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  • Should I choose Doctrine 2 or Propel 1.5/1.6, and why?

    - by Billy ONeal
    I'd like to hear from those who have used Doctrine 2 (or later) and Propel 1.5 (or later). Most comparisons between these two object relational mappers are based on old versions -- Doctrine 1 versus Propel 1.3/1.4, and both ORMs went through significant redesigns in their recent revisions. For example, most of the criticism of Propel seems to center around the "ModelName Peer" classes, which are deprecated in 1.5 in any case. Here's what I've accumulated so far (And I've tried to make this list as balanced as possible...): Propel Pros Extremely IDE friendly, because actual code is generated, instead of relying on PHP magic methods. This means IDE features like code completion are actually helpful. Fast (In terms of database usage -- no runtime introspection is done on the database) Clean migration between schema versions (at least in the 1.6 beta) Can generate PHP 5.3 models (i.e. namespaces) Easy to chain a lot of things into a single database query with things like useXxx methods. (See the "code completion" video above) Cons Requires an extra build step, namely building the model classes. Generated code needs rebuilt whenever Propel version is changed, a setting is changed, or the schema changes. This might be unintuitive to some and custom methods applied to the model are lost. (I think?) Some useful features (i.e. version behavior, schema migrations) are in beta status. Doctrine Pros More popular Doctrine Query Language can express potentially more complicated relationships between data than easily possible with Propel's ActiveRecord strategy. Easier to add reusable behaviors when compared with Propel. DocBlock based commenting for building the schema is embedded in the actual PHP instead of a separate XML file. Uses PHP 5.3 Namespaces everywhere Cons Requires learning an entirely new programming language (Doctrine Query Language) Implemented in terms of "magic methods" in several places, making IDE autocomplete worthless. Requires database introspection and thus is slightly slower than Propel by default; caching can remove this but the caching adds considerable complexity. Fewer behaviors are included in the core codebase. Several features Propel provides out of the box (such as Nested Set) are available only through extensions. Freakin' HUGE :) This I have gleaned though only through reading the documentation available for both tools -- I've not actually built anything yet. I'd like to hear from those who have used both tools though, to share their experience on pros/cons of each library, and what their recommendation is at this point :)

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  • Where and how to reference composite MVP components?

    - by Lea Hayes
    I am learning about the MVP (Model-View-Presenter) Passive View flavour of MVC. I intend to expose events from view interfaces rather than using the observer pattern to remove explicit coupling with presenter. Context: Windows Forms / Client-Side JavaScript. I am led to believe that the MVP (or indeed MVC in general) pattern can be applied at various levels of a user interface ranging from the main "Window" to an embedded "Text Field". For instance, the model to the text field is probably just a string whereas the model to the "Window" contains application specific view state (like a persons name which resides within the contained text field). Given a more complex scenario: Documentation viewer which contains: TOC navigation pane Document view Search pane Since each of these 4 user interface items are complex and can be reused elsewhere it makes sense to design these using MVP. Given that each of these user interface items comprises of 3 components; which component should be nested? where? who instantiates them? Idea #1 - Embed View inside View from Parent View public class DocumentationViewer : Form, IDocumentationViewerView { public DocumentationViewer() { ... // Unclear as to how model and presenter are injected... TocPane = new TocPaneView(); } protected ITocPaneView TocPane { get; private set; } } Idea #2 - Embed Presenter inside View from Parent View public class DocumentationViewer : Form, IDocumentationViewerView { public DocumentationViewer() { ... // This doesn't seem like view logic... var tocPaneModel = new TocPaneModel(); var tocPaneView = new TocPaneView(); TocPane = new TocPanePresenter(tocPaneModel, tocPaneView); } protected TocPanePresenter TocPane { get; private set; } } Idea #3 - Embed View inside View from Parent Presenter public class DocumentationViewer : Form, IDocumentationViewerView { ... // Part of IDocumentationViewerView: public ITocPaneView TocPane { get; set; } } public class DocumentationViewerPresenter { public DocumentationViewerPresenter(DocumentationViewerModel model, IDocumentationViewerView view) { ... var tocPaneView = new TocPaneView(); var tocPaneModel = new TocPaneModel(model.Toc); var tocPanePresenter = new TocPanePresenter(tocPaneModel, tocPaneView); view.TocPane = tocPaneView; } } Some better idea...

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  • Oracle????????????????????????~????????????????????

    - by Yusuke.Yamamoto
    RDBMS ???????·????????????????????????????????????????????????????????????????????????? ????????Oracle ?????????????????????????????????? Oracle Database ???????????????????????????????? ????????????????????? ????Oracle???????????????????????????????????????????????????????????????????????????? ?????????????? Oracle Database ???????????????????????? ??????????????????????????????????2????????????? 1. ??????(Query Transformation) Query Transformation ???????SQL??????????????????SQL????????????????????? Query Transformation ???Predicate Transformation ? Common Sub-expression Elimination (CSE), Order-BY Elimination (OBYE), Outer Join Elimination (OJE), Simple View Meging (SVM), Predicate Move around (PM), Complex View Merging (CVM), Sub-query Unnesting (SU), Join Predicate Push Down (JPPD) ???? OR Expansion, Star Transformation (ST) ????????????? ···???????????????????????????????????????????????????? Predicate Transformation ?????? Transitive Predicate Generation ????????????? ?????????????SQL???deptno ? 10 ????????????????????????????? select e.ename, d.loc from emp e, dept d where e.deptno=d.deptno and e.deptno=10; ???????????????emp ??? deptno=10 ??????????????dept ??? d.deptno=10 ??????????????????? emp ?? deptno=10 ????????????????????emp ?? deptno=10 ??????10???????10? dept ????????????dept ??20???????????????????????10?*20?=200?????(??????????·?????????)? ??SQL?? Transitive Predicate Generation ??????SQL????????????????? select e.ename, d.location from emp e, dept d where e.deptno=d.deptno and e.deptno=10 and d.deptno=10; ^^^^^^^^^^^ ??????dept ?????? deptno=10 ??????????????????????????10?*1?=10(dept.deptno ?unique????)?1/20????????????????1/20????????????????10??????????30???????????????Query Transformation ???????????????????????????? ?:??????????? dept ?? 1-row table ??????dept ?? driving ???(Outer Table)??? emp ?? probe ???(Inner Table)????????????1?*10?=10 ????????????????????????????????????????????????????????1/20????????????? ?????? Query Transformation ??????SQL????????????????????????????????? Transformation ??????????????????????????????????? 2. ????·????(Access Path Analysis) Access Path Analysis ??Query Transformation ??SQL????????????(Access Path)?????????(Join Method)?????(Join Order)?????????? ??????????????????(FTS)?ROWID?????????????????????????????·?????(Nested Loop Join)???????(Hash Join)????/?????(Sort Merge Join)????????????????????????????????????????????????????????????????????????? Oracle Database ????????? Query Transformation ???? Logical Optimizer?Access Path Analysis ???? Physical Optimizer ????????? ??????????????????????????????????????????????????????????????????????????????????????????????????? ????????????????????????????????????????????????????? Oracle Database ????????????????????? "Oracle ????????" ?????????? Sustaining Engineering?? ?(??? ???) ???????????????? Sustaining Engineering ????????????????????????Oracle Database ???????????????????????? ?????????????????????Ruby????????????????????????? Oracle????????????????????????! Oracle????????????? Oracle????????????????????????

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  • Drawing multiple Textures as tilemap

    - by DocJones
    I am trying to draw a 2d game map and the objects on the map in a single pass. Here is my OpenGL initialization code // Turn off unnecessary operations glDisable(GL_DEPTH_TEST); glDisable(GL_LIGHTING); glDisable(GL_CULL_FACE); glDisable(GL_STENCIL_TEST); glDisable(GL_DITHER); glEnable(GL_BLEND); glEnable(GL_TEXTURE_2D); // activate pointer to vertex & texture array glEnableClientState(GL_VERTEX_ARRAY); glEnableClientState(GL_TEXTURE_COORD_ARRAY); My drawing code is being called by a NSTimer every 1/60 s. Here is the drawing code of my world object: - (void) draw:(NSRect)rect withTimedDelta:(double)d { GLint *t; glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, [_textureManager textureByName:@"blocks"]); glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE); for (int x=0; x<[_map getWidth] ; x++) { for (int y=0; y<[_map getHeight] ; y++) { GLint v[] = { 16*x ,16*y, 16*x+16,16*y, 16*x+16,16*y+16, 16*x ,16*y+16 }; t=[_textureManager getBlockWithNumber:[_map getBlockAtX:x andY:y]]; glVertexPointer(2, GL_INT, 0, v); glTexCoordPointer(2, GL_INT, 0, t); glDrawArrays(GL_QUADS, 0, 4); } } } (_textureManager is a Singelton only loading a texture once!) The object drawing codes is identical (except the nested loops) in terms of OpenGL calls: - (void) drawWithTimedDelta:(double)d { GLint *t; GLint v[] = { 16*xpos ,16*ypos, 16*xpos+16,16*ypos, 16*xpos+16,16*ypos+16, 16*xpos ,16*ypos+16 }; glBindTexture(GL_TEXTURE_2D, [_textureManager textureByName:_textureName]); t=[_textureManager getBlockWithNumber:12]; glVertexPointer(2, GL_INT, 0, v); glTexCoordPointer(2, GL_INT, 0, t); glDrawArrays(GL_QUADS, 0, 4); } As soon as my central drawing routine calls the two drawing methods the second call overlays the first one. i would expect the call to world.draw to draw the map and "stamp" the objects upon it. Debugging shows me, that the first call is performed correctly (world is being drawn), but the following call to all objects ONLY draws the objects, the rest of the scene is getting black. I think i need to blend the drawn textures, but i cant seem to figure out how. Any help is appreciated. Thanks PS: Here is the github link to the project. It may not be in sync of my post here, but for some more in-depth analysis it may help.

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  • Unit testing in Django

    - by acjohnson55
    I'm really struggling to write effective unit tests for a large Django project. I have reasonably good test coverage, but I've come to realize that the tests I've been writing are definitely integration/acceptance tests, not unit tests at all, and I have critical portions of my application that are not being tested effectively. I want to fix this ASAP. Here's my problem. My schema is deeply relational, and heavily time-oriented, giving my model object high internal coupling and lots of state. Many of my model methods query based on time intervals, and I've got a lot of auto_now_add going on in timestamped fields. So take a method that looks like this for example: def summary(self, startTime=None, endTime=None): # ... logic to assign a proper start and end time # if none was provided, probably using datetime.now() objects = self.related_model_set.manager_method.filter(...) return sum(object.key_method(startTime, endTime) for object in objects) How does one approach testing something like this? Here's where I am so far. It occurs to me that the unit testing objective should be given some mocked behavior by key_method on its arguments, is summary correctly filtering/aggregating to produce a correct result? Mocking datetime.now() is straightforward enough, but how can I mock out the rest of the behavior? I could use fixtures, but I've heard pros and cons of using fixtures for building my data (poor maintainability being a con that hits home for me). I could also setup my data through the ORM, but that can be limiting, because then I have to create related objects as well. And the ORM doesn't let you mess with auto_now_add fields manually. Mocking the ORM is another option, but not only is it tricky to mock deeply nested ORM methods, but the logic in the ORM code gets mocked out of the test, and mocking seems to make the test really dependent on the internals and dependencies of the function-under-test. The toughest nuts to crack seem to be the functions like this, that sit on a few layers of models and lower-level functions and are very dependent on the time, even though these functions may not be super complicated. My overall problem is that no matter how I seem to slice it, my tests are looking way more complex than the functions they are testing.

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  • What are the arguments against parsing the Cthulhu way?

    - by smarmy53
    I have been assigned the task of implementing a Domain Specific Language for a tool that may become quite important for the company. The language is simple but not trivial, it already allows nested loops, string concatenation, etc. and it is practically sure that other constructs will be added as the project advances. I know by experience that writing a lexer/parser by hand -unless the grammar is trivial- is a time consuming and error prone process. So I was left with two options: a parser generator à la yacc or a combinator library like Parsec. The former was good as well but I picked the latter for various reasons, and implemented the solution in a functional language. The result is pretty spectacular to my eyes, the code is very concise, elegant and readable/fluent. I concede it may look a bit weird if you never programmed in anything other than java/c#, but then this would be true of anything not written in java/c#. At some point however, I've been literally attacked by a co-worker. After a quick glance at my screen he declared that the code is uncomprehensible and that I should not reinvent parsing but just use a stack and String.Split like everybody does. He made a lot of noise, and I could not convince him, partially because I've been taken by surprise and had no clear explanation, partially because his opinion was immutable (no pun intended). I even offered to explain him the language, but to no avail. I'm positive the discussion is going to re-surface in front of management, so I'm preparing some solid arguments. These are the first few reasons that come to my mind to avoid a String.Split-based solution: you need lot of ifs to handle special cases and things quickly spiral out of control lots of hardcoded array indexes makes maintenance painful extremely difficult to handle things like a function call as a method argument (ex. add( (add a, b), c) very difficult to provide meaningful error messages in case of syntax errors (very likely to happen) I'm all for simplicity, clarity and avoiding unnecessary smart-cryptic stuff, but I also believe it's a mistake to dumb down every part of the codebase so that even a burger flipper can understand it. It's the same argument I hear for not using interfaces, not adopting separation of concerns, copying-pasting code around, etc. A minimum of technical competence and willingness to learn is required to work on a software project after all. (I won't use this argument as it will probably sound offensive, and starting a war is not going to help anybody) What are your favorite arguments against parsing the Cthulhu way?* *of course if you can convince me he's right I'll be perfectly happy as well

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  • WebLogic Server 11gR1 Interactive Quick Reference

    - by JuergenKress
    The WebLogic Server 11gR1 Administration interactive quick reference is a multimedia tool for various terms and concepts used in WebLogic Server architecture. This tool is available for administrators for online or offline use. This is built as a multimedia web page which provides descriptions of WebLogic Server Architectural components, and references to relevant documentation. This tool offers valuable reference information for any complex concept or product in an intuitive and useful manner. Each interactive type presents data that may be available in the documentation (in the case of Oracle products), but presents it in a way that is more intuitive and useful to a user of Oracle products because it displays data the way it is used in a real world, best practice scenario. For example, the architectural diagram interactive type provides an image of an architectural diagram that is typically larger than a single slide or paper. The image is scrollable and provides zoom capabilities to easily and clearly view any part of the image. The image itself contains a hotspot map that you can click to get more information about a feature, including reference links to the documentation in question. Linking the visual image of the component and where it fits in the overall architecture of the product, or technology in use, to the technical explanation and how-to materials related to that component is something not offered by the documentation. In a future release, the poster will also enable you to drill down even further into the individual subsystems in nested diagrams to look at the details of that subsystem. In short, the interactive posters are good at showing you the big picture, then quickly and easily getting you to the detailed information you need. In an instant, you can see where a technical component fits into an overall architecture, and zero in on the nitty-gritty details that show you how to do it yourself. Note: This is a first initial release with more features in development. Currently known information: Only Firefox 8.0 and higher is known to work with this product. This product may work with Chrome and Safari browsers, but is known to have issues in Internet Explorer at this time. Smartphones, such as iPads and iPhones, are partially supported WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. BlogTwitterLinkedInMixForumWiki Technorati Tags: WebLogic server quick reference,weblogic overview,weblogic 12c,WebLogic Community,Oracle,OPN,Jürgen Kress

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  • Particle System in XNA - cannot draw particle

    - by Dave Voyles
    I'm trying to implement a simple particle system in my XNA project. I'm going by RB Whitaker's tutorial, and it seems simple enough. I'm trying to draw particles within my menu screen. Below I've included the code which I think is applicable. I'm coming up with one error in my build, and it is stating that I need to create a new instance of the EmitterLocation from the particleEngine. When I hover over particleEngine.EmitterLocation = new Vector2(Mouse.GetState().X, Mouse.GetState().Y); it states that particleEngine is returning a null value. What could be causing this? /// <summary> /// Base class for screens that contain a menu of options. The user can /// move up and down to select an entry, or cancel to back out of the screen. /// </summary> abstract class MenuScreen : GameScreen ParticleEngine particleEngine; public void LoadContent(ContentManager content) { if (content == null) { content = new ContentManager(ScreenManager.Game.Services, "Content"); } base.LoadContent(); List<Texture2D> textures = new List<Texture2D>(); textures.Add(content.Load<Texture2D>(@"gfx/circle")); textures.Add(content.Load<Texture2D>(@"gfx/star")); textures.Add(content.Load<Texture2D>(@"gfx/diamond")); particleEngine = new ParticleEngine(textures, new Vector2(400, 240)); } public override void Update(GameTime gameTime, bool otherScreenHasFocus, bool coveredByOtherScreen) { base.Update(gameTime, otherScreenHasFocus, coveredByOtherScreen); // Update each nested MenuEntry object. for (int i = 0; i < menuEntries.Count; i++) { bool isSelected = IsActive && (i == selectedEntry); menuEntries[i].Update(this, isSelected, gameTime); } particleEngine.EmitterLocation = new Vector2(Mouse.GetState().X, Mouse.GetState().Y); particleEngine.Update(); } public override void Draw(GameTime gameTime) { // make sure our entries are in the right place before we draw them UpdateMenuEntryLocations(); GraphicsDevice graphics = ScreenManager.GraphicsDevice; SpriteBatch spriteBatch = ScreenManager.SpriteBatch; SpriteFont font = ScreenManager.Font; spriteBatch.Begin(); // Draw stuff logic spriteBatch.End(); particleEngine.Draw(spriteBatch); }

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  • What Precalculus knowledge is required before learning Discrete Math Computer Science topics?

    - by Ein Doofus
    Below I've listed the chapters from a Precalculus book as well as the author recommended Computer Science chapters from a Discrete Mathematics book. Although these chapters are from two specific books on these subjects I believe the topics are generally the same between any Precalc or Discrete Math book. What Precalculus topics should one know before starting these Discrete Math Computer Science topics?: Discrete Mathematics CS Chapters 1.1 Propositional Logic 1.2 Propositional Equivalences 1.3 Predicates and Quantifiers 1.4 Nested Quantifiers 1.5 Rules of Inference 1.6 Introduction to Proofs 1.7 Proof Methods and Strategy 2.1 Sets 2.2 Set Operations 2.3 Functions 2.4 Sequences and Summations 3.1 Algorithms 3.2 The Growths of Functions 3.3 Complexity of Algorithms 3.4 The Integers and Division 3.5 Primes and Greatest Common Divisors 3.6 Integers and Algorithms 3.8 Matrices 4.1 Mathematical Induction 4.2 Strong Induction and Well-Ordering 4.3 Recursive Definitions and Structural Induction 4.4 Recursive Algorithms 4.5 Program Correctness 5.1 The Basics of Counting 5.2 The Pigeonhole Principle 5.3 Permutations and Combinations 5.6 Generating Permutations and Combinations 6.1 An Introduction to Discrete Probability 6.4 Expected Value and Variance 7.1 Recurrence Relations 7.3 Divide-and-Conquer Algorithms and Recurrence Relations 7.5 Inclusion-Exclusion 8.1 Relations and Their Properties 8.2 n-ary Relations and Their Applications 8.3 Representing Relations 8.5 Equivalence Relations 9.1 Graphs and Graph Models 9.2 Graph Terminology and Special Types of Graphs 9.3 Representing Graphs and Graph Isomorphism 9.4 Connectivity 9.5 Euler and Hamilton Ptahs 10.1 Introduction to Trees 10.2 Application of Trees 10.3 Tree Traversal 11.1 Boolean Functions 11.2 Representing Boolean Functions 11.3 Logic Gates 11.4 Minimization of Circuits 12.1 Language and Grammars 12.2 Finite-State Machines with Output 12.3 Finite-State Machines with No Output 12.4 Language Recognition 12.5 Turing Machines Precalculus Chapters R.1 The Real-Number System R.2 Integer Exponents, Scientific Notation, and Order of Operations R.3 Addition, Subtraction, and Multiplication of Polynomials R.4 Factoring R.5 Rational Expressions R.6 Radical Notation and Rational Exponents R.7 The Basics of Equation Solving 1.1 Functions, Graphs, Graphers 1.2 Linear Functions, Slope, and Applications 1.3 Modeling: Data Analysis, Curve Fitting, and Linear Regression 1.4 More on Functions 1.5 Symmetry and Transformations 1.6 Variation and Applications 1.7 Distance, Midpoints, and Circles 2.1 Zeros of Linear Functions and Models 2.2 The Complex Numbers 2.3 Zeros of Quadratic Functions and Models 2.4 Analyzing Graphs of Quadratic Functions 2.5 Modeling: Data Analysis, Curve Fitting, and Quadratic Regression 2.6 Zeros and More Equation Solving 2.7 Solving Inequalities 3.1 Polynomial Functions and Modeling 3.2 Polynomial Division; The Remainder and Factor Theorems 3.3 Theorems about Zeros of Polynomial Functions 3.4 Rational Functions 3.5 Polynomial and Rational Inequalities 4.1 Composite and Inverse Functions 4.2 Exponential Functions and Graphs 4.3 Logarithmic Functions and Graphs 4.4 Properties of Logarithmic Functions 4.5 Solving Exponential and Logarithmic Equations 4.6 Applications and Models: Growth and Decay 5.1 Systems of Equations in Two Variables 5.2 System of Equations in Three Variables 5.3 Matrices and Systems of Equations 5.4 Matrix Operations 5.5 Inverses of Matrices 5.6 System of Inequalities and Linear Programming 5.7 Partial Fractions 6.1 The Parabola 6.2 The Circle and Ellipse 6.3 The Hyperbola 6.4 Nonlinear Systems of Equations

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  • Start Time & Calculated Column Wonkiness in a SharePoint Event Calendar

    - by _zekeMouseOver
    I was creating some custom rollups on some of our event calendars and came across a very odd bug when trying to grab only the date component of the built-in Start Time field. One's first inclination will be to create a calculated column and give it the formula... =[Start Time]... and then assign its output type to be "Date Only." This works well until a user adds an All Day Event. For reasons unexplainable, the All Day Event flag causes your =[Start Time] to display the date minus one day. Here is an example of this in action:  Start Date and Time, Duration, Start Date Value and Start Day are all calculated fields. Notice how the Start Date and Time (=[Start Time]) is reporting 6:00PM of the previous day. The Start Date Value (=[Start Time] - Output Type: Number) confirms this (.75 = 6:00 PM.) Curiously enough, the Duration (=[End Time]-[Start Time]) is properly reporting the duration between 12:00AM and 11:59PM. Why? I don't know. Perhaps it's somehow bound to the regional settings on the site, but I'm not interested in changing a global site setting for the sake of one calculated field.With this information at our disposal, our calculated column to display the date part of the start date needs to be modified to add one day to the [Start Time] field if an All Day Event is selected. To determine this, we use the Duration above to assume the item is an all-day event and change our formula to be:=IF(TEXT(([End Time]-[Start Time])-TRUNC(([End Time]-[Start Time]),0),"0.000000000")="0.999305556",[Start Time] + 1, [Start Time])This will work, but what happens when the user de-selects the "All Day Event" checkbox? The duration stays the same, but all other values begin reporting the correct time: Since our formula above is strictly based on an expected duration, it will add one to the correct date, causing the date 5/11/2010 to appear. Notice though that the raw value of the start time (in this case) is a non-fractional number (40,308) whereas the all-day event was being represented as 6:00 PM (.75) of the previous day. We can use this to add one more nested branch of logic to our calculation:=IF(TEXT(([End Time]-[Start Time])-TRUNC(([End Time]-[Start Time]),0),"0.000000000")="0.999305556",IF([Start Time]=ROUND([Start Time],0),[Start Time],[Start Time]+1),[Start Time]) I feel somewhat... dirty about having to resort to this kind of calculation in what SHOULD have been a simple =[Start Time] to extract the date part of the Start Time field, but there you have it. Make sure to shower extra longer after having used it.

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  • Marshalling C# Structs into DX11 cbuffers

    - by Craig
    I'm having some issues with the packing of my structure in C# and passing them through to cbuffers I have registered in HLSL. When I pack my struct in one manner the information seems to be able to pass to the shader: [StructLayout(LayoutKind.Explicit, Size = 16)] internal struct TestStruct { [FieldOffset(0)] public Vector3 mEyePosition; [FieldOffset(12)] public int type; } This works perfectly when used against this HLSL fragment: cbuffer PerFrame : register(b0) { Vector3 eyePos; int type; } float3 GetColour() { float3 returnColour = float(0.0f, 0.0f, 0.0f); switch(type) { case 0: returnColour = float3(1.0f, 0.0f, 0.0f); break; case 1: returnColour = float3(0.0f, 1.0f, 0.0f); break; case 2: returnColour = float3(0.0f, 0.0f, 1.0f); break; } return returnColour; } However, when I use the following structure definitions... // Note this is 16 because HLSL packs in 4 float 'chunks'. // It is also simplified, but still demonstrates the problem. [StructLayout(Layout.Explicit, Size = 16)] internal struct InternalTestStruct { [FieldOffset(0)] public int type; } [StructLayout(LayoutKind.Explicit, Size = 32)] internal struct TestStruct { [FieldOffset(0)] public Vector3 mEyePosition; //Missing 4 bytes here for correct packing. [FieldOffset(16)] public InternalTestStruct mInternal; } ... the following HLSL fragment no longer works. struct InternalType { int type; } cbuffer PerFrame : register(b0) { Vector3 eyePos; InternalType internalStruct; } float3 GetColour() { float3 returnColour = float(0.0f, 0.0f, 0.0f); switch(internaltype.type) { case 0: returnColour = float3(1.0f, 0.0f, 0.0f); break; case 1: returnColour = float3(0.0f, 1.0f, 0.0f); break; case 2: returnColour = float3(0.0f, 0.0f, 1.0f); break; } return returnColour; } Is there a problem with the way I am packing the struct, or is it another issue? To re-iterate: I can pass a struct in a cbuffer so long as it does not contain a nested struct.

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  • Syncing client and server CRUD operations using json and php

    - by Justin
    I'm working on some code to sync the state of models between client (being a javascript application) and server. Often I end up writing redundant code to track the client and server objects so I can map the client supplied data to the server models. Below is some code I am thinking about implementing to help. What I don't like about the below code is that this method won't handle nested relationships very well, I would have to create multiple object trackers. One work around is for each server model after creating or loading, simply do $model->clientId = $clientId; IMO this is a nasty hack and I want to avoid it. Adding a setCientId method to all my model object would be another way to make it less hacky, but this seems like overkill to me. Really clientIds are only good for inserting/updating data in some scenarios. I could go with a decorator pattern but auto generating a proxy class seems a bit involved. I could use a generic proxy class that uses a __call function to allow for original object data to be accessed, but this seems wrong too. Any thoughts or comments? $clientData = '[{name: "Bob", action: "update", id: 1, clientId: 200}, {name:"Susan", action:"create", clientId: 131} ]'; $jsonObjs = json_decode($clientData); $objectTracker = new ObjectTracker(); $objectTracker->trackClientObjs($jsonObjs); $query = $this->em->createQuery("SELECT x FROM Application_Model_User x WHERE x.id IN (:ids)"); $query->setParameters("ids",$objectTracker->getClientSpecifiedServerIds()); $models = $query->getResults(); //Apply client data to server model foreach ($models as $model) { $clientModel = $objectTracker->getClientJsonObj($model->getId()); ... } //Create new models and persist foreach($objectTracker->getNewClientObjs() as $newClientObj) { $model = new Application_Model_User(); .... $em->persist($model); $objectTracker->trackServerObj($model); } $em->flush(); $resourceResponse = $objectTracker->createResourceResponse(); //Id mappings will be an associtave array representing server id resources with client side // id. //This method Dosen't seem to flexible if we want to return additional data with each resource... //Would have to modify the returned data structure, seems like tight coupling... //Ex return value: //[{clientId: 200, id:1} , {clientId: 131, id: 33}];

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  • WebCenter Content Web Search Performance: Do you really need that folder path info?

    - by Nicolas Montoya
    End-users want content at their fingertips at the speed of thought if possible. When running search operations in the WebCenter Conter Web Interface every second or fraction of a second improvement does matter. When doing some trace analysis on the systemdatabase tracing on a customer environment, we came across some SQL queries that were unnecessarily being triggered! These were related to determining the folder path for every entry part of the search result set. However, this folder path was not even being used as part of the displayed information in the user interface.Why was the folder path information being collected when it was not even displayed in the UI? We found that the configuration parameter 'FolderPathInSearchResults' was set to 'true' under Administration > Admin Server > General Configuration > Additional Configuration Variables as shown below:When executing a quicksearch by keyword we were getting 100 out of 2280 entries in the first page of the result set.When thera 'FolderPathInSearchResults' configuration parameter is set to 'true', the following queries appear in the systemdatabase tracing:100 executions for a query on the FolderFiles table for each of the documents displayed in the first page:>systemdatabase/6       12.13 11:17:48.188      IdcServer-199   1.45 ms. SELECT * FROM FolderFiles WHERE dDocName='SLC02VGVUSORAC140641' AND fLinkRank=0[Executed. Returned row(s): true]382 executions for a query of the folders tables - most of the documents that match the keyword criteria are at a folder depth level of three or four:>systemdatabase/6       12.13 11:17:48.114      IdcServer-199   2.57 ms. SELECT FolderFolders.*,FolderMetaDefaults.* FROM FolderFolders,FolderMetaDefaults WHERE FolderFolders.fFolderGUID=FolderMetaDefaults.fFolderGUID(+) AND((FolderFolders.fFolderGUID = '1EB8E527E19B09ED3FE82EE310AEA13A' ) )[Executed.Returned row(s): true]By setting this 'FolderPathInSearchResults' configuration parameter to 'false', the above queries were no longer reported in the Server Output System Audit Information.Now, let's consider a practical scenario:Search result set page = 100Average folder depth der document in the search result set: 5The number of folder path related queries will be: 100 + 5*500 = 600If each query takes slightly over 3 ms. You would have 2000 ms (2 seconds) spent in server time to get this information.The overall performance impact goes beyond seerver time execution, as this information needs to travel from the server to the browser. If the documents are further nested into the folder hierarchy, additional hundreds of queries may be executed. If folder path is not being displayed in the end-user interface profile, your system may be better of with the 'FolderPathInSearchResults' configuration parameter disabled.

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  • IPS Package Groups

    - by Alan_Solaris_RE
    IPS group packages consist solely of dependencies on other packages that make up a logical grouping of software. These are similar to, but not the equivalent of, Solaris 10 metaclusters. The main difference is that metaclusters are nested subsets ranging from a minimal install to nearly all packages on the media. Group packages have no such hierarchy. They can overlap other groups, or be completely disjoint sets. A group dependency is set this way in an IPS package manifest file: depend fmri=full/pkg/name type=group Current Solaris Groups Solaris currently has 4 system groups defined. These are used for different types of installation, and are included in the xml manifest files used by the various Solaris installers: Package Name Summary Description Default Installation For:  group/system/solaris-desktop Oracle Solaris Desktop Provides an Oracle Solaris desktop environment Live Media  group/system/solaris-large-server Oracle Solaris Large Server Provides an Oracle Solaris large server environment Text Installer  group/system/solaris-small-server Oracle Solaris Small Server Provides a useful command-line Oracle Solaris environment  Zones  group/system/solaris-auto-install  Oracle Solaris Automated Installer Client  Provides an Oracle Solaris Automated Installer client  Automated Installer There are also several "feature" groups such as AMP and GNU Developer Tools. These are provided for convenience, but are not used directly by any installers. Retrieving Group Package Information A listing of all current groups can be found with the command: pkg info -r group/* A listing of all the packages in a group can be obtained with: pkg contents -o fmri -H -rt depend -a type=group groupname An example: $ pkg contents -o fmri -H -rt depend -a type=group solaris-desktop archiver/gnu-tar audio/audio-utilities codec/flac codec/libtheora codec/ogg-vorbis codec/speex communication/im/pidgin etc. You can determine which package group is currently installed on your system: $ pkg list group/system/\* Output would look like: NAME (PUBLISHER) VERSION IFO group/system/solaris-desktop 0.5.11-0.175.0.0.0.0.0 i-- Note that there are not version numbers associated with a group package dependency. The package version that best fits the system will be used, based on other dependencies such as what is listed in incorporation files. Installing a Group To Install a group, simple use the group package name as you would any other package: $ pkg install solaris-small-server  If you want to exclude a package from installing, you can use the --reject flag: $ pkg install --reject audio/audio-utilities solaris-desktop Creating Your Own Group To create your own group package, you can follow the pkg(5) documentation on how to create a package, and use this action for each package that is part of your group:   depend fmri=full/pkg/name type=group

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  • What are good design practices when working with Entity Framework

    - by AD
    This will apply mostly for an asp.net application where the data is not accessed via soa. Meaning that you get access to the objects loaded from the framework, not Transfer Objects, although some recommendation still apply. This is a community post, so please add to it as you see fit. Applies to: Entity Framework 1.0 shipped with Visual Studio 2008 sp1. Why pick EF in the first place? Considering it is a young technology with plenty of problems (see below), it may be a hard sell to get on the EF bandwagon for your project. However, it is the technology Microsoft is pushing (at the expense of Linq2Sql, which is a subset of EF). In addition, you may not be satisfied with NHibernate or other solutions out there. Whatever the reasons, there are people out there (including me) working with EF and life is not bad.make you think. EF and inheritance The first big subject is inheritance. EF does support mapping for inherited classes that are persisted in 2 ways: table per class and table the hierarchy. The modeling is easy and there are no programming issues with that part. (The following applies to table per class model as I don't have experience with table per hierarchy, which is, anyway, limited.) The real problem comes when you are trying to run queries that include one or many objects that are part of an inheritance tree: the generated sql is incredibly awful, takes a long time to get parsed by the EF and takes a long time to execute as well. This is a real show stopper. Enough that EF should probably not be used with inheritance or as little as possible. Here is an example of how bad it was. My EF model had ~30 classes, ~10 of which were part of an inheritance tree. On running a query to get one item from the Base class, something as simple as Base.Get(id), the generated SQL was over 50,000 characters. Then when you are trying to return some Associations, it degenerates even more, going as far as throwing SQL exceptions about not being able to query more than 256 tables at once. Ok, this is bad, EF concept is to allow you to create your object structure without (or with as little as possible) consideration on the actual database implementation of your table. It completely fails at this. So, recommendations? Avoid inheritance if you can, the performance will be so much better. Use it sparingly where you have to. In my opinion, this makes EF a glorified sql-generation tool for querying, but there are still advantages to using it. And ways to implement mechanism that are similar to inheritance. Bypassing inheritance with Interfaces First thing to know with trying to get some kind of inheritance going with EF is that you cannot assign a non-EF-modeled class a base class. Don't even try it, it will get overwritten by the modeler. So what to do? You can use interfaces to enforce that classes implement some functionality. For example here is a IEntity interface that allow you to define Associations between EF entities where you don't know at design time what the type of the entity would be. public enum EntityTypes{ Unknown = -1, Dog = 0, Cat } public interface IEntity { int EntityID { get; } string Name { get; } Type EntityType { get; } } public partial class Dog : IEntity { // implement EntityID and Name which could actually be fields // from your EF model Type EntityType{ get{ return EntityTypes.Dog; } } } Using this IEntity, you can then work with undefined associations in other classes // lets take a class that you defined in your model. // that class has a mapping to the columns: PetID, PetType public partial class Person { public IEntity GetPet() { return IEntityController.Get(PetID,PetType); } } which makes use of some extension functions: public class IEntityController { static public IEntity Get(int id, EntityTypes type) { switch (type) { case EntityTypes.Dog: return Dog.Get(id); case EntityTypes.Cat: return Cat.Get(id); default: throw new Exception("Invalid EntityType"); } } } Not as neat as having plain inheritance, particularly considering you have to store the PetType in an extra database field, but considering the performance gains, I would not look back. It also cannot model one-to-many, many-to-many relationship, but with creative uses of 'Union' it could be made to work. Finally, it creates the side effet of loading data in a property/function of the object, which you need to be careful about. Using a clear naming convention like GetXYZ() helps in that regards. Compiled Queries Entity Framework performance is not as good as direct database access with ADO (obviously) or Linq2SQL. There are ways to improve it however, one of which is compiling your queries. The performance of a compiled query is similar to Linq2Sql. What is a compiled query? It is simply a query for which you tell the framework to keep the parsed tree in memory so it doesn't need to be regenerated the next time you run it. So the next run, you will save the time it takes to parse the tree. Do not discount that as it is a very costly operation that gets even worse with more complex queries. There are 2 ways to compile a query: creating an ObjectQuery with EntitySQL and using CompiledQuery.Compile() function. (Note that by using an EntityDataSource in your page, you will in fact be using ObjectQuery with EntitySQL, so that gets compiled and cached). An aside here in case you don't know what EntitySQL is. It is a string-based way of writing queries against the EF. Here is an example: "select value dog from Entities.DogSet as dog where dog.ID = @ID". The syntax is pretty similar to SQL syntax. You can also do pretty complex object manipulation, which is well explained [here][1]. Ok, so here is how to do it using ObjectQuery< string query = "select value dog " + "from Entities.DogSet as dog " + "where dog.ID = @ID"; ObjectQuery<Dog> oQuery = new ObjectQuery<Dog>(query, EntityContext.Instance)); oQuery.Parameters.Add(new ObjectParameter("ID", id)); oQuery.EnablePlanCaching = true; return oQuery.FirstOrDefault(); The first time you run this query, the framework will generate the expression tree and keep it in memory. So the next time it gets executed, you will save on that costly step. In that example EnablePlanCaching = true, which is unnecessary since that is the default option. The other way to compile a query for later use is the CompiledQuery.Compile method. This uses a delegate: static readonly Func<Entities, int, Dog> query_GetDog = CompiledQuery.Compile<Entities, int, Dog>((ctx, id) => ctx.DogSet.FirstOrDefault(it => it.ID == id)); or using linq static readonly Func<Entities, int, Dog> query_GetDog = CompiledQuery.Compile<Entities, int, Dog>((ctx, id) => (from dog in ctx.DogSet where dog.ID == id select dog).FirstOrDefault()); to call the query: query_GetDog.Invoke( YourContext, id ); The advantage of CompiledQuery is that the syntax of your query is checked at compile time, where as EntitySQL is not. However, there are other consideration... Includes Lets say you want to have the data for the dog owner to be returned by the query to avoid making 2 calls to the database. Easy to do, right? EntitySQL string query = "select value dog " + "from Entities.DogSet as dog " + "where dog.ID = @ID"; ObjectQuery<Dog> oQuery = new ObjectQuery<Dog>(query, EntityContext.Instance)).Include("Owner"); oQuery.Parameters.Add(new ObjectParameter("ID", id)); oQuery.EnablePlanCaching = true; return oQuery.FirstOrDefault(); CompiledQuery static readonly Func<Entities, int, Dog> query_GetDog = CompiledQuery.Compile<Entities, int, Dog>((ctx, id) => (from dog in ctx.DogSet.Include("Owner") where dog.ID == id select dog).FirstOrDefault()); Now, what if you want to have the Include parametrized? What I mean is that you want to have a single Get() function that is called from different pages that care about different relationships for the dog. One cares about the Owner, another about his FavoriteFood, another about his FavotireToy and so on. Basicly, you want to tell the query which associations to load. It is easy to do with EntitySQL public Dog Get(int id, string include) { string query = "select value dog " + "from Entities.DogSet as dog " + "where dog.ID = @ID"; ObjectQuery<Dog> oQuery = new ObjectQuery<Dog>(query, EntityContext.Instance)) .IncludeMany(include); oQuery.Parameters.Add(new ObjectParameter("ID", id)); oQuery.EnablePlanCaching = true; return oQuery.FirstOrDefault(); } The include simply uses the passed string. Easy enough. Note that it is possible to improve on the Include(string) function (that accepts only a single path) with an IncludeMany(string) that will let you pass a string of comma-separated associations to load. Look further in the extension section for this function. If we try to do it with CompiledQuery however, we run into numerous problems: The obvious static readonly Func<Entities, int, string, Dog> query_GetDog = CompiledQuery.Compile<Entities, int, string, Dog>((ctx, id, include) => (from dog in ctx.DogSet.Include(include) where dog.ID == id select dog).FirstOrDefault()); will choke when called with: query_GetDog.Invoke( YourContext, id, "Owner,FavoriteFood" ); Because, as mentionned above, Include() only wants to see a single path in the string and here we are giving it 2: "Owner" and "FavoriteFood" (which is not to be confused with "Owner.FavoriteFood"!). Then, let's use IncludeMany(), which is an extension function static readonly Func<Entities, int, string, Dog> query_GetDog = CompiledQuery.Compile<Entities, int, string, Dog>((ctx, id, include) => (from dog in ctx.DogSet.IncludeMany(include) where dog.ID == id select dog).FirstOrDefault()); Wrong again, this time it is because the EF cannot parse IncludeMany because it is not part of the functions that is recognizes: it is an extension. Ok, so you want to pass an arbitrary number of paths to your function and Includes() only takes a single one. What to do? You could decide that you will never ever need more than, say 20 Includes, and pass each separated strings in a struct to CompiledQuery. But now the query looks like this: from dog in ctx.DogSet.Include(include1).Include(include2).Include(include3) .Include(include4).Include(include5).Include(include6) .[...].Include(include19).Include(include20) where dog.ID == id select dog which is awful as well. Ok, then, but wait a minute. Can't we return an ObjectQuery< with CompiledQuery? Then set the includes on that? Well, that what I would have thought so as well: static readonly Func<Entities, int, ObjectQuery<Dog>> query_GetDog = CompiledQuery.Compile<Entities, int, string, ObjectQuery<Dog>>((ctx, id) => (ObjectQuery<Dog>)(from dog in ctx.DogSet where dog.ID == id select dog)); public Dog GetDog( int id, string include ) { ObjectQuery<Dog> oQuery = query_GetDog(id); oQuery = oQuery.IncludeMany(include); return oQuery.FirstOrDefault; } That should have worked, except that when you call IncludeMany (or Include, Where, OrderBy...) you invalidate the cached compiled query because it is an entirely new one now! So, the expression tree needs to be reparsed and you get that performance hit again. So what is the solution? You simply cannot use CompiledQueries with parametrized Includes. Use EntitySQL instead. This doesn't mean that there aren't uses for CompiledQueries. It is great for localized queries that will always be called in the same context. Ideally CompiledQuery should always be used because the syntax is checked at compile time, but due to limitation, that's not possible. An example of use would be: you may want to have a page that queries which two dogs have the same favorite food, which is a bit narrow for a BusinessLayer function, so you put it in your page and know exactly what type of includes are required. Passing more than 3 parameters to a CompiledQuery Func is limited to 5 parameters, of which the last one is the return type and the first one is your Entities object from the model. So that leaves you with 3 parameters. A pitance, but it can be improved on very easily. public struct MyParams { public string param1; public int param2; public DateTime param3; } static readonly Func<Entities, MyParams, IEnumerable<Dog>> query_GetDog = CompiledQuery.Compile<Entities, MyParams, IEnumerable<Dog>>((ctx, myParams) => from dog in ctx.DogSet where dog.Age == myParams.param2 && dog.Name == myParams.param1 and dog.BirthDate > myParams.param3 select dog); public List<Dog> GetSomeDogs( int age, string Name, DateTime birthDate ) { MyParams myParams = new MyParams(); myParams.param1 = name; myParams.param2 = age; myParams.param3 = birthDate; return query_GetDog(YourContext,myParams).ToList(); } Return Types (this does not apply to EntitySQL queries as they aren't compiled at the same time during execution as the CompiledQuery method) Working with Linq, you usually don't force the execution of the query until the very last moment, in case some other functions downstream wants to change the query in some way: static readonly Func<Entities, int, string, IEnumerable<Dog>> query_GetDog = CompiledQuery.Compile<Entities, int, string, IEnumerable<Dog>>((ctx, age, name) => from dog in ctx.DogSet where dog.Age == age && dog.Name == name select dog); public IEnumerable<Dog> GetSomeDogs( int age, string name ) { return query_GetDog(YourContext,age,name); } public void DataBindStuff() { IEnumerable<Dog> dogs = GetSomeDogs(4,"Bud"); // but I want the dogs ordered by BirthDate gridView.DataSource = dogs.OrderBy( it => it.BirthDate ); } What is going to happen here? By still playing with the original ObjectQuery (that is the actual return type of the Linq statement, which implements IEnumerable), it will invalidate the compiled query and be force to re-parse. So, the rule of thumb is to return a List< of objects instead. static readonly Func<Entities, int, string, IEnumerable<Dog>> query_GetDog = CompiledQuery.Compile<Entities, int, string, IEnumerable<Dog>>((ctx, age, name) => from dog in ctx.DogSet where dog.Age == age && dog.Name == name select dog); public List<Dog> GetSomeDogs( int age, string name ) { return query_GetDog(YourContext,age,name).ToList(); //<== change here } public void DataBindStuff() { List<Dog> dogs = GetSomeDogs(4,"Bud"); // but I want the dogs ordered by BirthDate gridView.DataSource = dogs.OrderBy( it => it.BirthDate ); } When you call ToList(), the query gets executed as per the compiled query and then, later, the OrderBy is executed against the objects in memory. It may be a little bit slower, but I'm not even sure. One sure thing is that you have no worries about mis-handling the ObjectQuery and invalidating the compiled query plan. Once again, that is not a blanket statement. ToList() is a defensive programming trick, but if you have a valid reason not to use ToList(), go ahead. There are many cases in which you would want to refine the query before executing it. Performance What is the performance impact of compiling a query? It can actually be fairly large. A rule of thumb is that compiling and caching the query for reuse takes at least double the time of simply executing it without caching. For complex queries (read inherirante), I have seen upwards to 10 seconds. So, the first time a pre-compiled query gets called, you get a performance hit. After that first hit, performance is noticeably better than the same non-pre-compiled query. Practically the same as Linq2Sql When you load a page with pre-compiled queries the first time you will get a hit. It will load in maybe 5-15 seconds (obviously more than one pre-compiled queries will end up being called), while subsequent loads will take less than 300ms. Dramatic difference, and it is up to you to decide if it is ok for your first user to take a hit or you want a script to call your pages to force a compilation of the queries. Can this query be cached? { Dog dog = from dog in YourContext.DogSet where dog.ID == id select dog; } No, ad-hoc Linq queries are not cached and you will incur the cost of generating the tree every single time you call it. Parametrized Queries Most search capabilities involve heavily parametrized queries. There are even libraries available that will let you build a parametrized query out of lamba expressions. The problem is that you cannot use pre-compiled queries with those. One way around that is to map out all the possible criteria in the query and flag which one you want to use: public struct MyParams { public string name; public bool checkName; public int age; public bool checkAge; } static readonly Func<Entities, MyParams, IEnumerable<Dog>> query_GetDog = CompiledQuery.Compile<Entities, MyParams, IEnumerable<Dog>>((ctx, myParams) => from dog in ctx.DogSet where (myParams.checkAge == true && dog.Age == myParams.age) && (myParams.checkName == true && dog.Name == myParams.name ) select dog); protected List<Dog> GetSomeDogs() { MyParams myParams = new MyParams(); myParams.name = "Bud"; myParams.checkName = true; myParams.age = 0; myParams.checkAge = false; return query_GetDog(YourContext,myParams).ToList(); } The advantage here is that you get all the benifits of a pre-compiled quert. The disadvantages are that you most likely will end up with a where clause that is pretty difficult to maintain, that you will incur a bigger penalty for pre-compiling the query and that each query you run is not as efficient as it could be (particularly with joins thrown in). Another way is to build an EntitySQL query piece by piece, like we all did with SQL. protected List<Dod> GetSomeDogs( string name, int age) { string query = "select value dog from Entities.DogSet where 1 = 1 "; if( !String.IsNullOrEmpty(name) ) query = query + " and dog.Name == @Name "; if( age > 0 ) query = query + " and dog.Age == @Age "; ObjectQuery<Dog> oQuery = new ObjectQuery<Dog>( query, YourContext ); if( !String.IsNullOrEmpty(name) ) oQuery.Parameters.Add( new ObjectParameter( "Name", name ) ); if( age > 0 ) oQuery.Parameters.Add( new ObjectParameter( "Age", age ) ); return oQuery.ToList(); } Here the problems are: - there is no syntax checking during compilation - each different combination of parameters generate a different query which will need to be pre-compiled when it is first run. In this case, there are only 4 different possible queries (no params, age-only, name-only and both params), but you can see that there can be way more with a normal world search. - Noone likes to concatenate strings! Another option is to query a large subset of the data and then narrow it down in memory. This is particularly useful if you are working with a definite subset of the data, like all the dogs in a city. You know there are a lot but you also know there aren't that many... so your CityDog search page can load all the dogs for the city in memory, which is a single pre-compiled query and then refine the results protected List<Dod> GetSomeDogs( string name, int age, string city) { string query = "select value dog from Entities.DogSet where dog.Owner.Address.City == @City "; ObjectQuery<Dog> oQuery = new ObjectQuery<Dog>( query, YourContext ); oQuery.Parameters.Add( new ObjectParameter( "City", city ) ); List<Dog> dogs = oQuery.ToList(); if( !String.IsNullOrEmpty(name) ) dogs = dogs.Where( it => it.Name == name ); if( age > 0 ) dogs = dogs.Where( it => it.Age == age ); return dogs; } It is particularly useful when you start displaying all the data then allow for filtering. Problems: - Could lead to serious data transfer if you are not careful about your subset. - You can only filter on the data that you returned. It means that if you don't return the Dog.Owner association, you will not be able to filter on the Dog.Owner.Name So what is the best solution? There isn't any. You need to pick the solution that works best for you and your problem: - Use lambda-based query building when you don't care about pre-compiling your queries. - Use fully-defined pre-compiled Linq query when your object structure is not too complex. - Use EntitySQL/string concatenation when the structure could be complex and when the possible number of different resulting queries are small (which means fewer pre-compilation hits). - Use in-memory filtering when you are working with a smallish subset of the data or when you had to fetch all of the data on the data at first anyway (if the performance is fine with all the data, then filtering in memory will not cause any time to be spent in the db). Singleton access The best way to deal with your context and entities accross all your pages is to use the singleton pattern: public sealed class YourContext { private const string instanceKey = "On3GoModelKey"; YourContext(){} public static YourEntities Instance { get { HttpContext context = HttpContext.Current; if( context == null ) return Nested.instance; if (context.Items[instanceKey] == null) { On3GoEntities entity = new On3GoEntities(); context.Items[instanceKey] = entity; } return (YourEntities)context.Items[instanceKey]; } } class Nested { // Explicit static constructor to tell C# compiler // not to mark type as beforefieldinit static Nested() { } internal static readonly YourEntities instance = new YourEntities(); } } NoTracking, is it worth it? When executing a query, you can tell the framework to track the objects it will return or not. What does it mean? With tracking enabled (the default option), the framework will track what is going on with the object (has it been modified? Created? Deleted?) and will also link objects together, when further queries are made from the database, which is what is of interest here. For example, lets assume that Dog with ID == 2 has an owner which ID == 10. Dog dog = (from dog in YourContext.DogSet where dog.ID == 2 select dog).FirstOrDefault(); //dog.OwnerReference.IsLoaded == false; Person owner = (from o in YourContext.PersonSet where o.ID == 10 select dog).FirstOrDefault(); //dog.OwnerReference.IsLoaded == true; If we were to do the same with no tracking, the result would be different. ObjectQuery<Dog> oDogQuery = (ObjectQuery<Dog>) (from dog in YourContext.DogSet where dog.ID == 2 select dog); oDogQuery.MergeOption = MergeOption.NoTracking; Dog dog = oDogQuery.FirstOrDefault(); //dog.OwnerReference.IsLoaded == false; ObjectQuery<Person> oPersonQuery = (ObjectQuery<Person>) (from o in YourContext.PersonSet where o.ID == 10 select o); oPersonQuery.MergeOption = MergeOption.NoTracking; Owner owner = oPersonQuery.FirstOrDefault(); //dog.OwnerReference.IsLoaded == false; Tracking is very useful and in a perfect world without performance issue, it would always be on. But in this world, there is a price for it, in terms of performance. So, should you use NoTracking to speed things up? It depends on what you are planning to use the data for. Is there any chance that the data your query with NoTracking can be used to make update/insert/delete in the database? If so, don't use NoTracking because associations are not tracked and will causes exceptions to be thrown. In a page where there are absolutly no updates to the database, you can use NoTracking. Mixing tracking and NoTracking is possible, but it requires you to be extra careful with updates/inserts/deletes. The problem is that if you mix then you risk having the framework trying to Attach() a NoTracking object to the context where another copy of the same object exist with tracking on. Basicly, what I am saying is that Dog dog1 = (from dog in YourContext.DogSet where dog.ID == 2).FirstOrDefault(); ObjectQuery<Dog> oDogQuery = (ObjectQuery<Dog>) (from dog in YourContext.DogSet where dog.ID == 2 select dog); oDogQuery.MergeOption = MergeOption.NoTracking; Dog dog2 = oDogQuery.FirstOrDefault(); dog1 and dog2 are 2 different objects, one tracked and one not. Using the detached object in an update/insert will force an Attach() that will say "Wait a minute, I do already have an object here with the same database key. Fail". And when you Attach() one object, all of its hierarchy gets attached as well, causing problems everywhere. Be extra careful. How much faster is it with NoTracking It depends on the queries. Some are much more succeptible to tracking than other. I don't have a fast an easy rule for it, but it helps. So I should use NoTracking everywhere then? Not exactly. There are some advantages to tracking object. The first one is that the object is cached, so subsequent call for that object will not hit the database. That cache is only valid for the lifetime of the YourEntities object, which, if you use the singleton code above, is the same as the page lifetime. One page request == one YourEntity object. So for multiple calls for the same object, it will load only once per page request. (Other caching mechanism could extend that). What happens when you are using NoTracking and try to load the same object multiple times? The database will be queried each time, so there is an impact there. How often do/should you call for the same object during a single page request? As little as possible of course, but it does happens. Also remember the piece above about having the associations connected automatically for your? You don't have that with NoTracking, so if you load your data in multiple batches, you will not have a link to between them: ObjectQuery<Dog> oDogQuery = (ObjectQuery<Dog>)(from dog in YourContext.DogSet select dog); oDogQuery.MergeOption = MergeOption.NoTracking; List<Dog> dogs = oDogQuery.ToList(); ObjectQuery<Person> oPersonQuery = (ObjectQuery<Person>)(from o in YourContext.PersonSet select o); oPersonQuery.MergeOption = MergeOption.NoTracking; List<Person> owners = oPersonQuery.ToList(); In this case, no dog will have its .Owner property set. Some things to keep in mind when you are trying to optimize the performance. No lazy loading, what am I to do? This can be seen as a blessing in disguise. Of course it is annoying to load everything manually. However, it decreases the number of calls to the db and forces you to think about when you should load data. The more you can load in one database call the better. That was always true, but it is enforced now with this 'feature' of EF. Of course, you can call if( !ObjectReference.IsLoaded ) ObjectReference.Load(); if you want to, but a better practice is to force the framework to load the objects you know you will need in one shot. This is where the discussion about parametrized Includes begins to make sense. Lets say you have you Dog object public class Dog { public Dog Get(int id) { return YourContext.DogSet.FirstOrDefault(it => it.ID == id ); } } This is the type of function you work with all the time. It gets called from all over the place and once you have that Dog object, you will do very different things to it in different functions. First, it should be pre-compiled, because you will call that very often. Second, each different pages will want to have access to a different subset of the Dog data. Some will want the Owner, some the FavoriteToy, etc. Of course, you could call Load() for each reference you need anytime you need one. But that will generate a call to the database each time. Bad idea. So instead, each page will ask for the data it wants to see when it first request for the Dog object: static public Dog Get(int id) { return GetDog(entity,"");} static public Dog Get(int id, string includePath) { string query = "select value o " + " from YourEntities.DogSet as o " +

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  • Error when trying to start Apache after installing SSL cert

    - by chris
    I am trying to install an SSL certificate, and I get the following errors: AH02241: Init: Unable to read server certificate from file /path/my.crt SSL Library Error: error:0D0680A8:asn1 encoding routines:ASN1_CHECK_TLEN:wrong tag SSL Library Error: error:0D07803A:asn1 encoding routines:ASN1_ITEM_EX_D2I:nested asn1 error (Type=X509) AH02312: Fatal error initialising mod_ssl, exiting. Here's the process I followed: I generated my private key with: openssl genrsa -out my.key 2048 I created the CSR with: openssl req -new -key my.key -out my.csr I provided the CSR to our IT department, and they returned a crt - it starts with -----BEGIN CERTIFICATE----- My ssl.conf has (my.example.com matches the Common name used during the generation of the CSR): <VirtualHost my.example.com:443> SSLEngine On ServerName my.example.com SSLCertificateFile /path/my.crt SSLCertificateKeyFile /path/my.key </VirtualHost> I do not have SSLCertificateChainFile or SSLCACertificate file set. The private key starts with ----BEGIN RSA PRIVATE KEY----- The csr starts with -----BEGIN CERTIFICATE REQUEST----- I have verified that both: openssl rsa -noout -modulus -in my.key openssl req -noout -modulus -in my.csr produce the same output. I cannot figure out how to verify the crt - trying both x509 and rsa produce an error. Should this process have worked? Can I verify that my.crt matches the key somehow?

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  • How do I stop Sophos anti virus from scanning directories that are under source control

    - by user26453
    From googling it seems its well known that SophosAV as well as other AV programs have issues with how they interact and can inhibit source control utilities like TortoiseHG or TortoiseSVN. One solution is to exclude directories under source control from on-access scanning as detailed here on Sophos's support site. There is a corollary article that mentions some issues related to this, namely the need to place multiple entries for exclusions based on the possibility of the location being accessed through the short vs. long name (e.g., Progra~1 vs. "Program Files"). One other twist is I am using a junction to relocate my user directory, C:\Users\Username, to a second hard drive, E:. Since I am not sure how this interacts I have included the source control directory as they are nested in both locations. As a result, I have included the two exclusions for the on-access scanning exclusions (and to be on the safe side on-demand exclusions as well, although this should only come into play when I select a parent directory of the exclusion to be scanned on-demand, but still). You'll notice I have no need to add extra exclusions for those locations based on short vs. long name distinctions. The two exclusion I have then, for both on-access and on-demand scanning exclusions are: C:\Users\Username\source-control-directory E:\source-control-directory However, this does not seem to work as TortoiseHG still lags terribly in response to any request as AV software starts scanning when the directory is accessed via TortoiseHG. I can verify without a doubt that Sophos is causing the problems: I can completely disable on-access scanning. Once this is done TortoiseHG responds very fast to all operations. I cannot leave this disabled obviously, but since the exclusion don't seem to be working, what next?

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  • Why apache doesn't restart after configuring SSL?

    - by poz2k4444
    I've installed apache2 and then configure it to work with SSL following this and this tutorials, the problem becomes when I try to restart the service, the following error throws: (98)Address already in use: make_sock: could not bind to address 0.0.0.0:443 no listening sockets available, shutting down Unable to open logs the output of netstat -anp | grep 443 just display firefox listening and anything else, how could I solve this and get the service running?? The ouput of ps -Af|grep <firefox PID> is: root 1949 1 11 18:42 tty1 00:20:55 /opt/firefox/firefox-bin root 2025 1949 4 18:43 tty1 00:08:39 /opt/firefox/plugin-container /root/.mozilla/plugins/libflashplayer.so -greomni /opt/firefox/omni.ja 1949 true plugin after closing firefox and then cheking again for port 443 the output is: tcp 0 0 10.32.208.179:38923 74.125.139.155:443 TIME_WAIT - tcp 0 0 10.32.208.179:45706 74.125.139.113:443 TIME_WAIT - tcp 0 0 10.32.208.179:40456 74.125.139.156:443 TIME_WAIT - tcp 0 0 10.32.208.179:56823 69.171.227.62:443 FIN_WAIT2 - unix 3 [ ] STREAM CONNECTED 12443 1721/dbus-daemon @/tmp/dbus-8ee35rmOOS Seeing the error logs, which are not at the time when I'm doing this, the last errors are: [Tue Oct 02 18:41:54 2012] [error] Init: Unable to read server certificate from file /etc/apache2/ssl/sever.crt [Tue Oct 02 18:41:54 2012] [error] SSL Library Error: 218529960 error:0D0680A8:asn1 encoding routines:ASN1_CHECK_TLEN:wrong tag [Tue Oct 02 18:41:54 2012] [error] SSL Library Error: 218595386 error:0D07803A:asn1 encoding routines:ASN1_ITEM_EX_D2I:nested asn1 error

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  • How to stop SophosAV from scanning directories under source control

    - by user26453
    From googling it seems its well known that SophosAV as well as other AV programs have issues with how they interact and can inhibit source control utilities like TortoiseHG or TortoiseSVN. One solution is to exclude directories under source control from on-access scanning as detailed here on Sophos's support site. There is a corollary article that mentions some issues related to this, namely need to place multiple entries for exclusions based on the possibility of the location being accessed through the short vs. long name (e.g., Progra~1 vs. "Program Files"). One other twist is I am using a junction to relocate my user directory, C:\Users\Username, to a second hard drive, E:. Since I am not sure how this interacts I have included the source control directory as they are nested in both locations. As a result, I have included the two exclusions for the on-access scanning exclusions (and to be on the safe side on-demand exclusions as well, although this should only come into play when I select a parent directory of the exclusion to be scanned on-demand, but still). You'll notice I have no need to add extra exclusions for those locations based on short vs. long name distinctions. The two exclusion I have then, for both on-access and on-demand scanning exclusions are: C:\Users\Username\source-control-directory E:\source-control-directory However, this does not seem to work as TortoiseHG still lags terribly in response to any request as AV software starts scanning when the directory is accessed via TortoiseHG. I can verify without a doubt that Sophos is causing the problems: I can completely disable on-access scanning. Once this is done TortoiseHG responds very fast to all operations. I cannot leave this disabled obviously, but since the exclusion don't seem to be working, what next?

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  • Vserver: secure mails from a hacked webservice

    - by lukas
    I plan to rent and setup a vServer with Debian xor CentOS. I know from my host, that the vServers are virtualized with linux-vserver. Assume there is a lighthttpd and some mail transfer agent running and we have to assure that if the lighthttpd will be hacked, the stored e-mails are not readable easily. For me, this sounds impossible but may I missed something or at least you guys can validate the impossibility... :) I think basically there are three obvious approaches. The first is to encrypt all the data. Nevertheless, the server would have to store the key somewhere so an attacker (w|c)ould figure that out. Secondly one could isolate the critical services like lighthttpd. Since I am not allowed to do 'mknod' or remount /dev in a linux-vserver, it is not possible to setup a nested vServer with lxc or similar techniques. The last approach would be to do a chroot but I am not sure if it would provide enough security. Further I have not tried yet, if I am able to do a chroot in a linux-vserver...? Thanks in advance!

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  • Getting Error while running RED5 server - class path resource [red5.xml] cannot be opened because it does not exist

    - by sunil221
    HI , I have installed java version "1.6.0_14" and Ant version 1.8.2 for red5 Server. when i am trying to run red5 server i am getting the following error please help Root: /usr/local/red5 Deploy type: bootstrap Logback selector: org.red5.logging.LoggingContextSelector Setting default logging context: default 11:27:39.838 [main] INFO org.red5.server.Launcher - Red5 Server 1.0.0 RC1 $Rev: 4171 $ (http://code.google.com/p/red5/) Red5 Server 1.0.0 RC1 $Rev: 4171 $ (http://code.google.com/p/red5/) SLF4J: Class path contains multiple SLF4J bindings. SLF4J: Found binding in [jar:file:/usr/local/red5/red5.jar!/org/slf4j/impl/StaticLoggerBinder.class] SLF4J: Found binding in [jar:file:/usr/local/red5/lib/logback-classic-0.9.26.jar!/org/slf4j/impl/StaticLoggerBinder.class] SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation. 11:27:39.994 [main] INFO o.s.c.s.FileSystemXmlApplicationContext - Refreshing org.springframework.context.support.FileSystemXmlApplicationContext@39d85f79: startup date [Mon Dec 21 11:27:39 EST 2009]; root of context hierarchy 11:27:40.149 [main] INFO o.s.b.f.xml.XmlBeanDefinitionReader - Loading XML bean definitions from class path resource [red5.xml] Exception org.springframework.beans.factory.BeanDefinitionStoreException: IOException parsing XML document from class path resource [red5.xml]; nested exception is java.io.FileNotFoundException: class path resource [red5.xml] cannot be opened because it does not exist Bootstrap complete

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  • Getting Error while running RED5 server - class path resource [red5.xml] cannot be opened because it does not exist

    - by sunil221
    HI , I have installed java version "1.6.0_14" and Ant version 1.8.2 for red5 Server. when i am trying to run red5 server i am getting the following error please help Root: /usr/local/red5 Deploy type: bootstrap Logback selector: org.red5.logging.LoggingContextSelector Setting default logging context: default 11:27:39.838 [main] INFO org.red5.server.Launcher - Red5 Server 1.0.0 RC1 $Rev: 4171 $ (http://code.google.com/p/red5/) Red5 Server 1.0.0 RC1 $Rev: 4171 $ (http://code.google.com/p/red5/) SLF4J: Class path contains multiple SLF4J bindings. SLF4J: Found binding in [jar:file:/usr/local/red5/red5.jar!/org/slf4j/impl/StaticLoggerBinder.class] SLF4J: Found binding in [jar:file:/usr/local/red5/lib/logback-classic-0.9.26.jar!/org/slf4j/impl/StaticLoggerBinder.class] SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation. 11:27:39.994 [main] INFO o.s.c.s.FileSystemXmlApplicationContext - Refreshing org.springframework.context.support.FileSystemXmlApplicationContext@39d85f79: startup date [Mon Dec 21 11:27:39 EST 2009]; root of context hierarchy 11:27:40.149 [main] INFO o.s.b.f.xml.XmlBeanDefinitionReader - Loading XML bean definitions from class path resource [red5.xml] Exception org.springframework.beans.factory.BeanDefinitionStoreException: IOException parsing XML document from class path resource [red5.xml]; nested exception is java.io.FileNotFoundException: class path resource [red5.xml] cannot be opened because it does not exist Bootstrap complete

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  • Trying to build OpenSimulator.. nant fails

    - by Gary
    Output of nant is: Buildfile: file:///root/opensim-0.6.8-release/OpenSim.build Target framework: Mono 2.0 Profile Target(s) specified: build [echo] Using 'mono-2.0' Framework init: Debug: [echo] Platform unix build: [nant] /root/opensim-0.6.8-release/OpenSim/Framework/Servers/HttpServer/OpenSim.Framework.Servers.HttpServer.dll.build build Buildfile: file:///root/opensim-0.6.8-release/OpenSim/Framework/Servers/HttpServer/OpenSim.Framework.Servers.HttpServer.dll.build Target framework: Mono 2.0 Profile Target(s) specified: build build: [echo] Build Directory is /root/opensim-0.6.8-release/OpenSim/Framework/Servers/HttpServer/bin/Debug [csc] Compiling 29 files to '/root/opensim-0.6.8-release/OpenSim/Framework/Servers/HttpServer/bin/Debug/OpenSim.Framework.Servers.HttpServer.dll'. [csc] /root/opensim-0.6.8-release/OpenSim/Framework/Servers/HttpServer/AsynchronousRestObjectRequester.cs(103,41): error CS0246: The type or namespace name `TResponse' could not be found. Are you missing a using directive or an assembly reference? [csc] Compilation failed: 1 error(s), 0 warnings BUILD FAILED - 0 non-fatal error(s), 1 warning(s) /root/opensim-0.6.8-release/OpenSim/Framework/Servers/HttpServer/OpenSim.Framework.Servers.HttpServer.dll.build(14,6): External Program Failed: /usr/lib/pkgconfig/../../lib/mono/2.0/gmcs.exe (return code was 1) Total time: 1.2 seconds. BUILD FAILED Nested build failed. Refer to build log for exact reason. Total time: 1.3 seconds. OS is Fedora 7. Any ideas appreciated. :)

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  • Apache wont start after attempting to install SSL

    - by yummm
    Below is what my VirtualHosts look like in httpd.conf <VirtualHost *:80> # Admin email, Server Name (domain name) and any aliases ServerAdmin [email protected] ServerName mydomain.com ServerAlias www.mydomain.com # Index file and Document Root (where the public files are located) DirectoryIndex index.php DocumentRoot /home/mydomain/public_html/mydomain.com/public # Custom log file locations LogLevel warn ErrorLog /home/mydomain/public_html/mydomain.com/log/error.log CustomLog /home/mydomain/public_html/mydomain.com/log/access.log combined </VirtualHost> <VirtualHost *:443> SSLEngine on SSLCertificateFile /etc/httpd/conf/ssl.crt/mydomain.com.crt SSLCertificateKeyFile /etc/httpd/conf/ssl.key/mydomain.com.key ServerName mydomain.com DirectoryIndex index.php DocumentRoot /home/mydomain/public_html/mydomain.com/public </VirtualHost> I'm using the latest version of Apache on CentOS and there isn't any error being generated. Apache just will not start. Any ideas what I'm doing wrong? UPDATE - Found these messages in the error log: [Tue Mar 16 02:07:57 2010] [error] Init: Private key not found [Tue Mar 16 02:07:57 2010] [error] SSL Library Error: 218710120 error:0D094068:asn1 encoding routines:d2i_ASN1_SET:bad tag [Tue Mar 16 02:07:57 2010] [error] SSL Library Error: 218529960 error:0D0680A8:asn1 encoding routines:ASN1_CHECK_TLEN:wrong tag [Tue Mar 16 02:07:57 2010] [error] SSL Library Error: 218595386 error:0D07803A:asn1 encoding routines:ASN1_ITEM_EX_D2I:nested asn1 error [Tue Mar 16 02:07:57 2010] [error] SSL Library Error: 218734605 error:0D09A00D:asn1 encoding routines:d2i_PrivateKey:ASN1 lib

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  • How to solve SocketException: Permission denied: connect

    - by luxinxian
    I recently encountered a problem that is giving me a headache and I need help ... The System consists of two subsystems, called A and B, each running on a standalone Tomcat instance and currently running on the same machine. A invokes B's service via Spring httpInvoker (i.e. over HTTP). B system also invokes the other system's services via HTTP. Symptoms: the system starts to run and appears to work normally for around 10-15 days; the system will run for a period of time after an exception: org.springframework.remoting.RemoteAccessException: Could not access HTTP invoker remote service at [http://xxx.xxx.xxx.xxx/remoting/call]; The nested exception is java. net.SocketException: **Permission denied: connect** when the exception occurs, the system continues. This happens always, not only occasionally. (It looks like some resources are exhausted, but CPU rate < 5%, memory < 15%, network < 5%). when the system call between A and B fails, the B system call over HTTP to an external service also failed, with the same exception. Restarting both Tomcat services makes the whole system work properly. So repeatedly following steps 1 - 5, I have not found the root reason. Environment: windows 2008 R2 tomcat7.0.42 x86_64 oralce-jdk-1.7.0_40 Any ideas?

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