Does thrift provide a way to inspect struct fields at runtime?
My use case is with C# but the question is regarding the standard Thrift API.
There is no standard thrift API across languages so what you can do beyond serialization is highly language dependent. If you can't accomplish what you want using just reflection, examine the code that is generated by the thrift compiler for the thrift object you are interested in. I've not seen C# thrift generated code but it may contain additional data that could be useful to you.
I am very familiar with the Java implementation and I can tell you that using thrift with Java there is no need to use reflection at all. Every thrift generated class contains information that allows the deserializer to reconstruct the class from field id numbers. The java thrift compiler creates static members and methods which contain pretty much everything you would ever want. For Java it is actually better than reflection because it contains the element types for lists/maps/sets.
Now there is no guarantee that the formats of this data won't change in future versions of thrift but given that all of the various protocols depend on them the 'hidden' API should be fairly stable.
If you have access to the IDL at runtime you could use a parser for the IDL and infer the generated fields that way.
I'm not an expert in C# but you could maybe link to the native libparse library used in the Thrift executable (I'm not sure if the parse library is generic enough to use like that, I'm just assuming).
Alternatively you could use the parser from Facebook's Swift (https://github.com/facebook/swift/tree/master/swift-idl-parser, or download the JAR from http://central.maven.org/maven2/com/facebook/swift/swift-idl-parser/0.13.2/swift-idl-parser-0.13.2.jar). This is probably easier or better for your case IMO, even though it is a Java library I think it should convert just fine to CLR using IKVM.net.
A third stupidly simple and hackish way to do this would be to use the Thrift HTML generator to generate HTML documentation and parse that using regex or run it through HTML Tidy and parse it as XML
Related
We are doing online code editor using monaco editor.
One of the requirement is to provide intellisense, or code auto-complete for java/python language. I searched so many resources, and can not find any useful resource on introduction how to make auto-complete working. some said using language server, but it is really difficult to make it work.
May I ask what is the best way to make auto-complete working for java language? Are there any good material that I can refer? Or can we just use some json files to make auto-complete work as well?
I read LSP4J protocol and I understand the philosophy and solution for language server, but now, my question is how to get data file. In another word, how to create CompleteItem objects and return?
Some resource said we need to build java language AST or Source processor(string processor)? Are there any java library I can use directly?
I don't want to use eclipse here, we need to provide our own service.
Thanks
You can use the Language Server Protocol, as described here for python:
https://stackoverflow.com/a/71349842/10985072
For Java, you can use georgewfraser's java-language-server for example.
I'm writing a semantic analysis application written on C++ that is internally based on syntactic parses of sentences. SyntaxNet is used to provide required dependency trees, and it works quite well.
The only thing is that I have to call SyntaxNet as an external application with the following calling for every sentence that my application handles:
system("./syntaxnet/demo.sh");
I notice a remarkable time expenses with such method of using SyntaxNet and would like to know if it is possible to use SyntaxNet as a library with some programming language (preferably, C++) API.
what about using Serving API?
https://github.com/dmansfield/parsey-mcparseface-api/issues/1
you can modify parsey_api.cc for loading exported model and parsing.
for python user, python client code
https://github.com/dsindex/syntaxnet/blob/master/README_api.md
I'm trying to (HTTP) upload a binary file programmatically from within VBA. I intend to put an ASPX page on the server to accept the file and certain additional parameters.
I know there are lots of nice ways to do that (e.g. use web service instead of aspx), but my constraint is that it must run in VBA (in an excel file), and that I cannot install any additional components on the client.
So I guess I'll use WinHTTP, and I've found several examples to post form data, but not to post a binary file. I probably need to base64 the file contents?
So my questions are:
Do I need to do the encoding manually or can I make WinHTTP do that?
Is there a better utility to use than WinHTTP? (Remember I don't want to install any additional software, it must be shipped with WinXP Pro, Office 2007 or a .NET framework, e.g.)
Is there a better way to go, e.g. using ASP.NET web services?
Thx, chiccodoro
You may use base64 but typically writing binary is easier.
The hurdle you have to leap is constructing a valid multi-par/form POST. This is completely possible using WinHTTP, although I have not done it in years and am not tooled to provide sample code, it is not trivial.
You can reference the following articles for examples of how to do this with C# HttpWebRequest. The WinHTTP api is a bit different of course but the salient points to take away from the articles is the structure of the POST body.
C# File Upload with form fields, cookies and headers (by yours truly)
UploadFileEx: C#'s WebClient.UploadFile with more functionality (a bit more procedural and may be easier to suss out the format)
Typically I provide sample code, but as I said, I do not have any stone-age tools set up right now ;-).
HTH
With NInject (preferably 2.0), what options do we have wrt wiring up our object dependencies in a web application?
Can they be defined in an XML configuration file?
Or does it have to be done via code?
There is an extension for xml based configuration: https://github.com/ninject/ninject.extensions.xml
You can do a lot more powerful binding in code though.
Ninject doesn't have XML configuration, sorry but I can't provide a direct link (cos their site has flash elements), but here is a quotation from ninject.org:
Free yourself from XML
Most other .NET dependency injection
frameworks are designed around the use
of XML to declare type bindings.
Rather than forcing you to write
cumbersome and error-prone text,
Ninject arms you with a fluent
interface, which lets you connect the
pieces of your application using
full-fledged code. This means you can
take advantage of the features of the
IDE and compiler, like code completion
and type-safety.
The problem I see with defining bindings in the code only is that you have to add reference to the dll.
You cannot change the binding without adding reference to new dll (removing reference to old one), change code and recompile.
If we had xml config I wouldn't need reference at all, and wouldn't have to recompile.
Right now I have MVC app that is using DI to pass repositories to Controllers. Nothing else then Ninject code for adding bindings uses the concrete implementations of repositories. And still I need to add reference to dll containing the implementations. For only one line of code!
Or maybe there is a possibility to achieve this using Ninject?
What are you looking to achieve? What sort of stuff are you looking to configure? Dynamically selecting a Strategy ? Passing in Port numbers? You could offer a lot more information as to what you're thinking in order to get a better answer [that you can acccept :P].
You need to split the concerns of:
known object wiring (DI)
configuration - generally you'll want to split those into small focused subsets e.g. Strongly Typed config elements vs having a global pool of settings in a big pile mishmashed together a la appSettings
plugins / unknown object wiring (MEF?)
In the first pool, doing it in Code is just the right way and I cant think of any advantage XML would give, esp. in the context of strong names etc.
What are your best examples of using Reflection in production code?
ASP.NET MVC inferring the action and controller to invoke from URL. Routing in general.
Most recently, I had to use reflection to load an assembly (in order to investigate its public types) from just the path of the assembly.
Before Linq To Sql came out...I had to write my own ORM in .NET 2.0.
I used reflection heavily to reflect back on:
Classes to their CRUD stored procedures
Properties to their column names
Which operations were valid for the class
I also used reflection to handle all variable assignment after the results were retreived (all classes inherited an ActiveRecord class that handled the calls into the DAL).
Rough stuff...but after some performance tuning it wasn't half bad.
Pulling data out of an SQL table where you had an ID, a type, and other data
Then you could load "Chevrolet" and work with all of it's methods
I did have occasion to write a Python O/R mapper on one at one point, but it was a proof of concept and never went into production.
I do quite a lot of work that makes extensive use of the system data dictionary on a DBMS (for example a generic slowly-changing dimension loader). It might be argued that this is not dissimilar to reflective programming in principle.
Finally, Python in all its forms is very easy to do reflection with. In fact, it's so good at this that I've used it to poke about with underlying API's in other languages - and use the reflective capabilities to query the underlying interfaces. I have done this with pretty much every reflective mechanism that exists in the Python world: CPython on Python API's and COM API's using makepy, Jython for java API's and IronPython for .Net API's.
In one of my recent apps, an add-in for Kofax Express, I have an option to OCR a file and output a PDF. Since the OCR tool I'm using has a runtime fee, I made the OCR part a seperate assembly. If the file exists, I show the OCR options and late bind the assembly and invoke the required methods and attach to the events with reflection. A simple plug in architecture without interfaces, and saves customers from having to pay royalty fees if they don't need to OCR; we just don't give them the OCR dll.
WPF Databinding:
1) Binding path "(TextBox.Text)" vs "Text"?
If you bind to a path called Text, WPF uses reflection to resolve the name. If you use the class-qualified name, binding avoids the reflection performance hit. Class-qualified names also allows binding to attached properties!
(via http://dotnet.org.za/rudi/archive/2008/03/25/10-things-i-didn-t-know-about-wpf-data-binding.aspx)
NUnit Unit Testing Framework - Not very typical though
CSLA uses reflection a lot
Pretty much any Windows Forms app that supports plugins
My DAL is all reflection based. It reflects on the POCO properties to build SQL.
Within a factory, we use reflection to either pass back a "Dummy" implementation of an interface or a real (hooked to the DB) implementation of an interface, based on the class specified in a properties file (in Java).