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  • Recommended approach to port to ASP.NET MVC

    - by tshao
    I think many of us used to face the same question, what's the best practices to port existing web forms App to MVC. The situation for me is that we'll support both web forms and MVC at the same time. It means, we create new features in MVC, while maintaining legacy pages in web forms, and they're all in a same project. The point is: we want to keep the DRY (do not repeat yourself) principle and reduce duplicate code as much as possible. The ASPX page is not a problem as we only create new features in MVC, but there're still some shared components we want to re-use the both new / legacy pages: Master page UserControl The question here is: Is that possible to create a common master page / usercontrol that could be used in both web forms and MVC? I know that ViewMasterPage inherits from MasterPage and ViewUserControl inherits from UserControl, so it's maybe OK to let both web forms and MVC ASPX page refer to the MVC version. I did some testing and found sometimes it generates errors during the rendering of usercontrols. Any idea / experience you can share with me? Very appreciate to it.

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  • hadoop implementing a generic list writable

    - by Guruprasad Venkatesh
    I am working on building a map reduce pipeline of jobs(with one MR job's output feeding to another as input). The values being passed around are fairly complex, in that there are lists of different types and hash maps with values as lists. Hadoop api does not seem to have a ListWritable. Am trying to write a generic one, but it seems i can't instantiate a generic type in my readFields implementation, unless i pass in the class type itself: public class ListWritable<T extends Writable> implements Writable { private List<T> list; private Class<T> clazz; public ListWritable(Class<T> clazz) { this.clazz = clazz; list = new ArrayList<T>(); } @Override public void write(DataOutput out) throws IOException { out.writeInt(list.size()); for (T element : list) { element.write(out); } } @Override public void readFields(DataInput in) throws IOException{ int count = in.readInt(); this.list = new ArrayList<T>(); for (int i = 0; i < count; i++) { try { T obj = clazz.newInstance(); obj.readFields(in); list.add(obj); } catch (InstantiationException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } } } } But hadoop requires all writables to have a no argument constructor to read the values back. Has anybody tried to do the same and solved this problem? TIA.

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  • How should a process running outside Internet Explorer talk to JavaScript running inside it?

    - by Paul Crowley
    This may well be impossible; either way I'm sure people here will know. I'm trying to reduce three "OK" prompts to two. As part of my application, users will download and run an executable I supply; call it privileged.exe. privileged.exe will have a coda that asks for the highest privileges available. That's two OK prompts, one to run privileged.exe and one for UAC. I'd like privileged.exe to then install an ActiveX control, browser plugin or some such. The purpose of this ActiveX control is to allow the JavaScript running inside the browser to talk to the running privileged.exe process, to allow the user to perform certain operations that require high privileges by making choices in the browser. And I'd ideally like this to happen without the user having to restart their browser or explicitly OK the installation of the ActiveX control. Is that possible? Can you install an ActiveX control from outside the browser in such a way that it becomes immediately available to pages running inside the browser? Or should I give up, and allow the user to be explicitly prompted to install the ActiveX control?

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  • Lookup table size reduction

    - by Ryan
    Hello: I have an application in which I have to store a couple of millions of integers, I have to store them in a Look up table, obviously I cannot store such amount of data in memory and in my requirements I am very limited I have to store the data in an embebedded system so I am very limited in the space, so I would like to ask you about recommended methods that I can use for the reduction of the look up table. I cannot use function approximation such as neural networks, the values needs to be in a table. The range of the integers is not known at the moment. When I say integers I mean a 32 bit value. Basically the idea is use some copmpression method to reduce the amount of memory but without losing many precision. This thing needs to run in hardware so the computation overhead cannot be very high. In my algorithm I have to access to one value of the table do some operations with it and after update the value. In the end what I should have is a function which I pass an index to it and then I get a value, and after I have to use another function to write a value in the table. I found one called tile coding http://www.cs.ualberta.ca/~sutton/book/8/node6.html, this one is based on several look up tables, does anyone know any other method?. Thanks.

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  • Real time embeddable http server library required

    - by Howard May
    Having looked at several available http server libraries I have not yet found what I am looking for and am sure I can't be the first to have this set of requirements. I need a library which presents an API which is 'pipelined'. Pipelining is used to describe an HTTP feature where multiple HTTP requests can be sent across a TCP link at a time without waiting for a response. I want a similar feature on the library API where my application can receive all of those request without having to send a response (I will respond but want the ability to process multiple requests at a time to reduce the impact of internal latency). So the web server library will need to support the following flow 1) HTTP Client transmits http request 1 2) HTTP Client transmits http request 2 ... 3) Web Server Library receives request 1 and passes it to My Web Server App 4) My Web Server App receives request 1 and dispatches it to My System 5) Web Server receives request 2 and passes it to My Web Server App 6) My Web Server App receives request 2 and dispatches it to My System 7) My Web Server App receives response to request 1 from My System and passes it to Web Server 8) Web Server transmits HTTP response 1 to HTTP Client 9) My Web Server App receives response to request 2 from My System and passes it to Web Server 10) Web Server transmits HTTP response 2 to HTTP Client Hopefully this illustrates my requirement. There are two key points to recognise. Responses to the Web Server Library are asynchronous and there may be several HTTP requests passed to My Web Server App with responses outstanding. Additional requirements are Embeddable into an existing 'C' application Small footprint; I don't need all the functionality available in Apache etc. Efficient; will need to support thousands of requests a second Allows asynchronous responses to requests; their is a small latency to responses and given the required request throughput a synchronous architecture is not going to work for me. Support persistent TCP connections Support use with Server-Push Comet connections Open Source / GPL support for HTTPS Portable across linux, windows; preferably more. I will be very grateful for any recommendation Best Regards

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  • Parsing a JSON feed from YQL using jQuery

    - by Keith
    I am using YQL's query.multi to grab multiple feeds so I can parse a single JSON feed with jQuery and reduce the number of connections I'm making. In order to parse a single feed, I need to be able to check the type of result (photo, item, entry, etc) so I can pull out items in specific ways. Because of the way the items are nested within the JSON feed, I'm not sure the best way to loop through the results and check the type and then loop through the items to display them. Here is a YQL (http://developer.yahoo.com/yql/console/) query.multi example and you can see three different result types (entry, photo, and item) and then the items nested within them: select * from query.multi where queries= "select * from twitter.user.timeline where id='twitter'; select * from flickr.photos.search where has_geo='true' and text='san francisco'; select * from delicious.feeds.popular" or here is the JSON feed itself: http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20query.multi%20where%20queries%3D%22select%20*%20from%20flickr.photos.search%20where%20user_id%3D'23433895%40N00'%3Bselect%20*%20from%20delicious.feeds%20where%20username%3D'keith.muth'%3Bselect%20*%20from%20twitter.user.timeline%20where%20id%3D'keithmuth'%22&format=json&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys&callback=

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  • GROUP BY ID range?

    - by d0ugal
    Given a data set like this; +-----+---------------------+--------+ | id | date | result | +-----+---------------------+--------+ | 121 | 2009-07-11 13:23:24 | -1 | | 122 | 2009-07-11 13:23:24 | -1 | | 123 | 2009-07-11 13:23:24 | -1 | | 124 | 2009-07-11 13:23:24 | -1 | | 125 | 2009-07-11 13:23:24 | -1 | | 126 | 2009-07-11 13:23:24 | -1 | | 127 | 2009-07-11 13:23:24 | -1 | | 128 | 2009-07-11 13:23:24 | -1 | | 129 | 2009-07-11 13:23:24 | -1 | | 130 | 2009-07-11 13:23:24 | -1 | | 131 | 2009-07-11 13:23:24 | -1 | | 132 | 2009-07-11 13:23:24 | -1 | | 133 | 2009-07-11 13:23:24 | -1 | | 134 | 2009-07-11 13:23:24 | -1 | | 135 | 2009-07-11 13:23:24 | -1 | | 136 | 2009-07-11 13:23:24 | -1 | | 137 | 2009-07-11 13:23:24 | -1 | | 138 | 2009-07-11 13:23:24 | 1 | | 139 | 2009-07-11 13:23:24 | 0 | | 140 | 2009-07-11 13:23:24 | -1 | +-----+---------------------+--------+ How would I go about grouping the results by day 5 records at a time. The above results is part of the live data, there is over 100,000 results rows in the table and its growing. Basically I want to measure the change over time, so want to take a SUM of the result every X records. In the real data I'll be doing it ever 100 or 1000 but for the data above perhaps every 5. If i could sort it by date I would do something like this; SELECT DATE_FORMAT(date, '%h%i') ym, COUNT(result) 'Total Games', SUM(result) as 'Score' FROM nn_log GROUP BY ym; I can't figure out a way of doing something similar with numbers. The order is sorted by the date but I hope to split the data up every x results. It's safe to assume there are no blank rows. Doing it above with the data you could do multiple selects like; SELECT SUM(result) FROM table LIMIT 0,5; SELECT SUM(result) FROM table LIMIT 5,5; SELECT SUM(result) FROM table LIMIT 10,5; Thats obviously not a very good way to scale up to a bigger problem. I could just write a loop but I'd like to reduce the number of queries.

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  • C++ Switch won't compile with externally defined variable used as case

    - by C Nielsen
    I'm writing C++ using the MinGW GNU compiler and the problem occurs when I try to use an externally defined integer variable as a case in a switch statement. I get the following compiler error: "case label does not reduce to an integer constant". Because I've defined the integer variable as extern I believe that it should compile, does anyone know what the problem may be? Below is an example: test.cpp #include <iostream> #include "x_def.h" int main() { std::cout << "Main Entered" << std::endl; switch(0) { case test_int: std::cout << "Case X" << std::endl; break; default: std::cout << "Case Default" << std::endl; break; } return 0; } x_def.h extern const int test_int; x_def.cpp const int test_int = 0; This code will compile correctly on Visual C++ 2008. Furthermore a Montanan friend of mine checked the ISO C++ standard and it appears that any const-integer expression should work. Is this possibly a compiler bug or have I missed something obvious? Here's my compiler version information: Reading specs from C:/MinGW/bin/../lib/gcc/mingw32/3.4.5/specs Configured with: ../gcc-3.4.5-20060117-3/configure --with-gcc --with-gnu-ld --with-gnu-as --host=mingw32 --target=mingw32 --prefix=/mingw --enable-threads --disable-nls --enable-languages=c,c++,f77,ada,objc,java --disable-win32-registry --disable-shared --enable-sjlj-exceptions --enable-libgcj --disable-java-awt --without-x --enable-java-gc=boehm --disable-libgcj-debug --enable-interpreter --enable-hash-synchronization --enable-libstdcxx-debug Thread model: win32 gcc version 3.4.5 (mingw-vista special r3)

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  • Python's asyncore to periodically send data using a variable timeout. Is there a better way?

    - by Nick Sonneveld
    I wanted to write a server that a client could connect to and receive periodic updates without having to poll. The problem I have experienced with asyncore is that if you do not return true when dispatcher.writable() is called, you have to wait until after the asyncore.loop has timed out (default is 30s). The two ways I have tried to work around this is 1) reduce timeout to a low value or 2) query connections for when they will next update and generate an adequate timeout value. However if you refer to 'Select Law' in 'man 2 select_tut', it states, "You should always try to use select() without a timeout." Is there a better way to do this? Twisted maybe? I wanted to try and avoid extra threads. I'll include the variable timeout example here: #!/usr/bin/python import time import socket import asyncore # in seconds UPDATE_PERIOD = 4.0 class Channel(asyncore.dispatcher): def __init__(self, sock, sck_map): asyncore.dispatcher.__init__(self, sock=sock, map=sck_map) self.last_update = 0.0 # should update immediately self.send_buf = '' self.recv_buf = '' def writable(self): return len(self.send_buf) > 0 def handle_write(self): nbytes = self.send(self.send_buf) self.send_buf = self.send_buf[nbytes:] def handle_read(self): print 'read' print 'recv:', self.recv(4096) def handle_close(self): print 'close' self.close() # added for variable timeout def update(self): if time.time() >= self.next_update(): self.send_buf += 'hello %f\n'%(time.time()) self.last_update = time.time() def next_update(self): return self.last_update + UPDATE_PERIOD class Server(asyncore.dispatcher): def __init__(self, port, sck_map): asyncore.dispatcher.__init__(self, map=sck_map) self.port = port self.sck_map = sck_map self.create_socket(socket.AF_INET, socket.SOCK_STREAM) self.bind( ("", port)) self.listen(16) print "listening on port", self.port def handle_accept(self): (conn, addr) = self.accept() Channel(sock=conn, sck_map=self.sck_map) # added for variable timeout def update(self): pass def next_update(self): return None sck_map = {} server = Server(9090, sck_map) while True: next_update = time.time() + 30.0 for c in sck_map.values(): c.update() # <-- fill write buffers n = c.next_update() #print 'n:',n if n is not None: next_update = min(next_update, n) _timeout = max(0.1, next_update - time.time()) asyncore.loop(timeout=_timeout, count=1, map=sck_map)

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  • Tools to document/visualize call graph?

    - by Dave Griffiths
    Hi, having recently joined a project with a vast amount of code to get to grips with, I would like to start documenting and visualizing some of the flows through the call graph to give me a better understanding of how everything fits together. This is what I would like to see in my ideal tool: every node is a function/method nodes are connected if one function can call another optional square box in between detailing conditions under which call is made (or a label icon you can hover over like a tooltip) also icon on edge describing parameters hover over node and description is displayed optional icons for node to display pseudo code scenario/domain view - display subset of complete diagram for particular use-case slide view mode - for each frame, the currently executing function is highlighted plenty of options over what to display to reduce on-screen clutter the interactive use of such a tool is key, I'm not looking for a Graphviz type solution because there would be too much clutter. The ability to form a view of a subset of the entire graph would be very handy (maybe with the unimportant clutter greyed out). Don't need automatic generation from source code, happy to enter it manually. Almost like a mind-map. Does that make sense? If you are not aware of such a tool, do you also think it would be useful? (Just in case I decide to go and scratch that itch one day!)

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  • live.com setting can't be changed

    - by M M
    I'm on mail.live.com where, in the upper left corner it says "Windows Live™" and to the right of that it says "Hotmail([number])" "Messenger" "SkyDrive" "|" "MSN." Directly under the "Windows Live™," there is a square, bluish/gray avatar (with a generic, rotund peop with a head and trunk and arms). To the right of that there is a field (with a subtle, barely perceptible speech bubble-like arrow emanating from the avatar). But there's a word inside that field that I cannot get rid of. Coincidentally I think it's the same word I used as a search term a while back, having meant to put the search term in the "Search email and more" bing field on the other side of the screen. (Even that would have been by mistake because I had been aiming for the e-mail search field.) But it remains in the field connected to the avatar--and moreover the field is editable to the limited extent that a cursor can be placed into the field with a mouse click; the word just can't be deleted. I don't know if the avatar should be there either, but I'd rather have just simply that than the word next to it continuously there for time immemorial. If I click into the field hoping to delete the word, I'm confronted with options along the bottom of the same field (now expanded by my mouse click): "Add: Photo Link Document," and a button that says "Share" and an [X] to reduce the field back to its default state--which still contains the word I'm trying to delete.

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  • What is the best practice in regards to building composite dtos off of an aggregate root with domain

    - by Chance
    I'm trying to figure out the best approach/practice for assembling a composite data transfer object off of an aggregate root and would love to hear people's thoughts on this. For example, lets say I have a root that has a few domain objects as children. I want to assemble a specific view dto, based on some business logic, that either has attributes or full dto's of it's objects. What I'm struggling with is trying to figure out where that assembly should happen. I can see it going on the domain object of the aggregate root as there is some business logic associated with it. The benefits of this approach from what I've deduced thus far is that it should reduce the inevitable business logic from bleeding outisde of the domain object. It also allows for private methods that take care of tasks that could become more complex from an external builder. The downsides being that the domain object becomes much more entrenched in the application's workflow and represents much more than just the domain object. It also could become very large in the scenario where you need multiple composite Dtos. Alternatively, I could also see it belonging to some form of transfer object assembler where there is a builder for each domain object. The domain objects would still be responsible for GetDto() and UpdateFromDto(dto). Outside of that, the builder would handle the construction and deconstruction of composite dtos. The downside is kind of mentioned above, where I fear this will easily lead to developers unfamiliar with DDD bleeding a ton of business logic into the assembler which is what I want to desperately avoid. Any thoughts would be greatly apperciated.

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  • Technology and language for a stable Digital Audio Workstation development

    - by Kill KRT
    Hi, I'm designing a cross platform (Windows/Linux/OS X) application, something like a digital audio workstation. I'd like to create a software where users have a fully featured sequencer (multiple tracks with automation) and where it is possible to create instruments using a visual language (as Pure Data/Max MSP). Ehm... I know that I've already posted a question about a related issue... But in order to decide which technology I should use, I think I'd better to make more investigation. I'm a quite experted user of audio trackers (Renoise, Protracker,...) and sequencers (FL Studio, Cubase 5), but I didn't ever try to develop even a basic audio tracker. I know just the basic theory of mixing sound and know how basically a DSP works. My questions are: Where I can find a good tutorial/guide/book about this issue? Do you think using C# (with NAudio) could dramatically reduce performance? I know C++ would be the best choice, but I find C# so elegant and easy to build and port, while C++ is so powerful and fast, but there are too #define and bad things for my taste! ;-) Thank you.

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  • Printing to different printers using mozilla.

    - by Nick-ACNB
    I am currently creating a web application that will be deployed in an intranet environment. I chose firefox to be the browser that will run it. However, in the application I am building, I need to be able to print to different printers quickly since they use different paper size depending on what client is coming. To avoid many time-wasting mistakes that could occur, for instance someone choosing the wrong printer and wasting paper. Also, the time used to find the right printer for the job and then pressing print is considered too long in the current context. Is there any solution to this problem? I understand the potential security flaw behind this, but please be aware that this is solely an intranet project and that I can reduce the browser's security to the lowest since they don't access internet. I know there could be something doable behind IE (ActiveX or VBScript) but I am using firefox. Also, I guess there could also be something rather tricky that when you press print on the browser, it saves what needs to be printed to a DB and then there is an exe app that runs and fetch that DB every set ammount of time and print to the right printer. Any suggestion would be greatly appreciated. I doubt I am the only one to ever face this issue! :) Thank you very much.

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  • Any merit to a lazy-ish juxt function?

    - by NielsK
    In answering a question about a function that maps over multiple functions with the same arguments (A: juxt), I came up with a function that basically took the same form as juxt, but used map: (defn could-be-lazy-juxt [& funs] (fn [& args] (map #(apply %1 %2) funs (repeat args)))) => ((juxt inc dec str) 1) [2 0 "1"] => ((could-be-lazy-juxt inc dec str) 1) (2 0 "1") => ((juxt * / -) 6 2) [12 3 4] => ((could-be-lazy-juxt * / -) 6 2) (12 3 4) As posted in the original question, I have little clue about the laziness or performance of it, but timing in the REPL does suggest something lazy-ish is going on. => (time (apply (juxt + -) (range 1 100))) "Elapsed time: 0.097198 msecs" [4950 -4948] => (time (apply (could-be-lazy-juxt + -) (range 1 100))) "Elapsed time: 0.074558 msecs" (4950 -4948) => (time (apply (juxt + -) (range 10000000))) "Elapsed time: 1019.317913 msecs" [49999995000000 -49999995000000] => (time (apply (could-be-lazy-juxt + -) (range 10000000))) "Elapsed time: 0.070332 msecs" (49999995000000 -49999995000000) I'm sure this function is not really that quick (the print of the outcome 'feels' about as long in both). Doing a 'take x' on the function only limits the amount of functions evaluated, which probably is limited in it's applicability, and limiting the other parameters by 'take' should be just as lazy in normal juxt. Is this juxt really lazy ? Would a lazy juxt bring anything useful to the table, for instance as a compositing step between other lazy functions ? What are the performance (mem / cpu / object count / compilation) implications ? Is that why the Clojure juxt implementation is done with a reduce and returns a vector ? Edit: Somehow things can always be done simpler in Clojure. (defn could-be-lazy-juxt [& funs] (fn [& args] (map #(apply % args) funs)))

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  • Find all the child node of specific value in C#

    - by sara brown
    <main> <myself> <pid>1</pid> <name>abc</name> </myself> <myself> <pid>2</pid> <name>efg</name> </myself> </main> that is my XML file named simpan. I have two button. next and previous. What i want to do is, all the info will shows off on the TextBox when the user click the button. The searching node will be based on the pid. Next button will adding 1 value of pid (let's say pid=2) and it will search on the node that have the same value of pid=2. it also will show the name for the pid=2. (showing name=abc) Same goes to the previous button where it will reduce 1value of pid (pid=1). Does anybody knows how to do this? //-------------EDIT------------------ thanks to L.B, im trying to use his code. however i got an error. is my implementation of code correct? private void previousList_Click(object sender, EventArgs e) { pid = 14; XDocument xDoc = XDocument.Parse("C:\\Users\\HDAdmin\\Documents\\Fatty\\SliceEngine\\SliceEngine\\bin\\Debug\\simpan.xml"); var name = xDoc.Descendants("myself") .First(m => (int)m.Element("PatientID") == pid) .Value; textETA.Text = name; //////////////////// }

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  • Synchronizing in SQL Replication works when manually syncing, but not automatically

    - by Dominic Zukiewicz
    I'm using SQL Server 2005 to create a replication copy of the main databases, so that the reports can point to the replication copy instead of locking out our main databases. I have set up the 3 databases as publications and then 3 subscribers moving the transactions over to the subscribers, instantaneously I hope! What seems to be happening is that when using the "Insert Tracer" function, replication take publisher to distributor < 2 seconds, but to replicate to the subscribers can take over 7 minutes (and these are local databases on a SAN). This could be for 2 reasons: The SQL statements used to query the database are obtaining locks which are stopping the transactions updating the subscribers. The subscribers are just too busy for the replication to apply the changes. What seems to trouble me more, is that although the Replication Monitor / Insert Tracer are showing these statistics, if you use the "View Subscription Details" and then click Start, it will sync within seconds. My goal would be to have the data syncing (ideally) continuously, or every minute, perhaps I should reduce the batch size of the transactions? What am I doing wrong? [Note that the -Continuous flag is set!]

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  • Why is debugging better in an IDE?

    - by Bill Karwin
    I've been a software developer for over twenty years, programming in C, Perl, SQL, Java, PHP, JavaScript, and recently Python. I've never had a problem I could not debug using some careful thought, and well-placed debugging print statements. I respect that many people say that my techniques are primitive, and using a real debugger in an IDE is much better. Yet from my observation, IDE users don't appear to debug faster or more successfully than I can, using my stone knives and bear skins. I'm sincerely open to learning the right tools, I've just never been shown a compelling advantage to using visual debuggers. Moreover, I have never read a tutorial or book that showed how to debug effectively using an IDE, beyond the basics of how to set breakpoints and display the contents of variables. What am I missing? What makes IDE debugging tools so much more effective than thoughtful use of diagnostic print statements? Can you suggest resources (tutorials, books, screencasts) that show the finer techniques of IDE debugging? Sweet answers! Thanks much to everyone for taking the time. Very illuminating. I voted up many, and voted none down. Some notable points: Debuggers can help me do ad hoc inspection or alteration of variables, code, or any other aspect of the runtime environment, whereas manual debugging requires me to stop, edit, and re-execute the application (possibly requiring recompilation). Debuggers can attach to a running process or use a crash dump, whereas with manual debugging, "steps to reproduce" a defect are necessary. Debuggers can display complex data structures, multi-threaded environments, or full runtime stacks easily and in a more readable manner. Debuggers offer many ways to reduce the time and repetitive work to do almost any debugging tasks. Visual debuggers and console debuggers are both useful, and have many features in common. A visual debugger integrated into an IDE also gives you convenient access to smart editing and all the other features of the IDE, in a single integrated development environment (hence the name).

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  • Harvesting Dynamic HTTP Content to produce Replicating HTTP Static Content

    - by Neil Pitman
    I have a slowly evolving dynamic website served from J2EE. The response time and load capacity of the server are inadequate for client needs. Moreover, ad hoc requests can unexpectedly affect other services running on the same application server/database. I know the reasons and can't address them in the short term. I understand HTTP caching hints (expiry, etags....) and for the purpose of this question, please assume that I have maxed out the opportunities to reduce load. I am thinking of doing a brute force traversal of all URLs in the system to prime a cache and then copying the cache contents to geodispersed cache servers near the clients. I'm thinking of Squid or Apache HTTPD mod_disk_cache. I want to prime one copy and (manually) replicate the cache contents. I don't need a federation or intelligence amongst the slaves. When the data changes, invalidating the cache, I will refresh my master cache and update the slave versions, probably once a night. Has anyone done this? Is it a good idea? Are there other technologies that I should investigate? I can program this, but I would prefer a configuration of open source technologies solution Thanks

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  • How Can I Compress Texture in OpenGL on iPhone/iPad?

    - by nonamelive
    Hi, I'm making an iPad app which needs OpenGL to do a flip animation. I have a front image texture and a back image texture. Both the two textures are screenshots. // Capture an image of the screen UIGraphicsBeginImageContext(view.bounds.size); [view.layer renderInContext:UIGraphicsGetCurrentContext()]; image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); // Allocate some memory for the texture GLubyte *textureData = (GLubyte*)calloc(maxTextureSize*4, maxTextureSize); // Create a drawing context to draw image into texture memory CGContextRef textureContext = CGBitmapContextCreate(textureData, maxTextureSize, maxTextureSize, 8, maxTextureSize*4, CGImageGetColorSpace(image.CGImage), kCGImageAlphaPremultipliedLast); CGContextDrawImage(textureContext, CGRectMake(0, maxTextureSize-size.height, size.width, size.height), image.CGImage); CGContextRelease(textureContext); // ...done creating the texture data [EAGLContext setCurrentContext:context]; glGenTextures(1, &textureToView); glBindTexture(GL_TEXTURE_2D, textureToView); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, maxTextureSize, maxTextureSize, 0, GL_RGBA, GL_UNSIGNED_BYTE, textureData); // free texture data which is by now copied into the GL context free(textureData); Each of the texture takes up about 8MB memory, which is unacceptable for an iPhone/iPad app. Could anyone tell me how can I compress the texture to reduce the memory. I'm a complete newbie to OpenGL. Any help would be appreciated!

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  • Can a Generic Method handle both Reference and Nullable Value types?

    - by Adam Lassek
    I have a series of Extension methods to help with null-checking on IDataRecord objects, which I'm currently implementing like this: public static int? GetNullableInt32(this IDataRecord dr, int ordinal) { int? nullInt = null; return dr.IsDBNull(ordinal) ? nullInt : dr.GetInt32(ordinal); } public static int? GetNullableInt32(this IDataRecord dr, string fieldname) { int ordinal = dr.GetOrdinal(fieldname); return dr.GetNullableInt32(ordinal); } and so on, for each type I need to deal with. I'd like to reimplement these as a generic method, partly to reduce redundancy and partly to learn how to write generic methods in general. I've written this: public static Nullable<T> GetNullable<T>(this IDataRecord dr, int ordinal) { Nullable<T> nullValue = null; return dr.IsDBNull(ordinal) ? nullValue : (Nullable<T>) dr.GetValue(ordinal); } which works as long as T is a value type, but if T is a reference type it won't. This method would need to return either a Nullable type if T is a value type, and default(T) otherwise. How would I implement this behavior?

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  • Enum exeeding the 65535 bytes limit of static initializer... what's best to do?

    - by Daniel Bleisteiner
    I've started a rather large Enum of so called Descriptors that I've wanted to use as a reference list in my model. But now I've come across a compiler/VM limit the first time and so I'm looking for the best solution to handle this. Here is my error : The code for the static initializer is exceeding the 65535 bytes limit It is clear where this comes from - my Enum simply has far to much elements. But I need those elements - there is no way to reduce that set. Initialy I've planed to use a single Enum because I want to make sure that all elements within the Enum are unique. It is used in a Hibernate persistence context where the reference to the Enum is stored as String value in the database. So this must be unique! The content of my Enum can be devided into several groups of elements belonging together. But splitting the Enum would remove the unique safety I get during compile time. Or can this be achieved with multiple Enums in some way? My only current idea is to define some Interface called Descriptor and code several Enums implementing it. This way I hope to be able to use the Hibernate Enum mapping as if it were a single Enum. But I'm not even sure if this will work. And I loose unique safety. Any ideas how to handle that case?

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  • Convert image color space and output separate channels in OpenCV

    - by Victor May
    I'm trying to reduce the runtime of a routine that converts an RGB image to a YCbCr image. My code looks like this: cv::Mat input(BGR->m_height, BGR->m_width, CV_8UC3, BGR->m_imageData); cv::Mat output(BGR->m_height, BGR->m_width, CV_8UC3); cv::cvtColor(input, output, CV_BGR2YCrCb); cv::Mat outputArr[3]; outputArr[0] = cv::Mat(BGR->m_height, BGR->m_width, CV_8UC1, Y->m_imageData); outputArr[1] = cv::Mat(BGR->m_height, BGR->m_width, CV_8UC1, Cr->m_imageData); outputArr[2] = cv::Mat(BGR->m_height, BGR->m_width, CV_8UC1, Cb->m_imageData); split(output,outputArr); But, this code is slow because there is a redundant split operation which copies the interleaved RGB image into the separate channel images. Is there a way to make the cvtColor function create an output that is already split into channel images? I tried to use constructors of the _OutputArray class that accepts a vector or array of matrices as an input, but it didn't work.

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  • Using pointers to adjust global objects in objective-c

    - by Rob
    Ok, so I am working with two sets of data that are extremely similar, and at the same time, these data sets are both global NSMutableArrays within the object. data_set_one = [[NSMutableArray alloc] init]; data_set_two = [[NSMutableArray alloc] init]; Two new NSMutableArrays are loaded, which need to be added to the old, existing data. These Arrays are also global. xml_dataset_one = [[NSMutableArray alloc] init]; xml_dataset_two = [[NSMutableArray alloc] init]; To reduce code duplication (and because these data sets are so similar) I wrote a void method within the class to handle the data combination process for both Arrays: -(void)constructData:(NSMutableArray *)data fromDownloadArray:(NSMutableArray *)down withMatchSelector:(NSString *)sel_str Now, I have a decent understanding of object oriented programming, so I was thinking that if I were to invoke the method with the global Arrays in the data like so... [self constructData:data_set_one fromDownloadArray:xml_dataset_one withMatchSelector:@"id"]; Then the global NSMutableArrays (data_set_one) would reflect the changes that happen to "array" within the method. Sadly, this is not the case, data_set_one doesn't reflect the changes (ex: new objects within the Array) outside of the method. Here is a code snippet of the problem // data_set_one is empty // xml_dataset_one has a few objects [constructData:(NSMutableArray *)data_set_one fromDownloadArray:(NSMutableArray *)xml_dataset_one withMatchSelector:(NSString *)@"id"]; // data_set_one should now be xml_dataset_one, but when echoed to screen, it appears to remain empty And here is the gist of the code for the method, any help is appreciated. -(void)constructData:(NSMutableArray *)data fromDownloadArray:(NSMutableArray *)down withMatchSelector:(NSString *)sel_str { if ([data count] == 0) { data = down; // set data equal to downloaded data } else if ([down count] == 0) { // download yields no results, do nothing } else { // combine the two arrays here } } This project is not ARC enabled. Thanks for the help guys! Rob

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  • Spring Security ACL: NotFoundException from JDBCMutableAclService.createAcl

    - by user340202
    Hello, I've been working on this task for too long to abandon the idea of using Spring Security to achieve it, but I wish that the community will provide with some support that will help reduce the regret that I have for choosing Spring Security. Enough ranting and now let's get to the point. I'm trying to create an ACL by using JDBCMutableAclService.createAcl as follows: [code] public void addPermission(IWFArtifact securedObject, Sid recipient, Permission permission, Class clazz) { ObjectIdentity oid = new ObjectIdentityImpl(clazz.getCanonicalName(), securedObject.getId()); this.addPermission(oid, recipient, permission); } @Override @Transactional(propagation = Propagation.REQUIRED, isolation = Isolation.READ_UNCOMMITTED, readOnly = false) public void addPermission(ObjectIdentity oid, Sid recipient, Permission permission) { SpringSecurityUtils.assureThreadLocalAuthSet(); MutableAcl acl; try { acl = this.mutableAclService.createAcl(oid); } catch (AlreadyExistsException e) { acl = (MutableAcl) this.mutableAclService.readAclById(oid); } // try { // acl = (MutableAcl) this.mutableAclService.readAclById(oid); // } catch (NotFoundException nfe) { // acl = this.mutableAclService.createAcl(oid); // } acl.insertAce(acl.getEntries().length, permission, recipient, true); this.mutableAclService.updateAcl(acl); } [/code] The call throws a NotFoundException from the line: [code] // Retrieve the ACL via superclass (ensures cache registration, proper retrieval etc) Acl acl = readAclById(objectIdentity); [/code] I believe this is caused by something related to Transactional, and that's why I have tested with many TransactionDefinition attributes. I have also doubted the annotation and tried with declarative transaction definition, but still with no luck. One important point is that I have used the statement used to insert the oid in the database earlier in the method directly on the database and it worked, and also threw a unique constraint exception at me when it tried to insert it in the method. I'm using Spring Security 2.0.8 and IceFaces 1.8 (which doesn't support spring 3.0 but definetely supprorts 2.0.x, specially when I keep caling SpringSecurityUtils.assureThreadLocalAuthSet()). My AppServer is Tomcat 6.0, and my DB Server is MySQL 6.0 I wish to get back a reply soon because I need to get this task off my way

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