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  • Performing measures within the execution of a c++ code every t milliseconds

    - by user506901
    Given a while loop and the function ordering as follows: int k=0; int total=100; while(k<total){ doSomething(); if(approx. t milliseconds elapsed) { measure(); } ++k; } I want to perform 'measure' every t-th milliseconds. However, since 'doSomething' can be close to the t-th millisecond from the last execution, it is acceptable to perform the measure after approximately t milliseconds elapsed from the last measure. My question is: how could this be achieved? One solution would be to set timer to zero, and measure it after every 'doSomething'. When it is withing the acceptable range, I perform measures, and reset. However, I'm not which c++ function I should use for such a task. As I can see, there are certain functions, but the debate on which one is the most appropriate is outside of my understanding. Note that some of the functions actually take into account the time taken by some other processes, but I want my timer to only measure the time of the execution of my c++ code (I hope that is clear). Another thing is the resolution of the measurements, as pointed out below. Suppose the medium option of those suggested.

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  • How should I link two items with MouseMovementListeners?

    - by user1708810
    I'm working on a program that will display two "views" of the same set of items. So I need to have something set up so that when the top down view is changed, the side view is updated (and vice versa). Here's a brief outline of the relevant code so you can get an idea of my structure so far: public class DraggableComponent extends JComponent { //Contains code for MouseMovementListener that makes the item draggable } public class ItemGraphic extends DraggableComponent { //Code to render the graphic } public class Item { private ItemGraphic topGraphic; private ItemGraphic sideGraphic; } I'm able to get each graphic to display fine in my GUI. I can also independently drag each graphic. I'm missing the "linking." Some ideas I've been thinking about: Have one listener for the whole GUI. Loop through each Item and if the cursor is within the bounds of either graphic, move the other graphic. I'm concerned about the efficiency of this method. Multiple "paired" listeners (not quite sure how this would work, but the idea is that each graphic would have a listener for the other paired graphic)

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  • c# Convert LINQ var result to actual type

    - by DrBob
    In c#, Given the following code: public class Person { public int PersonID { get; set; } public int Age { get; set; } public string Name { get; set; } } and List<Person> people = new List<Person>(); for (int i = 0; i != 15; i++) { Person p = new Person(); p.PersonID = i; p.Age = i * 12; p.Name = "Name " + i; people.Add(p); } var sortedPeople = from qPeople in people where qPeople.Age > 0 && qPeople.Age < 25 || qPeople.Age > 100 orderby qPeople.Age descending select qPeople; Can I load the results of sortedPeople back into a List<Person without a loop? Thanks.

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  • All Callbacks on GUI Thread - Multithreading issues possible?

    - by miguel
    We have an external data provider which, in its construtor, takes a callback thread for returning data upon. There are some issues in the system which I am suspicious are related to threading, however, in theory they cannot be, due to the fact that the callbacks should all be returned on the same thread. My question is, does code like this require thread synchronisation? class Foo { ExternalDataProvider _provider; public Foo() { // This is the c'tor for the xternal data provider, taking a callback loop as param _provider = new ExternalDataProvider(UILoop); _provider.DataArrived += ExternalProviderCallbackMethod; } public ExternalProviderCallbackMethod(...) { //...(code omitted) var itemArray[] = new String[4] { "item1", "item2", "item3", "item4" }; for (int i = 0; i < itemArray.Length; i++) { string s = itemArray[i]; switch(s) { case "item1": DoItem1Action(); break; case "item2": DoItem2Action(); break; default: DoDefaultAction(); break; } //...(code omitted) } } } The issue is that, very infrequently, DoItem2Action is executingwhen DoItem1Action should be exectuing. Is it at all possible threading is at fault here? In theory, as all callbacks are arriving on the same thread, they should be serialized, right? So there should be no need for thread sync here?

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  • JQuery DataTables link item

    - by rogcg
    I'm trying to link the items from a specific column, but each one will be linked for a different id from the json string. Unfortunately I can't find a way to do this using the API (I know there is a lot of ways to do that without using the API ), but I'm looking for a way to link a item from a column (each one with a link for a specific id). So here is my code, I use getJSON to get the JSON from the server, and I load the data from this JSON to the table like this: $.getJSON("/method/from/server/", function(data) { var total = 0; $("#table_body").empty(); var oTable = $('#mytable').dataTable( { "sPaginationType" : "full_numbers", "aaSorting": [[ 0, "asc" ]] }); oTable.fnClearTable(); $.each(data, function(i, item) { oTable.fnAddData( [ item.contact_name, item.contact_email ] ); }); }); What I want to do, is for each row, link the contact_name to its id, which is also in the JSON, and can be accessed inside this $.each loop by using item.contact_id. Is there a way to do this using DataTables API, if yes, could you explain me and provide a good resource that will help me with this? Thanks.

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  • Goldbach theory in C

    - by nofe
    I want to write some code which takes any positive, even number (greater than 2) and gives me the smallest pair of primes that sum up to this number. I need this program to handle any integer up to 9 digits long. My aim is to make something that looks like this: Please enter a positive even integer ( greater than 2 ) : 10 The first primes adding : 3+7=10. Please enter a positive even integer ( greater than 2 ) : 160 The first primes adding : 3+157=160. Please enter a positive even integer ( greater than 2 ) : 18456 The first primes adding : 5+18451=18456. I don't want to use any library besides stdio.h. I don't want to use arrays, strings, or anything besides for the most basic toolbox: scanf, printf, for, while, do-while, if, else if, break, continue, and the basic operators (<,, ==, =+, !=, %, *, /, etc...). Please no other functions especially is_prime. I know how to limit the input to my needs so that it loops until given a valid entry. So now I'm trying to figure out the algorithm. I thought of starting a while loop like something like this: #include <stdio.h> long first, second, sum, goldbach, min; long a,b,i,k; //indices int main (){ while (1){ printf("Please enter a positive integer :\n"); scanf("%ld",&goldbach); if ((goldbach>2)&&((goldbach%2)==0)) break; else printf("Wrong input, "); } while (sum!=goldbach){ for (a=3;a<goldbach;a=(a+2)) for (i=2;(goldbach-a)%i;i++) first = a; for (b=5;b<goldbach;b=(b+2)) for (k=2;(goldbach-b)%k;k++) sum = first + second; } }

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  • How to draw shadows that don't suck?

    - by mystify
    A CAShapeLayer uses a CGPathRef to draw it's stuff. So I have a star path, and I want a smooth drop shadow with a radius of about 15 units. Probably there is some nice functionality in some new iPhone OS versions, but I need to do it myself for a old aged version of 3.0 (which most people still use). I tried to do some REALLY nasty stuff: I created a for-loop and sequentially created like 15 of those paths, transform-scaling them step by step to become bigger. Then assigning them to a new created CAShapeLayer and decreasing it's alpha a little bit on every iteration. Not only that this scaling is mathematically incorrect and sucks (it should happen relative to the outline!), the shadow is not rounded and looks really ugly. That's why nice soft shadows have a radius. The tips of a star shouldn't appear totally sharp after a shadow size of 15 units. They should be soft like cream. But in my ugly solution they're just as s harp as the star itself, since all I do is scale the star 15 times and decrease it's alpha 15 times. Ugly. I wonder how the big guys do it? If you had an arbitrary path, and that path must throw a shadow, how does the algorithm to do that work? Probably the path would have to be expanded like 30 times, point-by-point relative to the tangent of the outline away from the filled part, and just by 0.5 units to have a nice blending. Before I re-invent the wheel, maybe someone has a handy example or link?

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  • Indexing/Performance strategies for vast amount of the same value

    - by DrColossos
    Base information: This is in context to the indexing process of OpenStreetMap data. To simplify the question: the core information is divided into 3 main types with value "W", "R", "N" (VARCHAR(1)). The table has somewhere around ~75M rows, all columns with "W" make up ~42M rows. Existing indexes are not relevant to this question. Now the question itself: The indexing of the data is done via an procedure. Inside this procedure, there are some loops that do the following: [...] SELECT * FROM table WHERE the_key = "W"; [...] The results get looped again and the above query itself is also in a loop. This takes a lot of time and slows down the process massivly. An indexon the_key is obviously useless since all the values that the index might use are the same ("W"). The script itself is running with a speed that is OK, only the SELECTing takes very long. Do I need to create a "special" kind of index that takes this into account and makes the SELECT quicker? If so, which one? need to tune some of the server parameters (they are already tuned and the result that they deliver seem to be good. If needed, I can post them)? have to live with the speed and simply get more hardware to gain more power (Tim Taylor grunt grunt)? Any alternatives to the above points (except rewriting it or not using it)?

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  • What's the proper approach for writing multi-path "story" flows?

    - by Basiclife
    Hi, I wonder if you can help me. I'm writing a game (2d) which allows players to take multiple routes, some of which branch/merge - perhaps even loop. Each section of the game will decide which section is loaded next. I'm calling each section an IStoryElement - And I'm wondering how best to link these elements up in a way that is easily changed/configured and at the same time, graphable I'm going to have an engine/factory assembly which will load the appropriate StoryElement(s) based on various config options. I initially planned to give each StoryElement a NextElement() As IStoryElement property and a Completed() event. When the vent fires, the engine reads the NextElement property to find the next StoryElement. The downside to this is that if I ever wanted to graph all the routes through the game, I would be unable to - I couldn't determine all possible targets for each StoryElement. I considered a couple of other solutions but they all feel a little clunky - eg Do I need an additional layer of abstraction? ie StoryElementPlayers or similar - Each one would be responsible for stringing together multiple StoryElement perhaps a Series and a ChoicePlayer with each responsible for graphing its own StoryElement - But this will just move the problem up a layer. In short, I need some way of emulating a simple but dynamic workflow (but I'd rather not actually use WWF). Is there a pattern for something this simple? All the ones I've managed to find relate to more advanced control flow (parallel processing, etc.)

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  • Computation overhead in C# - Using getters/setters vs. modifying arrays directly and casting speeds

    - by Jeffrey Kern
    I was going to write a long-winded post, but I'll boil it down here: I'm trying to emulate the graphical old-school style of the NES via XNA. However, my FPS is SLOW, trying to modify 65K pixels per frame. If I just loop through all 65K pixels and set them to some arbitrary color, I get 64FPS. The code I made to look-up what colors should be placed where, I get 1FPS. I think it is because of my object-orented code. Right now, I have things divided into about six classes, with getters/setters. I'm guessing that I'm at least calling 360K getters per frame, which I think is a lot of overhead. Each class contains either/and-or 1D or 2D arrays containing custom enumerations, int, Color, or Vector2D, bytes. What if I combined all of the classes into just one, and accessed the contents of each array directly? The code would look a mess, and ditch the concepts of object-oriented coding, but the speed might be much faster. I'm also not concerned about access violations, as any attempts to get/set the data in the arrays will done in blocks. E.g., all writing to arrays will take place before any data is accessed from them. As for casting, I stated that I'm using custom enumerations, int, Color, and Vector2D, bytes. Which data types are fastest to use and access in the .net Framework, XNA, XBox, C#? I think that constant casting might be a cause of slowdown here. Also, instead of using math to figure out which indexes data should be placed in, I've used precomputed lookup tables so I don't have to use constant multiplication, addition, subtraction, division per frame. :)

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  • Reduce file size for charts pasted from excel into word

    - by Steve Clanton
    I have been creating reports by copying some charts and data from an excel document into a word document. I am pasting into a content control, so i use ChartObject.CopyPicture in excel and ContentControl.Range.Paste in word. This is done in a loop: Set ws = ThisWorkbook.Worksheets("Charts") With ws For Each cc In wordDocument.ContentControls If cc.Range.InlineShapes.Count > 0 Then scaleHeight = cc.Range.InlineShapes(1).scaleHeight scaleWidth = cc.Range.InlineShapes(1).scaleWidth cc.Range.InlineShapes(1).Delete .ChartObjects(cc.Tag).CopyPicture Appearance:=xlScreen, Format:=xlPicture cc.Range.Paste cc.Range.InlineShapes(1).scaleHeight = scaleHeight cc.Range.InlineShapes(1).scaleWidth = scaleWidth ElseIf ... Next cc End With Creating these reports using Office 2007 yielded files that were around 6MB, but creating them (using the same worksheet and document) in Office 2010 yields a file that is around 10 times as large. After unzipping the docx, I found that the extra size comes from emf files that correspond to charts that are pasted in using VBA. Where they range from 360 to 900 KB before, they are 5-18 MB. And the graphics are not visibly better. I am able to CopyPicture with the format xlBitmap, and while that is somewhat smaller, it is larger than the emf generated by Office 2007 and noticeably poorer quality. Are there any other options for reducing the file size? Ideally, I would like to produce a file with the same resolution for the charts as I did using Office 2007. Is there any way that uses VBA only (without modifying the charts in the spreadsheet)?

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  • Callbacks on GUI Thread

    - by miguel
    We have an external data provider which, in its construtor, takes a callback thread for returning data upon. There are some issues in the system which I am suspicious are related to threading, however, in theory they cannot be, due to the fact that the callbacks should all be returned on the same thread. My question is, does code like this require thread synchronisation? class Foo { ExternalDataProvider _provider; public Foo() { // This is the c'tor for the xternal data provider, taking a callback loop as param _provider = new ExternalDataProvider(UILoop); _provider.DataArrived += ExternalProviderCallbackMethod; } public ExternalProviderCallbackMethod() { var itemArray[] = new String[4] { "item1", "item2", "item3", "item4" }; for (int i = 0; i < itemArray.Length; i++) { string s = itemArray[i]; switch(s) { case "item1": DoItem1Action(); break; case "item2": DoItem2Action(); break; default: DoDefaultAction(); break; } } } } The issue is that, very infrequently, DoItem2Action is executingwhen DoItem1Action should be exectuing. Is it at all possible threading is at fault here? In theory, as all callbacks are arriving on the same thread, they should be serialized, right? So there should be no need for thread sync here?

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  • T-SQL: how to sort table rows based on 2 columns

    - by Criss Nautilus
    I'm quite stuck with this problem for sometime now.. How do I sort column A depending on the contents of Column B? I have this sample: ID count columnA ColumnB 12 1 A B 13 2 C D 14 3 B C I want to sort it like this: ID count ColumnA ColumnB 12 1 A B 14 3 B C 13 2 C D so I need to sort the rows if the previous row of ColumnB = the next row of ColumnA I'm thinking a loop? but can't quite imagine how it will work... I was thinking it will go like this (maybe) SELECT a.ID, a.ColumnA, a.ColumnB FROM TableA WITH a (NOLOCK) LEFT JOIN TableA b WITH (NOLOCK) ON a.ID = b.ID and a.counts = b.counts Where a.columnB = b.ColumnA the above code isn't working though and I was thinking more on the lines of... DECLARE @counts int = 1 DECLARE @done int = 0 --WHILE @done = 0 BEGIN SELECT a.ID, a.ColumnA, a.ColumnB FROM TableA WITH a (NOLOCK) LEFT JOIN TableA b WITH (NOLOCK) ON a.ID = b.ID and a.counts = @counts Where a.columnB = b.ColumnA set @count = @count +1 END If this was a C code, would be easier for me but t-sql's syntax is making it a bit harder for a noobie like me.

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  • Why is CoRegisterClassObject creating two extra threads?

    - by Stijn Sanders
    I'm trying to fix a problem that only recently happens on a number of machine's on a VPN. They each run a client application I wrote that exposes a COM automation object. For some strange reason I haven't been able to discover yet, one thread in the application takes up all of the available CPU time, slowing other operation on the machine. In observing the application's strange behaviour, I've noticed it's the third thread started, and if I debug on my machine I notice the first call to CoRegisterClassObject created two extra threads. If the second of these two threads is the one that gets into an infinite loop, I'm not at all shure how to fix this. Where could I check next about what's wrong? Could it have started by one of the recent patches rolled out by Microsoft this last 'patch tuesday'? I had a go with ProcessExplorer to extract a stack trace of the thread: ntoskrnl.exe!ExReleaseResourceLite+0x1a3 ntoskrnl.exe!PsGetContextThread+0x329 WLDAP32.dll!Ordinal325+0x1231 WLDAP32.dll!Ordinal325+0x129e WLDAP32.dll!Ordinal325+0x1178 ntdll.dll!LdrInitializeThunk+0x24 ntdll.dll!LdrShutdownThread+0xe9 kernel32.dll!ExitThread+0x3e kernel32.dll!FreeLibraryAndExitThread+0x1e ole32.dll!StringFromGUID2+0x65d kernel32.dll!GetModuleFileNameA+0x1ba

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  • How to insert several thousand columns into sqlite3?

    - by user291071
    Similar to my last question, but I ran into problem lets say I have a simple dictionary like below but its Big, when I try inserting a big dictionary using the methods below I get operational error for the c.execute(schema) for too many columns so what should be my alternate method to populate an sql databases columns? Using the alter table command and add each one individually? import sqlite3 con = sqlite3.connect('simple.db') c = con.cursor() dic = { 'x1':{'y1':1.0,'y2':0.0}, 'x2':{'y1':0.0,'y2':2.0,'joe bla':1.5}, 'x3':{'y2':2.0,'y3 45 etc':1.5} } # 1. Find the unique column names. columns = set() for _, cols in dic.items(): for key, _ in cols.items(): columns.add(key) # 2. Create the schema. col_defs = [ # Start with the column for our key name '"row_name" VARCHAR(2) NOT NULL PRIMARY KEY' ] for column in columns: col_defs.append('"%s" REAL NULL' % column) schema = "CREATE TABLE simple (%s);" % ",".join(col_defs) c.execute(schema) # 3. Loop through each row for row_name, cols in dic.items(): # Compile the data we have for this row. col_names = cols.keys() col_values = [str(val) for val in cols.values()] # Insert it. sql = 'INSERT INTO simple ("row_name", "%s") VALUES ("%s", "%s");' % ( '","'.join(col_names), row_name, '","'.join(col_values) )

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  • How to get timestamp of tick precision in .NET / C#?

    - by Hermann
    Up until now I used DateTime.Now for getting timestamps, but I noticed that if you print DateTime.Now in a loop you will see that it increments in descrete jumps of approx. 15 ms. But for certain scenarios in my application I need to get the most accurate timestamp possible, preferably with tick (=100 ns) precision. Any ideas? Update: Apparently, StopWatch / QueryPerformanceCounter is the way to go, but it can only be used to measure time, so I was thinking about calling DateTime.Now when the application starts up and then just have StopWatch run and then just add the elapsed time from StopWatch to the initial value returned from DateTime.Now. At least that should give me accurate relative timestamps, right? What do you think about that (hack)? NOTE: StopWatch.ElapsedTicks is different from StopWatch.Elapsed.Ticks! I used the former assuming 1 tick = 100 ns, but in this case 1 tick = 1 / StopWatch.Frequency. So to get ticks equivalent to DateTime use StopWatch.Elapsed.Ticks. I just learned this the hard way. NOTE 2: Using the StopWatch approach, I noticed it gets out of sync with the real time. After about 10 hours, it was ahead by 5 seconds. So I guess one would have to resync it every X or so where X could be 1 hour, 30 min, 15 min, etc. I am not sure what the optimal timespan for resyncing would be since every resync will change the offset which can be up to 20 ms.

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  • How to optimize paging for large in memory database

    - by snakefoot
    I have an application where the entire database is implemented in memory using a stl-map for each table in the database. Each item in the stl-map is a complex object with references to other items in the other stl-maps. The application works with a large amount of data, so it uses more than 500 MByte RAM. Clients are able to contact the application and get a filtered version of the entire database. This is done by running through the entire database, and finding items relevant for the client. When the application have been running for an hour or so, then Windows 2003 SP2 starts to page out parts of the RAM for the application (Eventhough there is 16 GByte RAM on the machine). After the application have been partly paged out then a client logon takes a long time (10 mins) because it now generates a page fault for each pointer lookup in the stl-map. I can see it is possible to tell Windows to lock memory in RAM, but this is generally only recommended for device drivers, and only for "small" amounts of memory. I guess a poor mans solution could be to loop through the entire memory database, and thus tell Windows we are still interested in keeping the datamodel in RAM. I guess another poor mans solution could be to disable the pagefile completely on Windows. I guess the expensive solution would be a SQL database, and then rewrite the entire application to use a database layer. Then hopefully the database system will have implemented means to for fast access. Are there other more elegant solutions ?

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  • Why initialize an object to empty

    - by ProgEnthu
    I am learning windows programming with the help of MSDN.Why would somebody initialize an object like the following? WNDCLASS wc = { }; Will this zero all the memory of the object? Whole source code is following: #ifndef UNICODE #define UNICODE #endif #include <windows.h> LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam); int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE, PWSTR pCmdLine, int nCmdShow) { // Register the window class. const wchar_t CLASS_NAME[] = L"Sample Window Class"; WNDCLASS wc = { }; wc.lpfnWndProc = WindowProc; wc.hInstance = hInstance; wc.lpszClassName = CLASS_NAME; RegisterClass(&wc); // Create the window. HWND hwnd = CreateWindowEx( 0, // Optional window styles. CLASS_NAME, // Window class L"Learn to Program Windows", // Window text WS_OVERLAPPEDWINDOW, // Window style // Size and position CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, // Parent window NULL, // Menu hInstance, // Instance handle NULL // Additional application data ); if (hwnd == NULL) { return 0; } ShowWindow(hwnd, nCmdShow); // Run the message loop. MSG msg = { }; while (GetMessage(&msg, NULL, 0, 0)) { TranslateMessage(&msg); DispatchMessage(&msg); } return 0; } LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) { switch (uMsg) { case WM_DESTROY: PostQuitMessage(0); return 0; case WM_PAINT: { PAINTSTRUCT ps; HDC hdc = BeginPaint(hwnd, &ps); FillRect(hdc, &ps.rcPaint, (HBRUSH) (COLOR_WINDOW+1)); EndPaint(hwnd, &ps); } return 0; } return DefWindowProc(hwnd, uMsg, wParam, lParam); }

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  • parsing python to csv

    - by user185955
    I'm trying to download some game stats to do some analysis, only problem is each season the data their isn't 100% consistent. I grab the json file from the site, then wish to save it to a csv with the first line in the csv containing the heading for that column, so the heading would be essentially the key from the python data type. #!/usr/bin/env python import requests import json import csv base_url = 'http://www.afl.com.au/api/cfs/afl/' token_url = base_url + 'WMCTok' player_url = base_url + 'matchItems/round' def printPretty(data): print(json.dumps(data, sort_keys=True, indent=2, separators=(',', ': '))) session = requests.Session() # session makes it simple to use the token across the requests token = session.post(token_url).json()['token'] # get the token session.headers.update({'X-media-mis-token': token}) # set the token Season = 2014 Roundno = 4 if Roundno<10: strRoundno = '0'+str(Roundno) else: strRoundno = str(Roundno) # get some data (could easily be a for loop, might want to put in a delay using Sleep so that you don't get IP blocked) data = session.get(player_url + '/CD_R'+str(Season)+'014'+strRoundno) # print everything printPretty(data.json()) with open('stats_game_test.csv', 'w', newline='') as csvfile: spamwriter = csv.writer(csvfile, delimiter="'",quotechar='|', quoting=csv.QUOTE_ALL) for profile in data.json()['items']: spamwriter.writerow(['%s' %(profile)]) #for key in data.json().keys(): # print("key: %s , value: %s" % (key, data.json()[key])) The above code grabs the json and writes it to a csv, but it puts the key in each individual cell next to the value (eg 'venueId': 'CD_V190'), the key needs to be just across the first row as a heading. It gives me a csv file with data in the cells like this Column A B 'tempInCelsius': 17.0 'totalScore': 32 'tempInCelsius': 16.0 'totalScore': 28 What I want is the data like this tempInCelsius totalScore 17 32 16 28 As I mentioned up the top, the data isn't always consistent so if I define what fields to grab with spamwriter.writerow([profile['tempInCelsius'], profile['totalScore']]) then it will error out on certain data grabs. This is why I'm now trying the above method so it just grabs everything regardless of what data is there.

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  • Objective C: Function returning correct data for the first time of call and null for other times

    - by Kooshal Bhungy
    Hi all, Am a beginner in objective C, i am implementing a function that would query a web server and display the returning string in console. I am calling the function (getDatafromServer) repeatedly in a loop. The problem is that the first time am getting the value whereas the other times, it returns me a (null) in console... I've searched about memory management and check out on the forums but none have worked. Can you please guys tell me where am wrong in the codes below? Thanks in advance.... @implementation RequestThread +(void)startthread:(id)param{ while (true) { //NSLog(@"Test threads"); sleep(5); NSLog(@"%@",[self getDatafromServer]); } } +(NSString *) getDatafromServer{ NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; NSString *myRequestString = @"name=Hello%20&[email protected]"; NSData *myRequestData = [NSData dataWithBytes:[myRequestString UTF8String] length:[myRequestString length]]; NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL: [NSURL URLWithString:@"http://192.168.1.32/gs/includes/widget/getcalls.php?user=asdasd&passw=asdasdasd"]]; [request setHTTPMethod:@"POST"]; [request setHTTPBody: myRequestData]; [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"content-type"]; NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil]; NSString *myString = [NSString stringWithUTF8String:[returnData bytes]]; [myRequestString release]; [request release]; [returnData release]; return myString; [pool release]; } @end

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  • Callers block until getFoo() has a value ready?

    - by Sean Owen
    I have a Java Thread which exposes a property which other threads want to access: class MyThread extends Thread { private Foo foo; ... Foo getFoo() { return foo; } ... public void run() { ... foo = makeTheFoo(); ... } } The problem is that it takes some short time from the time this runs until foo is available. Callers may call getFoo() before this and get a null. I'd rather they simply block, wait, and get the value once initialization has occurred. (foo is never changed afterwards.) It will be a matter of milliseconds until it's ready, so I'm comfortable with this approach. Now, I can make this happen with wait() and notifyAll() and there's a 95% chance I'll do it right. But I'm wondering how you all would do it; is there a primitive in java.util.concurrent that would do this, that I've missed? Or, how would you structure it? Yes, make foo volatile. Yes, synchronize on an internal lock Object and put the check in a while loop until it's not null. Am I missing anything?

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  • Redeploying an ASP.NET site in IIS7 without files in use interfering

    - by fyjham
    Hey, We've got a process currently which causes ASP.NET websites to be redeployed. The code is itself an ASP.NET application. The current method, which has worked for quite a while, is simply to loop over all the files in one folder and copy them over the top of the files in the webroot. The problem that's arisen is that occasionally files end up being in use and hence can't be copied over. This has in the past been intermittent to the point it didn't matter but on some of our higher traffic sites it happens the majority of the time now. I'm wondering if anyone has a workaround or alternative approach to this that I haven't thought of. Currently my ideas are: Simply retry each file until it works. That's going to cause errors for a short time though which isn't really that good. Deploy to a new folder and update IIS's webroot to the new folder. I'm not sure how to do this short of running the application as an administrator and running batch files, which is very untidy. Does anyone know what the best way to do this is, or if it's possible to do #2 without running the publishing application as a user who has admin access (Willing to grant it special privileges, but I'd prefer to stop short of administrator)?

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  • Bruteforcing Blackberry PersistentStore?

    - by Haoest
    Hello, I am experimenting with Blackberry's Persistent Store, but I have gotten nowhere so far, which is good, I guess. So I have written a a short program that attempts iterator through 0 to a specific upper bound to search for persisted objects. Blackberry seems to intentionally slow the loop. Check this out: String result = "result: \n"; int ub = 3000; Date start = Calendar.getInstance().getTime(); for(int i=0; i<ub; i++){ PersistentObject o = PersistentStore.getPersistentObject(i); if (o.getContents() != null){ result += (String) o.getContents() + "\n"; } } result += "end result\n"; result += "from 0 to " + ub + " took " + (Calendar.getInstance().getTime().getTime() - start.getTime()) / 1000 + " seconds"; From 0 to 3000 took 20 seconds. Is this enough to conclude that brute-forcing is not a practical method to breach the Blackberry? In general, how secure is BB Persistent Store?

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  • Generating a python file

    - by fema
    Hi! I'm havin issues with python (imo python itself is an issue). I have a txt file, it contains a custom language and I have to translate it to a working python code. The input: import sys n = int(sys.argv[1]) ;;print "Beginning of the program!" LOOP i in range(1,n) {print "The number:";;print i} BRANCH n < 5 {print n ;;print "less than 5"} The wanted output looks exactly like this: import sys n = int(sys.argv[1]) print "Beginning of the program!" for i in range(1,n) : print "The number:" print i if n < 5 : print n print "less than 5" The name of the input file is read from parameter. The out file is out.py. In case of a wrong parameter, it gives an error message. The ;; means a new line. When I tried to do it, I made an array, I read all the lines into it, split by " ". Then I wanted to strip it from the marks I don't need. I made 2 loops, one for the lines, one for the words. So then I started to replace the things. Everything went fine until it came to the } mark. It finds it, but it can not replace or strip it. I have no more idea what to do. Could someone help me, please? Thanks in advance!

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  • std::ifstream buffer caching

    - by ledokol
    Hello everybody, In my application I'm trying to merge sorted files (keeping them sorted of course), so I have to iterate through each element in both files to write the minimal to the third one. This works pretty much slow on big files, as far as I don't see any other choice (the iteration has to be done) I'm trying to optimize file loading. I can use some amount of RAM, which I can use for buffering. I mean instead of reading 4 bytes from both files every time I can read once something like 100Mb and work with that buffer after that, until there will be no element in buffer, then I'll refill the buffer again. But I guess ifstream is already doing that, will it give me more performance and is there any reason? If fstream does, maybe I can change size of that buffer? added My current code looks like that (pseudocode) // this is done in loop int i1 = input1.read_integer(); int i2 = input2.read_integer(); if (!input1.eof() && !input2.eof()) { if (i1 < i2) { output.write(i1); input2.seek_back(sizeof(int)); } else input1.seek_back(sizeof(int)); output.write(i2); } } else { if (input1.eof()) output.write(i2); else if (input2.eof()) output.write(i1); } What I don't like here is seek_back - I have to seek back to previous position as there is no way to peek 4 bytes too much reading from file if one of the streams is in EOF it still continues to check that stream instead of putting contents of another stream directly to output, but this is not a big issue, because chunk sizes are almost always equal. Can you suggest improvement for that? Thanks.

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