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  • Is Ogre's use of Exceptions a good way of using them?

    - by identitycrisisuk
    I've managed to get through my C++ game programming career so far virtually never touching exceptions but recently I've been working on a project with the Ogre engine and I'm trying to learn properly. I've found a lot of good questions and answers here on the general usage of C++ exceptions but I'd like to get some outside opinions from here on whether Ogre's usage is good and how best to work with them. To start with, quoting from Ogre's documentation of it's own Exception class: OGRE never uses return values to indicate errors. Instead, if an error occurs, an exception is thrown, and this is the object that encapsulates the detail of the problem. The application using OGRE should always ensure that the exceptions are caught, so all OGRE engine functions should occur within a try{} catch(Ogre::Exception& e) {} block. Really? Every single Ogre function could throw an exception and be wrapped in a try/catch block? At present this is handled in our usage of it by a try/catch in main that will show a message box with the exception description before exiting. This can be a bit awkward for debugging though as you don't get a stack trace, just the function that threw the error - more important is the function from our code that called the Ogre function. If it was an assert in Ogre code then it would go straight to the code in the debugger and I'd be able to find out what's going on much easier - I don't know if I'm missing something that would allow me to debug exceptions already? I'm starting to add a few more try/catch blocks in our code now, generally thinking about whether it matters if the Ogre function throws an exception. If it's something that will stop everything working then let the main try/catch handle it and exit the program. If it's not of great importance then catch it just after the function call and let the program continue. One recent example of this was building up a vector of the vertex/fragment program parameters for materials applied to an entity - if a material didn't have any parameters then it would throw an exception, which I caught and then ignored as it didn't need to add to my list of parameters. Does this seem like a reasonable way of dealing with things? Any specific advice for working with Ogre is much appreciated.

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  • user generated / user specific functions

    - by pedalpete
    I'm looking for the most elegant and secure method to do the following. I have a calendar, and groups of users. Users can add events to specific days on the calendar, and specify how long each event lasts for. I've had a few requests from users to add the ability for them to define that events of a specific length include a break, of a certain amount of time, or require that a specific amount of time be left between events. For example, if event is 2 hours, include a 20min break. for each event, require 30 minutes before start of next event. The same group that has asked for an event of 2 hours to include a 20 min break, could also require that an event 3 hours include a 30 minute break. In the end, what the users are trying to get is an elapsed time excluding breaks calculated for them. Currently I provide them a total elapsed time, but they are looking for a running time. However, each of these requests is different for each group. Where one group may want a 30 minute break during a 2 hour event, and another may want only 10 minutes for each 3 hour event. I was kinda thinking I could write the functions into a php file per group, and then include that file and do the calculations via php and then return a calculated total to the user, but something about that doesn't sit right with me. Another option is to output the groups functions to javascript, and have it run client-side, as I'm already returning the duration of the event, but where the user is part of more than one group with different rules, this seems like it could get rather messy. I currently store the start and end time in the database, but no 'durations', and I don't think I should be storing the calculated totals in the db, because if a group decides to change their calculations, I'd need to change it throughout the db. Is there a better way of doing this? I would just store the variables in mysql, but I don't see how I can then say to mysql to calculate based on those variables. I'm REALLY lost here. Any suggestions? I'm hoping somebody has done something similar and can provide some insight into the best direction. If it helps, my table contains eventid, user, group, startDate, startTime, endDate, endTime, type The json for the event which I return to the user is {"eventid":"'.$eventId.'", "user":"'.$userId.'","group":"'.$groupId.'","type":"'.$type.'","startDate":".$startDate.'","startTime":"'.$startTime.'","endDate":"'.$endDate.'","endTime":"'.$endTime.'","durationLength":"'.$duration.'", "durationHrs":"'.$durationHrs.'"} where for example, duration length is 2.5 and duration hours is 2:30.

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  • Millions of SYN_RECV connections, no DDoS

    - by ThomK
    We have such server structure: reverse proxy (nginx) - worker (uwsgi) - postgresql / memcached. All servers are in local network behind router, with NATed external ip:ports (http/s 80/443 to proxy, and ssh 22 to all servers). Problem is, that sometimes proxy server netstat reports MILLIONS of SYN_RECV connections. From same IP / same ports. Like that: nginx ~ # netstat -n | grep 83.238.153.195 tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV tcp 0 0 192.168.1.1:80 83.238.153.195:3107 SYN_RECV [...] And this is not DDoS, because all IPs affected belongs to our website users. On side note, users says that it's not affecting them. Website is online and working, but... that particular one (from example above) told me that website is down and Firefox can't connect. I've done tcpdump. 19:42:14.826011 IP 83.238.153.195.zephyr-srv > 192.168.1.1.http: Flags [S], seq 1845850583, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:42:14.826042 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:17.887331 IP 83.238.153.195.zephyr-srv > 192.168.1.1.http: Flags [S], seq 1845850583, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:42:17.887343 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:19.065497 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:23.918064 IP 83.238.153.195.zephyr-srv > 192.168.1.1.http: Flags [S], seq 1845850583, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:42:23.918076 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:25.265499 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:37.265501 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:37.758051 IP 83.238.153.195.2107 > 192.168.1.1.http: Flags [S], seq 564208067, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:42:37.758069 IP 192.168.1.1.http > 83.238.153.195.2107: Flags [S.], seq 3188568660, ack 564208068, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:40.714360 IP 83.238.153.195.2107 > 192.168.1.1.http: Flags [S], seq 564208067, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:42:40.714374 IP 192.168.1.1.http > 83.238.153.195.2107: Flags [S.], seq 3188568660, ack 564208068, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:41.665503 IP 192.168.1.1.http > 83.238.153.195.2107: Flags [S.], seq 3188568660, ack 564208068, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:46.751073 IP 83.238.153.195.2107 > 192.168.1.1.http: Flags [S], seq 564208067, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:42:46.751087 IP 192.168.1.1.http > 83.238.153.195.2107: Flags [S.], seq 3188568660, ack 564208068, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:47.665498 IP 192.168.1.1.http > 83.238.153.195.2107: Flags [S.], seq 3188568660, ack 564208068, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:42:59.865499 IP 192.168.1.1.http > 83.238.153.195.2107: Flags [S.], seq 3188568660, ack 564208068, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:01.265500 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:13.320382 IP 83.238.153.195.2114 > 192.168.1.1.http: Flags [S], seq 2136055006, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:43:13.320399 IP 192.168.1.1.http > 83.238.153.195.2114: Flags [S.], seq 3754336171, ack 2136055007, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:16.320556 IP 83.238.153.195.2114 > 192.168.1.1.http: Flags [S], seq 2136055006, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:43:16.320569 IP 192.168.1.1.http > 83.238.153.195.2114: Flags [S.], seq 3754336171, ack 2136055007, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:17.665498 IP 192.168.1.1.http > 83.238.153.195.2114: Flags [S.], seq 3754336171, ack 2136055007, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:22.250069 IP 83.238.153.195.2114 > 192.168.1.1.http: Flags [S], seq 2136055006, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:43:22.250080 IP 192.168.1.1.http > 83.238.153.195.2114: Flags [S.], seq 3754336171, ack 2136055007, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:23.665500 IP 192.168.1.1.http > 83.238.153.195.2114: Flags [S.], seq 3754336171, ack 2136055007, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:23.865501 IP 192.168.1.1.http > 83.238.153.195.2107: Flags [S.], seq 3188568660, ack 564208068, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:35.665498 IP 192.168.1.1.http > 83.238.153.195.2114: Flags [S.], seq 3754336171, ack 2136055007, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:37.903038 IP 83.238.153.195.2213 > 192.168.1.1.http: Flags [S], seq 2918118729, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:43:37.903054 IP 192.168.1.1.http > 83.238.153.195.2213: Flags [S.], seq 4145523337, ack 2918118730, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:40.772899 IP 83.238.153.195.2213 > 192.168.1.1.http: Flags [S], seq 2918118729, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:43:40.772912 IP 192.168.1.1.http > 83.238.153.195.2213: Flags [S.], seq 4145523337, ack 2918118730, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:41.865500 IP 192.168.1.1.http > 83.238.153.195.2213: Flags [S.], seq 4145523337, ack 2918118730, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:46.793057 IP 83.238.153.195.2213 > 192.168.1.1.http: Flags [S], seq 2918118729, win 65535, options [mss 1412,nop,wscale 0,nop,nop,sackOK], length 0 19:43:46.793069 IP 192.168.1.1.http > 83.238.153.195.2213: Flags [S.], seq 4145523337, ack 2918118730, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:47.865500 IP 192.168.1.1.http > 83.238.153.195.2213: Flags [S.], seq 4145523337, ack 2918118730, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 19:43:49.465503 IP 192.168.1.1.http > 83.238.153.195.zephyr-srv: Flags [S.], seq 2835837547, ack 1845850584, win 5840, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 Anyone have some thoughts on that?

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  • OpenGL - Frustum not culling polygons beyond far plane

    - by Pladnius Brooks
    I have implemented frustum culling and am checking the bounding box for its intersection with the frustum planes. I added the ability to pause frustum updates which lets me see if the frustum culling has been working correctly. When I turn around after I have paused it, nothing renders behind me and to the left and right side, they taper off as well just as you would expect. Beyond the clip distance (far plane), they still render and I am not sure whether it is a problem with my frustum updating or bounding box checking code or I am using the wrong matrix or what. As I put the distance in the projection matrix at 3000.0f, it still says that bounding boxes well past that are still in the frustum, which isn't the case. Here is where I create my modelview matrix: projectionMatrix = glm::perspective(newFOV, 4.0f / 3.0f, 0.1f, 3000.0f); viewMatrix = glm::mat4(1.0); viewMatrix = glm::scale(viewMatrix, glm::vec3(1.0, 1.0, -1.0)); viewMatrix = glm::rotate(viewMatrix, anglePitch, glm::vec3(1.0, 0.0, 0.0)); viewMatrix = glm::rotate(viewMatrix, angleYaw, glm::vec3(0.0, 1.0, 0.0)); viewMatrix = glm::translate(viewMatrix, glm::vec3(-x, -y, -z)); modelViewProjectiomMatrix = projectionMatrix * viewMatrix; The reason I scale it by -1 in the Z direction is because the levels were designed to be rendered with DirectX so I reverse the Z direction. Here is where I update my frustum: void CFrustum::calculateFrustum() { glm::mat4 mat = camera.getModelViewProjectionMatrix(); // Calculate the LEFT side m_Frustum[LEFT][A] = (mat[0][3]) + (mat[0][0]); m_Frustum[LEFT][B] = (mat[1][3]) + (mat[1][0]); m_Frustum[LEFT][C] = (mat[2][3]) + (mat[2][0]); m_Frustum[LEFT][D] = (mat[3][3]) + (mat[3][0]); // Calculate the RIGHT side m_Frustum[RIGHT][A] = (mat[0][3]) - (mat[0][0]); m_Frustum[RIGHT][B] = (mat[1][3]) - (mat[1][0]); m_Frustum[RIGHT][C] = (mat[2][3]) - (mat[2][0]); m_Frustum[RIGHT][D] = (mat[3][3]) - (mat[3][0]); // Calculate the TOP side m_Frustum[TOP][A] = (mat[0][3]) - (mat[0][1]); m_Frustum[TOP][B] = (mat[1][3]) - (mat[1][1]); m_Frustum[TOP][C] = (mat[2][3]) - (mat[2][1]); m_Frustum[TOP][D] = (mat[3][3]) - (mat[3][1]); // Calculate the BOTTOM side m_Frustum[BOTTOM][A] = (mat[0][3]) + (mat[0][1]); m_Frustum[BOTTOM][B] = (mat[1][3]) + (mat[1][1]); m_Frustum[BOTTOM][C] = (mat[2][3]) + (mat[2][1]); m_Frustum[BOTTOM][D] = (mat[3][3]) + (mat[3][1]); // Calculate the FRONT side m_Frustum[FRONT][A] = (mat[0][3]) + (mat[0][2]); m_Frustum[FRONT][B] = (mat[1][3]) + (mat[1][2]); m_Frustum[FRONT][C] = (mat[2][3]) + (mat[2][2]); m_Frustum[FRONT][D] = (mat[3][3]) + (mat[3][2]); // Calculate the BACK side m_Frustum[BACK][A] = (mat[0][3]) - (mat[0][2]); m_Frustum[BACK][B] = (mat[1][3]) - (mat[1][2]); m_Frustum[BACK][C] = (mat[2][3]) - (mat[2][2]); m_Frustum[BACK][D] = (mat[3][3]) - (mat[3][2]); // Normalize all the sides NormalizePlane(m_Frustum, LEFT); NormalizePlane(m_Frustum, RIGHT); NormalizePlane(m_Frustum, TOP); NormalizePlane(m_Frustum, BOTTOM); NormalizePlane(m_Frustum, FRONT); NormalizePlane(m_Frustum, BACK); } And finally, where I check the bounding box: bool CFrustum::BoxInFrustum( float x, float y, float z, float x2, float y2, float z2) { // Go through all of the corners of the box and check then again each plane // in the frustum. If all of them are behind one of the planes, then it most // like is not in the frustum. for(int i = 0; i < 6; i++ ) { if(m_Frustum[i][A] * x + m_Frustum[i][B] * y + m_Frustum[i][C] * z + m_Frustum[i][D] > 0) continue; if(m_Frustum[i][A] * x2 + m_Frustum[i][B] * y + m_Frustum[i][C] * z + m_Frustum[i][D] > 0) continue; if(m_Frustum[i][A] * x + m_Frustum[i][B] * y2 + m_Frustum[i][C] * z + m_Frustum[i][D] > 0) continue; if(m_Frustum[i][A] * x2 + m_Frustum[i][B] * y2 + m_Frustum[i][C] * z + m_Frustum[i][D] > 0) continue; if(m_Frustum[i][A] * x + m_Frustum[i][B] * y + m_Frustum[i][C] * z2 + m_Frustum[i][D] > 0) continue; if(m_Frustum[i][A] * x2 + m_Frustum[i][B] * y + m_Frustum[i][C] * z2 + m_Frustum[i][D] > 0) continue; if(m_Frustum[i][A] * x + m_Frustum[i][B] * y2 + m_Frustum[i][C] * z2 + m_Frustum[i][D] > 0) continue; if(m_Frustum[i][A] * x2 + m_Frustum[i][B] * y2 + m_Frustum[i][C] * z2 + m_Frustum[i][D] > 0) continue; // If we get here, it isn't in the frustum return false; } // Return a true for the box being inside of the frustum return true; }

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  • SignalR recording when a Web Page has closed

    - by Benjamin Rogers
    I am using MassTransit request and response with SignalR. The web site makes a request to a windows service that creates a file. When the file has been created the windows service will send a response message back to the web site. The web site will open the file and make it available for the users to see. I want to handle the scenario where the user closes the web page before the file is created. In that case I want the created file to be emailed to them. Regardless of whether the user has closed the web page or not, the message handler for the response message will be run. What I want to be able to do is have some way of knowing within the response message handler that the web page has been closed. This is what I have done already. It doesnt work but it does illustrate my thinking. On the web page I have $(window).unload(function () { if (event.clientY < 0) { // $.connection.hub.stop(); $.connection.exportcreate.setIsDisconnected(); } }); exportcreate is my Hub name. In setIsDisconnected would I set a property on Caller? Lets say I successfully set a property to indicate that the web page has been closed. How do I find out that value in the response message handler. This is what it does now protected void BasicResponseHandler(BasicResponse message) { string groupName = CorrelationIdGroupName(message.CorrelationId); GetClients()[groupName].display(message.ExportGuid); } private static dynamic GetClients() { return AspNetHost.DependencyResolver.Resolve<IConnectionManager>().GetClients<ExportCreateHub>(); } I am using the message correlation id as a group. Now for me the ExportGuid on the message is very important. That is used to identify the file. So if I am going to email the created file I have to do it within the response handler because I need the ExportGuid value. If I did store a value on Caller in my hub for the web page close, how would I access it in the response handler. Just in case you need to know. display is defined on the web page as exportCreate.display = function (guid) { setTimeout(function () { top.location.href = 'GetExport.ashx?guid=' + guid; }, 500); }; GetExport.ashx opens the file and returns it as a response. Thank you, Regards Ben

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  • "Wrapping" a BindingList<T> propertry with a List<T> property for serialization.

    - by Eric
    I'm writing an app that allows users search and browse catalogs of widgets. My WidgetCatalog class is serialized and deserialized to and from XML files using DataContractSerializer. My app is working now but I think I can make the code a lot more efficient if I started taking advantage of data binding rather then doing everything manually. Here's a stripped down version of my current WidgetCatalog class. [DataContract(Name = "WidgetCatalog")] class WidgetCatalog { [DataContract(Name = "Name")] public string Name { get; set; } [DataContract(Name = "Widgets")] public List<Widget> Widgets { get; set; } } I had to write a lot of extra code to keep my UI in sync when widgets are added or removed from a catalog, or their internal properties change. I'm pretty inexperienced with data-binding, but I think I want a BindingList<Widget> rather than a plain old List<Widget>. Is this right? In the past when I had similar needs I found that BindingList<T> does not serialize very well. Or at least the Event Handers between the items and the list are not serialized. I was using XmlSerializer though, and DataContractSerializer may work better. So I'm thinking of doing something like the code below. [DataContract(Name = "WidgetCatalog")] class WidgetCatalog { [DataMember(Name = "Name")] public string Name { get; set; } [DataMember(Name = "Widgets")] private List<Widget> WidgetSerializationList { get { return this._widgetBindingList.ToList<Widget>(); } set { this._widgetBindingList = new BindingList<Widget>(value); } } //these do not get serialized private BindingList<Widget> _widgetBindingList; public BindingList<Widget> WidgetBindingList { get { return this._widgetBindingList; } } public WidgetCatalog() { this.WidgetSerializationList = new List<Widget>(); } } So I'm serializing a private List<Widget> property, but the GET and SET accessors of the property are reading from, and writing to theBindingList<Widget> property. Will this even work? It seems like there should be a better way to do this.

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  • System architecture: simple approach for setting up background tasks behind a web application -- wil

    - by Tim Molendijk
    I have a Django web application and I have some tasks that should operate (or actually: be initiated) on the background. The application is deployed as follows: apache2-mpm-worker; mod_wsgi in daemon mode (1 process, 15 threads). The background tasks have the following characteristics: they need to operate in a regular interval (every 5 minutes or so); they require the application context (i.e. the application packages need to be available in memory); they do not need any input other than database access, in order to perform some not-so-heavy tasks such as sending out e-mail and updating the state of the database. Now I was thinking that the most simple approach to this problem would be simply to piggyback on the existing application process (as spawned by mod_wsgi). By implementing the task as part of the application and providing an HTTP interface for it, I would prevent the overhead of another process that is holding all of the application into memory. A simple cronjob can be setup that sends a request to this HTTP interface every 5 minutes and that would be it. Since the application process provides 15 threads and the tasks are quite lightweight and only running every 5 minutes, I figure they would not be hindering the performance of the web application's user-facing operations. Yet... I have done some online research and I have seen nobody advocating this approach. Many articles suggest a significantly more complex approach based on a full-blown messaging component (such as Celery, which uses RabbitMQ). Although that's sexy, it sounds like overkill to me. Some articles suggest setting up a cronjob that executes a script which performs the tasks. But that doesn't feel very attractive either, as it results in creating a new process that loads the entire application into memory, performs some tiny task, and destroys the process again. And this is repeated every 5 minutes. Does not sound like an elegant solution. So, I'm looking for some feedback on my suggested approach as described in the paragraph before the preceeding paragraph. Is my reasoning correct? Am I overlooking (potential) problems? What about my assumption that application's performance will not be impeded?

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  • OSGI classcast exception on felix

    - by Nico
    Hi, i'm fairly new to osgi and am trying to get a functional proof of concept together. The setup is that my common api is created in a bundle creatively named common-api.jar with no bundle activator, but it exports all it's interfaces. the one of interest in this situation is DatabaseService.java. I then have a Second bundle called systemx-database-service. That implements the database service interface. this works fine as in the activator of the implementation bundle i test the connection to the database and select some arbitraty values. I also register the service i want to be available to the other bundle's like so: context.registerService(DatabaseService.class.getName(), new SystemDatabaseServiceImpl(context), new Properties()); The basic idea being when you look for a service reference for a Database service you'll get back the SystemDatabaseService implementation. When i do a inspect service the output it this: -> inspect s c 69 System Database Service (69) provides services: ---------------------------------------------- objectClass = za.co.xxx.xxx.common.api.DatabaseService service.id = 39 which would lead me to believe that if i do this in a test bundle: context.getService(context.getServiceReference(DatabaseService.class)); i should get back an instance of DatabaseService.class, but alas no such luck. it simply seems like it cannot find the service. stick with me here my story gets stranger. figuring there is no where to go but up i wrote this monstrosity: for (Bundle bundle : bundles) { if (bundle.getSymbolicName().equals("za.co.xxx.xxx.database-service")) { ServiceReference[] registeredServices = bundle.getRegisteredServices(); for (ServiceReference ref : registeredServices) { DatabaseService service = (DatabaseService) context.getService(ref); // use service here. } } } } now i can actually see the service reference, but i get this error java.lang.ClassCastException: za.co.xxx.xxx.database.service.impl.SystemDatabaseServiceImpl cannot be cast to za.co.xxx.xx.common.api.DatabaseService which is crazy since the implementation clearly implements the interface! Any help would be appreciated. Please keep in mind i'm very new at the osgi way of thinking so my whole approach here might be flawed. oh. if anyone wants the manifests i can post them. and i'm using the maven-bnd-plugin to build and executing on felix. thanks Nico

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  • In MySQL, what is the most effective query design for joining large tables with many to many relatio

    - by lighthouse65
    In our application, we collect data on automotive engine performance -- basically source data on engine performance based on the engine type, the vehicle running it and the engine design. Currently, the basis for new row inserts is an engine on-off period; we monitor performance variables based on a change in engine state from active to inactive and vice versa. The related engineState table looks like this: +---------+-----------+---------------+---------------------+---------------------+-----------------+ | vehicle | engine | engine_state | state_start_time | state_end_time | engine_variable | +---------+-----------+---------------+---------------------+---------------------+-----------------+ | 080025 | E01 | active | 2008-01-24 16:19:15 | 2008-01-24 16:24:45 | 720 | | 080028 | E02 | inactive | 2008-01-24 16:19:25 | 2008-01-24 16:22:17 | 304 | +---------+-----------+---------------+---------------------+---------------------+-----------------+ For a specific analysis, we would like to analyze table content based on a row granularity of minutes, rather than the current basis of active / inactive engine state. For this, we are thinking of creating a simple productionMinute table with a row for each minute in the period we are analyzing and joining the productionMinute and engineEvent tables on the date-time columns in each table. So if our period of analysis is from 2009-12-01 to 2010-02-28, we would create a new table with 129,600 rows, one for each minute of each day for that three-month period. The first few rows of the productionMinute table: +---------------------+ | production_minute | +---------------------+ | 2009-12-01 00:00 | | 2009-12-01 00:01 | | 2009-12-01 00:02 | | 2009-12-01 00:03 | +---------------------+ The join between the tables would be engineState AS es LEFT JOIN productionMinute AS pm ON es.state_start_time <= pm.production_minute AND pm.production_minute <= es.event_end_time. This join, however, brings up multiple environmental issues: The engineState table has 5 million rows and the productionMinute table has 130,000 rows When an engineState row spans more than one minute (i.e. the difference between es.state_start_time and es.state_end_time is greater than one minute), as is the case in the example above, there are multiple productionMinute table rows that join to a single engineState table row When there is more than one engine in operation during any given minute, also as per the example above, multiple engineState table rows join to a single productionMinute row In testing our logic and using only a small table extract (one day rather than 3 months, for the productionMinute table) the query takes over an hour to generate. In researching this item in order to improve performance so that it would be feasible to query three months of data, our thoughts were to create a temporary table from the engineEvent one, eliminating any table data that is not critical for the analysis, and joining the temporary table to the productionMinute table. We are also planning on experimenting with different joins -- specifically an inner join -- to see if that would improve performance. What is the best query design for joining tables with the many:many relationship between the join predicates as outlined above? What is the best join type (left / right, inner)?

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  • Determining what frequencies correspond to the x axis in aurioTouch sample application

    - by eagle
    I'm looking at the aurioTouch sample application for the iPhone SDK. It has a basic spectrum analyzer implemented when you choose the "FFT" option. One of the things the app is lacking is X axis labels (i.e. the frequency labels). In the aurioTouchAppDelegate.mm file, in the function - (void)drawOscilloscope at line 652, it has the following code: if (displayMode == aurioTouchDisplayModeOscilloscopeFFT) { if (fftBufferManager->HasNewAudioData()) { if (fftBufferManager->ComputeFFT(l_fftData)) [self setFFTData:l_fftData length:fftBufferManager->GetNumberFrames() / 2]; else hasNewFFTData = NO; } if (hasNewFFTData) { int y, maxY; maxY = drawBufferLen; for (y=0; y<maxY; y++) { CGFloat yFract = (CGFloat)y / (CGFloat)(maxY - 1); CGFloat fftIdx = yFract * ((CGFloat)fftLength); double fftIdx_i, fftIdx_f; fftIdx_f = modf(fftIdx, &fftIdx_i); SInt8 fft_l, fft_r; CGFloat fft_l_fl, fft_r_fl; CGFloat interpVal; fft_l = (fftData[(int)fftIdx_i] & 0xFF000000) >> 24; fft_r = (fftData[(int)fftIdx_i + 1] & 0xFF000000) >> 24; fft_l_fl = (CGFloat)(fft_l + 80) / 64.; fft_r_fl = (CGFloat)(fft_r + 80) / 64.; interpVal = fft_l_fl * (1. - fftIdx_f) + fft_r_fl * fftIdx_f; interpVal = CLAMP(0., interpVal, 1.); drawBuffers[0][y] = (interpVal * 120); } cycleOscilloscopeLines(); } } From my understanding, this part of the code is what is used to decide which magnitude to draw for each frequency in the UI. My question is how can I determine what frequency each iteration (or y value) represents inside the for loop. For example, if I want to know what the magnitude is for 6kHz, I'm thinking of adding a line similar to the following: if (yValueRepresentskHz(y, 6)) NSLog(@"The magnitude for 6kHz is %f", (interpVal * 120)); Please note that although they chose to use the variable name y, from what I understand, it actually represents the x-axis in the visual graph of the spectrum analyzer, and the value of the drawBuffers[0][y] represents the y-axis.

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  • Soon to be PhD in Computer Science - Which Path to Follow?

    - by mttr
    I am going to submit my PhD thesis within the next six months. My PhD is on managing the availabiity of large-scale distributed systems, so I have some experience actually building non-trivial systems (+ I have four years experience working as a programmer). I am now trying to figure out what I should do following the PhD. I enjoy research (a quick definition: identify problem, come up with solution, ask interesting questions, find ways to answer them, build system, experiment, contribute some new knowledge and publish). I also like teaching and supervising students. It would seem that a career in academia is the ideal thing to do (can work on non-trivial problems and contribute something of use to some or more people). However, a career in academia has two significant drawbacks. First, it can be difficult to gain access to real systems with real users which then display real problems. This creates the danger that you do work that seems important (to you and maybe to some of your colleagues), but is not really relevant to anything or anyone. Second, the pay is pretty sad. Apparently, you have to sacrifice this for the privilege of doing research. I enjoy programming, but don't just want to hack some web-based system for the rest of my life. That is, working in IT for a bank is not a future I see myself enjoying. I want to work on interesting problms (that's difficult to define clearly): things where you don't know how to start, that take some time to figure out and attack, that require a rigorous approach to demonstrate that the problem has been solved, and problems that need a solution in the real world. Give the experience of people on stackoverflow, what do you think suitable options are and why (or alternatively, what gaps in my thinking does the above reveal)? Is industrial research (aka IBM Research, Microsoft Research) the only alternative avenue to a career in academia? What other areas, companies, occupations, etc. could provide me with stimulating, inspiring work? Which regions, countries am I most likely to find such work? Please share your experience.

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  • Most efficient method to query a Young Tableau

    - by Matthieu M.
    A Young Tableau is a 2D matrix A of dimensions M*N such that: i,j in [0,M)x[0,N): for each p in (i,M), A[i,j] <= A[p,j] for each q in (j,N), A[i,j] <= A[i,q] That is, it's sorted row-wise and column-wise. Since it may contain less than M*N numbers, the bottom-right values might be represented either as missing or using (in algorithm theory) infinity to denote their absence. Now the (elementary) question: how to check if a given number is contained in the Young Tableau ? Well, it's trivial to produce an algorithm in O(M*N) time of course, but what's interesting is that it is very easy to provide an algorithm in O(M+N) time: Bottom-Left search: Let x be the number we look for, initialize i,j as M-1, 0 (bottom left corner) If x == A[i,j], return true If x < A[i,j], then if i is 0, return false else decrement i and go to 2. Else, if j is N-1, return false else increment j This algorithm does not make more than M+N moves. The correctness is left as an exercise. It is possible though to obtain a better asymptotic runtime. Pivot Search: Let x be the number we look for, initialize i,j as floor(M/2), floor(N/2) If x == A[i,j], return true If x < A[i,j], search (recursively) in A[0:i-1, 0:j-1], A[i:M-1, 0:j-1] and A[0:i-1, j:N-1] Else search (recursively) in A[i+1:M-1, 0:j], A[i+1:M-1, j+1:N-1] and A[0:i, j+1:N-1] This algorithm proceed by discarding one of the 4 quadrants at each iteration and running recursively on the 3 left (divide and conquer), the master theorem yields a complexity of O((N+M)**(log 3 / log 4)) which is better asymptotically. However, this is only a big-O estimation... So, here are the questions: Do you know (or can think of) an algorithm with a better asymptotical runtime ? Like introsort prove, sometimes it's worth switching algorithms depending on the input size or input topology... do you think it would be possible here ? For 2., I am notably thinking that for small size inputs, the bottom-left search should be faster because of its O(1) space requirement / lower constant term.

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  • C# Begin/EndReceive - how do I read large data?

    - by ryeguy
    When reading data in chunks of say, 1024, how do I continue to read from a socket that receives a message bigger than 1024 bytes until there is no data left? Should I just use BeginReceive to read a packet's length prefix only, and then once that is retrieved, use Receive() (in the async thread) to read the rest of the packet? Or is there another way? edit: I thought Jon Skeet's link had the solution, but there is a bit of a speedbump with that code. The code I used is: public class StateObject { public Socket workSocket = null; public const int BUFFER_SIZE = 1024; public byte[] buffer = new byte[BUFFER_SIZE]; public StringBuilder sb = new StringBuilder(); } public static void Read_Callback(IAsyncResult ar) { StateObject so = (StateObject) ar.AsyncState; Socket s = so.workSocket; int read = s.EndReceive(ar); if (read > 0) { so.sb.Append(Encoding.ASCII.GetString(so.buffer, 0, read)); if (read == StateObject.BUFFER_SIZE) { s.BeginReceive(so.buffer, 0, StateObject.BUFFER_SIZE, 0, new AyncCallback(Async_Send_Receive.Read_Callback), so); return; } } if (so.sb.Length > 0) { //All of the data has been read, so displays it to the console string strContent; strContent = so.sb.ToString(); Console.WriteLine(String.Format("Read {0} byte from socket" + "data = {1} ", strContent.Length, strContent)); } s.Close(); } Now this corrected works fine most of the time, but it fails when the packet's size is a multiple of the buffer. The reason for this is if the buffer gets filled on a read it is assumed there is more data; but the same problem happens as before. A 2 byte buffer, for exmaple, gets filled twice on a 4 byte packet, and assumes there is more data. It then blocks because there is nothing left to read. The problem is that the receive function doesn't know when the end of the packet is. This got me thinking to two possible solutions: I could either have an end-of-packet delimiter or I could read the packet header to find the length and then receive exactly that amount (as I originally suggested). There's problems with each of these, though. I don't like the idea of using a delimiter, as a user could somehow work that into a packet in an input string from the app and screw it up. It also just seems kinda sloppy to me. The length header sounds ok, but I'm planning on using protocol buffers - I don't know the format of the data. Is there a length header? How many bytes is it? Would this be something I implement myself? Etc.. What should I do?

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  • How to store wiki sites (vcs)

    - by Eugen
    Hello, as a personal project I am trying to write a wiki with the help of django. I'm a beginner when it comes to web development. I am at the (early) point where I need to decide how to store the wiki sites. I have three approaches in mind and would like to know your suggestion. Flat files I considered a flat file approach with a version control system like git or mercurial. Firstly, I would have some example wikis to look at like http://hatta.sheep.art.pl/. Secondly, the vcs would probably deal with editing conflicts and keeping the edit history, so I would not have to reinvent the wheel. And thirdly, I could probably easily clone the wiki repository, so I (or for that matter others) can have an offline copy of the wiki. On the other hand, as far as I know, I can not use django models with flat files. Then, if I wanted to add fields to a wiki site, like a category, I would need to somehow keep a reference to that flat file in order to associate the fields in the database with the flat file. Besides, I don't know if it is a good idea to have all the wiki sites in one repository. I imagine it is more natural to have kind of like a repository per wiki site resp. file. Last but not least, I'm not sure, but I think using flat files would limit my deploying capabilities because web hosts maybe don't allow creating files (I'm thinking, for example, of Google App Engine) Storing in a database By storing the wiki sites in the database I can utilize django models and associate arbitrary fields with the wiki site. I probably would also have an easier life deploying the wiki. But I would not get vcs features like history and conflict resolving per se. I searched for django-extensions to help me and I found django-reversion. However, I do not fully understand if it fit my needs. Does it track model changes like for example if I change the django model file, or does it track the content of the models (which would fit my need). Plus, I do not see if django reversion would help me with edit conflicts. Storing a vcs repository in a database field This would be my ideal solution. It would combine the advantages of both previous approaches without the disadvantages. That is; I would have vcs features but I would save the wiki sites in a database. The problem is: I have no idea how feasible that is. I just imagine saving a wiki site/source together with a git/mercurial repository in a database field. Yet, I somehow doubt database fields work like that. So, I'm open for any other approaches but this is what I came up with. Also, if you're interested, you can find the crappy early test I'm working on here http://github.com/eugenkiss/instantwiki-test

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  • Htaccess rewrite rule .aspx to .php

    - by Markus Ossi
    Background: I have a website that has been built with ASP.NET 2.0 and is on Windows hosting. I now have to rewrite my site in PHP and move it into Linux hosting. I have a lot of incoming links to my site from around the web that point directly into the old .aspx-pages. The site itself is very simple, one dynamic page and five static ones. I saved the static .aspx pages as .php-pages and rewrote the dynamic page in PHP. The dynamic page is called City.aspx and I have written it in PHP and it is now called City.php. On my old Windows hosting, I used ASP.NET's URL mapping for friendly URL. For example, incoming URL request for Laajakaista/Ypaja.aspx was mapped into City.aspx?CityID=981. My goal: To redirect all human visitors and search engines looking for the old .aspx pages into the new .php pages. I am thinking that the easiest way to redirect visitors into new pages will be by making a redirect, where all requests for .aspx-files will be redirected into .php filetypes. So, if someone asks for MYSITE/City.aspx?CityID=5, they will be taken into MYSITE/City.php?CityID=5 instead. However, I am having a lot of trouble getting this to work. So far this is what I have found: rewriterule ^([.]+)\.aspx$ http://www.example.com/$1.php [R=301,L] However, I think this can not handle the parameters after the filetype and I am also not quite sure what to put on front. To make things a bit more complicated, at my previous site I used friendly URL's so that I had a huge mapping file with mappings like this: <add url="~/Laajakaista/Ypaja.aspx" mappedUrl="~/City.aspx?CityID=981" /> <add url="~/Laajakaista/Aetsa.aspx" mappedUrl="~/City.aspx?CityID=988" /> <add url="~/Laajakaista/Ahtari.aspx" mappedUrl="~/City.aspx?CityID=989" /> <add url="~/Laajakaista/Aanekoski.aspx" mappedUrl="~/City.aspx?CityID=992" /> I tried to make a simple redirect like this: Redirect 301 Laajakaista/Aanekoski.aspx City.php?CityID=992 but was not able to get it to work. I ended up with an internal server error and a 50k .htaccess-file... Any help is greatly appreciated.

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  • jQuery: How can select clicked element in table without define unique id for each element

    - by Yosef
    Hello, I have table (that generated by server) below. I want to get input element value class="itemQuantity" of clicked row. I write jQuery code but he missing "this" of clicked element. <script type="text/javascript"> $(document).ready(function() { $('.updateButton').click(function() { alert($('.itemQuantity').val()); }); }); </script> How can I do it with jQuery (I thinking to use this and not create id for each element, but I have low knowledge in jQuery). Thanks, Yosef <table id="items"> <tr> <th>item id</th> <th>item name</th> <th>item quantity</th> <th>item update</th> </tr> <tr> <td class="itemID"> 1 </td> <td class="itemName"> Ferari </td> <td > <input class="itemQuantity" type="text" size="4" /> </td> <td> <button class="updateButton">update item</button> </td> </tr> <tr> <td class="itemID"> 2 </td> <td class="itemName"> Fiat </td> <td > <input class="itemQuantity" type="text" size="4" /> </td> <td> <button class="updateButton">update item</button> </td> </tr> <tr> <td class="itemID"> 3 </td> <td class="itemName"> Hundai </td> <td > <input class="itemQuantity" type="text" size="4" /> </td> <td> <button class="updateButton">update item</button> </td> </tr> </table>

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  • Jquery:: How can select clicked element in table without define unique id for each element

    - by Yosef
    Hello, I have table (that generated by server) below. I want to get input element value class="itemQuantity" of clicked row. I write Jquery code but he missing "this" of clicked element. <script type="text/javascript"> $(document).ready(function() { $('.updateButton').click(function() { alert($('.itemQuantity').val()); }); }); </script> How Can I do it with jquery(I thinking to use this and not create id for each element, but I have low knoledge in jquery). Thanks, Yosef <table id="items"> <tr> <th>item id</th> <th>item name</th> <th>item quantity</th> <th>item update</th> </tr> <tr> <td class="itemID"> 1 </td> <td class="itemName"> Ferari </td> <td > <input class="itemQuantity" type="text" size="4"/> </td> <td> <button class="updateButton" >update item</button> </td> </tr> <tr> <td class="itemID"> 2 </td> <td class="itemName"> Fiat </td> <td > <input class="itemQuantity" type="text" size="4"/> </td> <td> <button class="updateButton" >update item</button> </td> </tr> <tr> <td class="itemID"> 3 </td> <td class="itemName"> Hundai </td> <td > <input class="itemQuantity" type="text" size="4"/> </td> <td> <button class="updateButton" >update item</button> </td> </tr> </table>

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  • NoSQL DB for .Net document-based database (ECM)

    - by Dane
    I'm halfway through coding a basic multi-tenant SaaS ECM solution. Each client has it's own instance of the database / datastore, but the .Net app is single instance. The documents are pretty much read only (i.e. an image archive of tiffs or PDFs) I've used MSSQL so far, but then started thinking this might be viable in a NoSQL DB (e.g. MongoDB, CouchDB). The basic premise is that it stores documents, each with their own particular indexes. Each tenant can have multiple document types. e.g. One tenant might have an invoice type, which has Customer ID, Invoice Number and Invoice Date. Another tenant might have an application form, which has Member Number, Application Number, Member Name, and Application Date. So far I've used the old method which Sharepoint (used?) to use, and created a document table which has int_field_1, int_field_2, date_field_1, date_field_2, etc. Then, I've got a "mapping" table which stores the customer specific index name, and the database field that will map to. I've avoided the key-value pair model in the DB due to volume of documents. This way, we can support multiple document types in the one table, and get reasonably high performance out of it, and allow for custom document type searches (i.e. user selects a document type, then they're presented with a list of search fields). However, a NoSQL DB might make this a lot simpler, as I don't need to worry about denormalizing the document. However, I've just got concerns about the rest of the data around a document. We store an "action history" against the document. This tracks views, whether someone emails the document from within the system, and other "future" functionality (e.g. faxing). We have control over the document load process, so we can manipulate the data however it needs to be to get it in the document store (e.g. assign unique IDs). Users will not be adding in their own documents, so we shouldn't need to worry about ACID compliance, as the documents are relatively static. So, my questions I guess : Is a NoSQL DB a good fit Is MongoDB the best for Asp.Net (I saw Raven and Velocity, but they're still kinda beta) Can I store a key for each document, and then store the action history in a MSSQL DB with this key? I don't need to do joins, it would be if a person clicks "View History" against a document. How would performance compare between the two (NoSQL DB vs denormalized "document" table) Volumes would be up to 200,000 new documents per month for a single tenant. My current scaling plan with the SQL DB involves moving the SQL DB into a cluster when certain thresholds are reached, and then reviewing partitioning and indexing structures.

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  • PHP + Code Igniter Timecode Calculation Logic Error

    - by Tim
    Hello everyone, I have what I suspect to be a logic problem with an algorithm I am using to work with Video timecode in PHP. All help is appreciated. The Objective Well basically I want to work with timecode and perform calculations For those not familiar with timecode it looks like this 01:10:58:12 or HH:MM:SS:FF 'AKA' HOURS:MINUTES:SECONDS:FRAMES I have used the script from HERE to help me with working with this format. The Problem Now can i just say that this script works!!! Timecode calculations (in this case additions) are being performed correctly. However this script continually throws the following errors, yet still produces the correct output when I try and do the following calculation 00:01:26:00 + 00:02:00:12 The errors from this calculation are shown below A PHP Error was encountered Severity: Notice Message: Undefined index: key Filename: staff/tools.php Line Number: 169 A PHP Error was encountered Severity: Notice Message: Undefined index: key Filename: staff/tools.php Line Number: 169 Line Number 169 is in the parseInput() function // feed it into the tc array $i=0; foreach ($tc AS $key=>$value) { if ( is_numeric($array["$i"]) ) { $tc["$key"]= $array["$i"]; if ($tc["$key"] < 10 && $tc["$key"] > 0 && strlen($tc['key'])==1 ) $tc["$key"]= "0".$tc["$key"]; } $i++; } return $tc; Now I should also mention that the number of times the above error is thrown depends on what I am calculating 00:00:00:00 + 00:00:00:00 returns no errors. 01:01:01:01 + 02:02:02:02 produces 8 of the above errors. For your reference, here is the code in it's entirety function add_cue_sheet_clips_process() { $sheetID = $_POST['sheet_id']; $clipName = $_POST['clip_name']; $tcIn = $_POST['tc_in']; $tcOut = $_POST['tc_out']; // string $input // returns an associative array of hours, minutes, seconds, and frames // function parseInput ($input) { // timecode should look something like hh:mm:ss;ff // allowed separators are : ; . , // values may be single or double digits // hours are least-significant -- 5.4 == 00:00:05;04 $tc= array("frames"=>"00", "seconds"=>"00", "minutes"=>"00", "hours"=>"00"); $punct= array(":", ";", ".", ","); // too big? too small? $input= trim($input); if (strlen($input)>11 || $input=="") { // invalid input, too long -- bzzt return $tc; } // normalize punctuation $input= str_replace( $punct, ":", $input); // blow it up and reverse it so frames come first $array= explode(":", $input); $array= array_reverse($array); // feed it into the tc array $i=0; foreach ($tc AS $key=>$value) { if ( is_numeric($array["$i"]) ) { $tc["$key"]= $array["$i"]; if ($tc["$key"] < 10 && $tc["$key"] > 0 && strlen($tc['key'])==1 ) $tc["$key"]= "0".$tc["$key"]; } $i++; } return $tc; } // array $tc // returns a float number of seconds // function tcToSec($tc) { $wholeseconds= ($tc['hours']*3600) + ($tc['minutes'] * 60) + ($tc['seconds']); $partseconds= ( $tc['frames'] / 25 ); $seconds= $wholeseconds + $partseconds; return $seconds; } // float $seconds // bool $subtract // returns a timecode array // function secToTc ($seconds=0, $subtract=0) { $tc= array("frames"=>"00", "seconds"=>"00", "minutes"=>"00", "hours"=>"00"); $partseconds= fmod($seconds, 1); $wholeseconds= $seconds - $partseconds; // frames if ($subtract==1) $tc['frames']= floor( $partseconds * 25 ); else $tc['frames']= floor( $partseconds * 25 ); // hours $tc['hours']= floor( $wholeseconds / 3600 ); $minsec= ($wholeseconds - ($tc['hours'] * 3600)); // minutes $tc['minutes']= floor( $minsec / 60 ); // seconds $tc['seconds']= ( $minsec - ($tc['minutes'] * 60) ); // padding foreach ( $tc AS $key=>$value ) { if ($value > 0 && $value < 10) $tc["$key"]= "0".$value; if ($value=="0") $tc["$key"]= "00"; } return $tc; } // array $tc // returns string of well-formed timecode // function tcToString (&$tc) { return $tc['hours'].":".$tc['minutes'].":".$tc['seconds'].";".$tc['frames']; } $timecodeIN = parseInput($tcIn); $timecodeOUT = parseInput($tcOut); // normalized inputs... $tc1 = tcToString($timecodeIN); $tc2 = tcToString($timecodeOUT); // get seconds $seconds1 = tcToSec($timecodeIN); $seconds2 = tcToSec($timecodeOUT); $result = $seconds1 + $seconds2; $timecode3 = secToTc($result, 0); $timecodeDUR = tcToString($timecode3); $clipArray = array('clip_name' => $clipName, 'tc_in' => $tcIn, 'tc_out' => $tcOut, 'tc_duration' => $timecodeDUR); $this->db->insert('tools_cue_sheets_clips', $clipArray); redirect('staff/tools/add_cue_sheet_clips/'.$sheetID); } I hope this is enough information for someone to help me get on top of this, I would be extremely greatful. Thanks, Tim

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  • What are five things you hate about your favorite language?

    - by brian d foy
    There's been a cluster of Perl-hate on Stackoverflow lately, so I thought I'd bring my "Five things you hate about your favorite language" question to StackOverflow. Take your favorite language and tell me five things you hate about it. Those might be things that just annoy you, admitted design flaws, recognized performance problems, or any other category. You just have to hate it, and it has to be your favorite language. Don't compare it to another language, and don't talk about languages that you already hate. Don't talk about the things you like in your favorite language. I just want to hear the things that you hate but tolerate so you can use all of the other stuff, and I want to hear it about the language you wished other people would use. I ask this whenever someone tries to push their favorite language on me, and sometimes as an interview question. If someone can't find five things to hate about his favorite tool, he don't know it well enough to either advocate it or pull in the big dollars using it. He hasn't used it in enough different situations to fully explore it. He's advocating it as a culture or religion, which means that if I don't choose his favorite technology, I'm wrong. I don't care that much which language you use. Don't want to use a particular language? Then don't. You go through due diligence to make an informed choice and still don't use it? Fine. Sometimes the right answer is "You have a strong programming team with good practices and a lot of experience in Bar. Changing to Foo would be stupid." This is a good question for code reviews too. People who really know a codebase will have all sorts of suggestions for it, and those who don't know it so well have non-specific complaints. I ask things like "If you could start over on this project, what would you do differently?" In this fantasy land, users and programmers get to complain about anything and everything they don't like. "I want a better interface", "I want to separate the model from the view", "I'd use this module instead of this other one", "I'd rename this set of methods", or whatever they really don't like about the current situation. That's how I get a handle on how much a particular developer knows about the codebase. It's also a clue about how much of the programmer's ego is tied up in what he's telling me. Hate isn't the only dimension of figuring out how much people know, but I've found it to be a pretty good one. The things that they hate also give me a clue how well they are thinking about the subject.

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  • IE and Content-disposition inline vs. extension-token

    - by pinkgothic
    Preamble So IE does Mime-Type sniffing. That part's old news. Suggestions of how to combat it tend to be along the lines of 'supply a content-type IE trusts' (i.e. anything that isn't text/plain or application/octet-stream) or 'add extraneous data at the start of the file that is definitely of the type you're serving'. Now, I'm working on an application that has to allow message attachments (like in e-mails), and we want to close up XSS vectors. IE's mime sniffing is one of those vectors - a text/plain file with html content will trigger as html. Recoding isn't an option at this point, changing the attachments the user has provided can only happen if there is absolutely no doubt about the maliciousness of the file - and someone might want to send HTML as text. Now, Microsoft's MSDN article implies the situation might be easier to fix than advertised: If Internet Explorer knows the Content-Type specified and there is no Content-Disposition data, Internet Explorer performs a "MIME sniff," [...] Great! Except I don't have IE nor current means to reliably install it (I realise this is a fairly sad state for a webdeveloper to be in, I hope to fix this soon) and this is grey theory that I can't quite seem to get confirmed one way or the other. Local sources say that line is hogwash - IE will mime sniff anything that is Content-Disposition: inline / <default> and not specific enough for its tastes in -Type. But what about x-* ('extension-token' in the RFC)? Trying to google for how browsers handle Content-Disposition: <extension-token> hasn't yielded anything (though I may just be doing it wrong, my understanding of Google is seriously slipping lately). I found one question that looked promising, but turned out to be a misunderstanding on side of the thread author, meaning that the train of thought was never actually addressed there. Question(s) Does IE really Mime sniff if you expressly pass Content-Disposition: inline? If so: Does anyone here know how browsers handle Content-Disposition: <extension-token>? If they do this in a way that is for my purposes benign, by presuming it to be synonymous with the default (effectively 'inline', though I hear it's not defined anywhere?), is it specific enough for IE not to Mime sniff? Or am I actually shooting myself in the foot by thinking of pursuing this avenue?

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  • Oracle Coding Standards Feature Implementation

    - by Mike Hofer
    Okay, I have reached a sort of an impasse. In my open source project, a .NET-based Oracle database browser, I've implemented a bunch of refactoring tools. So far, so good. The one feature I was really hoping to implement was a big "Global Reformat" that would make the code (scripts, functions, procedures, packages, views, etc.) standards compliant. (I've always been saddened by the lack of decent SQL refactoring tools, and wanted to do something about it.) Unfortunatey, I am discovering, much to my chagrin, that there doesn't seem to be any one widely-used or even "generally accepted" standard for PL-SQL. That kind of puts a crimp on my implementation plans. My search has been fairly exhaustive. I've found lots of conflicting documents, threads and articles and the opinions are fairly diverse. (Comma placement, of all things, seems to generate quite a bit of debate.) So I'm faced with a couple of options: Add a feature that lets the user customize the standard and then reformat the code according to that standard. —OR— Add a feature that lets the user customize the standard and simply generate a violations list like StyleCop does, leaving the SQL untouched. In my mind, the first option saves the end-users a lot of work, but runs the risk of modifying SQL in potentially unwanted ways. The second option runs the risk of generating lots of warnings and doing no work whatsoever. (It'd just be generally annoying.) In either scenario, I still have no standard to go by. What I'd need to know from you guys is kind of poll-ish, but kind of not. If you were going to use a tool of this nature, what parts of your SQL code would you want it to warn you about or fix? Again, I'm just at a loss due to a lack of a cohesive standard. And given that there isn't anything out there that's officially published by Oracle, I think this is something the community could weigh in on. Also, given the way that voting works on SO, the votes would help to establish the popularity of a given "refactoring." P.S. The engine parses SQL into an expression tree so it can robustly analyze the SQL and reformat it. There should be quite a bit that we can do to correct the format of the SQL. But I am thinking that for the first release of the thing, layout is the primary concern. Though it is worth noting that the thing already has refactorings for converting keywords to upper case, and identifiers to lower case.

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  • Volunteer for a potential employer?

    - by EoRaptor013
    I've been looking for work since March, and haven't had much luck. Recently, however, I interviewed with a small company near my home for a C#, .NET, SQL development position. I hit it off very well with the hiring manager during the phone screen, and even more so during the face to face. Unfortunately, I failed the practical test: wiring up a web form, creating a couple of SQL stored procedures, saving new data with validation, and creating a minimal search screen. I knew what I was doing, but I was too slow to meet their standards as all the work needed to be done within an hour. Nevertheless, I really liked the place, the environment, the people who I would have been working with, and the boss. (I gave the company an 11 on Joel's 12 point scale.) So, the obvious next step was to scrape the rust off. I've been trying to create little projects for myself, but I don't know that I've been effective in getting any faster. What with all that goes into creating a project, I'm not heads-down coding as much as I think I need. Now, with all that introduction, here's the question. I have been thinking about calling the hiring manager at that place, and asking him to let me volunteer for three or four weeks, with no strings attached. I think it would benefit me, and wouldn't cost him anything (as long as I didn't slow the existing people down!). At the end of that period, he might, or might not, be inclined to hire me, but even if not, I would have had as much as 160 hours of in the trenches development. Maybe not all shiny, but no more rust, I would think. Does this plan make any sense at all? I certainly don't want to sound desperate (although, I'm not far from being there), and I very much need the tuneup, lube, and change the oil. What's the downside, if any, to me doing this? Do any of you see red flags going up—either from the prerspective of the hiring manager, or from the perspective of a developer?

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  • How is IObservable<double>.Average supposed to work?

    - by Dan Tao
    Update Looks like Jon Skeet was right (big surprise!) and the issue was with my assumption about the Average extension providing a continuous average (it doesn't). For the behavior I'm after, I wrote a simple ContinuousAverage extension method, the implementation of which I am including here for the benefit of others who may want something similar: public static class ObservableExtensions { private class ContinuousAverager { private double _mean; private long _count; public ContinuousAverager() { _mean = 0.0; _count = 0L; } // undecided whether this method needs to be made thread-safe or not // seems that ought to be the responsibility of the IObservable (?) public double Add(double value) { double delta = value - _mean; _mean += (delta / (double)(++_count)); return _mean; } } public static IObservable<double> ContinousAverage(this IObservable<double> source) { var averager = new ContinuousAverager(); return source.Select(x => averager.Add(x)); } } I'm thinking of going ahead and doing something like the above for the other obvious candidates as well -- so, ContinuousCount, ContinuousSum, ContinuousMin, ContinuousMax ... perhaps ContinuousVariance and ContinuousStandardDeviation as well? Any thoughts on that? Original Question I use Rx Extensions a little bit here and there, and feel I've got the basic ideas down. Now here's something odd: I was under the impression that if I wrote this: var ticks = Observable.FromEvent<QuoteEventArgs>(MarketDataProvider, "MarketTick"); var bids = ticks .Where(e => e.EventArgs.Quote.HasBid) .Select(e => e.EventArgs.Quote.Bid); var bidsSubscription = bids.Subscribe( b => Console.WriteLine("Bid: {0}", b) ); var avgOfBids = bids.Average(); var avgOfBidsSubscription = avgOfBids.Subscribe( b => Console.WriteLine("Avg Bid: {0}", b) ); I would get two IObservable<double> objects (bids and avgOfBids); one would basically be a stream of all the market bids from my MarketDataProvider, the other would be a stream of the average of these bids. So something like this: Bid Avg Bid 1 1 2 1.5 1 1.33 2 1.5 It seems that my avgOfBids object isn't doing anything. What am I missing? I think I've probably misunderstood what Average is actually supposed to do. (This also seems to be the case for all of the aggregate-like extension methods on IObservable<T> -- e.g., Max, Count, etc.)

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  • Creating a variable list Pashua, OS X & Bash.

    - by S1syphus
    First of all, for those that don't know pashua is a tool for creating native Aqua dialog windows. An example of what a window config looks like is # pashua_run() # Define what the dialog should be like # Take a look at Pashua's Readme file for more info on the syntax conf=" # Set transparency: 0 is transparent, 1 is opaque *.transparency=0.95 # Set window title *.title = Introducing Pashua # Introductory text tb.type = text tb.default = "HELLO WORLD" tb.height = 276 tb.width = 310 tb.x = 340 tb.y = 44 if [ -e "$icon" ] then # Display Pashua's icon conf="$conf img.type = image img.x = 530 img.y = 255 img.path = $icon" fi if [ -e "$bgimg" ] then # Display background image conf="$conf bg.type = image bg.x = 30 bg.y = 2 bg.path = $bgimg" fi pashua_run "$conf" echo " tb = $tb" The problem is, Pashua can't really get output from stdout, but it can get arguments. Following on from what Dennis Williamson posted here. What ideally it should do is generate an output file based on information from a text file, To executed in pashua_run ore add the pashua_run around the window argument: count=1 while read -r i do echo "AB${count}.type = openbrowser" echo "AB${count}.label = Choose a master playlist file" echo "AB${count}.width=310" echo "AB${count}.tooltip = Blabla filesystem browser" echo "some text with a line from the file: $i" (( count++ )) done < TEST.txt >> long.txt SO the output is AB1.type = openbrowser AB1.label = Choose a master playlist file AB1.width=310 AB1.tooltip = Blabla filesystem browser some text with a line from the file: foo AB2.type = openbrowser AB2.label = Choose a master playlist file AB2.width=310 AB2.tooltip = Blabla filesystem browser some text with a line from the file: bar AB3.type = openbrowser AB3.label = Choose a master playlist file AB3.width=310 AB3.tooltip = Blabla filesystem browser some text with a line from the file: dev AB4.type = openbrowser AB4.label = Choose a master playlist file AB4.width=310 AB4.tooltip = Blabla filesystem random So if there is a clever way to get the output of that and place it into pashua run would be cool, on the fly: I.E load te contents of TEST.txt and generate the place it into pashua_run, I've tried using cat and opening the file... but because it's in Pashua_run it doesn't work, is there a smart way to break out then back in? Or the second way which I was thinking, was create get the output then append it into the middle text file containing the pashua runtime, then execute it, maybe slightly hacky, but I would imagine it will do the job. Any ideas? ++ I know I probably could make my life a lot easier, by doing this in actionscript and cocoa, although at present don't have time for such a learning curve, although I do plan to get round to it.

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