conversion operators - Page 64

simplify expression k/m%n

- by aaa

hello. Simple question, is it possible to simplify (or replace division or modulo by less-expensive operation) (k/m)%n where variables are integers and operators are C style division and modulo operators. what about the case where m and n are constants (both or just one), not based 2? Thank you

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Prefix and Postfix operator's necessity

- by Karthi prime

What is the necessity of both prefix and postfix increment operators? Is not one enough? To the point, there exists like a similar while/do-while necessity problem, yet, there in no so much confusion (in understanding and usage) in having them, but with having both prefix and postfix (like priority of these operators, their association, usage, working). And do anyone been through a situation where you saidd "Hey, I am going to use postfix increment. Its useful here"

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Doubt in Conditional inclusion

- by Philando Gullible

This is actually extracted from my module (Pre-processor in C) The conditional expression could contain any C operator except for the assignment operators,increment, and decrement operators. I am not sure if I am getting this statement or not since I tried using this and it worked.Also for other manipulation a probable work around would be to simply declare macro or function inside the conditional expression,something like this to be precise. Also I don't understand what is the rationale behind this rule. Could somebody explain? Thanks

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Where namespace does operator<< (stream) go to?

- by aaa

If I have have some overloaded ostream operators, defined for library local objects, is its okay for them to go to std namespace? If I do not declare them in std namespace, then I must use using ns:: operator <<. As a possible follow-up question, are there any operators which should go to standard or global namespace?

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How to Convert Videos to 3GP for Mobile Phones

- by DigitalGeekery

Would you like to play videos on your phone, but the device only supports 3GP files? We’ll show you how to convert popular video files into 3GP mobile phone video format with Pazera Free Video to 3GP Converter. Download the Pazera Free Video to 3GP Converter (Download link below). It will allow you to convert popular video files (AVI, MPEG, MP4, FLV, MKV, and MOV) to work on your mobile phone. There is no installation to run. You’ll just need to unzip the download folder and double-click the videoto3gp.exe file to run the application. To add video files to the queue, click on the Add files button. Browse for your file, and click Open. Your video will be added to the Queue. You can add multiple files to the queue and convert them all at one time. The converter comes with several pre-configured profiles for conversion settings. To load a profile, select one from the Profile drop down list and then click the Load button. The settings in the panels at the bottom of the application will be automatically updated. If you are a more advanced user, the options on the lower panels allow for adjusting settings to your liking. You can choose between 3GP and 3G2 (for some older phones), H.263, MPEG-4, and XviD video codecs, AAC or AMR-NB audio codecs, as well as a variety of bitrates, resolutions, etc. By default, the converted file will be output to the same location as the input directory. You can change it by clicking the text box input radio button and browsing for a different folder. Click Convert to start the conversion process. A conversion output box will open and display the progress. When finished, click Close. Now you’re ready to load the video onto your phone and enjoy. Conclusion Pazera Free Video to 3GP Converter is not exactly the ultimate video conversion tool, but it is quick and simple enough for the average user to convert most video formats to 3GP. Plus, it’s portable. You can copy the folder to a USB drive and take it with you. Do you have some 3GP video files you’d like to convert to more common formats? Check out our earlier article on how to convert 3GP to AVI and MPEG for free. Link Download Pazera Free Video to 3GP Converter Similar Articles Productive Geek Tips Convert .3GP and .3G2 Files to AVI / MPEG for FreeExtract Audio from a Video File with Pazera Free Audio ExtractorConvert PDF Files to Word Documents and Other FormatsConvert YouTube Videos to MP3 with YouTube DownloaderFriday Fun: Watch HD Video Content with Meevid TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips VMware Workstation 7 Acronis Online Backup DVDFab 6 Revo Uninstaller Pro Daily Motivator (Firefox) FetchMp3 Can Download Videos & Convert Them to Mp3 Use Flixtime To Create Video Slideshows Creating a Password Reset Disk in Windows Bypass Waiting Time On Customer Service Calls With Lucyphone MELTUP – "The Beginning Of US Currency Crisis And Hyperinflation"

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How to add new filters to CAML queries in SharePoint 2007

- by uruit

Normal 0 21 false false false ES-UY X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} One flexibility SharePoint has is CAML (Collaborative Application Markup Language). CAML it’s a markup language like html that allows developers to do queries against SharePoint lists, it’s syntax is very easy to understand and it allows to add logical conditions like Where, Contains, And, Or, etc, just like a SQL Query. For one of our projects we have the need to do a filter on SharePoint views, the problem here is that the view it’s a list containing a CAML Query with the filters the view may have, so in order to filter the view that’s already been filtered before, we need to append our filters to the existing CAML Query. That’s not a trivial task because the where statement in a CAML Query it’s like this: <Where> <And> <Filter1 /> <Filter2 /> </And> </Where> If we want to add a new logical operator, like an OR it’s not just as simple as to append the OR expression like the following example: <Where> <And> <Filter1 /> <Filter2 /> </And> <Or> <Filter3 /> </Or> </Where> But instead the correct query would be: <Where> <Or> <And> <Filter1 /> <Filter2 /> </And> <Filter3 /> </Or> </Where> Notice that the <Filter# /> tags are for explanation purpose only. In order to solve this problem we created a simple component, it has a method that receives the current query (could be an empty query also) and appends the expression you want to that query. Example: string currentQuery = @“ <Where> <And> <Contains><FieldRef Name='Title' /><Value Type='Text'>A</Value></Contains> <Contains><FieldRef Name='Title' /><Value Type='Text'>B</Value></Contains> </And> </Where>”; currentQuery = CAMLQueryBuilder.AppendQuery( currentQuery, “<Contains><FieldRef Name='Title' /><Value Type='Text'>C</Value></Contains>”, CAMLQueryBuilder.Operators.Or); The fist parameter this function receives it’s the actual query, the second it’s the filter you want to add, and the third it’s the logical operator, so basically in this query we want all the items that the title contains: the character A and B or the ones that contains the character C. The result query is: <Where> <Or> <And> <Contains><FieldRef Name='Title' /><Value Type='Text'>A</Value></Contains> <Contains><FieldRef Name='Title' /><Value Type='Text'>B</Value></Contains> </And> <Contains><FieldRef Name='Title' /><Value Type='Text'>C</Value></Contains> </Or> </Where> The code: First of all we have an enumerator inside the CAMLQueryBuilder class that has the two possible Options And, Or. public enum Operators { And, Or } Then we have the main method that’s the one that performs the append of the filters. public static string AppendQuery(string containerQuery, string logicalExpression, Operators logicalOperator){ In this method the first we do is create a new XmlDocument and wrap the current query (that may be empty) with a “<Query></Query>” tag, because the query that comes with the view doesn’t have a root element and the XmlDocument must be a well formatted xml. XmlDocument queryDoc = new XmlDocument(); queryDoc.LoadXml("<Query>" + containerQuery + "</Query>"); The next step is to create a new XmlDocument containing the logical expression that has the filter needed. XmlDocument logicalExpressionDoc = new XmlDocument(); logicalExpressionDoc.LoadXml("<root>" + logicalExpression + "</root>"); In these next four lines we extract the expression from the recently created XmlDocument and create an XmlElement. XmlElement expressionElTemp = (XmlElement)logicalExpressionDoc.SelectSingleNode("/root/*"); XmlElement expressionEl = queryDoc.CreateElement(expressionElTemp.Name); expressionEl.InnerXml = expressionElTemp.InnerXml; Below are the main steps in the component logic. The first “if” checks if the actual query doesn’t contains a “Where” clause. In case there’s no “Where” we add it and append the expression. In case that there’s already a “Where” clause, we get the entire statement that’s inside the “Where” and reorder the query removing and appending elements to form the correct query, that will finally filter the list. XmlElement whereEl; if (!containerQuery.Contains("Where")) { queryDoc.FirstChild.AppendChild(queryDoc.CreateElement("Where")); queryDoc.SelectSingleNode("/Query/Where").AppendChild(expressionEl); } else { whereEl = (XmlElement)queryDoc.SelectSingleNode("/Query/Where"); if (!containerQuery.Contains("<And>") && !containerQuery.Contains("<Or>")) { XmlElement operatorEl = queryDoc.CreateElement(GetName(logicalOperator)); XmlElement existingExpression = (XmlElement)whereEl.SelectSingleNode("/Query/Where/*"); whereEl.RemoveChild(existingExpression); operatorEl.AppendChild(existingExpression); operatorEl.AppendChild(expressionEl); whereEl.AppendChild(operatorEl); } else { XmlElement operatorEl = queryDoc.CreateElement(GetName(logicalOperator)); XmlElement existingOperator = (XmlElement)whereEl.SelectSingleNode("/Query/Where/*"); whereEl.RemoveChild(existingOperator); operatorEl.AppendChild(existingOperator); operatorEl.AppendChild(expressionEl); whereEl.AppendChild(operatorEl); } } return queryDoc.FirstChild.InnerXml } Finally the GetName method converts the Enum option to his string equivalent. private static string GetName(Operators logicalOperator) { return Enum.GetName(typeof(Operators), logicalOperator); } This component helped our team a lot using SharePoint 2007 and modifying the queries, but now in SharePoint 2010; that wouldn’t be needed because of the incorporation of LINQ to SharePoint. This new feature enables the developers to do typed queries against SharePoint lists without the need of writing any CAML code. Normal 0 21 false false false ES-UY X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-fareast-language:EN-US;} Post written by Sebastian Rodriguez - Portals and Collaboration Solutions @ UruIT

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How to add new filters to CAML queries in SharePoint 2007

- by uruit

Normal 0 21 false false false ES-UY X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} One flexibility SharePoint has is CAML (Collaborative Application Markup Language). CAML it’s a markup language like html that allows developers to do queries against SharePoint lists, it’s syntax is very easy to understand and it allows to add logical conditions like Where, Contains, And, Or, etc, just like a SQL Query. For one of our projects we have the need to do a filter on SharePoint views, the problem here is that the view it’s a list containing a CAML Query with the filters the view may have, so in order to filter the view that’s already been filtered before, we need to append our filters to the existing CAML Query. That’s not a trivial task because the where statement in a CAML Query it’s like this: <Where> <And> <Filter1 /> <Filter2 /> </And> </Where> If we want to add a new logical operator, like an OR it’s not just as simple as to append the OR expression like the following example: <Where> <And> <Filter1 /> <Filter2 /> </And> <Or> <Filter3 /> </Or> </Where> But instead the correct query would be: <Where> <Or> <And> <Filter1 /> <Filter2 /> </And> <Filter3 /> </Or> </Where> Notice that the <Filter# /> tags are for explanation purpose only. In order to solve this problem we created a simple component, it has a method that receives the current query (could be an empty query also) and appends the expression you want to that query. Example: string currentQuery = @“ <Where> <And> <Contains><FieldRef Name='Title' /><Value Type='Text'>A</Value></Contains> <Contains><FieldRef Name='Title' /><Value Type='Text'>B</Value></Contains> </And> </Where>”; currentQuery = CAMLQueryBuilder.AppendQuery( currentQuery, “<Contains><FieldRef Name='Title' /><Value Type='Text'>C</Value></Contains>”, CAMLQueryBuilder.Operators.Or); The fist parameter this function receives it’s the actual query, the second it’s the filter you want to add, and the third it’s the logical operator, so basically in this query we want all the items that the title contains: the character A and B or the ones that contains the character C. The result query is: <Where> <Or> <And> <Contains><FieldRef Name='Title' /><Value Type='Text'>A</Value></Contains> <Contains><FieldRef Name='Title' /><Value Type='Text'>B</Value></Contains> </And> <Contains><FieldRef Name='Title' /><Value Type='Text'>C</Value></Contains> </Or> </Where> The code: First of all we have an enumerator inside the CAMLQueryBuilder class that has the two possible Options And, Or. public enum Operators { And, Or } Then we have the main method that’s the one that performs the append of the filters. public static string AppendQuery(string containerQuery, string logicalExpression, Operators logicalOperator){ In this method the first we do is create a new XmlDocument and wrap the current query (that may be empty) with a “<Query></Query>” tag, because the query that comes with the view doesn’t have a root element and the XmlDocument must be a well formatted xml. XmlDocument queryDoc = new XmlDocument(); queryDoc.LoadXml("<Query>" + containerQuery + "</Query>"); The next step is to create a new XmlDocument containing the logical expression that has the filter needed. XmlDocument logicalExpressionDoc = new XmlDocument(); logicalExpressionDoc.LoadXml("<root>" + logicalExpression + "</root>"); In these next four lines we extract the expression from the recently created XmlDocument and create an XmlElement. XmlElement expressionElTemp = (XmlElement)logicalExpressionDoc.SelectSingleNode("/root/*"); XmlElement expressionEl = queryDoc.CreateElement(expressionElTemp.Name); expressionEl.InnerXml = expressionElTemp.InnerXml; Below are the main steps in the component logic. The first “if” checks if the actual query doesn’t contains a “Where” clause. In case there’s no “Where” we add it and append the expression. In case that there’s already a “Where” clause, we get the entire statement that’s inside the “Where” and reorder the query removing and appending elements to form the correct query, that will finally filter the list. XmlElement whereEl; if (!containerQuery.Contains("Where")) { queryDoc.FirstChild.AppendChild(queryDoc.CreateElement("Where")); queryDoc.SelectSingleNode("/Query/Where").AppendChild(expressionEl); } else { whereEl = (XmlElement)queryDoc.SelectSingleNode("/Query/Where"); if (!containerQuery.Contains("<And>") && !containerQuery.Contains("<Or>")) { XmlElement operatorEl = queryDoc.CreateElement(GetName(logicalOperator)); XmlElement existingExpression = (XmlElement)whereEl.SelectSingleNode("/Query/Where/*"); whereEl.RemoveChild(existingExpression); operatorEl.AppendChild(existingExpression); operatorEl.AppendChild(expressionEl); whereEl.AppendChild(operatorEl); } else { XmlElement operatorEl = queryDoc.CreateElement(GetName(logicalOperator)); XmlElement existingOperator = (XmlElement)whereEl.SelectSingleNode("/Query/Where/*"); whereEl.RemoveChild(existingOperator); operatorEl.AppendChild(existingOperator); operatorEl.AppendChild(expressionEl); whereEl.AppendChild(operatorEl); } } return queryDoc.FirstChild.InnerXml } Finally the GetName method converts the Enum option to his string equivalent. private static string GetName(Operators logicalOperator) { return Enum.GetName(typeof(Operators), logicalOperator); } Normal 0 21 false false false ES-UY X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Normal 0 21 false false false ES-UY X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} This component helped our team a lot using SharePoint 2007 and modifying the queries, but now in SharePoint 2010; that wouldn’t be needed because of the incorporation of LINQ to SharePoint. This new feature enables the developers to do typed queries against SharePoint lists without the need of writing any CAML code. But there is still much development to the 2007 version, so I hope this information is useful for other members. Post Normal 0 21 false false false ES-UY X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-fareast-language:EN-US;} written by Sebastian Rodriguez - Portals and Collaboration Solutions @ UruIT

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Constant NSDictionary/NSArray for class methods.

- by Jeff B

I am trying to code a global lookup table of sorts. I have game data that is stored in character/string format in a plist, but which needs to be in integer/id format when it is loaded. For instance, in the level data file, a "p" means player. In the game code a player is represented as the integer 1. This let's me do some bitwise operations, etc. I am simplifying greatly here, but trying to get the point across. Also, there is a conversion to coordinates for the sprite on a sprite sheet. Right now this string-integer, integer-string, integer-coordinate, etc. conversion is taking place in several places in code using a case statement. This stinks, of course, and I would rather do it with a dictionary lookup. I created a class called levelInfo, and want to define the dictionary for this conversion, and then class methods to call when I need to do a conversion, or otherwise deal with level data. NSString *levelObjects = @"empty,player,object,thing,doohickey"; int levelIDs[] = [0,1,2,4,8]; // etc etc @implementation LevelInfo +(int) crateIDfromChar: (char) crateChar { int idx = [[crateTypes componentsSeparatedByString:@","] indexOfObject: crateChar]; return levelIDs[idx]; } +(NSString *) crateStringFromID: (int) crateID { return [[crateTypes componentsSeparatedByString:@","] objectAtIndex: crateID]; } @end Is there a better way to do this? It feels wrong to basically build these temporary arrays, or dictionaries, or whatever for each call to do this translation. And I don't know of a way to declare a constant NSArray or NSDictionary. Please, tell me a better way....

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Cucumber could not find table; but its there. What is going on?

- by JZ

I'm working with cucumber and I'm running into difficulties. When I run "cucumber features", I am met with errors, cucumber is unable to find my requests table. What obvious mistake am I making? Thank you in advance! Bash: justin-zollarss-mac-pro:conversion justinz$ cucumber features Using the default profile... /Users/justinz/.gem/ruby/1.8/gems/rails-2.3.5/lib/rails/gem_dependency.rb:119:Warning: Gem::Dependency#version_requirements is deprecated and will be removed on or after August 2010. Use #requirement F-- (::) failed steps (::) Could not find table 'requests' (ActiveRecord::StatementInvalid) ./features/article_steps.rb:3 ./features/article_steps.rb:2:in `each' ./features/article_steps.rb:2:in `/^I have requests named (.+)$/' features/manage_articles.feature:7:in `Given I have requests named Foo, Bar' Failing Scenarios: cucumber features/manage_articles.feature:6 # Scenario: Conversion 1 scenario (1 failed) 3 steps (1 failed, 2 skipped) 0m0.154s justin-zollarss-mac-pro:conversion justinz$ Manage_articles.feature: Feature: Manage Articles In order to make sales As a customer I want to make conversions Scenario: Conversion Given I have requests named Foo, Bar When I go to the list of customers Then I should see a new "customer" Article_steps.rb: Given /^I have requests named (.+)$/ do |firsts| firsts.split(', ').each do |first| Request.create!(:first => first) pending # express the regexp above with the code you wish you had end end Then /^I should see a new "([^"]*)"$/ do |arg1| pending # express the regexp above with the code you wish you had end DB schema: ActiveRecord::Schema.define(:version => 20100528011731) do create_table "requests", :force => true do |t| t.string "institution" t.string "website" t.string "type" t.string "users" t.string "first" t.string "last" t.string "jobtitle" t.string "phone" t.string "email" t.datetime "created_at" t.datetime "updated_at" end end

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Django1.1 model field value preprocessing before returning

- by Satoru.Logic

Hi, all. I have a model class like this: class Note(models.Model): author = models.ForeignKey(User, related_name='notes') content = NoteContentField(max_length=256) NoteContentField is a custom sub-class of CharField that override the to_python method in purpose of doing some twitter-text-conversion processing. class NoteContentField(models.CharField): __metaclass__ = models.SubfieldBase def to_python(self, value): value = super(NoteContentField, self).to_python(value) from ..utils import linkify return mark_safe(linkify(value)) However, this doesn't work. When I save a Note object like this: note = Note(author=request.use, content=form.cleaned_data['content']) note.save() The conversed value is saved into the database, which is not what I wanna see. What I'm trying to do is to save the raw content into the database, and only make the conversion when the content attribute is later accessed. Would you please tell me what's wrong with this? Thanks to Pierre and Daniel. I have figured out what's wrong. I thought the text-conversion code should be in either to_python or get_db_prep_value, and that's wrong. I should override both of them, make to_python do the conversion and get_db_prep_value return the unconversed value: from ..utils import linkify class NoteContentField(models.CharField): __metaclass__ = models.SubfieldBase def to_python(self, value): self._raw_value = super(NoteContentField, self).to_python(value) return mark_safe(linkify(self._raw_value)) def get_db_prep_value(self, value): return self._raw_value I wonder if there is a better way to implement this?

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Retrieve Records from paypal csv file

- by Pankaj Khurana

Hi, I want to retrieve all the records from paypal csv file where type='Payment Processed' and store it in a database table.It should be available in the following format: 'Heading':'Value' The format of the csv is: "Transaction ID","Reference Transaction ID","Date","Type","Subject","Item Number","Item Name","Invoice ID","Name","Email","Shipping Name","Shipping Address Line 1","Shipping Address Line 2","Shipping Address City","Shipping State/Province","Shipping Zip/Postal Code","Shipping Address Country","Shipping Method","Address Status","Contact Phone Number","Gross Amount","Receipt ID","Custom Field","Option 1 Name","Option 1 Value","Option 2 Name","Option 2 Value","Note","Auction Site","Auction User ID","Item URL","Auction Closing Date","Insurance Amount","Currency","Fees","Net Amount","Shipping & Handling Amount","Sales Tax Amount","To Email","Time","Time Zone" "1T","",5/5/2010 2:10:44 PM,"Payment Processed","CFP Self Study Kit","1","CFP Self Study Kit","","User1","[email protected]","","","","","","","","","N","","68.18","R1","","","","","","","","","",,"","USD","-2.62","65.56","0","0","[email protected]","01:40","Asia/Calcutta" "2T","",5/19/2010 4:04:08 PM,"Payment Processed","CFP Self Study Kit","1","CFP Self Study Kit","","User2","[email protected]","","","","","","","","","N","","68.18","R2","","","","","","","","","",,"","USD","-2.62","65.56","0","0","[email protected]","03:34","Asia/Calcutta" "3T","1RT",5/19/2010 5:28:45 PM,"Currency Conversion Completed","","","",""," ","","","","","","","","","","N","","17492.6","","","","","","","","","","",,"","INR","0","17492.6","0","0","","04:58","Asia/Calcutta" "4T","2RT",5/19/2010 5:28:45 PM,"Currency Conversion Completed","","","",""," ","","","","","","","","","","N","","-393.36","","","","","","","","","","",,"","USD","0","-393.36","0","0","","04:58","Asia/Calcutta" "5T","",5/19/2010 5:28:45 PM,"Transfer to Bank Initiated","P1006","","P1006",""," ","","","","","","","","","","N","","-17492.6","","","","","","","","","","",,"","INR","0","-17492.6","0","0","","04:58","Asia/Calcutta" "6T","",5/20/2010 5:38:02 PM,"Transfer to Bank Completed","P1006","","P1006",""," ","","","","","","","","","","N","","-17492.6","","","","","","","","","","",,"","INR","0","-17492.6","0","0","","05:08","Asia/Calcutta" "7T","",5/21/2010 12:32:37 PM,"Payment Processed","FP - LVC Plus","","FP - LVC Plus","","User3","[email protected]","User3","NEW DELHI","BEHIND KARNATAKA BANK LD","SOUTH","NEW DELHI","110023","IN","","N","","283.96","","","","","","","","","","",,"","USD","-9.95","274.01","0","0","[email protected]","00:02","Asia/Calcutta" "8T","",5/25/2010 4:40:48 PM,"Transfer to Bank Initiated","P1006","","P1006",""," ","","","","","","","","","","N","","-12569.85","","","","","","","","","","",,"","INR","0","-12569.85","0","0","","04:10","Asia/Calcutta" "9T","3RT",5/25/2010 4:40:48 PM,"Currency Conversion Completed","","","",""," ","","","","","","","","","","N","","-274.01","","","","","","","","","","",,"","USD","0","-274.01","0","0","","04:10","Asia/Calcutta" "10T","4RT",5/25/2010 4:40:48 PM,"Currency Conversion Completed","","","",""," ","","","","","","","","","","N","","12569.85","","","","","","","","","","",,"","INR","0","12569.85","0","0","","04:10","Asia/Calcutta" "11T","",5/26/2010 4:57:39 PM,"Transfer to Bank Completed","P1006","","P1006",""," ","","","","","","","","","","N","","-12569.85","","","","","","","","","","",,"","INR","0","-12569.85","0","0","","04:27","Asia/Calcutta" "Total","-247.05 USD","-15.19","-262.24" "Total","0.00 INR","0.00","0.00" Please help me on this Thanks

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SQL SERVER – Weekly Series – Memory Lane – #032

- by Pinal Dave

Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Complete Series of Database Coding Standards and Guidelines SQL SERVER Database Coding Standards and Guidelines – Introduction SQL SERVER – Database Coding Standards and Guidelines – Part 1 SQL SERVER – Database Coding Standards and Guidelines – Part 2 SQL SERVER Database Coding Standards and Guidelines Complete List Download Explanation and Example – SELF JOIN When all of the data you require is contained within a single table, but data needed to extract is related to each other in the table itself. Examples of this type of data relate to Employee information, where the table may have both an Employee’s ID number for each record and also a field that displays the ID number of an Employee’s supervisor or manager. To retrieve the data tables are required to relate/join to itself. Insert Multiple Records Using One Insert Statement – Use of UNION ALL This is very interesting question I have received from new developer. How can I insert multiple values in table using only one insert? Now this is interesting question. When there are multiple records are to be inserted in the table following is the common way using T-SQL. Function to Display Current Week Date and Day – Weekly Calendar Straight blog post with script to find current week date and day based on the parameters passed in the function. 2008 In my beginning years, I have almost same confusion as many of the developer had in their earlier years. Here are two of the interesting question which I have attempted to answer in my early year. Even if you are experienced developer may be you will still like to read following two questions: Order Of Column In Index Order of Conditions in WHERE Clauses Example of DISTINCT in Aggregate Functions Have you ever used DISTINCT with the Aggregation Function? Here is a simple example about how users can do it. Create a Comma Delimited List Using SELECT Clause From Table Column Straight to script example where I explained how to do something easy and quickly. Compound Assignment Operators SQL SERVER 2008 has introduced new concept of Compound Assignment Operators. Compound Assignment Operators are available in many other programming languages for quite some time. Compound Assignment Operators is operator where variables are operated upon and assigned on the same line. PIVOT and UNPIVOT Table Examples Here is a very interesting question – the answer to the question can be YES or NO both. “If we PIVOT any table and UNPIVOT that table do we get our original table?” Read the blog post to get the explanation of the question above. 2009 What is Interim Table – Simple Definition of Interim Table The interim table is a table that is generated by joining two tables and not the final result table. In other words, when two tables are joined they create an interim table as resultset but the resultset is not final yet. It may be possible that more tables are about to join on the interim table, and more operations are still to be applied on that table (e.g. Order By, Having etc). Besides, it may be possible that there is no interim table; sometimes final table is what is generated when the query is run. 2010 Stored Procedure and Transactions If Stored Procedure is transactional then, it should roll back complete transactions when it encounters any errors. Well, that does not happen in this case, which proves that Stored Procedure does not only provide just the transactional feature to a batch of T-SQL. Generate Database Script for SQL Azure When talking about SQL Azure the most common complaint I hear is that the script generated from stand-along SQL Server database is not compatible with SQL Azure. This was true for some time for sure but not any more. If you have SQL Server 2008 R2 installed you can follow the guideline below to generate a script which is compatible with SQL Azure. Convert IN to EXISTS – Performance Talk It is NOT necessary that every time when IN is replaced by EXISTS it gives better performance. However, in our case listed above it does for sure give better performance. You can read about this subject in the associated blog post. Subquery or Join – Various Options – SQL Server Engine Knows the Best Every single time whenever there is a performance tuning exercise, I hear the conversation from developer where some prefer subquery and some prefer join. In this two part blog post, I explain the same in the detail with examples. Part 1 | Part 2 Merge Operations – Insert, Update, Delete in Single Execution MERGE is a new feature that provides an efficient way to do multiple DML operations. In earlier versions of SQL Server, we had to write separate statements to INSERT, UPDATE, or DELETE data based on certain conditions; however, at present, by using the MERGE statement, we can include the logic of such data changes in one statement that even checks when the data is matched and then just update it, and similarly, when the data is unmatched, it is inserted. 2011 Puzzle – Statistics are not updated but are Created Once Here is the quick scenario about my setup. Create Table Insert 1000 Records Check the Statistics Now insert 10 times more 10,000 indexes Check the Statistics – it will be NOT updated – WHY? Question to You – When to use Function and When to use Stored Procedure Personally, I believe that they are both different things - they cannot be compared. I can say, it will be like comparing apples and oranges. Each has its own unique use. However, they can be used interchangeably at many times and in real life (i.e., production environment). I have personally seen both of these being used interchangeably many times. This is the precise reason for asking this question. 2012 In year 2012 I had two interesting series ran on the blog. If there is no fun in learning, the learning becomes a burden. For the same reason, I had decided to build a three part quiz around SEQUENCE. The quiz was to identify the next value of the sequence. I encourage all of you to take part in this fun quiz. Guess the Next Value – Puzzle 1 Guess the Next Value – Puzzle 2 Guess the Next Value – Puzzle 3 Guess the Next Value – Puzzle 4 Simple Example to Configure Resource Governor – Introduction to Resource Governor Resource Governor is a feature which can manage SQL Server Workload and System Resource Consumption. We can limit the amount of CPU and memory consumption by limiting /governing /throttling on the SQL Server. If there are different workloads running on SQL Server and each of the workload needs different resources or when workloads are competing for resources with each other and affecting the performance of the whole server resource governor is a very important task. Tricks to Replace SELECT * with Column Names – SQL in Sixty Seconds #017 – Video Retrieves unnecessary columns and increases network traffic When a new columns are added views needs to be refreshed manually Leads to usage of sub-optimal execution plan Uses clustered index in most of the cases instead of using optimal index It is difficult to debug SQL SERVER – Load Generator – Free Tool From CodePlex The best part of this SQL Server Load Generator is that users can run multiple simultaneous queries again SQL Server using different login account and different application name. The interface of the tool is extremely easy to use and very intuitive as well. A Puzzle – Swap Value of Column Without Case Statement Let us assume there is a single column in the table called Gender. The challenge is to write a single update statement which will flip or swap the value in the column. For example if the value in the gender column is ‘male’ swap it with ‘female’ and if the value is ‘female’ swap it with ‘male’. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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Take,Skip and Reverse Operator in Linq

- by Jalpesh P. Vadgama

I have found three more new operators in Linq which is use full in day to day programming stuff. Take,Skip and Reverse. Here are explanation of operators how it works. Take Operator: Take operator will return first N number of element from entities. Skip Operator: Skip operator will skip N number of element from entities and then return remaining elements as a result. Reverse Operator: As name suggest it will reverse order of elements of entities. Here is the examples of operators where i have taken simple string array to demonstrate that. C#, using GeSHi 1.0.8.6 using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace ConsoleApplication1 { class Program { static void Main(string[] args) { string[] a = { "a", "b", "c", "d" }; Console.WriteLine("Take Example"); var TkResult = a.Take(2); foreach (string s in TkResult) { Console.WriteLine(s); } Console.WriteLine("Skip Example"); var SkResult = a.Skip(2); foreach (string s in SkResult) { Console.WriteLine(s); } Console.WriteLine("Reverse Example"); var RvResult = a.Reverse(); foreach (string s in RvResult) { Console.WriteLine(s); } } } } Parsed in 0.020 seconds at 44.65 KB/s Here is the output as expected. hope this will help you.. Technorati Tags: Linq,Linq-To-Sql,ASP.NET,C#.NET

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apcupsd on Linux does not report on APC BackUPS Pro 900

- by lserni

From what documentation I could find, the UPS should be (is!) supported by Linux and ought to work with apcupsd. I looked for specific problems such as the infamous Microlink protocol, and found none. I have found a feedback from a guy in UK that reports using this very model on a not-too-different OS version (his OpenSuSE 12.1, mine 12.3 x86_64). The USB port is detected, lsusb reports Bus 002 Device 003: ID 051d:0002 American Power Conversion Uninterruptible Power Supply and lsusb -v -s002:003 confirms and expands: Bus 002 Device 003: ID 051d:0002 American Power Conversion Uninterruptible Power Supply Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.00 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 64 idVendor 0x051d American Power Conversion idProduct 0x0002 Uninterruptible Power Supply bcdDevice 0.90 iManufacturer 1 American Power Conversion iProduct 2 Back-UPS RS 900G FW:879.L4 .I USB FW:L4 bNumConfigurations 1 Configuration Descriptor: [...] Interface Descriptor: [...] bInterfaceClass 3 Human Interface Device bInterfaceSubClass 0 No Subclass bInterfaceProtocol 0 None iInterface 0 HID Device Descriptor: bLength 9 bDescriptorType 33 bcdHID 1.00 bCountryCode 33 US bNumDescriptors 1 bDescriptorType 34 Report wDescriptorLength 1134 Report Descriptors: ** UNAVAILABLE ** Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0008 1x 8 bytes bInterval 100 Device Status: 0x0000 (Bus Powered) The kernel recognizes this and duly sets up crw------- 1 root root 180, 96 Nov 4 16:11 /dev/usb/hiddev0 As far as I know, everything is as it should be. I have put the standard configuration in /etc/apcupsd/apcupsd.conf (which is Unix-terminated, ASCII-only, no BOM (just in case)) UPSCABLE usb UPSTYPE usb DEVICE (I have also tried commenting out DEVICE, and setting a device of /dev/puppa results in an access attempt to /dev/puppa, not some /var/lib/dev/puppa or /dev/puppa\r\n). Yet, what apcaccess tells me is VERSION : 3.14.10 (13 September 2011) suse CABLE : USB Cable DRIVER : USB UPS Driver UPSMODE : Stand Alone STARTTIME: 2013-11-04 16:24:22 +0100 MODEL : STATUS : NOBATT LINEV : 000.0 Volts LOADPCT : 0.0 Percent Load Capacity BCHARGE : 000.0 Percent TIMELEFT : 0.0 Minutes MBATTCHG : 5 Percent MINTIMEL : 3 Minutes MAXTIME : 0 Seconds SENSE : Low LOTRANS : 000.0 Volts HITRANS : 000.0 Volts It doesn't recognize the model, and reports no battery (and no voltage). This confirms that it's not the Microlink problem, or it would report the battery status, if precious little else. If I disconnect the USB cable, I get an apcupsd message to the effect that communications have been lost; and I get the "communication restored" broadcast too, if I reconnect the cable. apcupsd is monitoring. So everything tells me that it should work -- only it doesn't. Does anyone spot what I'm missing?

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Oracle Fusion Supply Chain Management (SCM) Designs May Improve End User Productivity

- by Applications User Experience

By Applications User Experience on March 10, 2011 Michele Molnar, Senior Usability Engineer, Applications User Experience The Challenge: The SCM User Experience team, in close collaboration with product management and strategy, completely redesigned the user experience for Oracle Fusion applications. One of the goals of this redesign was to increase end user productivity by applying design patterns and guidelines and incorporating findings from extensive usability research. But a question remained: How do we know that the Oracle Fusion designs will actually increase end user productivity? The Test: To answer this question, the SCM Usability Engineers compared Oracle Fusion designs to their corresponding existing Oracle applications using the workflow time analysis method. The workflow time analysis method breaks tasks into a sequence of operators. By applying standard time estimates for all of the operators in the task, an estimate of the overall task time can be calculated. The workflow time analysis method has been recently adopted by the Applications User Experience group for use in predicting end user productivity. Using this method, a design can be tested and refined as needed to improve productivity even before the design is coded. For the study, we selected some of our recent designs for Oracle Fusion Product Information Management (PIM). The designs encompassed tasks performed by Product Managers to create, manage, and define products for their organization. (See Figure 1 for an example.) In applying this method, the SCM Usability Engineers collaborated with Product Management to compare the new Oracle Fusion Applications designs against Oracle’s existing applications. Together, we performed the following activities: Identified the five most frequently performed tasks Created detailed task scenarios that provided the context for each task Conducted task walkthroughs Analyzed and documented the steps and flow required to complete each task Applied standard time estimates to the operators in each task to estimate the overall task completion time Figure 1. The interactions on each Oracle Fusion Product Information Management screen were documented, as indicated by the red highlighting. The task scenario and script provided the context for each task. The Results: The workflow time analysis method predicted that the Oracle Fusion Applications designs would result in productivity gains in each task, ranging from 8% to 62%, with an overall productivity gain of 43%. All other factors being equal, the new designs should enable these tasks to be completed in about half the time it takes with existing Oracle Applications. Further analysis revealed that these performance gains would be achieved by reducing the number of clicks and screens needed to complete the tasks. Conclusions: Using the workflow time analysis method, we can expect the Oracle Fusion Applications redesign to succeed in improving end user productivity. The workflow time analysis method appears to be an effective and efficient tool for testing, refining, and retesting designs to optimize productivity. The workflow time analysis method does not replace usability testing with end users, but it can be used as an early predictor of design productivity even before designs are coded. We are planning to conduct usability tests later in the development cycle to compare actual end user data with the workflow time analysis results. Such results can potentially be used to validate the productivity improvement predictions. Used together, the workflow time analysis method and usability testing will enable us to continue creating, evaluating, and delivering Oracle Fusion designs that exceed the expectations of our end users, both in the quality of the user experience and in productivity. (For more information about studying productivity, refer to the Measuring User Productivity blog.)

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Should I expose IObservable<T> on my interfaces?

- by Alex

My colleague and I have dispute. We are writing a .NET application that processes massive amounts of data. It receives data elements, groups subsets of them into blocks according to some criterion and processes those blocks. Let's say we have data items of type Foo arriving some source (from the network, for example) one by one. We wish to gather subsets of related objects of type Foo, construct an object of type Bar from each such subset and process objects of type Bar. One of us suggested the following design. Its main theme is exposing IObservable objects directly from the interfaces of our components. // ********* Interfaces ********** interface IFooSource { // this is the event-stream of objects of type Foo IObservable<Foo> FooArrivals { get; } } interface IBarSource { // this is the event-stream of objects of type Bar IObservable<Bar> BarArrivals { get; } } / ********* Implementations ********* class FooSource : IFooSource { // Here we put logic that receives Foo objects from the network and publishes them to the FooArrivals event stream. } class FooSubsetsToBarConverter : IBarSource { IFooSource fooSource; IObservable<Bar> BarArrivals { get { // Do some fancy Rx operators on fooSource.FooArrivals, like Buffer, Window, Join and others and return IObservable<Bar> } } } // this class will subscribe to the bar source and do processing class BarsProcessor { BarsProcessor(IBarSource barSource); void Subscribe(); } // ******************* Main ************************ class Program { public static void Main(string[] args) { var fooSource = FooSourceFactory.Create(); var barsProcessor = BarsProcessorFactory.Create(fooSource) // this will create FooSubsetToBarConverter and BarsProcessor barsProcessor.Subscribe(); fooSource.Run(); // this enters a loop of listening for Foo objects from the network and notifying about their arrival. } } The other suggested another design that its main theme is using our own publisher/subscriber interfaces and using Rx inside the implementations only when needed. //********** interfaces ********* interface IPublisher<T> { void Subscribe(ISubscriber<T> subscriber); } interface ISubscriber<T> { Action<T> Callback { get; } } //********** implementations ********* class FooSource : IPublisher<Foo> { public void Subscribe(ISubscriber<Foo> subscriber) { /* ... */ } // here we put logic that receives Foo objects from some source (the network?) publishes them to the registered subscribers } class FooSubsetsToBarConverter : ISubscriber<Foo>, IPublisher<Bar> { void Callback(Foo foo) { // here we put logic that aggregates Foo objects and publishes Bars when we have received a subset of Foos that match our criteria // maybe we use Rx here internally. } public void Subscribe(ISubscriber<Bar> subscriber) { /* ... */ } } class BarsProcessor : ISubscriber<Bar> { void Callback(Bar bar) { // here we put code that processes Bar objects } } //********** program ********* class Program { public static void Main(string[] args) { var fooSource = fooSourceFactory.Create(); var barsProcessor = barsProcessorFactory.Create(fooSource) // this will create BarsProcessor and perform all the necessary subscriptions fooSource.Run(); // this enters a loop of listening for Foo objects from the network and notifying about their arrival. } } Which one do you think is better? Exposing IObservable and making our components create new event streams from Rx operators, or defining our own publisher/subscriber interfaces and using Rx internally if needed? Here are some things to consider about the designs: In the first design the consumer of our interfaces has the whole power of Rx at his/her fingertips and can perform any Rx operators. One of us claims this is an advantage and the other claims that this is a drawback. The second design allows us to use any publisher/subscriber architecture under the hood. The first design ties us to Rx. If we wish to use the power of Rx, it requires more work in the second design because we need to translate the custom publisher/subscriber implementation to Rx and back. It requires writing glue code for every class that wishes to do some event processing.

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Simple Java calculator

- by Kevin Duke

Firstly this is not a homework question. I am practicing my knowledge on java. I figured a good way to do this is to write a simple program without help. Unfortunately, my compiler is telling me errors I don't know how to fix. Without changing much logic and code, could someone kindly point out where some of my errors are? Thanks import java.lang.*; import java.util.*; public class Calculator { private int solution; private int x; private int y; private char operators; public Calculator() { solution = 0; Scanner operators = new Scanner(System.in); Scanner operands = new Scanner(System.in); } public int addition(int x, int y) { return x + y; } public int subtraction(int x, int y) { return x - y; } public int multiplication(int x, int y) { return x * y; } public int division(int x, int y) { solution = x / y; return solution; } public void main (String[] args) { System.out.println("What operation? ('+', '-', '*', '/')"); System.out.println("Insert 2 numbers to be subtracted"); System.out.println("operand 1: "); x = operands; System.out.println("operand 2: "); y = operands.next(); switch(operators) { case('+'): addition(operands); operands.next(); break; case('-'): subtraction(operands); operands.next(); break; case('*'): multiplication(operands); operands.next(); break; case('/'): division(operands); operands.next(); break; } } }

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How can I specify the character encoding to be used by OLEDB when querying a DBF?

- by Manga Lee

Is it possible to specify which character encoding should be used by OLEDB when querying a DBF file? A possible work-around would be to encode the query string before the OLEDB call to the DBF file's character encoding and then encode all the results when they are returned. This will work but it would be nice if OLEDB or possibly ADO.NET could do this for me. UPDATE The suggestion by Viktor Jevdokimov does not seem to work automatically. But it made me investigate manual conversion of the strings. It is possible to use the TextInfo property of CultureInfo to find out the OemCodePage and the WindowsCodePage and use those to get the corresponding Encoding instances to perform manual conversion. But I can not get ADO.NET use these encondings to perform the conversion for me.

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Google Website Optimizer - Multi Variant Testing - Make a specific page a test page for two experime

- by wawawowo

Im having a little issue with setting up Multi Variant Tests in Google Website Optimizer. I wish to have two tests. One being which is a header banner which appears on every page and the conversion for example would be if the visitor lands on the contact us page. This was very easy to set up. However when I intend to add another test, again this will be on a element which appears on every page and the conversion page is if the visitor lands on the checkout page. But I am now having problems installing the control script. I get the error: Expected to find: }(function(){var k='0651116117',d=docum Found on line 7: (function(){var k='2666211118',d=docum Im assuming I have this error because I now have two control scripts in the header - one for each experiment. However I cannot combine each variation into just one experiment because each one is different and has a different conversion page? Please advise, thanks.

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Pros and cons of ways of storing an unsigned int without an unsigned int data type

- by fields

I have values that are 64-bit unsigned ints, and I need to store them in mongodb, which has no unsigned int type. I see three main possibilities for storing them in other field types, and converting on going in and out: Using a signed int is probably easiest and most space efficient, but has the disadvantage that they're not human readable and if someone forgets to do the conversion, some of them will work, which may obscure errors. Raw binary is probably most difficult for inexperienced programmers to deal with, and also suffers from non-human-readability. A string representation is the least space efficient (~40 bytes in unicode vs 8 bytes per field), but then at least all of the possible values will map properly, and for querying only a conversion to string is required instead of a more complicated conversion. I need these values to be available from different platforms, so a single driver-specific solution isn't an option. Any major pros and cons I've missed? Which one would you use?

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What are the precise rules/PHP function for encoding strings into POST arrays?

- by AlexeyMK

Greetings, Just getting into PHP web development. I've got an HTML form where a user checks some series of dynamically-generated checkboxes, and submits via POST. On the PHP side, I want to check which of the check-boxes were clicked. I have an array $full_list, and am doing something like $selected_checkboxes = array_filter($full_list, function($item) { array_key_exists($item, $_POST); } I run into problems when a list item is named, for example "Peanut Butter", since in the POST array it is named "Peanut_Butter". I could certainly just str_replace " " with "_" before checking array_key_exists, but I imagine that there is a more fundamental encoding problem here; specifically, I'm not sure of exactly what layer transforms normal strings in HTML Forms (value="Peanut Butter") into "Peanut_Butter". So: what layer is responsible for this conversion? Is it the browser? what are the exact conversion rules, and is there a PHP function out there that will replicate that exact conversion? Thanks!

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C++0x rvalue references - lvalues-rvalue binding

- by Doug

This is a follow-on question to http://stackoverflow.com/questions/2748866/c0x-rvalue-references-and-temporaries In the previous question, I asked how this code should work: void f(const std::string &); //less efficient void f(std::string &&); //more efficient void g(const char * arg) { f(arg); } It seems that the move overload should probably be called because of the implicit temporary, and this happens in GCC but not MSVC (or the EDG front-end used in MSVC's Intellisense). What about this code? void f(std::string &&); //NB: No const string & overload supplied void g1(const char * arg) { f(arg); } void g2(const std::string & arg) { f(arg); } It seems that, based on the answers to my previous question that function g1 is legal (and is accepted by GCC 4.3-4.5, but not by MSVC). However, GCC and MSVC both reject g2 because of clause 13.3.3.1.4/3, which prohibits lvalues from binding to rvalue ref arguments. I understand the rationale behind this - it is explained in N2831 "Fixing a safety problem with rvalue references". I also think that GCC is probably implementing this clause as intended by the authors of that paper, because the original patch to GCC was written by one of the authors (Doug Gregor). However, I don't this is quite intuitive. To me, (a) a const string & is conceptually closer to a string && than a const char *, and (b) the compiler could create a temporary string in g2, as if it were written like this: void g2(const std::string & arg) { f(std::string(arg)); } Indeed, sometimes the copy constructor is considered to be an implicit conversion operator. Syntactically, this is suggested by the form of a copy constructor, and the standard even mentions this specifically in clause 13.3.3.1.2/4, where the copy constructor for derived-base conversions is given a higher conversion rank than other implicit conversions: A conversion of an expression of class type to the same class type is given Exact Match rank, and a conversion of an expression of class type to a base class of that type is given Conversion rank, in spite of the fact that a copy/move constructor (i.e., a user-defined conversion function) is called for those cases. (I assume this is used when passing a derived class to a function like void h(Base), which takes a base class by value.) Motivation My motivation for asking this is something like the question asked in http://stackoverflow.com/questions/2696156/how-to-reduce-redundant-code-when-adding-new-c0x-rvalue-reference-operator-over ("How to reduce redundant code when adding new c++0x rvalue reference operator overloads"). If you have a function that accepts a number of potentially-moveable arguments, and would move them if it can (e.g. a factory function/constructor: Object create_object(string, vector<string>, string) or the like), and want to move or copy each argument as appropriate, you quickly start writing a lot of code. If the argument types are movable, then one could just write one version that accepts the arguments by value, as above. But if the arguments are (legacy) non-movable-but-swappable classes a la C++03, and you can't change them, then writing rvalue reference overloads is more efficient. So if lvalues did bind to rvalues via an implicit copy, then you could write just one overload like create_object(legacy_string &&, legacy_vector<legacy_string> &&, legacy_string &&) and it would more or less work like providing all the combinations of rvalue/lvalue reference overloads - actual arguments that were lvalues would get copied and then bound to the arguments, actual arguments that were rvalues would get directly bound. Questions My questions are then: Is this a valid interpretation of the standard? It seems that it's not the conventional or intended one, at any rate. Does it make intuitive sense? Is there a problem with this idea that I"m not seeing? It seems like you could get copies being quietly created when that's not exactly expected, but that's the status quo in places in C++03 anyway. Also, it would make some overloads viable when they're currently not, but I don't see it being a problem in practice. Is this a significant enough improvement that it would be worth making e.g. an experimental patch for GCC?

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PDF search on the iPhone

- by pt2ph8

After two days trying to read annotations from a PDF using Quartz, I've managed to do it and posted my code. Now I'd like to do the same for another frequently asked question: searching PDF documents with Quartz. Same situation as before, this question has been asked many times with almost no practical answers. So I need some pointers first, as I still haven't implemented this myself. What I tried: I tried using CGPDFScannerScan handling the TJ and Tj operators - returns the right text on some PDF, whereas on other documents it returns mostly random letters. Maybe it's related to text encoding? Someone pointed out that text blocks (marked by BT/ET operators) should be handled instead, but I still haven't managed to do so. Anyone managed to extract text from any PDF? After that, searching should be easy by storing all the text in a NSMutableString and using rangeOfString (if there's a better way please let me know). But then how to highlight the result? I know there are a few operators to find the glyph sizes, so I could calculate the resulting rect based on those values, but I've been reading the spec for hours... it's a bloated mess and I'm going insane. Anyone with a practical explanation? Thanks.

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storing huge amount of records into classic asp cache object is SLOW

- by aspm

we have some nasty legacy asp that is performing like a dog and i narrowed it down to because we are trying to store 15K+ records into the application cache object. but that's not the killer. before it stores it, it converts the ADO stream to XML then stores it. this conversion of the huge record set to XML spikes the CPU and causes all kinds of havoc on users when it's happening. and unfortunately we do this XML conversion to read the cache a lot, causing site wide performance problems. i don't have the resources to convert everything to .net. so that's out. but i need to obviously use caching, but int his case the caching is hurting instead of helping. is there a more effecient way to store this data instead of doing this xml conversion to/from every time we read/update the cache?

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PTLQueue : a scalable bounded-capacity MPMC queue

- by Dave

Title: Fast concurrent MPMC queue -- I've used the following concurrent queue algorithm enough that it warrants a blog entry. I'll sketch out the design of a fast and scalable multiple-producer multiple-consumer (MPSC) concurrent queue called PTLQueue. The queue has bounded capacity and is implemented via a circular array. Bounded capacity can be a useful property if there's a mismatch between producer rates and consumer rates where an unbounded queue might otherwise result in excessive memory consumption by virtue of the container nodes that -- in some queue implementations -- are used to hold values. A bounded-capacity queue can provide flow control between components. Beware, however, that bounded collections can also result in resource deadlock if abused. The put() and take() operators are partial and wait for the collection to become non-full or non-empty, respectively. Put() and take() do not allocate memory, and are not vulnerable to the ABA pathologies. The PTLQueue algorithm can be implemented equally well in C/C++ and Java. Partial operators are often more convenient than total methods. In many use cases if the preconditions aren't met, there's nothing else useful the thread can do, so it may as well wait via a partial method. An exception is in the case of work-stealing queues where a thief might scan a set of queues from which it could potentially steal. Total methods return ASAP with a success-failure indication. (It's tempting to describe a queue or API as blocking or non-blocking instead of partial or total, but non-blocking is already an overloaded concurrency term. Perhaps waiting/non-waiting or patient/impatient might be better terms). It's also trivial to construct partial operators by busy-waiting via total operators, but such constructs may be less efficient than an operator explicitly and intentionally designed to wait. A PTLQueue instance contains an array of slots, where each slot has volatile Turn and MailBox fields. The array has power-of-two length allowing mod/div operations to be replaced by masking. We assume sensible padding and alignment to reduce the impact of false sharing. (On x86 I recommend 128-byte alignment and padding because of the adjacent-sector prefetch facility). Each queue also has PutCursor and TakeCursor cursor variables, each of which should be sequestered as the sole occupant of a cache line or sector. You can opt to use 64-bit integers if concerned about wrap-around aliasing in the cursor variables. Put(null) is considered illegal, but the caller or implementation can easily check for and convert null to a distinguished non-null proxy value if null happens to be a value you'd like to pass. Take() will accordingly convert the proxy value back to null. An advantage of PTLQueue is that you can use atomic fetch-and-increment for the partial methods. We initialize each slot at index I with (Turn=I, MailBox=null). Both cursors are initially 0. All shared variables are considered "volatile" and atomics such as CAS and AtomicFetchAndIncrement are presumed to have bidirectional fence semantics. Finally T is the templated type. I've sketched out a total tryTake() method below that allows the caller to poll the queue. tryPut() has an analogous construction. Zebra stripping : alternating row colors for nice-looking code listings. See also google code "prettify" : https://code.google.com/p/google-code-prettify/ Prettify is a javascript module that yields the HTML/CSS/JS equivalent of pretty-print. -- pre:nth-child(odd) { background-color:#ff0000; } pre:nth-child(even) { background-color:#0000ff; } border-left: 11px solid #ccc; margin: 1.7em 0 1.7em 0.3em; background-color:#BFB; font-size:12px; line-height:65%; " // PTLQueue : Put(v) : // producer : partial method - waits as necessary assert v != null assert Mask = 1 && (Mask & (Mask+1)) == 0 // Document invariants // doorway step // Obtain a sequence number -- ticket // As a practical concern the ticket value is temporally unique // The ticket also identifies and selects a slot auto tkt = AtomicFetchIncrement (&PutCursor, 1) slot * s = &Slots[tkt & Mask] // waiting phase : // wait for slot's generation to match the tkt value assigned to this put() invocation. // The "generation" is implicitly encoded as the upper bits in the cursor // above those used to specify the index : tkt div (Mask+1) // The generation serves as an epoch number to identify a cohort of threads // accessing disjoint slots while s-Turn != tkt : Pause assert s-MailBox == null s-MailBox = v // deposit and pass message Take() : // consumer : partial method - waits as necessary auto tkt = AtomicFetchIncrement (&TakeCursor,1) slot * s = &Slots[tkt & Mask] // 2-stage waiting : // First wait for turn for our generation // Acquire exclusive "take" access to slot's MailBox field // Then wait for the slot to become occupied while s-Turn != tkt : Pause // Concurrency in this section of code is now reduced to just 1 producer thread // vs 1 consumer thread. // For a given queue and slot, there will be most one Take() operation running // in this section. // Consumer waits for producer to arrive and make slot non-empty // Extract message; clear mailbox; advance Turn indicator // We have an obvious happens-before relation : // Put(m) happens-before corresponding Take() that returns that same "m" for T v = s-MailBox if v != null : s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 // unlock slot to admit next producer and consumer return v Pause tryTake() : // total method - returns ASAP with failure indication for auto tkt = TakeCursor slot * s = &Slots[tkt & Mask] if s-Turn != tkt : return null T v = s-MailBox // presumptive return value if v == null : return null // ratify tkt and v values and commit by advancing cursor if CAS (&TakeCursor, tkt, tkt+1) != tkt : continue s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 return v The basic idea derives from the Partitioned Ticket Lock "PTL" (US20120240126-A1) and the MultiLane Concurrent Bag (US8689237). The latter is essentially a circular ring-buffer where the elements themselves are queues or concurrent collections. You can think of the PTLQueue as a partitioned ticket lock "PTL" augmented to pass values from lock to unlock via the slots. Alternatively, you could conceptualize of PTLQueue as a degenerate MultiLane bag where each slot or "lane" consists of a simple single-word MailBox instead of a general queue. Each lane in PTLQueue also has a private Turn field which acts like the Turn (Grant) variables found in PTL. Turn enforces strict FIFO ordering and restricts concurrency on the slot mailbox field to at most one simultaneous put() and take() operation. PTL uses a single "ticket" variable and per-slot Turn (grant) fields while MultiLane has distinct PutCursor and TakeCursor cursors and abstract per-slot sub-queues. Both PTL and MultiLane advance their cursor and ticket variables with atomic fetch-and-increment. PTLQueue borrows from both PTL and MultiLane and has distinct put and take cursors and per-slot Turn fields. Instead of a per-slot queues, PTLQueue uses a simple single-word MailBox field. PutCursor and TakeCursor act like a pair of ticket locks, conferring "put" and "take" access to a given slot. PutCursor, for instance, assigns an incoming put() request to a slot and serves as a PTL "Ticket" to acquire "put" permission to that slot's MailBox field. To better explain the operation of PTLQueue we deconstruct the operation of put() and take() as follows. Put() first increments PutCursor obtaining a new unique ticket. That ticket value also identifies a slot. Put() next waits for that slot's Turn field to match that ticket value. This is tantamount to using a PTL to acquire "put" permission on the slot's MailBox field. Finally, having obtained exclusive "put" permission on the slot, put() stores the message value into the slot's MailBox. Take() similarly advances TakeCursor, identifying a slot, and then acquires and secures "take" permission on a slot by waiting for Turn. Take() then waits for the slot's MailBox to become non-empty, extracts the message, and clears MailBox. Finally, take() advances the slot's Turn field, which releases both "put" and "take" access to the slot's MailBox. Note the asymmetry : put() acquires "put" access to the slot, but take() releases that lock. At any given time, for a given slot in a PTLQueue, at most one thread has "put" access and at most one thread has "take" access. This restricts concurrency from general MPMC to 1-vs-1. We have 2 ticket locks -- one for put() and one for take() -- each with its own "ticket" variable in the form of the corresponding cursor, but they share a single "Grant" egress variable in the form of the slot's Turn variable. Advancing the PutCursor, for instance, serves two purposes. First, we obtain a unique ticket which identifies a slot. Second, incrementing the cursor is the doorway protocol step to acquire the per-slot mutual exclusion "put" lock. The cursors and operations to increment those cursors serve double-duty : slot-selection and ticket assignment for locking the slot's MailBox field. At any given time a slot MailBox field can be in one of the following states: empty with no pending operations -- neutral state; empty with one or more waiting take() operations pending -- deficit; occupied with no pending operations; occupied with one or more waiting put() operations -- surplus; empty with a pending put() or pending put() and take() operations -- transitional; or occupied with a pending take() or pending put() and take() operations -- transitional. The partial put() and take() operators can be implemented with an atomic fetch-and-increment operation, which may confer a performance advantage over a CAS-based loop. In addition we have independent PutCursor and TakeCursor cursors. Critically, a put() operation modifies PutCursor but does not access the TakeCursor and a take() operation modifies the TakeCursor cursor but does not access the PutCursor. This acts to reduce coherence traffic relative to some other queue designs. It's worth noting that slow threads or obstruction in one slot (or "lane") does not impede or obstruct operations in other slots -- this gives us some degree of obstruction isolation. PTLQueue is not lock-free, however. The implementation above is expressed with polite busy-waiting (Pause) but it's trivial to implement per-slot parking and unparking to deschedule waiting threads. It's also easy to convert the queue to a more general deque by replacing the PutCursor and TakeCursor cursors with Left/Front and Right/Back cursors that can move either direction. Specifically, to push and pop from the "left" side of the deque we would decrement and increment the Left cursor, respectively, and to push and pop from the "right" side of the deque we would increment and decrement the Right cursor, respectively. We used a variation of PTLQueue for message passing in our recent OPODIS 2013 paper. ul { list-style:none; padding-left:0; padding:0; margin:0; margin-left:0; } ul#myTagID { padding: 0px; margin: 0px; list-style:none; margin-left:0;} -- -- There's quite a bit of related literature in this area. I'll call out a few relevant references: Wilson's NYU Courant Institute UltraComputer dissertation from 1988 is classic and the canonical starting point : Operating System Data Structures for Shared-Memory MIMD Machines with Fetch-and-Add. Regarding provenance and priority, I think PTLQueue or queues effectively equivalent to PTLQueue have been independently rediscovered a number of times. See CB-Queue and BNPBV, below, for instance. But Wilson's dissertation anticipates the basic idea and seems to predate all the others. Gottlieb et al : Basic Techniques for the Efficient Coordination of Very Large Numbers of Cooperating Sequential Processors Orozco et al : CB-Queue in Toward high-throughput algorithms on many-core architectures which appeared in TACO 2012. Meneghin et al : BNPVB family in Performance evaluation of inter-thread communication mechanisms on multicore/multithreaded architecture Dmitry Vyukov : bounded MPMC queue (highly recommended) Alex Otenko : US8607249 (highly related). John Mellor-Crummey : Concurrent queues: Practical fetch-and-phi algorithms. Technical Report 229, Department of Computer Science, University of Rochester Thomasson : FIFO Distributed Bakery Algorithm (very similar to PTLQueue). Scott and Scherer : Dual Data Structures I'll propose an optimization left as an exercise for the reader. Say we wanted to reduce memory usage by eliminating inter-slot padding. Such padding is usually "dark" memory and otherwise unused and wasted. But eliminating the padding leaves us at risk of increased false sharing. Furthermore lets say it was usually the case that the PutCursor and TakeCursor were numerically close to each other. (That's true in some use cases). We might still reduce false sharing by incrementing the cursors by some value other than 1 that is not trivially small and is coprime with the number of slots. Alternatively, we might increment the cursor by one and mask as usual, resulting in a logical index. We then use that logical index value to index into a permutation table, yielding an effective index for use in the slot array. The permutation table would be constructed so that nearby logical indices would map to more distant effective indices. (Open question: what should that permutation look like? Possibly some perversion of a Gray code or De Bruijn sequence might be suitable). As an aside, say we need to busy-wait for some condition as follows : "while C == 0 : Pause". Lets say that C is usually non-zero, so we typically don't wait. But when C happens to be 0 we'll have to spin for some period, possibly brief. We can arrange for the code to be more machine-friendly with respect to the branch predictors by transforming the loop into : "if C == 0 : for { Pause; if C != 0 : break; }". Critically, we want to restructure the loop so there's one branch that controls entry and another that controls loop exit. A concern is that your compiler or JIT might be clever enough to transform this back to "while C == 0 : Pause". You can sometimes avoid this by inserting a call to a some type of very cheap "opaque" method that the compiler can't elide or reorder. On Solaris, for instance, you could use :"if C == 0 : { gethrtime(); for { Pause; if C != 0 : break; }}". It's worth noting the obvious duality between locks and queues. If you have strict FIFO lock implementation with local spinning and succession by direct handoff such as MCS or CLH,then you can usually transform that lock into a queue. Hidden commentary and annotations - invisible : * And of course there's a well-known duality between queues and locks, but I'll leave that topic for another blog post. * Compare and contrast : PTLQ vs PTL and MultiLane * Equivalent : Turn; seq; sequence; pos; position; ticket * Put = Lock; Deposit Take = identify and reserve slot; wait; extract & clear; unlock * conceptualize : Distinct PutLock and TakeLock implemented as ticket lock or PTL Distinct arrival cursors but share per-slot "Turn" variable provides exclusive role-based access to slot's mailbox field put() acquires exclusive access to a slot for purposes of "deposit" assigns slot round-robin and then acquires deposit access rights/perms to that slot take() acquires exclusive access to slot for purposes of "withdrawal" assigns slot round-robin and then acquires withdrawal access rights/perms to that slot At any given time, only one thread can have withdrawal access to a slot at any given time, only one thread can have deposit access to a slot Permissible for T1 to have deposit access and T2 to simultaneously have withdrawal access * round-robin for the purposes of; role-based; access mode; access role mailslot; mailbox; allocate/assign/identify slot rights; permission; license; access permission; * PTL/Ticket hybrid Asymmetric usage ; owner oblivious lock-unlock pairing K-exclusion add Grant cursor pass message m from lock to unlock via Slots[] array Cursor performs 2 functions : + PTL ticket + Assigns request to slot in round-robin fashion Deconstruct protocol : explication put() : allocate slot in round-robin fashion acquire PTL for "put" access store message into slot associated with PTL index take() : Acquire PTL for "take" access // doorway step seq = fetchAdd (&Grant, 1) s = &Slots[seq & Mask] // waiting phase while s-Turn != seq : pause Extract : wait for s-mailbox to be full v = s-mailbox s-mailbox = null Release PTL for both "put" and "take" access s-Turn = seq + Mask + 1 * Slot round-robin assignment and lock "doorway" protocol leverage the same cursor and FetchAdd operation on that cursor FetchAdd (&Cursor,1) + round-robin slot assignment and dispersal + PTL/ticket lock "doorway" step waiting phase is via "Turn" field in slot * PTLQueue uses 2 cursors -- put and take. Acquire "put" access to slot via PTL-like lock Acquire "take" access to slot via PTL-like lock 2 locks : put and take -- at most one thread can access slot's mailbox Both locks use same "turn" field Like multilane : 2 cursors : put and take slot is simple 1-capacity mailbox instead of queue Borrow per-slot turn/grant from PTL Provides strict FIFO Lock slot : put-vs-put take-vs-take at most one put accesses slot at any one time at most one put accesses take at any one time reduction to 1-vs-1 instead of N-vs-M concurrency Per slot locks for put/take Release put/take by advancing turn * is instrumental in ... * P-V Semaphore vs lock vs K-exclusion * See also : FastQueues-excerpt.java dice-etc/queue-mpmc-bounded-blocking-circular-xadd/ * PTLQueue is the same as PTLQB - identical * Expedient return; ASAP; prompt; immediately * Lamport's Bakery algorithm : doorway step then waiting phase Threads arriving at doorway obtain a unique ticket number Threads enter in ticket order * In the terminology of Reed and Kanodia a ticket lock corresponds to the busy-wait implementation of a semaphore using an eventcount and a sequencer It can also be thought of as an optimization of Lamport's bakery lock was designed for fault-tolerance rather than performance Instead of spinning on the release counter, processors using a bakery lock repeatedly examine the tickets of their peers --

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