either: Do an instanceof which limits the check to runtime. I'm not a huge fan of this. Remove setRoot from the interface and have the base class implement this method. This means that it is not part of the contract and anyone who wants to make a new type of tree needs to remember to implement this method. Is there a better way? The second question I have concerns the return type of postOrder which is List<Node<T>>. This means that if a user is operating on a GenericTree<T> object and calls postOrder, he or she receives a list that consists of Node<T> objects. This means when iterating through (using a foreach construct) they would have perform an explicit cast to GenericNode<T> if they want to use methods that are only defined in that class. I don't like having to place this burden on the user. What are my options in this case? I can only think of removing the method from the interface and have the subclass implement this method making sure that it returns a list of appropriate subtype of Node<T>. However, this once again removes it from the contract and it's anyone who wants to create a new type of tree has to remember to implement this method. Is there a better way?

    Read the article

  • SaaS Architecture Question from Newbie

    - by user226767
    I have developed a number of departmental client-server applications, and am now ready to begin working on moving one of these applications to a SaaS model. I have done some basic web development, but I'm a newbie when it comes to SaaS architectures. One of the first questions that comes to mind as I try to design the architecture is the question of single vs. multi tenancy. The pros and cons of each vary significantly depending on the type of application and scale required, so I'd like to describe my application and scale needs below, and hope others can comment on how I should get started with the architecture. The client-server application currently consists of a Firebird database and a Windows application. The database contains about 20 tables containing a few thousand records in 4 primary tables, and a few hundred records in various lookup and related tables. Although the number of records is small, the size can get large, as the database can contain large BLOBS. Each customer sets up their own database and has a handful of users within the organization connected to it. When I update the db schema, a new windows application is released, and it checks the db schema and then applies the updates as needed. For the SaaS application, I am designing for 100's (not 1000's or millions) of new customers per year. My first thought was to go with a multi tenancy model to make updates easy (shut down apply the updates to one database, and then start up). On the other hand, a single tenancy model would provide a means to roll updates out to a group of customers at a time, and spread the risk of data corruption - i.e. if something goes wrong with a database, it will impact one customer instead of all customers. With this idea, I was thinking of having a single web front-end which would connect to a single customer database upon login. Thus, when a new customer creates an account, a new database would be created (each customer would have their own db with multiple users as needed for the customer). In this model, a db update would require either a process to go through each db to apply schema changes, or a trigger upon logging in to initiate a schema update similar to the client-server model currently in use. Can anyone point me to information for similar applications which have been ported from client-server to SaaS? Or provide any pointers to consider? Basically I'm looking for architecture examples of taking a departmental application and making it available as a self service website for multiple customers. Thanks for any suggestions, resources, etc.

    Read the article

  • The question about the basics of LINQ to SQL

    - by Alex
    I just started learning LINQ to SQL, and so far I'm impressed with the easy of use and good performance. I used to think that when doing LINQ queries like from Customer in DB.Customers where Customer.Age > 30 select Customer LINQ gets all customers from the database ("SELECT * FROM Customers"), moves them to the Customers array and then makes a search in that Array using .NET methods. This is very inefficient, what if there are hundreds of thousands of customers in the database? Making such big SELECT queries would kill the web application. Now after experiencing how actually fast LINQ to SQL is, I start to suspect that when doing that query I just wrote, LINQ somehow converts it to a SQL Query string SELECT * FROM Customers WHERE Age > 30 And only when necessary it will run the query. So my question is: am I right? And when is the query actually run? The reason why I'm asking is not only because I want to understand how it works in order to build good optimized applications, but because I came across the following problem. I have 2 tables, one of them is Books, the other has information on how many books were sold on certain days. My goal is to select books that had at least 50 sales/day in past 10 days. It's done with this simple query: from Book in DB.Books where (from Sale in DB.Sales where Sale.SalesAmount >= 50 && Sale.DateOfSale >= DateTime.Now.AddDays(-10) select Sale.BookID).Contains(Book.ID) select Book The point is, I have to use the checking part in several queries and I decided to create an array with IDs of all popular books: var popularBooksIDs = from Sale in DB.Sales where Sale.SalesAmount >= 50 && Sale.DateOfSale >= DateTime.Now.AddDays(-10) select Sale.BookID; BUT when I try to do the query now: from Book in DB.Books where popularBooksIDs.Contains(Book.ID) select Book It doesn't work! That's why I think that we can't use thins kinds of shortcuts in LINQ to SQL queries, like we can't use them in real SQL. We have to create straightforward queries, am I right?

    Read the article

  • A Question about using jython when run a receving socket in python

    - by abusemind
    Hi, I have not a lot of knowledge of python and network programming. Currently I am trying to implement a simple application which can receive a text message sent by the user, fetch some information from the google search api, and return the results via text message to the user. This application will continue to listening to the users messages and reply immediately. How I get the text short message sent by the user? It's a program named fetion from the mobile supplier in China. The client side fetion, just like a instant communication tool, can send/receive messages to/from other people who are using mobile to receive/send SMS. I am using a open source python program that simulates the fetion program. So basically I can use this python program to communate with others who using cell phone via SMS. My core program is based on java, so I need to take this python program into java environment. I am using jython, and now I am available to send messages to users by some lines of java codes. But the real question is the process of receving from users via SMS. In python code, a new thread is created to continuously listen to the user. It should be OK in Python, but when I run the similar process in Jython, the following exception occurs: Exception in thread Thread:Traceback (most recent call last): File "D:\jython2.5.1\Lib\threading.py", line 178, in _Thread__bootstrap self.run() File "<iostream>", line 1389, in run File "<iostream>", line 1207, in receive File "<iostream>", line 1207, in receive File "<iostream>", line 150, in recv File "D:\jython2.5.1\Lib\select.py", line 223, in native_select pobj.register(fd, POLLIN) File "D:\jython2.5.1\Lib\select.py", line 104, in register raise _map_exception(jlx) error: (20000, 'socket must be in non-blocking mode') The line 150 in the python code is as follows: def recv(self,timeout=False): if self.login_type == "HTTP": time.sleep(10) return self.get_offline_msg() pass else: if timeout: infd,outfd,errfd = select([self.__sock,],[],[],timeout)//<---line 150 here else: infd,outfd,errfd = select([self.__sock,],[],[]) if len(infd) != 0: ret = self.__tcp_recv() num = len(ret) d_print(('num',),locals()) if num == 0: return ret if num == 1: return ret[0] for r in ret: self.queue.put(r) d_print(('r',),locals()) if not self.queue.empty(): return self.queue.get() else: return "TimeOut" Because of I am not very familiar with python, especially the socket part, and also new in Jython use, I really need your help or only advice or explanation. Thank you very much!

    Read the article

< Previous Page | 50 51 52 53 54 55 56 57 58 59 60 61  | Next Page >