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  • Why is my mdadm raid-1 recovery so slow?

    - by dimmer
    On a system I'm running Ubuntu 10.04. My raid-1 restore started out fast but quickly became ridiculously slow (at this rate the restore will take 150 days!): dimmer@paimon:~$ cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : active raid1 sdc1[2] sdb1[1] 1953513408 blocks [2/1] [_U] [====>................] recovery = 24.4% (477497344/1953513408) finish=217368.0min speed=113K/sec unused devices: <none> Eventhough I have set the kernel variables to reasonably quick values: dimmer@paimon:~$ cat /proc/sys/dev/raid/speed_limit_min 1000000 dimmer@paimon:~$ cat /proc/sys/dev/raid/speed_limit_max 100000000 I am using 2 2.0TB Western Digital Hard Disks, WDC WD20EARS-00M and WDC WD20EARS-00J. I believe they have been partitioned such that their sectors are aligned. dimmer@paimon:/sys$ sudo parted /dev/sdb GNU Parted 2.2 Using /dev/sdb Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) p Model: ATA WDC WD20EARS-00M (scsi) Disk /dev/sdb: 2000GB Sector size (logical/physical): 512B/512B Partition Table: gpt Number Start End Size File system Name Flags 1 1049kB 2000GB 2000GB ext4 (parted) unit s (parted) p Number Start End Size File system Name Flags 1 2048s 3907028991s 3907026944s ext4 (parted) q dimmer@paimon:/sys$ sudo parted /dev/sdc GNU Parted 2.2 Using /dev/sdc Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) p Model: ATA WDC WD20EARS-00J (scsi) Disk /dev/sdc: 2000GB Sector size (logical/physical): 512B/4096B Partition Table: gpt Number Start End Size File system Name Flags 1 1049kB 2000GB 2000GB ext4 I am beginning to think that I have a hardware problem, otherwise I can't imagine why the mdadm restore should be so slow. I have done a benchmark on /dev/sdc using Ubuntu's disk utility GUI app, and the results looked normal so I know that sdc has the capability to write faster than this. I also had the same problem on a similar WD drive that I RMAd because of bad sectors. I suppose it's possible they sent me a replacement with bad sectors too, although there are no SMART values showing them yet. Any ideas? Thanks. As requested, output of top sorted by cpu usage (notice there is ~0 cpu usage). iowait is also zero which seems strange: top - 11:35:13 up 2 days, 9:40, 3 users, load average: 2.87, 2.58, 2.30 Tasks: 142 total, 1 running, 141 sleeping, 0 stopped, 0 zombie Cpu(s): 0.0%us, 0.2%sy, 0.0%ni, 99.8%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 3096304k total, 1482164k used, 1614140k free, 617672k buffers Swap: 1526132k total, 0k used, 1526132k free, 535416k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 45 root 20 0 0 0 0 S 0 0.0 2:17.02 scsi_eh_0 1 root 20 0 2808 1752 1204 S 0 0.1 0:00.46 init 2 root 20 0 0 0 0 S 0 0.0 0:00.00 kthreadd 3 root RT 0 0 0 0 S 0 0.0 0:00.02 migration/0 4 root 20 0 0 0 0 S 0 0.0 0:00.17 ksoftirqd/0 5 root RT 0 0 0 0 S 0 0.0 0:00.00 watchdog/0 6 root RT 0 0 0 0 S 0 0.0 0:00.02 migration/1 ... dmesg errors, definitely looking like hardware: [202884.000157] ata5.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen [202884.007015] ata5.00: failed command: FLUSH CACHE EXT [202884.013728] ata5.00: cmd ea/00:00:00:00:00/00:00:00:00:00/a0 tag 0 [202884.013730] res 40/00:00:ff:59:2e/00:00:35:00:00/e0 Emask 0x4 (timeout) [202884.033667] ata5.00: status: { DRDY } [202884.040329] ata5: hard resetting link [202889.400050] ata5: link is slow to respond, please be patient (ready=0) [202894.048087] ata5: COMRESET failed (errno=-16) [202894.054663] ata5: hard resetting link [202899.412049] ata5: link is slow to respond, please be patient (ready=0) [202904.060107] ata5: COMRESET failed (errno=-16) [202904.066646] ata5: hard resetting link [202905.840056] ata5: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [202905.849178] ata5.00: configured for UDMA/133 [202905.849188] ata5: EH complete [203899.000292] ata5.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen [203899.007096] ata5.00: failed command: IDENTIFY DEVICE [203899.013841] ata5.00: cmd ec/00:01:00:00:00/00:00:00:00:00/00 tag 0 pio 512 in [203899.013843] res 40/00:00:ff:f9:f6/00:00:38:00:00/e0 Emask 0x4 (timeout) [203899.041232] ata5.00: status: { DRDY } [203899.048133] ata5: hard resetting link [203899.816134] ata5: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [203899.826062] ata5.00: configured for UDMA/133 [203899.826079] ata5: EH complete [204375.000200] ata5.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen [204375.007421] ata5.00: failed command: IDENTIFY DEVICE [204375.014799] ata5.00: cmd ec/00:01:00:00:00/00:00:00:00:00/00 tag 0 pio 512 in [204375.014800] res 40/00:00:ff:0c:0f/00:00:39:00:00/e0 Emask 0x4 (timeout) [204375.044374] ata5.00: status: { DRDY } [204375.051842] ata5: hard resetting link [204380.408049] ata5: link is slow to respond, please be patient (ready=0) [204384.440076] ata5: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [204384.449938] ata5.00: configured for UDMA/133 [204384.449955] ata5: EH complete [204395.988135] ata5.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen [204395.988140] ata5.00: failed command: IDENTIFY DEVICE [204395.988147] ata5.00: cmd ec/00:01:00:00:00/00:00:00:00:00/00 tag 0 pio 512 in [204395.988149] res 40/00:00:ff:0c:0f/00:00:39:00:00/e0 Emask 0x4 (timeout) [204395.988151] ata5.00: status: { DRDY } [204395.988156] ata5: hard resetting link [204399.320075] ata5: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [204399.330487] ata5.00: configured for UDMA/133 [204399.330503] ata5: EH complete

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  • Create PDF from HTML page with formatting retained in PDF in ASP.Net

    - by Vishal Avhad
    I am trying to convert an HTML page to a PDF using iTextSharp.dll in ASP.Net. I am able to convert the contents to my PDF , but the problem is that the Formatting of HTML page (which is inline) get removed from my PDF created. For instance I have the following code block to be formatted from my HTML page to PDF. <table style="width:90%; float:left; background:#dddddd; padding:15px; border:1px solid #000; color:#000;"><tr><td style="text-transform:uppercase; font-size:14px;font-weight:bold;">SPECIAL DELIVERY FOR:</td></tr><tr><td style="padding-left:40px; font-size:12px; color:#4e4e4e;">Name: #CustomerName# <br /><br /><label> <b>Date: #CreatedOn# </b></label><br /> </td></tr> </table> I have to format my PDF with much more HTML codes like this. I have used the Stylesheet class also, but that was not much of help.

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  • Vertically Merge Multiple Tables in MySQL by Joint Primary Key

    - by world
    Hello, I'll attempt to make my question as clear as possible. I'm fairly unexperienced with SQL, only know the really basic queries. In order to have a better idea I'd been reading the MySQL manual for the past few days, but I couldn't really find a concrete solution and my needs are quite specific. I've got 3 MySQL MyISAM tables: table1, table2 and table3. Each table has an ID column (ID, ID2, ID3 respectively), and different data columns. For example table1 has [ID, Name, Birthday, Status, ...] columns, table2 has [ID2, Country, Zip, ...], table3 has [ID3, Source, Phone, ...] you get the idea. The ID, ID2, ID3 columns are common to all three tables... if there's an ID value in table1 it will also appear in table2 and table3. The number of rows in these tables is identical, about 10m rows in each table. What I'd like to do is create a new table that contains (most of) the columns of all three tables and merge them into it. The dates, for instance, must be converted because right now they're in VARCHAR YYYYMMDD format. Reading the MySQL manual I figured STR_TO_DATE() would do the job, but I don't know how to write the query itself in the first place so I have no idea how to integrate the date conversion. So basically, after I create the new table (which I do know how to do), how can I merge the three tables into it, integrating into the query the date conversion?

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  • Change select's class based on selected option's class

    - by Alasdair
    I have a page that contains numerous <select> elements. What I'm trying to achieve is to ensure that if a <select>'s selected <option> has a class called italic, then the <select> then has the italic class added (i.e. jQuery.addClass('italic')). If it doesn't, then the italic class is removed from the <select> to ensure other <option> elements are displayed correctly (i.e. jQuery.removeClass('italic')). What I'm noticing with most of my attempts is that either all the <select> have the italic class or that the italic class isn't being removed accordingly. Since I'm unsure my choice in selectors and callback logic are particularly sound or good practice in this instance (as I've been frustratingly trying to make it work) I've decided not to include the code I used in previous attempts. Instead, refer to this small HTML & CSS example: .italic { font-style: italic; } <select id="foo" name="foo" size="1" <option value="NA" selected="selected" - Select - </option <option value="1"Bar</option <option value="2"Fu</option <option value="3"Baz</option </select Also, I am aware that not all browsers support CSS styling of <select> and <option>. The related J2EE web application will only ever be accessed via Firefox under a controlled environment.

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  • use startActivityForResult from non-activity

    - by rayman
    Hi, I have MainActivity which is an Activity and other class(which is a simple java class), we`ll call it "SimpleClass". now i want to run from that class the command startActivityForResult. now i though that i could pass that class(SimpleClass), only MainActivity's context, problem is that, u cant run context.startActivityForResult(...); so the only way making SimpleClass to use 'startActivityForResult; is to pass the reference of MainActivity as an Activity variable to the SimpleClass something like that: inside the MainActivity class i create the instance of SimpleClass this way: SimpleClass simpleClass=new SimpleClass(MainActivity.this); now this is how SimpleClass looks like: public Class SimpleClass { Activity myMainActivity; public SimpleClass(Activity mainActivity) { super(); this.myMainActivity=mainActivity; } .... } public void someMethod(...) { myMainActivity.startActivityForResult(...); } now its working, but isnt a proper way of doing this? I`am afraid i could have some memory leaks in the future. thanks. ray.

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  • Populate textboxes with XmlNode.Attributes

    - by Doug
    I have Data.xml: <?xml version="1.0" encoding="utf-8" ?> <data> <album> <slide title="Autum Leaves" description="Leaves from the fall of 1986" source="images/Autumn Leaves.jpg" thumbnail="images/Autumn Leaves_thumb.jpg" /> <slide title="Creek" description="Creek in Alaska" source="images/Creek.jpg" thumbnail="images/Creek_thumb.jpg" /> </album> </data> I'd like to be able to edit the attributes of each Slide node via GridView (that has a "Select" column added.) And so far I have: protected void GridView1_SelectedIndexChanged(object sender, EventArgs e) { int selectedIndex = GridView1.SelectedIndex; LoadXmlData(selectedIndex); } private void LoadXmlData(int selectedIndex) { XmlDocument xmldoc = new XmlDocument(); xmldoc.Load(MapPath(@"..\photo_gallery\Data.xml")); XmlNodeList nodelist = xmldoc.DocumentElement.ChildNodes; XmlNode xmlnode = nodelist.Item(selectedIndex); titleTextBox.Text = xmlnode.Attributes["title"].InnerText; descriptionTextBox.Text = xmlnode.Attributes["description"].InnerText; sourceTextBox.Text = xmlnode.Attributes["source"].InnerText; thumbTextBox.Text = xmlnode.Attributes["thumbnail"].InnerText; } The code for LoadXmlData is just a guess on my part - I'm new to working with xml in this way. I'd like have the user to slected the row from the gridview, then populate a set of text boxes with each slide attributed for updating back to the Data.xml file. The error I'm getting is Object reference not set to an instance of an object" at the line: titleTextBox.Text = xmlnode.Attributes["@title"].InnerText; so I'm not reaching the attribute "title" of the slide node. Thanks for any ideas you may have.

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  • generating images with php based on css3 gradient settings?

    - by thrice801
    Hi, Does anyone know if there is a php library, or if there isnt, have any input on how one would go about generating an image via php, from basic HTML element input settings, and CSS 3 gradient parameters. To give an example on why this would be useful, I have found as of a couple days ago, that laying out the wireframe for a webpage using basic Css3 gradient styling speeds up my design and development time by, well, alot. I cant design from photoshop, Ill spend hours tweaking stupid little things that only lead to me tweaking more stupid little things to compensate for stupid little changes. -- So, I had an epiphany to stop using photoshop until the end, and just focus on the main styling of elements, text-shadow, and borders for highlights, and I feel I am able to make super clean, more focused layout by being more restricted to the basics of graphic design with just css. Anyways, so Im planning on after I have the layouts done, to then recreate the graphics in photoshop, so that every browser is able to render the images. This wont take long, but as far as repeating it goes, if I could just do it with PHP, that would be incredible. For instance, take this style for example, which renders a clean looking ipad/pod ish menu/button gradient. [code] background: -moz-linear-gradient(top, #808080, #454545 50%, #313131 51%, #333333); background: -webkit-gradient(linear, left top, left bottom, color-stop(0, #808080), color-stop(.5, #454545), color-stop(.5, #313131), to(#333333));[/code] Basically what Im looking to do is take one or more inputs that control rendering the image as you see there. Take a width and a height input, and then render the image gradient accordingly, so I can save it, upload it and then use it in my designs. So ya, I know PHP has some image generation capabilities but I dont know to what extent, any input on the most effective way to go about doing this or whether it already exists, would be appreciated!

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  • How can I create object in abstract class without having knowledge of implementation?

    - by Greg
    Hi, Is there a way to implement the "CreateNode" method in my library abstract below? Or can this only be done in client code outside the library? I current get the error "Cannot create an instance of the abstract class or interface 'ToplogyLibrary.AbstractNode" public abstract class AbstractTopology<T> { // Properties public Dictionary<T, AbstractNode<T>> Nodes { get; private set; } public List<AbstractRelationship<T>> Relationships { get; private set; } // Constructors protected AbstractTopology() { Nodes = new Dictionary<T, AbstractNode<T>>(); } // Methods public AbstractNode<T> CreateNode() { var node = new AbstractNode<T>(); // ** Does not work ** Nodes.Add(node.Key, node); } } } public abstract class AbstractNode<T> { public T Key { get; set; } } public abstract class AbstractRelationship<T> { public AbstractNode<T> Parent { get; set; } public AbstractNode<T> Child { get; set; } }

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  • Exception thrown while accessing HTML DataTable in backing bean

    - by Denzil
    Hi folks, I am building a simple application in JSF with the CrUD functionality. I am trying to implement edit functionality using the tomahawk component .I am unable to retrieve the selected row in my backing bean. Here's my JSP file snip: <t:dataTable id="data" binding="#{selectOneRowList.dataTable}" styleClass="scrollerTable" headerClass="standardTable_Header" footerClass="standardTable_Header" rowClasses="standardTable_Row1,standardTable_Row2" columnClasses="standardTable_Column,standardTable_ColumnCentered,standardTable_Column" var="car" value="#{selectOneRowList.list}" sortColumn="#{selectOneRowList.sortColumn}" sortAscending="#{selectOneRowList.sortAscending}" preserveDataModel="false" preserveSort="true" preserveRowStates="true" rows="10" > <h:column> <f:facet name="header"> <h:outputText value="Select"/> </f:facet> <t:selectOneRow groupName="selection" id="hugo" value="#{selectOneRowList.selectedRowIndex}" onchange="submit();" immediate="true" valueChangeListener="#{selectOneRowList.processRowSelection}"/> </h:column> <h:column> <f:facet name="header"> </f:facet> <h:outputText value="#{car.id}" /> </h:column> <h:column> <f:facet name="header"> <h:outputText value="Cars" /> </f:facet> <h:outputText value="#{car.type}" /> </h:column> <t:column sortable="true"> <f:facet name="header"> <h:outputText value="Color" /> </f:facet> <h:outputText value="#{car.color}" /> </t:column> </t:dataTable> Here's my backing bean SelectOneRowList.java : public void editCar(ActionEvent event) { System.out.println("Row number ## " + _selectedRowIndex.toString() + " selected!"); System.out.println("Datatable ::"+ dataTable); System.out.println("Row Count ::" + dataTable.getRowCount()); dataItem = (SimpleCar) getDataTable().getRowData(); //selectedCar = (SimpleCar) _list.get(Integer.parseInt(_selectedRowIndex.toString())); selectedCar = (SimpleCar) dataTable.getRowData(); System.out.println(dataTable.getRowData()); } My DTO{Data Transfer Object} which is SimpleCar.java contains the variables ID, type, color and their respective setters/getters. The dataItem variable is of type "SimpleCar". The dataTable is of type HTMLDataTable. I am able to get the the first 3 SOP's but the 4th SOP isn't printed. I receive the following exception on the server : javax.faces.el.EvaluationException: Exception while invoking expression #{selectOneRowList.editCar} org.apache.myfaces.el.MethodBindingImpl.invoke(MethodBindingImpl.java:156) javax.faces.component.UICommand.broadcast(UICommand.java:89) javax.faces.component.UIViewRoot._broadcastForPhase(UIViewRoot.java:97) javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:171) org.apache.myfaces.lifecycle.InvokeApplicationExecutor.execute(InvokeApplicationExecutor.java:32) org.apache.myfaces.lifecycle.LifecycleImpl.executePhase(LifecycleImpl.java:95) org.apache.myfaces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:70) javax.faces.webapp.FacesServlet.service(FacesServlet.java:139) org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:341) On click of the edit button the editCar method in my backing bean is invoked. I need to get the data of the selected row in my backing bean. Why is the exception occurring ? The above example is taken from the tomawhawk examples WAR distributed on the website. I have gone through many links including the ones on BalusC but none of them have helped. Regards,

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  • Disposing underlying object from finalizer in an immutable object

    - by Juan Luis Soldi
    I'm trying to wrap around Awesomium and make it look to the rest of my code as close as possible to NET's WebBrowser since this is for an existing application that already uses the WebBrowser. In this library, there is a class called JSObject which represents a javascript object. You can get one of this, for instance, by calling the ExecuteJavascriptWithResult method of the WebView class. If you'd call it like myWebView.ExecuteJavascriptWithResult("document", string.Empty).ToObject(), then you'd get a JSObject that represents the document. I'm writing an immutable class (it's only field is a readonly JSObject object) called JSObjectWrap that wraps around JSObject which I want to use as base class for other classes that would emulate .NET classes such as HtmlElement and HtmlDocument. Now, these classes don't implement Dispose, but JSObject does. What I first thought was to call the underlying JSObject's Dispose method in my JSObjectWrap's finalizer (instead of having JSObjectWrap implement Dispose) so that the rest of my code can stay the way it is (instead of having to add using's everywhere and make sure every JSObjectWrap is being properly disposed). But I just realized if more than two JSObjectWrap's have the same underlying JSObject and one of them gets finalized this will mess up the other JSObjectWrap. So now I'm thinking maybe I should keep a static Dictionary of JSObjects and keep count of how many of each of them are being referenced by a JSObjectWrap but this sounds messy and I think could cause major performance issues. Since this sounds to me like a common pattern I wonder if anyone else has a better idea.

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  • Java performance issue

    - by Colby77
    Hi, I've got a question related to java performance and method execution. In my app there are a lot of place where I have to validate some parameter, so I've written a Validator class and put all the validation methods into it. Here is an example: public class NumberValidator { public static short shortValidator(String s) throws ValidationException{ try{ short sh = Short.parseShort(s); if(sh < 1){ throw new ValidationException(); } return sh; }catch (Exception e) { throw new ValidationException("The parameter is wrong!"); } } ... But I'm thinking about that. Is this OK? It's OO and modularized, but - considering performance - is it a good idea? What if I had awful lot of invocation at the same time? The snippet above is short and fast, but there are some methods that take more time. What happens when there are a lot of calling to a static method or an instance method in the same class and the method is not synchronized? All the calling methods have to fall in line and the JVM executes them sequentially? Is it a good idea to have some class that are identical to the above-mentioned and randomly call their identical methods? I think it is not, because "Don't repeat yourself " and "Duplication is Evil" etc. But what about performance? Thanks is advance.

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  • Too many open files in one of my java routine.

    - by Irfan Zulfiqar
    I have a multithreaded code that has to generated a set of objects and write them to a file. When I run it I sometime get "Too many open files" message in Exception. I have checked the code to make sure that all the file streams are being closed properly. Here is the stack trace. When I do ulimit -a, open files allowed is set to 1024. We think increasing this number is not a viable option / solution. [java] java.io.FileNotFoundException: /export/event_1_0.dtd (Too many open files) [java] at java.io.FileInputStream.open(Native Method) [java] at java.io.FileInputStream.<init>(FileInputStream.java:106) [java] at java.io.FileInputStream.<init>(FileInputStream.java:66) [java] at sun.net.www.protocol.file.FileURLConnection.connect(FileURLConnection.java:70) [java] at sun.net.www.protocol.file.FileURLConnection.getInputStream(FileURLConnection.java:161) [java] at java.net.URL.openStream(URL.java:1010) Now what we have identified so far by looking closely at the list of open files is that the VM is opening same class file multiple times. /export/BaseEvent.class 236 /export/EventType1BaseEvent.class 60 /export/EventType2BaseEvent.class 48 /export/EventType2.class 30 /export/EventType1.class 14 Where BaseEvent is partent of all the classes and EventType1 ant EventType2 inherits EventType1BaseEvent and EventType2BaseEvent respectively. Why would a class loader load the same class file 200+ times. It seems it is opening up the base class as many time it create any child instance. Is this normal? Can it be handler any other way apart from increasing the number of open files?

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  • Making a query result equal to zero when a condition is null

    - by John
    Hello, I believe the query below should work. However, when I run it, the results are blank. I think this is happening since for now, the table "comment" is empty. So there is no instance where s.submissionid = c.submissionid. I would like to have the query below to work even if there if no s.submissionid that equals a c.submissionid. In this case, I would like countComments to equal zero. How can I do this? Thanks in advance, John $sqlStr = "SELECT s.loginid, s.submissionid s.title, s.url, s.displayurl, l.username, count(c.comment) AS countComments FROM submission AS s, login AS l, comment AS c, WHERE s.loginid = l.loginid AND s.submissionid = c.submissionid GROUP BY s.loginid, s.submissionid s.title, s.url, s.displayurl, l.username ORDER BY s.datesubmitted DESC LIMIT 10"; $result = mysql_query($sqlStr); $arr = array(); echo "<table class=\"samplesrec\">"; while ($row = mysql_fetch_array($result)) { echo '<tr>'; echo '<td class="sitename1"><a href="http://www.'.$row["url"].'">'.$row["title"].'</a></td>'; echo '</tr>'; echo '<tr>'; echo '<td class="sitename2"><a href="http://www...com/sandbox/members/index.php?profile='.$row["username"].'">'.$row["username"].'</a><a href="http://www...com/sandbox/comments/index.php?submission='.$row["title"].'">'.$row["countComments"].'</a></td>'; echo '</tr>'; } echo "</table>";

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  • error detection/correction/recovery in serial protocols

    - by Jason S
    I have some designing to do for a serial protocol and am running into some questions that I figure must have been considered elsewhere. So I'm wondering if there are some recommendations for best practices in designing serial protocols. (Please either state a fact that is easily verifiable, or cite a reputable source if you make a claim.) General recommendations for websites/books are also welcome. In particular I have to deal with issues like parsing a stream of bytes into packets verifying a packet is correct (easy with a CRC, for instance) identifying reasonable types of errors that can occur (e.g. in a point-to-point serial stream, sporadic single bit errors, and dropped series of bytes, are both likely, but extra phantom bytes are unlikely; whereas with a record stored in flash memory or on a disk drive the types of errors that predominate are different) error correction or recovery (if I detect an error in a packet, can I correct it? If not, can I resync to the boundary of the next packet?) how to make variable-length packets robust to error correction / recovery. Any suggestions?

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  • Error handling in PHP

    - by Industrial
    Hi guys, We're building a PHP app based on Good old MVC (codeigniter framework) and have run into trouble with a massive chained action that consists of multiple model calls, that together is a part of a big transaction to the database. We want to be able to do a list of actions and get a status report of each one back from the function, whatever the outcome is. Our first initial idea was to utilize the exceptions of PHP5, but since we want to also need status messages that doesnt break the execution of the script, this was our solution that we came up with. It goes a little something like this: $sku = $this->addSku( $name ); if ($sku === false) { $status[] = 'Something gone terrible wrong'; $this->db->trans_rollback(); return $status; } $image= $this->addImage( $filename); if ($image=== false) { $error[] = 'Image could not be uploaded, check filesize'; $this->db->trans_rollback(); return $status; } Our controller looks like this: $var = $this->products->addProductGroup($array); if (is_array($var)) { foreach ($var as $error) { echo $error . '<br />'; } } It appears to be a very fragile solution to do what we need, but it's neither scalable, neither effective when compared to pure PHP exceptions for instance. Is this really the way that this kind of stuff generally is handled in MVC based apps? Thanks!

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  • Creating circular generic references

    - by M. Jessup
    I am writing an application to do some distributed calculations in a peer to peer network. In defining the network I have two class the P2PNetwork and P2PClient. I want these to be generic and so have the definitions of: P2PNetwork<T extends P2PClient<? extends P2PNetwork<T>>> P2PClient<T extends P2PNetwork<? extends T>> with P2PClient defining a method of setNetwork(T network). What I am hoping to describe with this code is: A P2PNetwork is constituted of clients of a certain type A P2PClient may only belong to a network whose clients consist of the same type as this client (the circular-reference) This seems correct to me but if I try to create a non-generic version such as MyP2PClient<MyP2PNetwork<? extends MyP2PClient>> myClient; and other variants I receive numerous errors from the compiler. So my questions are as follows: Is a generic circular reference even possible (I have never seen anything explicitly forbidding it)? Is the above generic definition a correct definition of such a circular relationship? If it is valid, is it the "correct" way to describe such a relationship (i.e. is there another valid definition, which is stylistically preferred)? How would I properly define a non-generic instance of a Client and Server given the proper generic definition?

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  • Authentication Error when accessing Sharepoint list via web service

    - by Joe
    I wrote a windows service a few months ago that would ping a Sharepoint list using _vti_bin/lists.asmx function GetListItemChanges. It was working fine until a few weeks ago when my company upgraded our Sharepoint instance to SP1. Now whenever my service attempts to access Sharepoint I receive an 401.1 authentication error: Error: You are not authorized to view this page You do not have permission to view this directory or page using the credentials that you supplied. Please try the following: Contact the Web site administrator if you believe you should be able to view this directory or page. HTTP Error 401.1 - Unauthorized: Access is denied due to invalid credentials. Internet Information Services (IIS) I have checked and my privileges on the site have not changed. here is the code In which I call the list: Lists listsService = new Lists(); listsService.Credentials = new NetworkCredential("UserName", "Password", "domain"); Result = listsService.GetListItemChanges("List name", null, dTime.ToString(), null); It has also been brought to my attention that basic authentication may have been disabled on our farm. I don't believe I'm using that but I may be mistaken.

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  • How to store dynamic references to parts of a text

    - by Antoine L
    In fact, my question concerns an algorithm. I need to be able to attach annotations to certain parts of a text, like a word or a group of words. The first thing that came to me to do so is to store the position of this part (indexes) in the text. For instance, in the text 'The quick brown fox jumps over the lazy dog', I'd like to attach an annotation to 'quick brown fox', so the indexes of the annotation would be 4 - 14. But since the text is editable (other annotations could provoke a modification from text's author), the annoted part is likely to move (the indexes could change). In fact, I don't know how to update the indexes of the annoted part. What if the text becomes 'Everyday, the quick brown fox jumps over the lazy dog' ? I guess I have to watch every change of the text in the front-end application ? The front-end part of the application will be HTML with Javascript. I will be using PHP to develop the back-end part and every text and annotation will be stored in a database.

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  • Django Image Upload: IOErrno2 Could not find path -- and yet it's saving the image there anyway?

    - by Rob
    I have an issue where the local version of django is handling image upload as expected but my server is not. Note: I am using a Django Container on MediaTemple.net (grid server) Here is my code. def view_settings(request): <snip> if request.POST: success_msgs = () mForm = MainProfileForm(request.POST, request.FILES, instance = mProfile) pForm = ChangePasswordForm(request.POST) eForm = ChangeEmailForm(request.POST) if mForm.is_valid(): m = mForm.save(commit = False) if mForm.cleaned_data['avatar']: m.avatar = upload_photo(request.FILES['avatar'], settings.AVATAR_SAVE_LOCATION) m.save() success_msgs += ('profile pictured updated',) <snip> def upload_photo(data,saveLocation): savePath = os.path.join(settings.MEDIA_ROOT, saveLocation, data.name) destination = open(savePath, 'wb+') for chunk in data.chunks(): destination.write(chunk) destination.close() return os.path.join(saveLocation, data.name) Here's where it gets whacky and I was hoping someone could shed a light on this error, because either a) it's the wrong error code, or b) something is happening with the file before it's completely handled. To recap, the file was actually uploaded to the server in the intended directory - and yet this err msg continues to persist. IOError at /user/settings [Errno 2] No such file or directory: u'/home/user66666/domains/example.com/html/media/images/avatars/DSC03852.JPG' Environment: Request Method: POST Request URL: http://111.111.111.111:2011/user/settings Django Version: 1.0.2 final Python Version: 2.4.4 Installed Applications: ['django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.sites', 'ctrlme', 'usertools', 'easy_thumbnails'] Installed Middleware: ('django.middleware.common.CommonMiddleware', 'django.contrib.sessions.middleware.SessionMiddleware', 'django.contrib.auth.middleware.AuthenticationMiddleware') Traceback: File "/home/user6666/containers/django/leonidas/usertools/views.py" in view_settings m.avatar = upload_photo(request.FILES['avatar'], settings.AVATAR_SAVE_LOCATION) File "/home/user666666/containers/django/leonidas/usertools/functions.py" in upload_photo destination = open(savePath, 'wb+')

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  • Does isEmpty method in Stream evaluate the whole Stream?

    - by abhin4v
    In Scala, does calling isEmtpy method on an instance of Stream class cause the stream to be evaluated completely? My code is like this: import Stream.cons private val odds: Stream[Int] = cons(3, odds.map(_ + 2)) private val primes: Stream[Int] = cons(2, odds filter isPrime) private def isPrime(n: Int): Boolean = n match { case 1 => false case 2 => true case 3 => true case 5 => true case 7 => true case x if n % 3 == 0 => false case x if n % 5 == 0 => false case x if n % 7 == 0 => false case x if (x + 1) % 6 == 0 || (x - 1) % 6 == 0 => true case x => primeDivisors(x) isEmpty } import Math.{sqrt, ceil} private def primeDivisors(n: Int) = primes takeWhile { _ <= ceil(sqrt(n))} filter {n % _ == 0 } So, does the call to isEmpty on the line case x => primeDivisors(x) isEmpty cause all the prime divisors to be evaluated or only the first one?

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  • How to load JPG file into NSBitmapImageRep?

    - by Adam
    Objective-C / Cocoa: I need to load the image from a JPG file into a two dimensional array so that I can access each pixel. I am trying (unsuccessfully) to load the image into a NSBitmapImageRep. I have tried several variations on the following two lines of code: NSString *filePath = [NSString stringWithFormat: @"%@%@",@"/Users/adam/Documents/phoneimages/", [outLabel stringValue]]; //this coming from a window control NSImageRep *controlBitmap = [[NSImageRep alloc] imageRepWithContentsOfFile:filePath]; With the code shown, I get a runtime error: -[NSImageRep imageRepWithContentsOfFile:]: unrecognized selector sent to instance 0x100147070. I have tried replacing the second line of code with: NSImage *controlImage = [[NSImage alloc] initWithContentsOfFile:filePath]; NSBitmapImageRep *controlBitmap = [[NSBitmapImageRep alloc] initWithData:controlImage]; But this yields a compiler error 'incompatible type' saying that initWithData wants a NSData variable not an NSImage. I have also tried various other ways to get this done, but all are unsuccessful either due to compiler or runtime error. Can someone help me with this? I will eventually need to load some PNG files in the same way (so it would be nice to have a consistent technique for both). And if you know of an easier / simpler way to accomplish what I am trying to do (i.e., get the images into a two-dimensional array), rather than using NSBitmapImageRep, then please let me know! And by the way, I know the path is valid (confirmed with fileExistsAtPath) -- and the filename in outLabel is a file with .jpg extension. Thanks for any help!

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  • [hibernate - jpa] @CollectionOfElements without create the apposite table

    - by blow
    Hi all. I have this: Municipality class @Entity public class Municipality implements Serializable { @Id @GeneratedValue(strategy=GenerationType.IDENTITY) private Long id; private String country; private String province; private String name; @Column(name="cod_catasto") private String codCatastale; private String cap; @CollectionOfElements private List<Address> addressList; public Municipality() { } ... Address class @Embeddable public class Address implements Serializable { @ManyToOne(fetch=FetchType.LAZY) @Cascade(CascadeType.SAVE_UPDATE) private Municipality municipality; @Column(length=45) private String address; public Address() { } ... Address is embedded in another class Person. When i save an instance of Person, hibernate create 3 tables: PERSON, MUNICIPALITY and MUNICIPALITY_ADDRESSLIST. MUNICIPALITY_ADDRESSLIST contains 2 fields: MUNICIPALITY_ID (FK) and STREET. I don't want this table, i only want the ID of table MUNICIPALITY into table PERSON(that embeds Address), what should i do? I tried to add @JoinTable in Municipality entity like this: @CollectionOfElements @JoinTable(name="person") private List<Address> addressList; It partially worked, but i cant choose the column name of table PERSON that contains ID of the table MUNICIPALITY, it is, by hibernate choose, simply "MUNICIPALITY_ID"... Thbaks.

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  • Class 'org.springframework.http.converter.ResourceHttpMessageConverter' not found - how to correct?

    - by Ash Kim
    Eclipse STS is reporting I have problem with my spring project. It's a fresh project generated from the Spring Web MVC Project Template (File-New-Spring Template Project-Spring Web MVC ). When I create the project it has no problems - it's only once I modify the pom (by adding the hibernate dependencies) that STS then picks up the spring problem. Strangely if I revert the pom the problem remains. Also I can run the project on a spring tc server and all works correctly. Any ideas how I can satisfy this problem report? "Class 'org.springframework.http.converter.ResourceHttpMessageConverter' not found" mvc-config.xml /src/main/webapp/WEB-INF/spring line 9 Spring Beans Problem mvc-config.xml: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd"> <mvc:annotation-driven /> <!-- <= PROBLEMATIC LINE REPORTED BY STS --> <!-- Resolves view names to protected .jsp resources within the /WEB-INF/views directory --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/views/"/> <property name="suffix" value=".jsp"/> </bean> </beans>

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  • ASP.NET MVC View ReRenders Part of Itself

    - by Jason
    In all my years of .NET programming I have not run across a bug as weird as this one. I discovered the problem because some elements on the page were getting double-bound by jQuery. After some (ridiculous) debugging, I finally discovered that once the view is completely done rendering itself and all its children partial views, it goes back to an arbitrary yet consistent location and re-renders itself. I have been pulling my hair out about this for two days now and I simply cannot get it to render itself only once! For lack of any better debugging idea, I've painstakingly added logging tracers throughout the HTML just so I can pin down what may be causing this. For instance, this code ($log just logs to the console): ... <script type="text/javascript">var x = 0; $log('1');</script> <div id="new-ad-form"> <script type="text/javascript">x++;$log('1.5', x);</script> ... will yield ... <--- this happens before this snippet 1 1.5 1 ... 10 <--- bottom of my form, after snippet 1.5 2 <--- beginning of part that runs again! ... 9 <--- this happens after this snippet I've searched my codebase high and low, but there is NOTHING that says that it should re-render part of a page. I'm wondering if the jQueryUI has anything to do with it, as #new-ad-form is the container for a jQueryUI dialog box. If this is potentially the case, here's my init code for that: $('#new-ad-form').dialog({ autoOpen: false, modal: true, width: 470, title: 'Create A New Ad', position: ['center', 35], close: AdEditor.reset });

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  • Having an issue with Nullable MySQL columns in SubSonic 3.0 templates

    - by omegawkd
    Looking at this line in the Settings.ttinclude string CheckNullable(Column col){ string result=""; if(col.IsNullable && col.SysType !="byte[]" && col.SysType !="string") result="?"; return result; } It describes how it determines if the column is nullable based on requirements and returns either "" or "?" to the generated code. Now I'm not too familiar with the ? nullable type operator but from what I can see a cast is required. For instance, if I have a nullable integer MySQL column and I generate the code using the default template files it returns a line similar to this: int? _User_ID; When trying to compile the project I get the error: Cannot implicitly convert type 'int?' to 'int'. An explicit conversion exists (are you missing a cast?) I checked teh Settings files for the other database types and they all seems to have the same routine. So my question is, is this behaviour expected or is this a bug? I need to solve it one way or the other before I can procede. Thanks for your help.

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