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  • mysql timeout - c/C++

    - by user1262876
    Guys i'm facing a problem with this code, the problem is the timeout by timeout i mean the time it takes the program to tell me if the server is connected or not. If i use my localhost i get the answer fast, but when i connect to outside my localhost it takes 50sc - 1.5 min to response and the program frezz until it done. HOw can i fix the frezzing, or make my own timeout, like if still waiting after 50sc, tell me connection failed and stop? please use codes as help, becouse i would understand it better, thanks for any help i get PS: USING MAC #include "mysql.h" #include <stdio.h> #include <stdlib.h> // Other Linker Flags: -lmysqlclient -lm -lz // just going to input the general details and not the port numbers struct connection_details { char *server; char *user; char *password; char *database; }; MYSQL* mysql_connection_setup(struct connection_details mysql_details) { // first of all create a mysql instance and initialize the variables within MYSQL *connection = mysql_init(NULL); // connect to the database with the details attached. if (!mysql_real_connect(connection,mysql_details.server, mysql_details.user, mysql_details.password, mysql_details.database, 0, NULL, 0)) { printf("Conection error : %s\n", mysql_error(connection)); exit(1); } return connection; } MYSQL_RES* mysql_perform_query(MYSQL *connection, char *sql_query) { // send the query to the database if (mysql_query(connection, sql_query)) { printf("MySQL query error : %s\n", mysql_error(connection)); exit(1); } return mysql_use_result(connection); } int main() { MYSQL *conn; // the connection MYSQL_RES *res; // the results MYSQL_ROW row; // the results row (line by line) struct connection_details mysqlD; mysqlD.server = (char*)"Localhost"; // where the mysql database is mysqlD.user = (char*)"root"; // the root user of mysql mysqlD.password = (char*)"123456"; // the password of the root user in mysql mysqlD.database = (char*)"test"; // the databse to pick // connect to the mysql database conn = mysql_connection_setup(mysqlD); // assign the results return to the MYSQL_RES pointer res = mysql_perform_query(conn, (char*) "SELECT * FROM me"); printf("MySQL Tables in mysql database:\n"); while ((row = mysql_fetch_row(res)) !=NULL) printf("%s - %s\n", row[0], row[1], row[2]); // <-- Rows /* clean up the database result set */ mysql_free_result(res); /* clean up the database link */ mysql_close(conn); return 0; }

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  • Opening Macro definitions: tdfx_span.c: lvalue required as left operand of assignment

    - by anttir
    Hi, I'm trying to compile X11R6-7.0 under Ubuntu maverick and got some weird compilation errors I'm unable to resolve myself. I needed X11R6-7.0 as ati catalyst drivers don't support newer xorg and oss drivers don't support 3d acceleration of my hardware. Anyone know what this error message means? I know some C but I got a bit confused. Does it mean GET_FB_DATA macro returned NULL or some method/property not set? Any further insight how to "debug" preprocessor definitions at this point would be great. I don't think I can print anything useful with #error. The error I get: tdfx_span.c: In function ‘tdfxDDWriteDepthPixels’: tdfx_span.c:976: error: lvalue required as left operand of assignment tdfx_span.c:1008: error: lvalue required as left operand of assignment tdfx_span.c: In function ‘write_stencil_pixels’: tdfx_span.c:1242: error: lvalue required as left operand of assignment the Code: 958- switch (depth_size) { 959- case 16: 960- GetBackBufferInfo(fxMesa, &backBufferInfo); 961- /* 962- * Note that the _LOCK macro adds a curly brace, 963- * and the UNLOCK macro removes it. 964- */ 965- WRITE_FB_SPAN_LOCK(fxMesa, info, 966- GR_BUFFER_AUXBUFFER, GR_LFBWRITEMODE_ANY); 967- { 968- LFBParameters ReadParams; 969- GetFbParams(fxMesa, &info, &backBufferInfo, 970- &ReadParams, sizeof(GLushort)); 971- for (i = 0; i < n; i++) { 972- if (mask[i] && visible_pixel(fxMesa, x[i], y[i])) { 973- xpos = x[i] + fxMesa->x_offset; 974- ypos = bottom - y[i]; 975- d16 = depth[i]; 976: PUT_FB_DATA(&ReadParams, GLushort, xpos, ypos, d16); 977- } 978- } 979- } 980- WRITE_FB_SPAN_UNLOCK(fxMesa, GR_BUFFER_AUXBUFFER); 981- break; 982- case 24: And relative macros: #define GET_FB_DATA(ReadParamsp, type, x, y) \ (((x) < (ReadParamsp)->firstWrappedX) \ ? (((type *)((ReadParamsp)->lfbPtr)) \ [(y) * ((ReadParamsp)->LFBStrideInElts) \ + (x)]) \ : (((type *)((ReadParamsp)->lfbWrapPtr)) \ [((y)) * ((ReadParamsp)->LFBStrideInElts) \ + ((x) - (ReadParamsp)->firstWrappedX)])) #define GET_ORDINARY_FB_DATA(ReadParamsp, type, x, y) \ (((type *)((ReadParamsp)->lfbPtr)) \ [(y) * ((ReadParamsp)->LFBStrideInElts) \ + (x)]) #define GET_WRAPPED_FB_DATA(ReadParamsp, type, x, y) \ (((type *)((ReadParamsp)->lfbWrapPtr)) \ [((y)) * ((ReadParamsp)->LFBStrideInElts) \ + ((x) - (ReadParamsp)->firstWrappedX)]) #define PUT_FB_DATA(ReadParamsp, type, x, y, value) \ (GET_FB_DATA(ReadParamsp, type, x, y) = (type)(value)) #define PUT_ORDINARY_FB_DATA(ReadParamsp, type, x, y, value) \ (GET_ORDINARY_FB_DATA(ReadParamsp, type, x, y) = (type)(value)) #define PUT_WRAPPED_FB_DATA(ReadParamsp, type, x, y, value) \ (GET_WRAPPED_FB_DATA(ReadParamsp, type, x, y) = (type)(value)) The LFBParameters Struct 483-typedef struct 484-{ 485- void *lfbPtr; 486- void *lfbWrapPtr; 487- FxU32 LFBStrideInElts; 488- GLint firstWrappedX; 489-} 490:LFBParameters; Thanks for looking.

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  • .live event doesnt work till second click

    - by ChampionChris
    I have 2 list on a page that are linked. When I drag a li element from list 1 to list 2 the live events on list 1 don't work on the first click only second click. Below is the code that adds the li (obj) to list 2. function AddToDropBox(obj) { $(obj).children(".handle").animate({ width: "20px" }).children("strong").fadeOut(); $(obj).children("span:not(.track,.play,.handle,:has(.btn-edit))").fadeOut('fast'); $(obj).children(".play").css("margin-right", "8px"); $(obj).css({ "opacity": "0.0", "width": "284px" }).animate({ opacity: "1.0" }); if ($(".sidebar-drop-box ul").children(".admin-song").length > 0) { $(".dropTitle").fadeOut("fast"); $(".sidebar-drop-box ul.admin-song-list").css("min-height", "0"); } if (typeof SetLinks == 'function') { SetLinks(); } //CBG Changes adds media ID to hidden field //checks id there is a value in field then adds comma if(document.getElementById("ctl00_cphBody_hfRemoveMedia").value==""||document.getElementById("ctl00_cphBody_hfRemoveMedia").value==null) { document.getElementById("ctl00_cphBody_hfRemoveMedia").value=(obj).attr("mediaid"); } else { var localMediaIDs=document.getElementById("ctl00_cphBody_hfRemoveMedia").value; document.getElementById("ctl00_cphBody_hfRemoveMedia").value=localMediaIDs+", "+(obj).attr("mediaid"); } // alert("hfid: "+document.getElementById("ctl00_cphBody_hfRemoveMedia").value); //END CBG Modifications } this is one of the live() events that dont fire until the second click after the drag. This live() event is in a document.ready function(). // Live for deleting. $(".btn-del").live("click", function(e) { DeleteItem(this); $(this).removeClass("btn-del").addClass("btn-add").parents("li").removeClass("alt").addClass("removed"); var oldTxt = $(this).parents("li").find(".status").text(); $(this).parents("li").find(".status").text("Removed").attr("oldstat", oldTxt); $("#timeHolder input[type=hidden]").val(($("#timeHolder input[type=hidden]").val() * 1) - ($(this).parents("li").find(".time").attr("length") * 1)); CalculateAggregates(); isDirty = false; }); EDIT @dreaton.. Im new to jquery and javascript so thanks for the last tip... Im not sure what you mean about cache the query's. ... the delegete feature is giving me this Microsoft JScript runtime error: Object doesn't support this property or method this is the way I have the code $('#ulPlaylist').delegate('.btn-del', 'click', function (e) { DeleteItem(this); $(this).removeClass("btn-del").addClass("btn-add").parents("li").removeClass("alt").addClass("removed"); var oldTxt = $(this).parents("li").find(".status").text(); $(this).parents("li").find(".status").text("Removed").attr("oldstat", oldTxt); $("#timeHolder input[type=hidden]").val(($("#timeHolder input[type=hidden]").val() * 1) - ($(this).parents("li").find(".time").attr("length") * 1)); CalculateAggregates(); isDirty = false; });

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  • Few doubts regarding Bitmaps , Images & `using` blocks

    - by imageWorker
    I caught up in this problem. http://stackoverflow.com/questions/2559826/garbage-collector-not-doing-its-job-memory-consumption-1-5gb-outofmemory-exc I feel that there is something wrong in my understanding. Please clarify these things. Destructor & IDisposable.Dispose are two methods for freeing resources that are not not under the control of .NET. Which means, everything except memory. right? using blocks are just better way of calling IDisposable.Dispose() method of an object. This is the main code I'm referring to. class someclass { static someMethod(Bitmap img) { Bitmap bmp = new Bitmap(img); //statement1 // some code here and return } } here is class I'm using for testing: class someotherClass { public static voide Main() { foreach (string imagePath in imagePathsArray) { using (Bitmap img1 = new Bitmap(imagePath)) { someclass.someMethod(img1); // does some more processing on `img1` } } } } Is there any memory leak with statement1? Question1: If each image size is say 10MB. Then does this bmp object occupy atleast 10MB? What I mean is, will it make completely new copy of entire image? or just refer to it? Question2:should I or should I not put the statement1 in using block? My Argument: We should not. Because using is not for freeing memory but for freeing the resources (file handle in this case). If I use it in using block. It closes file handle here encapsulated by this bmp object. It means we are also closing filehandle for the caller's img1 object. Which is not correct? As of the memory leak. No there is no scope of memory leak here. Because reference bmp is destroyed when this method is returned. Which leaves memory it refered without any pointer. So, its garbage collected. Am I right? Edit: class someclass { static Bitmap someMethod(Bitmap img) { Bitmap bmp = new Bitmap(img); //can I use `using` block on this enclosing `return bmp`; ??? // do some processing on bmp here return bmp; } }

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  • MySQL error problem

    - by comma
    I keep getting the error listed below but it only says line 1 what does this mean and how do I fix it? Here is the error I keep getting? You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '1' at line 1 here is the code. if (isset($_POST['info_submitted'])) { $user_id = '5'; $mysqli = mysqli_connect("localhost", "root", "", "sitename"); $dbc = mysqli_query($mysqli,"SELECT learned_skills.*, users_skills.* FROM learned_skills INNER JOIN users_skills ON learned_skills.id = users_skills.skill_id WHERE user_id='$user_id'"); $skill = $_POST['skill']; $experience = $_POST['experience']; $year = $_POST['year']; if (mysqli_num_rows($dbc) == 0) { $mysqli = mysqli_connect("localhost", "root", "", "sitename"); $query1 = mysqli_query($mysqli,"INSERT INTO learned_skills (skill, experience, year) VALUES ('" . $skill . "', '" . $experience . "', '" . $year . "')"); } if (!mysqli_query($mysqli, $query1)) { print mysqli_error($mysqli); return; } $mysqli = mysqli_connect("localhost", "root", "", "sitename"); $dbc = mysqli_query($mysqli,"SELECT id FROM learned_skills WHERE id='" . $skill . "' AND experience='" . $experience . "' AND year='" . $year . "'"); if (!$dbc) { print mysqli_error($mysqli); } else { while($row = mysqli_fetch_array($dbc)){ $id = $row["id"]; } } $query2 = "INSERT INTO users_skills (skill_id, user_id, date_created) VALUES ('$id', '$user_id', NOW())"; if (!mysqli_query($mysqli, $query2)) { print mysqli_error($mysqli); return; } if ($dbc == TRUE) { $dbc = mysqli_query($mysqli,"UPDATE learned_skills JOIN users_skills ON (users_skills.skill_id = learned_skills.id) SET skill = '$skill', experience = '$experience', year = '$year'"); echo '<p class="changes-saved">Your changes have been saved!</p>'; } if (!$dbc) { print mysqli_error($mysqli); return; } }

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  • Wordpress pages address rewrite

    - by kemp
    UPDATE I tried using the internal wordpress rewrite. What I have to do is an address like this: http://example.com/galleria/artist-name sent to the gallery.php page with a variable containing the artist-name. I used these rules as per Wordpress' documentation: // REWRITE RULES (per gallery) {{{ add_filter('rewrite_rules_array','wp_insertMyRewriteRules'); add_filter('query_vars','wp_insertMyRewriteQueryVars'); add_filter('init','flushRules'); // Remember to flush_rules() when adding rules function flushRules(){ global $wp_rewrite; $wp_rewrite->flush_rules(); } // Adding a new rule function wp_insertMyRewriteRules($rules) { $newrules = array(); $newrules['(galleria)/(.*)$'] = 'index.php?pagename=gallery&galleryname=$matches[2]'; return $newrules + $rules; } // Adding the id var so that WP recognizes it function wp_insertMyRewriteQueryVars($vars) { array_push($vars, 'galleryname'); return $vars; } what's weird now is that on my local wordpress test install, that works fine: the gallery page is called and the galleryname variable is passed. On the real site, on the other hand, the initial URL is accepted (as in it doesn't go into a 404) BUT it changes to http://example.com/gallery (I mean it actually changes in the browser's address bar) and the variable is not defined in gallery.php. Any idea what could possibly cause this different behavior? Alternatively, any other way I couldn't think of which could achieve the same effect described in the first three lines is perfectly fine. Old question What I need to do is rewriting this address: (1) http://localhost/wordpress/fake/text-value to (2) http://localhost/wordpress/gallery?somevar=text-value Notes: the remapping must be transparent: the user always has to see address (1) gallery is a permalink to a wordpress page, not a real address I basically need to rewrite the address first (to modify it) and then feed it back to mod rewrite again (to let wordpress parse it its own way). Problems if I simply do RewriteRule ^fake$ http://localhost/wordpress/gallery [L] it works but the address in the browser changes, which is no good, if I do RewriteRule ^fake$ /wordpress/gallery [L] I get a 404. I tried different flags instead of [L] but to no avail. How can I get this to work? EDIT: full .htaccess # BEGIN WordPress <IfModule mod_rewrite.c> RewriteEngine On RewriteRule ^fake$ /wordpress/gallery [R] RewriteBase /wordpress/ RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule . /wordpress/index.php [L] </IfModule> # END WordPress

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  • On Click alert if $.get returns a value, if not, submit the form

    - by bradenkeith
    If the submit button is clicked, prevent the default action and see if the field 'account_name' is already in use. If the $.get() returns a result, alert the user of the results. If it doesn't, submit form with id="add_account_form". My problem is that my else{} statement is not submitting the form. I get no response when submit is clicked & there is no value returned. Also I would like to change my code where it goes $("#add_account_form").submit(..) instead of .click() however, would that cause a problem when trying to submit the form later in the script? <script type="text/javascript"> $(document).ready( function () { $("#submit").click( function () { var account_name = $("input[name=account_name]").val(); $.get( "'.url::site("ajax/check_account_name").'", {account_name: account_name}, function(data){ if(data.length > 0){ confirm( "The account name you entered looks like the following:\n" +data+ "Press cancel if this account already exists or ok to create it." ); }else{ $("#add_account_form").submit(); } }); return false; }); }); </script> <p> <input type="submit" id="submit" class="submit small" name="submit" value="Submit" /> </p> </form> Thanks for your help. EDIT So anyone who runs into my problems, it's that $.get() is asynchronous, so it will always return false, or true depending on what submitForm is defined as. $.ajax() however, allows async to be set as false, which allows the function to finish before moving on. See what I mean: $(document).ready( function () { $("#add_account_form").submit( function () { var submitForm = true; var account_name = $("input[name=account_name]").val(); $.ajax({ type: "GET", async: false, url: "'.url::site("ajax/check_account_name").'", data: ({account_name: account_name}), success: function(data){ if(data.length > 0){ if(!confirm( "The account name you entered looks like the following:\n" +data+ "Press cancel if this account already exists or ok to create it." )){ submitForm = false; } } } }); if (submitForm == false ) { return false; } }); }); Thanks for your help @Dan

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  • which way is correct to retrive data from oracle??

    - by rima
    before answer me plz thinking about the futures of these kind of program and answer me plz. I wanna get some data from oracle server like: 1-get all the function,package,procedure and etc for showing them or drop them & etc... 2-compile my *.sql files,get the result if they have problem & etc... becuz I was beginner in oracle first of all I for solve the second problem I try to connect to sqlPlus by RUN sqlplus and trace the output(I mean,I change the output stream of shell and trace what happend and handle the assigned message to customer. NOW THIS PART SUCCEED. just a little bit I have problem with get all result because the output is asynchronous.any way... [in this case I log in to oracle Server by send argument to the sqlplus by make a process in c#] after that I try to get all function,package or procedure name,but I have problem in speed!so I try to use oracle.DataAccess.dll to connect the database. now I m so confusing about: which way is correct way to build a program that work like Oracle Developer! I do not have any experience for like these program how work. If Your answer is I must use the second way follow this part plz: I search a little bit the Golden,PLedit (Benthic software),I have little bit problem how I must create the connection string?because I thinking about how I can find the host name or port number that oracle work on them?? am I need read the TNSNames.Ora file? IF your answer is I must use the first way follow this part plz: do u have any Idea for how I parse the output?because for example the result of a table is so confusing...[i can handle & program it but I really need someone experience,because the important things to me learn how such software work so nice and with quick response?] All of the has different style in output... If you are not sure Can u help me which book can help me in this way i become expert? becuz for example all the C# write just about how u can connect to DB and the DB books write how u can use this DB program,I looking for a book that give me some Idea how develop an interface for do transaction between these two.not simple send and receive data,for example how write a compiler for them. the language of book is not different for me i know C#,java,VB,sql,Oracle Thanks.

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  • Searching in Ruby on Rails - How do I search on each word entered and not the exact string?

    - by bgadoci
    I have built a blog application w/ ruby on rails and I am trying to implement a search feature. The blog application allows for users to tag posts. The tags are created in their own table and belong_to :post. When a tag is created, so is a record in the tag table where the name of the tag is tag_name and associated by post_id. Tags are strings. I am trying to allow a user to search for any word tag_name in any order. Here is what I mean. Lets say a particular post has a tag that is 'ruby code controller'. In my current search feature, that tag will be found if the user searches for 'ruby', 'ruby code', or 'ruby code controller'. It will not be found if the user types in 'ruby controller'. Essentially what I am saying is that I would like each word entered in the search to be searched for, not necessarily the 'string' that is entered into the search. I have been experimenting with providing multiple textfields to allow the user to type in multiple words, and also have been playing around with the code below, but can't seem to accomplish the above. I am new to ruby and rails so sorry if this is an obvious question and prior to installing a gem or plugin I thought I would check to see if there was a simple fix. Here is my code: View: /views/tags/index.html.erb <% form_tag tags_path, :method => 'get' do %> <p> <%= text_field_tag :search, params[:search], :class => "textfield-search" %> <%= submit_tag "Search", :name => nil, :class => "search-button" %> </p> <% end %> TagsController def index @tags = Tag.search(params[:search]).paginate :page => params[:page], :per_page => 5 @tagsearch = Tag.search(params[:search]) @tag_counts = Tag.count(:group => :tag_name, :order => 'count_all DESC', :limit => 100) respond_to do |format| format.html # index.html.erb format.xml { render :xml => @tags } end end Tag Model class Tag < ActiveRecord::Base belongs_to :post validates_length_of :tag_name, :maximum=>42 validates_presence_of :tag_name def self.search(search) if search find(:all, :order => "created_at DESC", :conditions => ['tag_name LIKE ?', "%#{search}%"]) else find(:all, :order => "created_at DESC") end end end

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  • div "top" bug IE and everything else. Big problem

    - by Victor
    Hi everyone. I am new in CSS so please help me in this problem. I hope to describe it wright. I am making div named content where my site content is. I made it with z-index:-1; so an image to be over this div. But in Chrome, FF and safari, content became inactive. I cant select text , click on link and write in the forms. So I tried with positive states in the z-index but IE don't know what this means. Damn. So I decided to make conditional div. Here is the code: .content { background:#FFF; width:990px; position:relative; float:left; top:50px; } .content_IE { background:#FFF; width:990px; position:relative; float:left; top: 50px; z-index:-1; } and here is the HTML: <!--[if IE 7]> <div class="content_IE" style="height:750px;"> <![endif]--> <div class="content" style="height:550px;"> Everything is fine with the z-index but the problem is that if there is no top in .content class everything looks fine in IE but there is no space in the other browsers. If i put back the top:50px; there onother 50px like padding in the .content_IE class. I mean that the page looks like I've put top:50px; and padding-top=50px;. I've try everything like margin-top:-50px; padding-top:-50px; and stuff like this but I am still in the circle. It look fine only if there is no top option in .content class. Please help.

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  • How to use Mozilla ActiveX Control without registry

    - by Andrew McKinlay
    I've been using the IE Browser component that is part of Windows. But I'm running into problems with security settings. For example, users get security warnings on pages with Javascript. So I'm looking at using the Mozilla ActiveX control instead. It's especially nice because it has a compatible interface. It works well if I let it install the control in the registry. But my users don't always have administrator rights to install things in the registry. So I'm trying to figure out how to use the control without registry changes. I'm using DllGetClassObject to get the class factory (IID_ICLASSFACTORY) and then CoRegisterClassObject to register it. All the API calls appear to succeed. And when I create an AtlAxWin window with the CLSID, it also appears to work. But when I try to call Navigate on the AtlAxGetControl it doesn't work - the interface doesn't have Navigate. I would show the code but it's in an obscure language (Suneido) so it wouldn't mean much. An example in C or C++ would be easy for me to translate. Or an example in another dynamic language like Python or Ruby might be helpful. Obviously I'm doing something wrong. Maybe I'm passing the wrong thing to CoRegisterClassObject? The MSDN documentation isn't very clear on what to pass and I haven't found any good examples. Or if there is another approach, I'm ok with that too. Note: I'm using the AtlAxWin window class so I'm not directly creating the control and can't use this approach. Another option is registry free com with a manifest. But again, I couldn't find a good example, especially since I'm not using Visual Studio. I tried to use the MT manifest tool, but couldn't figure it out. I don't think I can use DLL redirection since that doesn't get around the registry issue AFAIK. Another possibility is using WebKit but it seems even harder to use.

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  • Can MySQL reasonably perform queries on billions of rows?

    - by haxney
    I am planning on storing scans from a mass spectrometer in a MySQL database and would like to know whether storing and analyzing this amount of data is remotely feasible. I know performance varies wildly depending on the environment, but I'm looking for the rough order of magnitude: will queries take 5 days or 5 milliseconds? Input format Each input file contains a single run of the spectrometer; each run is comprised of a set of scans, and each scan has an ordered array of datapoints. There is a bit of metadata, but the majority of the file is comprised of arrays 32- or 64-bit ints or floats. Host system |----------------+-------------------------------| | OS | Windows 2008 64-bit | | MySQL version | 5.5.24 (x86_64) | | CPU | 2x Xeon E5420 (8 cores total) | | RAM | 8GB | | SSD filesystem | 500 GiB | | HDD RAID | 12 TiB | |----------------+-------------------------------| There are some other services running on the server using negligible processor time. File statistics |------------------+--------------| | number of files | ~16,000 | | total size | 1.3 TiB | | min size | 0 bytes | | max size | 12 GiB | | mean | 800 MiB | | median | 500 MiB | | total datapoints | ~200 billion | |------------------+--------------| The total number of datapoints is a very rough estimate. Proposed schema I'm planning on doing things "right" (i.e. normalizing the data like crazy) and so would have a runs table, a spectra table with a foreign key to runs, and a datapoints table with a foreign key to spectra. The 200 Billion datapoint question I am going to be analyzing across multiple spectra and possibly even multiple runs, resulting in queries which could touch millions of rows. Assuming I index everything properly (which is a topic for another question) and am not trying to shuffle hundreds of MiB across the network, is it remotely plausible for MySQL to handle this? UPDATE: additional info The scan data will be coming from files in the XML-based mzML format. The meat of this format is in the <binaryDataArrayList> elements where the data is stored. Each scan produces = 2 <binaryDataArray> elements which, taken together, form a 2-dimensional (or more) array of the form [[123.456, 234.567, ...], ...]. These data are write-once, so update performance and transaction safety are not concerns. My naïve plan for a database schema is: runs table | column name | type | |-------------+-------------| | id | PRIMARY KEY | | start_time | TIMESTAMP | | name | VARCHAR | |-------------+-------------| spectra table | column name | type | |----------------+-------------| | id | PRIMARY KEY | | name | VARCHAR | | index | INT | | spectrum_type | INT | | representation | INT | | run_id | FOREIGN KEY | |----------------+-------------| datapoints table | column name | type | |-------------+-------------| | id | PRIMARY KEY | | spectrum_id | FOREIGN KEY | | mz | DOUBLE | | num_counts | DOUBLE | | index | INT | |-------------+-------------| Is this reasonable?

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  • Error when passing data between views

    - by Kristoffer Bilek
    I'm using a plist (array of dictionaries) to populate a tableview. Now, when a cell i pressed, I want to pass the reprecented dictionary to the detail view with a segue. It's working properly to fill the tableview, but how do I send the same value to the detail view? This is my try: #import "WinesViewController.h" #import "WineObject.h" #import "WineCell.h" #import "WinesDetailViewController.h" @interface WinesViewController () @end @implementation WinesViewController - (id)initWithStyle:(UITableViewStyle)style { self = [super initWithStyle:style]; if (self) { // Custom initialization } return self; } - (void)viewDidLoad { [super viewDidLoad]; } - (void)viewDidUnload { [super viewDidUnload]; } - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { return (interfaceOrientation == UIInterfaceOrientationPortrait); } #pragma mark - Table view data source - (void)viewWillAppear:(BOOL)animated { wine = [[WineObject alloc] initWithLibraryName:@"Wine"]; self.title = @"Vinene"; [self.tableView deselectRowAtIndexPath:[self.tableView indexPathForSelectedRow] animated:YES]; } - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { // Return the number of sections. return 1; } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { // Return the number of rows in the section. return [wine libraryCount]; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"wineCell"; WineCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; // Configure the cell... cell.nameLabel.text = [[wine libraryItemAtIndex:indexPath.row] valueForKey:@"Name"]; cell.districtLabel.text = [[wine libraryItemAtIndex:indexPath.row] valueForKey:@"District"]; cell.countryLabel.text = [[wine libraryItemAtIndex:indexPath.row] valueForKey:@"Country"]; cell.bottleImageView.image = [UIImage imageNamed:[[wine libraryItemAtIndex:indexPath.row] valueForKey:@"Image"]]; cell.flagImageView.image = [UIImage imageNamed:[[wine libraryItemAtIndex:indexPath.row] valueForKey:@"Flag"]]; cell.fyldeImageView.image = [UIImage imageNamed:[[wine libraryItemAtIndex:indexPath.row] valueForKey:@"Fylde"]]; cell.friskhetImageView.image = [UIImage imageNamed:[[wine libraryItemAtIndex:indexPath.row] valueForKey:@"Friskhet"]]; cell.garvesyreImageView.image = [UIImage imageNamed:[[wine libraryItemAtIndex:indexPath.row] valueForKey:@"Garvesyre"]]; return cell; } #pragma mark - Table view delegate - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender { if ([[segue identifier] isEqualToString:@"DetailSegue"]) { NSIndexPath *selectedRowIndex = [self.tableView indexPathForSelectedRow]; WinesDetailViewController *winesdetailViewController = [segue destinationViewController]; //Here comes the error line: winesdetailViewController.winedetailName = [wine objectAtIndex:indexPath.row] valueForKey:@"Name"]; } } I get one error for: winesdetailViewController.winedetailName = [wine objectAtIndex:indexPath.row] valueForKey:@"Name"]; Use of undeclaired identifier: indexPath. did you mean NSIndexPath? I think I've missed something important here..

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  • How would you implement this "WorkerChain" functionality in .NET?

    - by Dan Tao
    Sorry for the vague question title -- not sure how to encapsulate what I'm asking below succinctly. (If someone with editing privileges can think of a more descriptive title, feel free to change it.) The behavior I need is this. I am envisioning a worker class that accepts a single delegate task in its constructor (for simplicity, I would make it immutable -- no more tasks can be added after instantiation). I'll call this task T. The class should have a simple method, something like GetToWork, that will exhibit this behavior: If the worker is not currently running T, then it will start doing so right now. If the worker is currently running T, then once it is finished, it will start T again immediately. GetToWork can be called any number of times while the worker is running T; the simple rule is that, during any execution of T, if GetToWork was called at least once, T will run again upon completion (and then if GetToWork is called while T is running that time, it will repeat itself again, etc.). Now, this is pretty straightforward with a boolean switch. But this class needs to be thread-safe, by which I mean, steps 1 and 2 above need to comprise atomic operations (at least I think they do). There is an added layer of complexity. I have need of a "worker chain" class that will consist of many of these workers linked together. As soon as the first worker completes, it essentially calls GetToWork on the worker after it; meanwhile, if its own GetToWork has been called, it restarts itself as well. Logically calling GetToWork on the chain is essentially the same as calling GetToWork on the first worker in the chain (I would fully intend that the chain's workers not be publicly accessible). One way to imagine how this hypothetical "worker chain" would behave is by comparing it to a team in a relay race. Suppose there are four runners, W1 through W4, and let the chain be called C. If I call C.StartWork(), what should happen is this: If W1 is at his starting point (i.e., doing nothing), he will start running towards W2. If W1 is already running towards W2 (i.e., executing his task), then once he reaches W2, he will signal to W2 to get started, immediately return to his starting point and, since StartWork has been called, start running towards W2 again. When W1 reaches W2's starting point, he'll immediately return to his own starting point. If W2 is just sitting around, he'll start running immediately towards W3. If W2 is already off running towards W3, then W2 will simply go again once he's reached W3 and returned to his starting point. The above is probably a little convoluted and written out poorly. But hopefully you get the basic idea. Obviously, these workers will be running on their own threads. Also, I guess it's possible this functionality already exists somewhere? If that's the case, definitely let me know!

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  • How to download file into string with progress callback?

    - by Kaminari
    I would like to use the WebClient (or there is another better option?) but there is a problem. I understand that opening up the stream takes some time and this can not be avoided. However, reading it takes a strangely much more amount of time compared to read it entirely immediately. Is there a best way to do this? I mean two ways, to string and to file. Progress is my own delegate and it's working good. FIFTH UPDATE: Finally, I managed to do it. In the meantime I checked out some solutions what made me realize that the problem lies elsewhere. I've tested custom WebResponse and WebRequest objects, library libCURL.NET and even Sockets. The difference in time was gzip compression. Compressed stream lenght was simply half the normal stream lenght and thus download time was less than 3 seconds with the browser. I put some code if someone will want to know how i solved this: (some headers are not needed) public static string DownloadString(string URL) { WebClient client = new WebClient(); client.Headers["User-Agent"] = "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/532.5 (KHTML, like Gecko) Chrome/4.1.249.1045 Safari/532.5"; client.Headers["Accept"] = "application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5"; client.Headers["Accept-Encoding"] = "gzip,deflate,sdch"; client.Headers["Accept-Charset"] = "ISO-8859-2,utf-8;q=0.7,*;q=0.3"; Stream inputStream = client.OpenRead(new Uri(URL)); MemoryStream memoryStream = new MemoryStream(); const int size = 32 * 4096; byte[] buffer = new byte[size]; if (client.ResponseHeaders["Content-Encoding"] == "gzip") { inputStream = new GZipStream(inputStream, CompressionMode.Decompress); } int count = 0; do { count = inputStream.Read(buffer, 0, size); if (count > 0) { memoryStream.Write(buffer, 0, count); } } while (count > 0); string result = Encoding.Default.GetString(memoryStream.ToArray()); memoryStream.Close(); inputStream.Close(); return result; } I think that asyncro functions will be almost the same. But i will simply use another thread to fire this function. I dont need percise progress indication.

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  • How to cache queries in EJB and return result efficient (performance POV)

    - by Maxym
    I use JBoss EJB 3.0 implementation (JBoss 4.2.3 server) At the beginning I created native query all the time using construction like Query query = entityManager.createNativeQuery("select * from _table_"); Of couse it is not that efficient, I performed some tests and found out that it really takes a lot of time... Then I found a better way to deal with it, to use annotation to define native queries: @NamedNativeQuery( name = "fetchData", value = "select * from _table_", resultClass=Entity.class ) and then just use it Query query = entityManager.createNamedQuery("fetchData"); the performance of code line above is two times better than where I started from, but still not that good as I expected... then I found that I can switch to Hibernate annotation for NamedNativeQuery (anyway, JBoss's implementation of EJB is based on Hibernate), and add one more thing: @NamedNativeQuery( name = "fetchData2", value = "select * from _table_", resultClass=Entity.class, readOnly=true) readOnly - marks whether the results are fetched in read-only mode or not. It sounds good, because at least in this case of mine I don't need to update data, I wanna just fetch it for report. When I started server to measure performance I noticed that query without readOnly=true (by default it is false) returns result with each iteration better and better, and at the same time another one (fetchData2) works like "stable" and with time difference between them is shorter and shorter, and after 5 iterations speed of both was almost the same... The questions are: 1) is there any other way to speed query using up? Seems that named queries should be prepared once, but I can't say it... In fact if to create query once and then just use it it would be better from performance point of view, but it is problematic to cache this object, because after creating query I can set parameters (when I use ":variable" in query), and it changes query object (isn't it?). well, is here any way to cache them? Or named query is the best option I can use? 2) any other approaches how to make results retrieveng faster. I mean, for instance I don't need those Entities to be attached, I won't update them, all I need is just fetch collection of data. Maybe readOnly is the only available way, so I can't speed it up, but who knows :) P.S. I don't ask about DB performance, all I need now is how not to create query all the time, so use it efficient, and to "allow" EJB to do less job with the same result concerning data returning.

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  • How to handle very frequent updates to a Lucene index

    - by fsm
    I am trying to prototype an indexing/search application which uses very volatile indexing data sources (forums, social networks etc), here are some of the performance requirements, Very fast turn-around time (by this I mean that any new data (such as a new message on a forum) should be available in the search results very soon (less than a minute)) I need to discard old documents on a fairly regular basis to ensure that the search results are not dated. Last but not least, the search application needs to be responsive. (latency on the order of 100 milliseconds, and should support at least 10 qps) All of the requirements I have currently can be met w/o using Lucene (and that would let me satisfy all 1,2 and 3), but I am anticipating other requirements in the future (like search relevance etc) which Lucene makes easier to implement. However, since Lucene is designed for use cases far more complex than the one I'm currently working on, I'm having a hard time satisfying my performance requirements. Here are some questions, a. I read that the optimize() method in the IndexWriter class is expensive, and should not be used by applications that do frequent updates, what are the alternatives? b. In order to do incremental updates, I need to keep committing new data, and also keep refreshing the index reader to make sure it has the new data available. These are going to affect 1 and 3 above. Should I try duplicate indices? What are some common approaches to solving this problem? c. I know that Lucene provides a delete method, which lets you delete all documents that match a certain query, in my case, I need to delete all documents which are older than a certain age, now one option is to add a date field to every document and use that to delete documents later. Is it possible to do range queries on document ids (I can create my own id field since I think that the one created by lucene keeps changing) to delete documents? Is it any faster than comparing dates represented as strings? I know these are very open questions, so I am not looking for a detailed answer, I will try to treat all of your answers as suggestions and use them to inform my design. Thanks! Please let me know if you need any other information.

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  • [c++] upload image to imageshack

    - by cinek1lol
    Hi! I would like to send pictures via a program written in C + +. - OK WinExec("C:\\curl\\curl.exe -H Expect: -F \"fileupload=@C:\\curl\\ok.jpg\" -F \"xml=yes\" -# \"http://www.imageshack.us/index.php\" -o data.txt -A \"Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.1) Gecko/20061204 Firefox/2.0.0.1\" -e \"http://www.imageshack.us\"", NULL); It works, but I would like to send the pictures from pre-loaded carrier to a variable char (you know what I mean? First off, I load the pictures into a variable and then send the variable), cause now I have to specify the path of the picture on a disk. I wanted to write this program in c++ by using the curl library, not through exe. extension. I have also found such a program (which has been modified by me a bit) #include <stdio.h> #include <string.h> #include <iostream> #include <curl/curl.h> #include <curl/types.h> #include <curl/easy.h> int main(int argc, char *argv[]) { CURL *curl; CURLcode res; struct curl_httppost *formpost=NULL; struct curl_httppost *lastptr=NULL; struct curl_slist *headerlist=NULL; static const char buf[] = "Expect:"; curl_global_init(CURL_GLOBAL_ALL); /* Fill in the file upload field */ curl_formadd(&formpost, &lastptr, CURLFORM_COPYNAME, "send", CURLFORM_FILE, "nowy.jpg", CURLFORM_END); curl_formadd(&formpost, &lastptr, CURLFORM_COPYNAME, "nowy.jpg", CURLFORM_COPYCONTENTS, "nowy.jpg", CURLFORM_END); curl_formadd(&formpost, &lastptr, CURLFORM_COPYNAME, "submit", CURLFORM_COPYCONTENTS, "send", CURLFORM_END); curl = curl_easy_init(); headerlist = curl_slist_append(headerlist, buf); if(curl) { curl_easy_setopt(curl, CURLOPT_URL, "http://www.imageshack.us/index.php"); if ( (argc == 2) && (!strcmp(argv[1], "xml=yes")) ) curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headerlist); curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost); res = curl_easy_perform(curl); curl_easy_cleanup(curl); curl_formfree(formpost); curl_slist_free_all (headerlist); } system("pause"); return 0; }

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  • Running OpenMPI on Windows XP

    - by iamweird
    Hi there. I'm trying to build a simple cluster based on Windows XP. I compiled OpenMPI-1.4.2 successfully, and tools like mpicc and ompi_info work too, but I can't get my mpirun working properly. The only output I can see is Z:\orterun --hostfile z:\hosts.txt -np 2 hostname [host0:04728] Failed to initialize COM library. Error code = -2147417850 [host0:04728] [[8946,0],0] ORTE_ERROR_LOG: Error in file ..\..\openmpi-1.4.2 \orte\mca\ess\hnp\ess_hnp_module.c at line 218 -------------------------------------------------------------------------- It looks like orte_init failed for some reason; your parallel process is likely to abort. There are many reasons that a parallel process can fail during orte_init; some of which are due to configuration or environment problems. This failure appears to be an internal failure; here's some additional information (which may only be relevant to an Open MPI developer): orte_plm_init failed -- Returned value Error (-1) instead of ORTE_SUCCESS -------------------------------------------------------------------------- [host0:04728] [[8946,0],0] ORTE_ERROR_LOG: Error in file ..\..\openmpi-1.4.2 \orte\runtime\orte_init.c at line 132 -------------------------------------------------------------------------- It looks like orte_init failed for some reason; your parallel process is likely to abort. There are many reasons that a parallel process can fail during orte_init; some of which are due to configuration or environment problems. This failure appears to be an internal failure; here's some additional information (which may only be relevant to an Open MPI developer): orte_ess_set_name failed -- Returned value Error (-1) instead of ORTE_SUCCESS -------------------------------------------------------------------------- [host0:04728] [[8946,0],0] ORTE_ERROR_LOG: Error in file ..\..\..\..\openmpi -1.4.2\orte\tools\orterun\orterun.c at line 543 Where z:\hosts.txt appears as follows: host0 host1 Z: is a shared network drive available to both host0 and host1. What my problem is and how do I fix it? Upd: Ok, this problem seems to be fixed. It seems to me that WideCap driver and/or software components causes this error to appear. A "clean" machine runs local task successfully. Anyway, I still cannot run a task within at least 2 machines, I'm getting following message: Z:\mpirun --hostfile z:\hosts.txt -np 2 hostname connecting to host1 username:cluster password:******** Save Credential?(Y/N) y [host0:04728] This feature hasn't been implemented yet. [host0:04728] Could not connect to namespace cimv2 on node host1. Error code =-2147024891 -------------------------------------------------------------------------- mpirun was unable to start the specified application as it encountered an error. More information may be available above. -------------------------------------------------------------------------- I googled a little and did all the things as described here: http://www.open-mpi.org/community/lists/users/2010/03/12355.php but I'm still getting the same error. Can anyone help me? Upd2: Error code -2147024891 might be WMI error WBEM_E_INVALID_PARAMETER (0x80041008) which occures when one of the parameters passed to the WMI call is not correct. Does this mean that the problem is in OpenMPI source code itself? Or maybe it's because of wrong/outdated wincred.h and credui.lib I used while building OpenMPI from the source code?

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  • WPF: Improving Performance for Running on Older PCs

    - by Phil Sandler
    So, I'm building a WPF app and did a test deployment today, and found that it performed pretty poorly. I was surprised, as we are really not doing much in the way of visual effects or animations. I deployed on two machines: the fastest and the slowest that will need to run the application (the slowest PC has an Intel Celeron 1.80GHz with 2GB RAM). The application ran pretty well on the faster machine, but was choppy on the slower machine. And when I say "choppy", I mean the cursor jumped even just passing it over any open window of the app that had focus. I opened the Task Manager Performance window, and could see that the CPU usage jumped whenever the app had focus and the cursor was moving over it. If I gave focus to another (e.g. Excel), the CPU usage went back down after a second. This happened on both machines, but the choppiness was only noticeable on the slower machine. I had very limited time to tinker on the deployment machines, so didn't do a lot of detailed testing. The app runs fine on my development machine, but I also see the CPU spiking up to 10% there, just running the cursor over the window. I downloaded the WPF performance tool from MS and have been tinkering with it (on my dev machine). The docs say this about the "Frame Rate" metric in the Perforator tool: For applications without animation, this value should be near 0. The app is not doing any heavy animation, but the frame rate stays near 50 when the cursor is over any window. The screens I tested on have column headers in a grid that "highlight" and buttons that change color and appearance when scrolled over. Even moving the mouse on blank areas of the windows cause the same Frame rate and CPU usage (doesn't seem to be related to these minor animations). (Also, I am unable to figure out how to get anything but the two default tools--Perforator and Visual Profiler--installed into the WPF performance tool. That is probably a separate question). I also have Redgate's profiling tool, but I'm not sure if that can shed any light on rendering performance. So, I realize this is not an easy thing to troubleshoot without specifics or sample code (which I can't post). My questions are: What are some general things to look for (or avoid) in the code to improve performance? What steps can I take using the WPF performance tool to narrow down the problem? Is the PC spec listed above (Intel Celeron 1.80GHz with 2GB RAM) too slow to be running even vanilla WPF applications?

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  • C++ - Breaking code implementation into different parts

    - by Kotti
    Hi! The question plot (a bit abstract, but answering this question will help me in my real app): So, I have some abstract superclass for objects that can be rendered on the screen. Let's call it IRenderable. struct IRenderable { // (...) virtual void Render(RenderingInterface& ri) = 0; virtual ~IRenderable() { } }; And suppose I also have some other objects that derive from IRenderable, e.g. Cat and Dog. So far so good. I add some Cat and Dog specific methods, like SeekForWhiskas(...) and Bark(...). After that I add specific Render(...) method for them, so my code looks this way: class Cat : public IRenderable { public: void SeekForWhiskas(...) { // Implementation could be here or moved // to a source file (depends on me wanting // to inline it or not) } virtual void Render(...) { // Here comes the rendering routine, that // is specific for cats SomehowDrawAppropriateCat(...); } }; class Dog : public IRenderable { public: void Bark(...) { // Same as for 'SeekForWhiskas(...)' } virtual void Render(...) { // Here comes the rendering routine, that // is specific for dogs DrawMadDog(...); } }; And then somewhere else I can do drawing the way that an appropriate rendering routine is called: IRenderable* dog = new Dog(); dog->Render(...); My question is about logical wrapping of such kind of code. I want to break apart the code, that corresponds to rendering of the current object and it's own methods (Render and Bark in this example), so that my class implementation doesn't turn into a mess (imagine that I have 10 methods like Bark and of course my Render method doesn't fit in their company and would be hard to find). Two ways of making what I want to (as far as I know) are: Making appropriate routines that look like RenderCat(Cat& cat, RenderInterface* ri), joining them to render namespace and then the functions inside a class would look like virtual void Render(...) { RenderCat(*this, ...); }, but this is plain stupid, because I'll lose access to Cat's private members and friending these functions looks like a total design disaster. Using visitor pattern, but this would also mean I have to rebuild my app's design and looks like an inadequate way to make my code complicated from the very beginning. Any brilliant ideas? :)

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  • Java replacement for C macros

    - by thkala
    Recently I refactored the code of a 3rd party hash function from C++ to C. The process was relatively painless, with only a few changes of note. Now I want to write the same function in Java and I came upon a slight issue. In the C/C++ code there is a C preprocessor macro that takes a few integer variables names as arguments and performs a bunch of bitwise operations with their contents and a few constants. That macro is used in several different places, therefore its presence avoids a fair bit of code duplication. In Java, however, there is no equivalent for the C preprocessor. There is also no way to affect any basic type passed as an argument to a method - even autoboxing produces immutable objects. Coupled with the fact that Java methods return a single value, I can't seem to find a simple way to rewrite the macro. Avenues that I considered: Expand the macro by hand everywhere: It would work, but the code duplication could make things interesting in the long run. Write a method that returns an array: This would also work, but it would repeatedly result into code like this: long tmp[] = bitops(k, l, m, x, y, z); k = tmp[0]; l = tmp[1]; m = tmp[2]; x = tmp[3]; y = tmp[4]; z = tmp[5]; Write a method that takes an array as an argument: This would mean that all variable names would be reduced to array element references - it would be rather hard to keep track of which index corresponds to which variable. Create a separate class e.g. State with public fields of the appropriate type and use that as an argument to a method: This is my current solution. It allows the method to alter the variables, while still keeping their names. It has the disadvantage, however, that the State class will get more and more complex, as more macros and variables are added, in order to avoid copying values back and forth among different State objects. How would you rewrite such a C macro in Java? Is there a more appropriate way to deal with this, using the facilities provided by the standard Java 6 Development Kit (i.e. without 3rd party libraries or a separate preprocessor)?

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  • How to get Augmented Reality: A Practical Guide examples working?

    - by Glen
    I recently bought the book: Augmented Reality: A Practical Guide (http://pragprog.com/titles/cfar/augmented-reality). It has example code that it says runs on Windows, MacOS and Linux. But I can't get the binaries to run. Has anyone got this book and got the binaries to run on ubuntu? I also can't figure out how to compile the examples in Ubuntu. How would I do this? Here is what it says to do: Compiling for Linux Refreshingly, there are no changes required to get the programs in this chapter to compile for Linux, but as with Windows, you’ll first have to find your GL and GLUT files. This may mean you’ll have to download the correct version of GLUT for your machine. You need to link in the GL, GLU, and GLUT libraries and provide a path to the GLUT header file and the files it includes. See whether there is a glut.h file in the /usr/include/GL directory; otherwise, look elsewhere for it—you could use the command find / -name "glut.h" to search your entire machine, or you could use the locate command (locate glut.h). You may need to customize the paths, but here is an example of the compile command: gcc -o opengl_template opengl_template.cpp -I /usr/include/GL -I /usr/include -lGL -lGLU -lglut gcc is a C/C++ compiler that should be present on your Linux or Unix machine. The -I /usr/include/GL command-line argument tells gcc to look in /usr/include/GL for the include files. In this case, you’ll find glut.h and what it includes. When linking in libraries with gcc, you use the -lX switch—where X is the name of your library and there is a correspond- ing libX.a file somewhere in your path. For this example, you want to link in the library files libGL.a, libGLU.a, and libglut.a, so you will use the gcc arguments -lGL -lGLU -lglut. These three files are found in the default directory /usr/lib/, so you don’t need to specify their location as you did with glut.h. If you did need to specify the library path, you would add -L to the path. To run your compiled program, type ./opengl_template or, if the current directory is in your shell’s paths, just opengl_template. When working in Linux, it’s important to know that you may need to keep your texture files to a maximum of 256 by 256 pixels or find the settings in your system to raise this limit. Often an OpenGL program will work in Windows but produce a blank white texture in Linux until the texture size is reduced. The above instructions make no sense to me. Do I have to use gcc to compile or can I use eclipse? If I use either eclipse or gcc what do I need to do to compile and run the program?

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  • Why do we have reinterpret_cast in C++ when two chained static_cast can do it's job?

    - by Nawaz
    Say I want to cast A* to char* and vice-versa, we have two choices (I mean, many of us think we've two choices, because both seems to work! Hence the confusion!): struct A { int age; char name[128]; }; A a; char *buffer = static_cast<char*>(static_cast<void*>(&a)); //choice 1 char *buffer = reinterpret_cast<char*>(&a); //choice 2 Both work fine. //convert back A *pA = static_cast<A*>(static_cast<void*>(buffer)); //choice 1 A *pA = reinterpret_cast<A*>(buffer); //choice 2 Even this works fine! So why do we have reinterpret_cast in C++ when two chained static_cast can do it's job? Some of you might think this topic is a duplicate of the previous topics such as listed at the bottom of this post, but it's not. Those topics discuss only theoretically, but none of them gives even a single example demonstrating why reintepret_cast is really needed, and two static_cast would surely fail. I agree, one static_cast would fail. But how about two? If the syntax of two chained static_cast looks cumbersome, then we can write a function template to make it more programmer-friendly: template<class To, class From> To any_cast(From v) { return static_cast<To>(static_cast<void*>(v)); } And then we can use this, as: char *buffer = any_cast<char*>(&a); //choice 1 char *buffer = reinterpret_cast<char*>(&a); //choice 2 //convert back A *pA = any_cast<A*>(buffer); //choice 1 A *pA = reinterpret_cast<A*>(buffer); //choice 2 Also, see this situation where any_cast can be useful: Proper casting for fstream read and write member functions. So my question basically is, Why do we have reinterpret_cast in C++? Please show me even a single example where two chained static_cast would surely fail to do the same job? Which cast to use; static_cast or reinterpret_cast? Cast from Void* to TYPE* : static_cast or reinterpret_cast

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  • remove data layer and put into it's own domain

    - by user334768
    I have a SL4 application that uses EF4 & RIA Services. DB is SQL 2008. All is working well. Now I want to put the Database and web services on one domain (A.com) with the web service exposing the same methods available in my working project. (one listed at top of message) Then put a Silverlight application (same one as above) on domain(B.com) and call the web services on A.com. I thought I had a fair understanding of RIA Services. Enough to get the above application working. Now when I say "working" I do mean on my local dev machine. I have yet to deployed as SL4 & .NET 4 application to my hosting site. But I don't think I understand it well enough. I normally create a new business app, add EF then create the RIA DomainService. Add any [Includes] I need, modify my linq queries and run application. And it works. Now I need to break off my data layer and put it on another hosting site (A.com) And put my UI and business logic on another hosting site (B.com) I think I need to do the following : On the Database & web service site: domain(A.com) create application, create EF4, create RIA Services and deploy. At this time, are the methods exposed available as a "WEB SERVICE" to other applications calling by http:// a.com/serviceName.svc address? I think I need to do the following : On the application site : domain(B.com) create a business application (later will need authentication and navigation). How can I create an EF when I don't have access to the database? (I know I do have access but I want know what happens here when I do not have access to the database, but only data provided by a web service) If I can not create an EF how do I create my RIA Service? I hope any one who takes time to help me understands what I'm asking. Sorry so long.

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