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  • Python Ephem calculation

    - by dassouki
    the output should process the first date as "day" and second as "night". I've been playing with this for a few hours now and can't figure out what I'm doing wrong. Any ideas? Output: $ python time_of_day.py * should be day: event date: 2010/4/6 16:00:59 prev rising: 2010/4/6 09:24:24 prev setting: 2010/4/5 23:33:03 next rise: 2010/4/7 09:22:27 next set: 2010/4/6 23:34:27 day * should be night: event date: 2010/4/6 00:01:00 prev rising: 2010/4/5 09:26:22 prev setting: 2010/4/5 23:33:03 next rise: 2010/4/6 09:24:24 next set: 2010/4/6 23:34:27 day time_of_day.py import datetime import ephem # install from http://pypi.python.org/pypi/pyephem/ #event_time is just a date time corresponding to an sql timestamp def type_of_light(latitude, longitude, event_time, utc_time, horizon): o = ephem.Observer() o.lat, o.long, o.date, o.horizon = latitude, longitude, event_time, horizon print "event date ", o.date print "prev rising: ", o.previous_rising(ephem.Sun()) print "prev setting: ", o.previous_setting(ephem.Sun()) print "next rise: ", o.next_rising(ephem.Sun()) print "next set: ", o.next_setting(ephem.Sun()) if o.previous_rising(ephem.Sun()) <= o.date <= o.next_setting(ephem.Sun()): return "day" elif o.previous_setting(ephem.Sun()) <= o.date <= o.next_rising(ephem.Sun()): return "night" else: return "error" print "should be day: ", type_of_light('45.959','-66.6405','2010/4/6 16:01','-4', '-6') print "should be night: ", type_of_light('45.959','-66.6405','2010/4/6 00:01','-4', '-6')

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  • win7 amd64 guest in kvm does not have sound

    - by davidshen84
    hi, my host system is gentoo amd64, guest system is win 7 amd64. the guest system can work, except it does not have sound. i start kvm with -soundhw ac97, QEMU_AUDIO_DRV='alsa', and after i get into the guest system, i can see a 'Multimedia Audio Controller' in the device manager. but win7 cannot find the driver for it. i searched the network for a long time, and i cannot find a driver for intel ac97 for win7 amd64. i also tried -soundhw sb16, es1370, none of them work. please help me fix this.

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  • Android setImageURI out of memory error

    - by Improver
    I have a very small activity that must show an image. If picture is not very small (for example 1.12 Mb 2560x1920) it produces out of memory on change screen orientation. I tried getDrawable.setCallback(null) but no luck. Where am I wrong? public class Fullscreen extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); System.gc(); setContentView(R.layout.fullscreen); ImageView imageView = (ImageView) findViewById(R.id.full_screen_image); long imageId = 2; imageView.setImageURI(Uri.withAppendedPath(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "" + imageId)); } }

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  • PHP DateTime Regex

    - by CogitoErgoSum
    Hey, long story short I have inherited some terrible code. As a result a string comparison is buggy when comparing dates due to the format of the date. I am trying to convert the date to a valid DateFormat syntax so I can run a proper comparison. These are some samples of the current format: 12/01/10 at 8:00PM 12/31/10 at 12:00PM 12/10/09 at 5:00AM and so forth. I'd like to convert this to a YYYYMMDDHHMM format i.e 201012012000 for comparison purposes. If anyone can give me a quick regex snippet to do this that'd be appreciated as right now i'm hitting a brick wall for a regex. I can do it by exploding the string over several times etc but I'd rather do it in a more efficient manner. Thanks!

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  • Find only physical network adapters with WMI Win32_NetworkAdapter class

    - by Mladen Prajdic
    WMI is Windows Management Instrumentation infrastructure for managing data and machines. We can access it by using WQL (WMI querying language or SQL for WMI). One thing to remember from the WQL link is that it doesn't support ORDER BY. This means that when you do SELECT * FROM wmiObject, the returned order of the objects is not guaranteed. It can return adapters in different order based on logged-in user, permissions of that user, etc… This is not documented anywhere that I've looked and is derived just from my observations. To get network adapters we have to query the Win32_NetworkAdapter class. This returns us all network adapters that windows detect, real and virtual ones, however it only supplies IPv4 data. I've tried various methods of combining properties that are common on all systems since Windows XP. The first thing to do to remove all virtual adapters (like tunneling, WAN miniports, etc…) created by Microsoft. We do this by adding WHERE Manufacturer!='Microsoft' to our WMI query. This greatly narrows the number of adapters we have to work with. Just on my machine it went from 20 adapters to 5. What was left were one real physical Realtek LAN adapter, 2 virtual adapters installed by VMware and 2 virtual adapters installed by VirtualBox. If you read the Win32_NetworkAdapter help page you'd notice that there's an AdapterType that enumerates various adapter types like LAN or Wireless and AdapterTypeID that gives you the same information as AdapterType only in integer form. The dirty little secret is that these 2 properties don't work. They are both hardcoded, AdapterTypeID to "0" and AdapterType to "Ethernet 802.3". The only exceptions I've seen so far are adapters that have no values at all for the two properties, "RAS Async Adapter" that has values of AdapterType = "Wide Area Network" and AdapterTypeID = "3" and various tunneling adapters that have values of AdapterType = "Tunnel" and AdapterTypeID = "15". In the help docs there isn't even a value for 15. So this property was of no help. Next property to give hope is NetConnectionId. This is the name of the network connection as it appears in the Control Panel -> Network Connections. Problem is this value is also localized into various languages and can have different names for different connection. So both of these properties don't help and we haven't even started talking about eliminating virtual adapters. Same as the previous one this property was also of no help. Next two properties I checked were ConfigManagerErrorCode and NetConnectionStatus in hopes of finding disabled and disconnected adapters. If an adapter is enabled but disconnected the ConfigManagerErrorCode = 0 with different NetConnectionStatus. If the adapter is disabled it reports ConfigManagerErrorCode = 22. This looked like a win by using (ConfigManagerErrorCode=0 or ConfigManagerErrorCode=22) in our condition. This way we get enabled (connected and disconnected adapters). Problem with all of the above properties is that none of them filter out the virtual adapters installed by virtualization software like VMware and VirtualBox. The last property to give hope is PNPDeviceID. There's an interesting observation about physical and virtual adapters with this property. Every virtual adapter PNPDeviceID starts with "ROOT\". Even VMware and VirtualBox ones. There were some really, really old physical adapters that had PNPDeviceID starting with "ROOT\" but those were in pre win XP era AFAIK. Since my minimum system to check was Windows XP SP2 I didn't have to worry about those. The only virtual adapter I've seen to not have PNPDeviceID start with "ROOT\" is the RAS Async Adapter for Wide Area Network. But because it is made by Microsoft we've eliminated it with the first condition for the manufacturer. Using the PNPDeviceID has so far proven to be really effective and I've tested it on over 20 different computers of various configurations from Windows XP laptops with wireless and bluetooth cards to virtualized Windows 2008 R2 servers. So far it always worked as expected. I will appreciate you letting me know if you find a configuration where it doesn't work. Let's see some C# code how to do this: ManagementObjectSearcher mos = null;// WHERE Manufacturer!='Microsoft' removes all of the // Microsoft provided virtual adapters like tunneling, miniports, and Wide Area Network adapters.mos = new ManagementObjectSearcher(@"SELECT * FROM Win32_NetworkAdapter WHERE Manufacturer != 'Microsoft'");// Trying the ConfigManagerErrorCode and NetConnectionStatus variations // proved to still not be enough and it returns adapters installed by // the virtualization software like VMWare and VirtualBox// ConfigManagerErrorCode = 0 -> Device is working properly. This covers enabled and/or disconnected devices// ConfigManagerErrorCode = 22 AND NetConnectionStatus = 0 -> Device is disabled and Disconnected. // Some virtual devices report ConfigManagerErrorCode = 22 (disabled) and some other NetConnectionStatus than 0mos = new ManagementObjectSearcher(@"SELECT * FROM Win32_NetworkAdapter WHERE Manufacturer != 'Microsoft' AND (ConfigManagerErrorCode = 0 OR (ConfigManagerErrorCode = 22 AND NetConnectionStatus = 0))");// Final solution with filtering on the Manufacturer and PNPDeviceID not starting with "ROOT\"// Physical devices have PNPDeviceID starting with "PCI\" or something else besides "ROOT\"mos = new ManagementObjectSearcher(@"SELECT * FROM Win32_NetworkAdapter WHERE Manufacturer != 'Microsoft' AND NOT PNPDeviceID LIKE 'ROOT\\%'");// Get the physical adapters and sort them by their index. // This is needed because they're not sorted by defaultIList<ManagementObject> managementObjectList = mos.Get() .Cast<ManagementObject>() .OrderBy(p => Convert.ToUInt32(p.Properties["Index"].Value)) .ToList();// Let's just show all the properties for all physical adapters.foreach (ManagementObject mo in managementObjectList){ foreach (PropertyData pd in mo.Properties) Console.WriteLine(pd.Name + ": " + (pd.Value ?? "N/A"));}   That's it. Hope this helps you in some way.

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  • NetBeans and Eclipse-like "run configurations"

    - by auramo
    Is it possible to create anything similar to Eclipse's "run configurations" in NetBeans? I am working on a huge project which is currently not divided into any subprojects in Eclipse. There are in fact many applications in the project which have their own main-methods and separate classpaths. I know, it's a mess. I'm considering about migrating the project to NetBeans. In the long run it would be sensible to create many projects but for now it would be a real life-saver if I could do similar stuff in NetBeans than in Eclipse: create "launchers" which have their own classpaths. Is this possible? If it's easy to emulate this behaviour with "external" projects, hints about that are welcome as well.

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  • Best method for Flex to PHP communication?

    - by davr
    What is the best method for communication between Flex and PHP? In the past, we used AMFPHP with AS2, and it worked great for the most part (advantage of AMFPHP is that it also has a JSON mode that can let you seamlessly use the same remote PHP with either Javascript or Actionscript frontends). However, it seems like AMFPHP isn't realy maintained anymore. So what do people recommend to replace it? So far, what I've found is: Zend_AMF (looks too complex for us, we're not using the Zend framework otherwise) AMFPHP (there were some updated made to support Flex, and it seems fairly stable, but not sure on long-term support) XML (AS3 has nice XML handling routines, but it's more of a pain on the PHP side) WebORB (I have no experience with this) Roll-our-own using JSON or some other data-to-text serialization system (php's serialize(), XML, etc etc) Mostly I'm leaning towards AMFPHP, even because of the downsides, since that's what I'm used to. Any reason I should consider switching to something else?

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  • Python's FTPLib too slow ?

    - by PyNEwbie
    I have been playing around with Python's FTP library and am starting to think that it is too slow as compared to using a script file in DOS? I run sessions where I download thousands of data files (I think I have over 8 million right now). My observation is that the download process seems to take five to ten times as long in Python than it does as compared to using the ftp commands in the DOS shell. Since I don't want anyone to fix my code I have not included any. I am more interested in understanding if my observation is valid or if I need to tinker more with the arguments.

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  • .NET and P2P - writing a P2P messenger

    - by brovar
    Hi there, Does anyone have any advice how to write such app? Or maybe knows some nice tutorial? I would like to use System.Net.PeerToPeer namespace, but everything I can find about it is MSDN which I can't read without getting mad. Or maybe using "old-school" TCP/IP would more efficient? I will appreciate every piece of advice. Every sample code I will shower with gold ;) And please, don't send me back to Google for I have searched for a long time for sth useful - maybe inaccurately but time is running out and I really need some help.

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  • Calculating determinant by hand

    - by ldigas
    Okey, this is only half programming, but let's see how you are on terms with manual calculations. I believe many of you did this on your university's while giving "linear systems" ... the problem is it's been so long I can't remember how to do it any more. I know quite a few algorithms for calculating determinants, and they all work fine ... for large systems, where one would never try to do it manually. Unfortunatelly, I'm soon going on an exam, where I do have to calculate it manually, up to the system of 5. So, I have a K(omega) matrix that looks like this: [2-(omega^2)*c -4 2 0 0] [-2 5-(omega^2)*c -4 1 0] [1 -4 6-(omega^2)*c -4 1] [0 1 -4 5-(omega^2)*c -2] [0 0 2 -4 2-(omega^2)*c] and I need all the omegas which satisfy the det[K(omega)]=0 criteria. What would be a good way to calculate it so it can be repeated in a manual process ?

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  • Net::Cassandra::Easy equivalent of "SELECT * FROM ..."

    - by knorv
    When using Perl's Net::Cassandra::Easy the following code will retrieve columns col[1-3] from rows row[1-3]: $result = $cassandra->get(['row1', 'row2', 'row3'], family => 'Standard1', byname => ['col1', 'col2', 'col3'); The corresponding SQL would be: SELECT col1, col2, col3 FROM rows WHERE id IN ('row1', 'row2', 'row3'); Suppose instead that I want to retrieve all columns. In SQL terms that would be: SELECT * FROM rows WHERE id IN ('row1', 'row2', 'row3'); To get all columns I am currently using: $result = $cassandra->get(['row1', 'row2', 'row3'], family => 'Standard1', byoffset => { "count" => 1_000_000 }); This works as long as the number of columns does not exceed one million. While this works I'd assume that there is a cleaner way to do it. My question is: Is there any cleaner way to specify to Cassandra that I want to retrieve all columns for the maching rows?

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  • Alternative Input Device(Midi) doesn't prevent Screen Saver in Winforms application

    - by DTig
    I have developed a c# winforms application whereby the user is providing input via a midi connected device. The user will go for long periods without using the keyboard or mouse. When I receive a midi message is there anything I can do to "tell" the system that this counts as user activity (ie key press). I don't want the screen saver or time lockouts to occur, if they are actively using the midi device. I think my request is different than other requests I've seen because they want to disable screen savers for the life of their application whereby I just want midi input I receive to count as user interactivity. Is there something I can call when I receive midi input to signify to the system user activity?

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  • Having a little trouble with this Java code. Beginner probably mixing some things with C#.

    - by Sergio Tapia
    package practico1; /** * Programador: Sergio Tapia Gutierrez * Fecha: Lunes 10, Mayo - 2010 * Practico: 1 */ public class Main { public static void main(String[] args) { System.out.println("Esta es una pequena aplicacion para mostrar los"); System.out.println("distintos tipos de datos que existen en Java 6."); //boolean, char, byte, short, int, long, float, double, String ejemplosBoolean(); } public void ejemplosBoolean(){ } } So, I'm just testing some things out, but I'm getting an error claiming that I'm trying to run ejemplosBoolean() in a static context when it isn't a static method. My question is, in Java do methods have to have static in order to use them even if they are in the same class?

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  • Tibco Unit Testing tools

    - by mezoid
    Does anyone know what unit testing tools are available when developing Tibco processes? In the next few months I'll be working on a Tibco project and I'm trying to find any existing unit testing frameworks that might make the job easier to build with a TDD approach. Thus far, the only one I've been able to locate is called BWUnit. It seems ok but its currently in beta and its commercial software. If possible I'd like to use an open source tool but as long as it is able to do a good job I'd be happy. So does anyone know of any other unit testing tools for Tibco development?

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  • gcc linking shared libraries with dependent libraries

    - by Geng
    I have a complicated project with multiple executable targets and multiple shared libraries. The shared libraries currently don't have their dependent shared libraries linked in, and the result is that linker arguments to build the executables are hideously long and hard to maintain. I'd like to add in the dependencies so the Makefiles become much cleaner. I want to add the following (example): gcc -shared -o libshared.so -lshared_dependent1 -lshared_dependent2 objfile1.o objfile2.o Is there a way to test if all the symbols in libshared.so will resolve based on that line? Is there a way to print out if any of the shared_dependent libraries specified were unnecessary? Thanks in advance.

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  • Compact representation of GUID/UUID?

    - by chakrit
    I need to generate a GUID and save it via a string representation. The string representation should be as short as possible as it will be used as part of an already-long URL string. Right now, instead of using the normal abcd-efgh-... representation, I use the raw bytes generated and base64-encode them instead, which results in a somewhat shorter string. But is it possible to make it even shorter? I'm OK with losing some degree of uniqueness and keeping a counter, but scanning all existing keys is not an option. Suggestions?

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  • Powerbuilder Dynamic Array Manipulation

    - by TomatoSandwich
    string array[] long lBound, uBound lBound = LowerBound(array[]) // = 1, empty array value uBound = UpperBound(array[]) // = 0, empty array value array[1] = 'Item 1' array[2] = 'Item 2' array[3] = 'Item 3' lBound = LowerBound(array[]) // = 1 uBound = UpperBound(array[]) // = 3 array[3] = '' //removing item 3 lBound = LowerBound(array[]) // = 1, still uBound = UpperBound(array[]) // = 3, still (but array[3] is nulled? I think the line 'array[3]' is wrong, but I think I've read that this should remove the array cell. What would be the right way to remove an array cell? Does it depend on object type? (String vs Number vs Object) Or Can one manipulate the UpperBound value to make it work? i.e. after removing Item 3, I want the UpperBound, or arraylength, to be 2, since this is logically correct.

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  • Properties in partial class not appearing in Data Sources window!

    - by Tim Murphy
    Entity Framework has created the required partial classes. I can add these partial classes to the Data Sources window and the properties display as expected. However, if I extend any of the classes in a separate source file these properties do not appear in the Data Sources window even after a build and refresh. All properties in partial classes across source files work as expected in the Data Sources window except when the partial class has been created with EF. EDIT: After removing the offending table for edm designer, adding back in it all works are expected. Hardly a long term solution. Anyone else come across a similar problem?

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  • The case of the phantom ADF developer (and other yarns)

    - by Chris Muir
    A few years of ADF experience means I see common mistakes made by different developers, some I regularly make myself.  This post is designed to assist beginners to Oracle JDeveloper Application Development Framework (ADF) avoid a common ADF pitfall, the case of the phantom ADF developer [add Scooby-Doo music here]. ADF Business Components - triggers, default table values and instead of views. Oracle's JDeveloper tutorials help with the A-B-Cs of ADF development, typically built on the nice 'n safe demo schema provided by with the Oracle database such as the HR demo schema. However it's not too long until ADF beginners, having built up some confidence from learning with the tutorials and vanilla demo schemas, start building ADF Business Components based upon their own existing database schema objects.  This is where unexpected problems can sneak in. The crime Developers may encounter a surprising error at runtime when editing a record they just created or updated and committed to the database, based on their own existing tables, namely the error: JBO-25014: Another user has changed the row with primary key oracle.jbo.Key[x] ...where X is the primary key value of the row at hand.  In a production environment with multiple users this error may be legit, one of the other users has updated the row since you queried it.  Yet in a development environment this error is just plain confusing.  If developers are isolated in their own database, creating and editing records they know other users can't possibly be working with, or all the other developers have gone home for the day, how is this error possible? There are no other users?  It must be the phantom ADF developer! [insert dramatic music here] The following picture is what you'll see in the Business Component Browser, and you'll receive a similar error message via an ADF Faces page: A false conclusion What can possibly cause this issue if it isn't our phantom ADF developer?  Doesn't ADF BC implement record locking, locking database records when the row is modified in the ADF middle-tier by a user?  How can our phantom ADF developer even take out a lock if this is the case?  Maybe ADF has a bug, maybe ADF isn't implementing record locking at all?  Shouldn't we see the error "JBO-26030: Failed to lock the record, another user holds the lock" as we attempt to modify the record, why do we see JBO-25014? : Let's verify that ADF is in fact issuing the correct SQL LOCK-FOR-UPDATE statement to the database. First we need to verify ADF's locking strategy.  It is determined by the Application Module's jbo.locking.mode property.  The default (as of JDev 11.1.1.4.0 if memory serves me correct) and recommended value is optimistic, and the other valid value is pessimistic. Next we need a mechanism to check that ADF is issuing the LOCK statements to the database.  We could ask DBAs to monitor locks with OEM, but optimally we'd rather not involve overworked DBAs in this process, so instead we can use the ADF runtime setting –Djbo.debugoutput=console.  At runtime this options turns on instrumentation within the ADF BC layer, which among a lot of extra detail displayed in the log window, will show the actual SQL statement issued to the database, including the LOCK statement we're looking to confirm. Setting our locking mode to pessimistic, opening the Business Components Browser of a JSF page allowing us to edit a record, say the CHARGEABLE field within a BOOKINGS record where BOOKING_NO = 1206, upon editing the record see among others the following log entries: [421] Built select: 'SELECT BOOKING_NO, EVENT_NO, RESOURCE_CODE, CHARGEABLE, MADE_BY, QUANTITY, COST, STATUS, COMMENTS FROM BOOKINGS Bookings'[422] Executing LOCK...SELECT BOOKING_NO, EVENT_NO, RESOURCE_CODE, CHARGEABLE, MADE_BY, QUANTITY, COST, STATUS, COMMENTS FROM BOOKINGS Bookings WHERE BOOKING_NO=:1 FOR UPDATE NOWAIT[423] Where binding param 1: 1206  As can be seen on line 422, in fact a LOCK-FOR-UPDATE is indeed issued to the database.  Later when we commit the record we see: [441] OracleSQLBuilder: SAVEPOINT 'BO_SP'[442] OracleSQLBuilder Executing, Lock 1 DML on: BOOKINGS (Update)[443] UPDATE buf Bookings>#u SQLStmtBufLen: 210, actual=62[444] UPDATE BOOKINGS Bookings SET CHARGEABLE=:1 WHERE BOOKING_NO=:2[445] Update binding param 1: N[446] Where binding param 2: 1206[447] BookingsView1 notify COMMIT ... [448] _LOCAL_VIEW_USAGE_model_Bookings_ResourceTypesView1 notify COMMIT ... [449] EntityCache close prepared statement ....and as a result the changes are saved to the database, and the lock is released. Let's see what happens when we use the optimistic locking mode, this time to change the same BOOKINGS record CHARGEABLE column again.  As soon as we edit the record we see little activity in the logs, nothing to indicate any SQL statement, let alone a LOCK has been taken out on the row. However when we save our records by issuing a commit, the following is recorded in the logs: [509] OracleSQLBuilder: SAVEPOINT 'BO_SP'[510] OracleSQLBuilder Executing doEntitySelect on: BOOKINGS (true)[511] Built select: 'SELECT BOOKING_NO, EVENT_NO, RESOURCE_CODE, CHARGEABLE, MADE_BY, QUANTITY, COST, STATUS, COMMENTS FROM BOOKINGS Bookings'[512] Executing LOCK...SELECT BOOKING_NO, EVENT_NO, RESOURCE_CODE, CHARGEABLE, MADE_BY, QUANTITY, COST, STATUS, COMMENTS FROM BOOKINGS Bookings WHERE BOOKING_NO=:1 FOR UPDATE NOWAIT[513] Where binding param 1: 1205[514] OracleSQLBuilder Executing, Lock 2 DML on: BOOKINGS (Update)[515] UPDATE buf Bookings>#u SQLStmtBufLen: 210, actual=62[516] UPDATE BOOKINGS Bookings SET CHARGEABLE=:1 WHERE BOOKING_NO=:2[517] Update binding param 1: Y[518] Where binding param 2: 1205[519] BookingsView1 notify COMMIT ... [520] _LOCAL_VIEW_USAGE_model_Bookings_ResourceTypesView1 notify COMMIT ... [521] EntityCache close prepared statement Again even though we're seeing the midtier delay the LOCK statement until commit time, it is in fact occurring on line 412, and released as part of the commit issued on line 419.  Therefore with either optimistic or pessimistic locking a lock is indeed issued. Our conclusion at this point must be, unless there's the unlikely cause the LOCK statement is never really hitting the database, or the even less likely cause the database has a bug, then ADF does in fact take out a lock on the record before allowing the current user to update it.  So there's no way our phantom ADF developer could even modify the record if he tried without at least someone receiving a lock error. Hmm, we can only conclude the locking mode is a red herring and not the true cause of our problem.  Who is the phantom? At this point we'll need to conclude that the error message "JBO-25014: Another user has changed" is somehow legit, even though we don't understand yet what's causing it. This leads onto two further questions, how does ADF know another user has changed the row, and what's been changed anyway? To answer the first question, how does ADF know another user has changed the row, the Fusion Guide's section 4.10.11 How to Protect Against Losing Simultaneous Updated Data , that details the Entity Object Change-Indicator property, gives us the answer: At runtime the framework provides automatic "lost update" detection for entity objects to ensure that a user cannot unknowingly modify data that another user has updated and committed in the meantime. Typically, this check is performed by comparing the original values of each persistent entity attribute against the corresponding current column values in the database at the time the underlying row is locked. Before updating a row, the entity object verifies that the row to be updated is still consistent with the current state of the database.  The guide further suggests to make this solution more efficient: You can make the lost update detection more efficient by identifying any attributes of your entity whose values you know will be updated whenever the entity is modified. Typical candidates include a version number column or an updated date column in the row.....To detect whether the row has been modified since the user queried it in the most efficient way, select the Change Indicator option to compare only the change-indicator attribute values. We now know that ADF BC doesn't use the locking mechanism at all to protect the current user against updates, but rather it keeps a copy of the original record fetched, separate to the user changed version of the record, and it compares the original record against the one in the database when the lock is taken out.  If values don't match, be it the default compare-all-columns behaviour, or the more efficient Change Indicator mechanism, ADF BC will throw the JBO-25014 error. This leaves one last question.  Now we know the mechanism under which ADF identifies a changed row, what we don't know is what's changed and who changed it? The real culprit What's changed?  We know the record in the mid-tier has been changed by the user, however ADF doesn't use the changed record in the mid-tier to compare to the database record, but rather a copy of the original record before it was changed.  This leaves us to conclude the database record has changed, but how and by who? There are three potential causes: Database triggers The database trigger among other uses, can be configured to fire PLSQL code on a database table insert, update or delete.  In particular in an insert or update the trigger can override the value assigned to a particular column.  The trigger execution is actioned by the database on behalf of the user initiating the insert or update action. Why this causes the issue specific to our ADF use, is when we insert or update a record in the database via ADF, ADF keeps a copy of the record written to the database.  However the cached record is instantly out of date as the database triggers have modified the record that was actually written to the database.  Thus when we update the record we just inserted or updated for a second time to the database, ADF compares its original copy of the record to that in the database, and it detects the record has been changed – giving us JBO-25014. This is probably the most common cause of this problem. Default values A second reason this issue can occur is another database feature, default column values.  When creating a database table the schema designer can define default values for specific columns.  For example a CREATED_BY column could be set to SYSDATE, or a flag column to Y or N.  Default values are only used by the database when a user inserts a new record and the specific column is assigned NULL.  The database in this case will overwrite the column with the default value. As per the database trigger section, it then becomes apparent why ADF chokes on this feature, though it can only specifically occur in an insert-commit-update-commit scenario, not the update-commit-update-commit scenario. Instead of trigger views I must admit I haven't double checked this scenario but it seems plausible, that of the Oracle database's instead of trigger view (sometimes referred to as instead of views).  A view in the database is based on a query, and dependent on the queries complexity, may support insert, update and delete functionality to a limited degree.  In order to support fully insertable, updateable and deletable views, Oracle introduced the instead of view, that gives the view designer the ability to not only define the view query, but a set of programmatic PLSQL triggers where the developer can define their own logic for inserts, updates and deletes. While this provides the database programmer a very powerful feature, it can cause issues for our ADF application.  On inserting or updating a record in the instead of view, the record and it's data that goes in is not necessarily the data that comes out when ADF compares the records, as the view developer has the option to practically do anything with the incoming data, including throwing it away or pushing it to tables which aren't used by the view underlying query for fetching the data. Readers are at this point reminded that this article is specifically about how the JBO-25014 error occurs in the context of 1 developer on an isolated database.  The article is not considering how the error occurs in a production environment where there are multiple users who can cause this error in a legitimate fashion.  Assuming none of the above features are the cause of the problem, and optimistic locking is turned on (this error is not possible if pessimistic locking is the default mode *and* none of the previous causes are possible), JBO-25014 is quite feasible in a production ADF application if 2 users modify the same record. At this point under project timelines pressure, the obvious fix for developers is to drop both database triggers and default values from the underlying tables.  However we must be careful that these legacy constructs aren't used and assumed to be in place by other legacy systems.  Dropping the database triggers or default value that the existing Oracle Forms  applications assumes and requires to be in place could cause unexpected behaviour and bugs in the Forms application.  Proficient software engineers would recognize such a change may require a partial or full regression test of the existing legacy system, a potentially costly and timely exercise, not ideal. Solving the mystery once and for all Luckily ADF has built in functionality to deal with this issue, though it's not a surprise, as Oracle as the author of ADF also built the database, and are fully aware of the Oracle database's feature set.  At the Entity Object attribute level, the Refresh After Insert and Refresh After Update properties.  Simply selecting these instructs ADF BC after inserting or updating a record to the database, to expect the database to modify the said attributes, and read a copy of the changed attributes back into its cached mid-tier record.  Thus next time the developer modifies the current record, the comparison between the mid-tier record and the database record match, and JBO-25014: Another user has changed" is no longer an issue. [Post edit - as per the comment from Oracle's Steven Davelaar below, as he correctly points out the above solution will not work for instead-of-triggers views as it relies on SQL RETURNING clause which is incompatible with this type of view] Alternatively you can set the Change Indicator on one of the attributes.  This will work as long as the relating column for the attribute in the database itself isn't inadvertently updated.  In turn you're possibly just masking the issue rather than solving it, because if another developer turns the Change Indicator back on the original issue will return.

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  • Is there any difference between null and 0 when assigning to pointers in unsafe code?

    - by Eloff
    This may seem odd, but in C (size_t)(void*)0 == 0 is not guaranteed by the language spec. Compilers are allowed to use any value they want for null (although they almost always use 0.) In C#, you can assign null or (T*)0 to a pointer in unsafe code. Is there any difference? (long)(void*)0 == 0 (guaranteed or not? put another way: IntPtr.Zero.ToInt64() == 0) MSDN has this to say about IntPtr.Zero: "The value of this field is not equivalent to null." Well if you want to be compatible with C code, that makes a lot of sense - it'd be worthless for interop if it didn't convert to a C null pointer. But I want to know if IntPtr.Zero.ToInt64() == 0 which may be possible, even if internally IntPtr.Zero is some other value (the CLR may or may not convert null to 0 in the cast operation) Not a duplicate of this question

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  • Passing a SAFEARRAY from C# to COM

    - by SlavaGu
    I use 3rd party COM to find faces in a picture. One of the methods has the following signature, from SDK: long FindMultipleFaces( IUnknown* pIDibImage, VARIANTARG* FacePositionArray ); Parameters: pIDibImage[in] - The image to search. FacePositionArray[out]- The array of FacePosition2 objects into which face information is placed. This array is in a safe array (VARIANT) of type VT_UNKNOWN. The size of the array dictates the maximum number of faces for which to search. which translates into the following C# method signature (from metadata): int FindMultipleFaces(object pIDibImage, ref object pIFacePositions); Being optimistic I call it the following way but get an exception that the memory is corrupt. The exception is thrown only when a face is present in the image. FacePosition2[] facePositions = new FacePosition2[10]; object positions = facePositions; int faceCount = FaceLocator.FindMultipleFaces(dibImage, ref positions); What's the right way to pass SAFEARRAY to unmanaged code?

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  • javascript/php - shorten string to fit into a certain # of lines

    - by Mala
    Hi I have a string that must fit into a box, and must be at most 3 lines long. To shorten it, I plan to truncate it and end it with '...'. I could shorten it to a certain # of characters but if i make it look good with "wwwwwwwww [...] wwww" it won't look right with "iiiiiiiiiii [...] iiii". Is there some way I can shorten it by how much space the string would take up, as opposed to how many characters there are in a string without using a fixed-width font? Ideally I'd like to do this server-side (php) but recognize that actual character width stuff is far more likely to be feasible client-side (JS / jQuery) Mala ps. Please no "simply create an image of '...' and overlay it over the end of the line" hacks or similar - I actually want to shorten the string to the appropriate length

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  • Sync Framework Peer Data Sharing Unable to Catch Conflicts, Source Provider Alwasy wins!

    - by Belliez
    Hi, I am using SQL Server 2008 and the WebSharingAppDemo-SqlProviderEndToEnd sample and this is almost perfect for my needs however I am unable to detect conflicts. By default ConflictResolutionPolicy is set to ApplicationDefined. I have tried setting the ResolutionPolicy to SourceWins, DestinationWins or ApplicationDefined and I always get the same results? The Destination Provider Proxy (Peer) always wins? Can someone please provide a sample of how I can detect a conflict and act upon it or point me in the right direction where I can start to look. I am not sure what to do and where I can create events for detecting collisions. Been staring at this too long now and going around in circles! Thanks in advanced. Paul

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  • Make Custom Project template in Eclipse IDE

    - by Mohit Deshpande
    I have been using Eclipse IDE for a long time. Its a really great IDE for Java/C/C++ (and other languages with its THOUSANDS of plugins). Every once in a while, I get the need for creating a Javax interface. To do this normally, I would setup the new java project then add what I need. But, wouldn't it be nice if I could just make a template project to automatically include the code for the files. How would I go about doing this? It it even possible? The Eclipse CDT can make a new project type. So can the Google ADT and Google App engine. So I would imagine it is possible. But how?

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  • Tracking fitness in a genetic algorithm

    - by Chuck Vose
    I'm still hacking on my old ruby for the undead post (I know, I know, stop trying to bring the post back from the dead Chuck). But the code has gotten a little out of hand and now I'm working on a genetic algorithm to create the ultimate battle of living and dead with the fitness being how long the battle lasts. So, I've got the basics of it down; how to adjust attributes of the game and how to acquire the fitness of a solution, what I can't figure out is how to store the fitness so that I know when I've tried a combination before. I've not been able to find much genetic code to look at let alone code that I can read well enough to tell what's going on. Does anyone have an idea how this is normally done or just simply an algorithm that could help point me in the right direction?

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