Comments by ShacharK - CodeProject

ShacharK 26-Sep-13 10:21am View

I don't see how implementing ISerializable is of any help. I have a custom object that exposes String instead of an object. I need it to be transparent, as if it never existed.

InternalStructureToStringSerializationObject should output a serialized string, and it could be initialized from a string as well.

Instead of: { "Output" : "EncryptedString" }, it should be serialized to "EncryptedString" only.

ShacharK 21-Jul-13 17:28pm View

Thanks a lot for your help, I tried to avoid this solution as I find it not very elegant, but I guess it is not that bad after all...

ShacharK 21-Jul-13 15:20pm View

Umm, Lets simplify things a little a bit. I can reduce the problem into that. (Although, I'm afraid that I'll be giving up on some measures of security).

I obviously need all my modules to be loaded during the initialization, as I need to resolve types that exist in modules that aren't loaded as dependencies.

Is there a better way to do that rather than the simple solution of loading all the modules that declare that they are defining types, and need to be loaded? Something like scanning the directory for them when initializing the resolver mechanism?

ShacharK 21-Jul-13 1:35am View

It knows only the base type, the rest is regular object population... I guess I might have re-implemented something, but it isn't the problem right now...

ShacharK 20-Jul-13 7:28am View

Of course I'm going to use standard serializers. I wrote my own JsonConverter that knows how to resolve my types, All I need to do is to translate the type of the member that is being populated. If it inherits some base class that has "Id" member, I query the "Id" value and translate it into a new type (I assert for assignability of course...). Then I simply populate the new type instead.

My architecture would look something like this:

Common:
Contains lots of stuff, mostly irrelevant. Mostly wrappers (Reflection, Cryptography wrappers) Also some Error Logging & Asserts, Debugging Utils).

Common.Serialization:
Contained within the Common.dll, exposes a BaseSerializer class, that all serializers must implement, along with the base type for the polymorphic serialization, the identification attribute and the resolver code, which can be used by inheriting Serializers.
Plugins.Serializers.Json: A separate DLL. Implements JsonSerializer (simple wrapper to an existing serializer).

Plugins.Communication.Protocol - Exposes a Command design pattern, with some basic classes, mostly dealing with authentication abstractly.

Plugins.Authentication.Email - Examples for a plugin that implement authentication logic using an email-address and password.
Plugins.Authentication.Email.Protocol - Implements the abstract classes needed for authentication by the forementioned protocol.

Use case in an Application:

The application is configured to use JsonSerializer along with the protocol.

It needs to know to resolve types from Plugins.Authentication.Email.Protocol lazily, if it exists. I just don't want the application to specify the modules it requires manually in any step (especially not the protocol which shouldn't be related to any project and technically be compiled once for several projects).

The only thing I could probably live with is loading the assemblies manually in my executable project, but I really prefer not to do so, as I'm trying to achieve a black-box framework that my project developers could use without touching my code at all, just write / add existing plugins wherever possible.

Thank you again :)

ShacharK 19-Jul-13 11:28am View

Um, first of all thank you for your answer.

Secondly, I would like to ask you how do you see your suggestions combine with my design.

Lets review the design:

1. A serialized request object is received, we should deserialize it into a Composite Request.

There's the simpler case, The request class is defined within an assembly which was already loaded (statically).
2. Id property of the main object is examined.
3. A matching type is found (or is already cached, because it was previously used...)
4. The deserializer starts to populate the type. Lets say the Type was a registration request.

Here comes the tricker part (at least for me...).

The RegistrationRequest is composite and contains an abstract-class member "Registrator".
If an authentication plugin wants to expose a protocol interface,
it should implement few classes such as "Registrator", "Authenticator", etc.
That way, the run-time binding process that we're reviewing should do the connection.

We have an unloaded email plugin. Now the resolving algorithm, that worked fine with the straight-forward case
needs to know that the ID "12345678" means an EmailRegistrator. (We can assume that the registrator has an identifying attribute that says 12345678...) How does it happen?

ShacharK 15-Feb-13 15:19pm View

The way I see it, Composition changes the way my requests are serialized.
I'll try to simplify what's on my mind by an example:

Imagine 3 layers of inheritance, I would expect my data structure to contain the parameters of all the layers, lets say the expected serialized object is (123).
If I use composition, I have 3 Parameters Structures, one for each layer, making it look like (1)(2)(3). It is possible to work like that, but not very comfortable in my opinion... In this case, assuming the serialization works properly. Errors and Exceptions can be handled in the same layer, utilizing the fact that the requests can still inherit from one another.

If the Inheritance is used, It is impossible to use the layered error handling, as every Request is inheriting a Parameters class. and although serialization works perfectly fine, lower-level exceptions are being handled in multiple requests.

I guess that Partial classes are just wishful thinking, and that if I ever decide to write such utility, I would choose the composition method before I would choose the Request Inheriting from Parameters class.

ShacharK 15-Feb-13 13:55pm View

The idea of using partial classes by auto-code generators is very common (Visual Studio Code Designers often use them). All I'm doing is translating data contracts from one language to another to enforce that no dumb mistakes are done.

ShacharK 14-Feb-13 19:44pm View

Actually, I am building a framework. My intentions are obviously minimizing the amount of boring repetitive code the developer has to write (even worse! duplicate :S). This is extremely error-prone, and might be annoying. Especially, when different people are working on every code base.

As you've mentioned, The client-server interface should be consistent. I obviously agree. I don't see any good reason why a user of my framework would have to change that. Especially when I'm offering many useful abstract base classes whose handling procedures do much of the validations and verification procedures needed by the average server. Anyhow, This is a cool feature to have, and if it works properly, along with some basic target-language communication framework that I can supply. An application's SDK can be created in a really short time.

I don't see why creating a copy of the request parameters on both side of the protocol is not a good solution.
Somebody who uses this framework feature would have synchronized enums, synchronized requests parameters. It ensures that the communication will be stable, as long as the client compiles properly. Serialization methods (Binary, JSON, XML, Protobuf, ...) are all configurable and the settings could be exported as well if I wanted them to. For example I could translate C# attributes to Java Annotations which would contain serialization relevant parameters (i.e JSON Keys)

TRK3 & Sergey, I think you've misunderstood my intentions. According to my design, the server is responsible to export an SDK, which one could simply assimilate into a layered protocol manager which is capable of fixing some issues without annoying the client side developers.

I don't think that I should be concerned about the division of labor. As my design is very "oniony" and every layer has a matching layer on the other side.

Thank you for your time, I really appreciate your efforts to help.

ShacharK 22-Jan-13 17:09pm View

It is indeed an excellent answer. Your insights were very helpful, I thank you very much for that.

ShacharK 20-Oct-12 4:43am View

Well, I'm not totally convinced yet, but I do appreciate your efforts, Thank you very much :)

ShacharK 19-Oct-12 20:39pm View

I will definitely look at it, by the way, is there a way to verify the validity of the sent objects? For debugging purposes, If a field is not found, would I be notified? As it is very important that the entire data is complete...

ShacharK 14-Oct-12 16:12pm View

Would that be better? Isn't WCF an overkill? I always found this technology far too complicated for any of my needs in the past. I would love to hear your opinion.

ShacharK 13-Oct-12 13:11pm View

I'm usually a low-level guy, but I really think that a C++ implementation for this project would be an overkill. By the way, are Visual Studio Ultimate 2010 and IIS sufficient for development of C# for Web-platform? are there any helpful add-ons? Thanks a lot.

ShacharK 13-Oct-12 9:04am View

I would like to write minimal amount of ASP code.
I have no real need for any web features provided by the HTTP protocol.
I use the http server as a platform to have clients communicating with my database using my custom JSON-based protocol.
You send a request, My protocol which I want to implement in C# processes information, makes the desired API Calls, and prints out a simple JSON-object response (instead of an actual website's html)

ShacharK 10-Jul-12 0:19am View

Well yeah, the storage engine is InnoDB. That's the main reason why I'm surprised... Those are two unrelated queries. All I'm trying to show is that when adding the FK during creation, it fails. But works properly when the table is altered after creation is done.

ShacharK 27-Nov-11 14:43pm View

I was hoping for an external reference... but never mind, I found something...

ShacharK 24-Nov-11 12:33pm View

Well, I was hoping for something constructive... A constructive example of how to design a solution, starting from the definition, up to the classification, I have read the theory, As a mathematician myself it makes sense, but is there an example that instead of just sharing their classifier with you, can actually give you hints how to start the design from scratch?

ShacharK 31-Oct-11 4:21am View

Well, I know that its activated, because there is another software installed on the destination PC that is using the same database... If I only had access to its connection string, life would have been easier.

ShacharK 31-Oct-11 4:19am View

It's a problem, because I'm actually not testing my application on my computer, but on a customer's computer... So I can't check it :S

ShacharK 30-Oct-11 5:53am View

Yep, irony :S

ShacharK 30-Oct-11 5:34am View

Damn it, Found it by myself... I am such an idiot... :)

ShacharK 30-Oct-11 5:20am View

My ExecuteNonQuery function is located within my DatabaseConnection class, which handles all my SqlCommands (opening connection, setting its SqlConnection as Command's connection, and then executing the command itself...)

ShacharK 30-Oct-11 5:19am View

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My ExecuteNonQuery function is located within my DatabaseConnection class, which handles all my SqlCommands (opening connection, setting its SqlConnection as Command's connection, and then executing the command itself...)

ShacharK 30-Oct-11 5:17am View

I added my GetProcedure method. Does it help you to help me?

ShacharK 30-Oct-11 4:56am View

Could you please be more specific? Maybe me send me to a relevant reference? This problem is very crucial... It happens quite a lot (unfortunately...)

ShacharK 29-Oct-11 20:36pm View

Well, my code works when I'm executing it directly using the server, but I just don't get why it wouldn't commit.

ShacharK 29-Oct-11 17:01pm View

Well, I'm executing my queries in very specific functions, so its not a problem to pool.
I have several main threads, only two of them are accessing the database. The one is actually a timer, used to load data from a specific database table (once in a while... haven't decided what would be the interval left, and I assume it would be for a few seconds once in real time).

The data is loaded into a queue of messages, which are sent by another thread to other instances of my program, and are received by the second database-accessing thread (in other instances), and it can do operations on the database.

So I have actually one reader, and one writer. The reader is used once in a few minutes, The writer runs whenever it gets data from the sockets...

ShacharK 29-Oct-11 16:35pm View

How can I debug the Procedure code?

By the way, how would you recommend handling multi-threaded database access? Should I be holding a connection for every thread?

ShacharK 29-Oct-11 9:25am View

Well, I was hoping that there was a way to find them using the SqlClient interfaces in C# (For example, I'm using it to get the table structures, columns and column types... So I was hoping (initially) that maybe I could use this interface to extract more data about the tables.

ShacharK 29-Oct-11 6:10am View

Oh, Of course... Thank you... I'll use a dictionary instead :)

ShacharK 28-Oct-11 10:38am View

Thanks :)

ShacharK 28-Oct-11 10:38am View

Thanks. :)

ShacharK 28-Oct-11 10:04am View

Well, Thanks, it seems really useful, but I chose implementing a naive solution (extracting the IDs, followed by the rest of the data...), because of C# reasons (I have a database generator, and I don't want to expand it to support views as well...)

Thanks again :)

ShacharK 28-Oct-11 8:00am View

Yeah I read about it, but should I CREATE the view every time? or should I make it permanent? I need high-performance in this query. Using a view would be more efficient, than selecting the t1.EventID, and then extracting the rest of the data?

ShacharK 28-Oct-11 7:15am View

Could you please be more specific? Should I CREATE the VIEW within the procedure and then delete it?

ShacharK 26-Oct-11 9:37am View

I've looked, I couldn't find anything constructive... I was hoping that someone here would have something constructive for me to learn from...

ShacharK 26-Oct-11 4:27am View

I mean the socket's async receive and send...

ShacharK 26-Oct-11 2:27am View

I'm actually not interested in using it, Not for now, I'm trying to implement my own logic. Could you please shed light on the RSS method please?

ShacharK 26-Oct-11 2:02am View

My service is actually server replication, but with some logic applied to the whole business. I want all my system's database to contain the same data (so I could, technically be working offline, and then when a connection is available, update everything... that while assuming that the connection would be available most of the time...).

I didn't say that prioritizing message is not simple, but it would require a scheduler algorithm, like in a process scheduler algorithm of every OS.

You think that I would benefit from sending my messages to the server, and then the server would "broadcast" them using RSS to all of his clients? Could you give me some more information on that? How can it be applied? and a big part of my tree hierarchy is in the LAN (if it matters...)

ShacharK 25-Oct-11 11:06am View

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Always nice to know, thank you.

ShacharK 25-Oct-11 11:06am View

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Always nice to know, thank you.

ShacharK 25-Oct-11 9:40am View

Finally... All I was waiting for was someone to say that its just like the regular query syntax... :)

ShacharK 25-Oct-11 8:39am View

@events should be a multiple-valued column... I know how to do the simple query.

I need to read @events or simply the EventID column from C#

ShacharK 25-Oct-11 7:36am View

'id' should be the number of the line. The primary key, or something like that would do.

CREATE TABLE table (
id int PRIMARY KEY IDENTITY(1,1)
record int
)

Fill the table with some values... let the id get the designated IDENTITY value.

and then apply the UPDATE query that I've suggested.

ShacharK 25-Oct-11 7:34am View

Can it? RETURN SELECT ...?

ShacharK 25-Oct-11 7:30am View

I'm not really interested in it as an output parameter, see it as a "pseudo-code", I just want the multiple values that are returned in the column EventID. How can I get them from an SQL Command?

ShacharK 25-Oct-11 7:10am View

So did it work for you?

ShacharK 25-Oct-11 4:45am View

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Yeah, but dictionaries can locate keys in O(1) because it uses a hashtable (I think according to the documentation). Maybe the O(1) way costs lots of memory.... But I'm storing integers, so boohoo... :)

ShacharK 25-Oct-11 4:14am View

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Math is my actual education... Anyway, All I'm saying is, that this map is used to recognize a client of the logical system (the ID from the database) and a physical connection ID to the server. I'm limiting the connection so only one connection can be identified as a client (otherwise, this is just bad use of my code). The only situation that can mess stuff up, is if there was an abnormal DC, and the client is trying to login again. Therefore, the simple mapping logic isn't sufficient for my needs, and I would have to encapsulate it within a more suitable interface & logic.

ShacharK 25-Oct-11 3:26am View

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Bill, My design ensures that the match is injective, because only one connection can identify at any time as a single client. I'll be implementing a class that would contain the simple map that would add the functionality, that if a client is already connected, and somebody identifies successfully as this client, the match would simply change.

ShacharK 25-Oct-11 3:03am View

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Thanks, it was very lazy of me to ask... The answer was quite obvious :) Thanks again.

ShacharK 25-Oct-11 1:56am View

I need it because the database that I'm working on has tables with multiple types as possible primary indices, and maybe even multiple. I'm trying to track the changes, if there was simply a row id, and the others would have been unique together life would have been so much easier... but no...

ShacharK 24-Oct-11 8:18am View

Great, and if I assume that data is variant, can it be converted automatically (or throwing an exception, I don't care...) to the input type of the destinated procedure?

@v1 and @v2 are variants that are supposed to be passed into the procedure...

I mean, exec (@sp_name) @v1 @v2

and the specified procedure is actually expecting integers...

ShacharK 24-Oct-11 1:47am View

Thanks, I figured out by myself how use the bulk copy interface.

My question is actually, how can I pass the data within the DataTable first to another location within my network that is familiar with the destination's actual connection string, and would be the one that will use the bulkcopy code (using its already active connection to the destination databaes).

I'm afraid that DataTable can not be binary serialized, is there a better way to do it?

ShacharK 22-Oct-11 13:08pm View

How is it done? The "Allow remote connections..." is checked by default, but what am I supposed to config in the Configuration Manager?

ShacharK 21-Oct-11 20:20pm View

Yes, but an "interesting" pattern can slow down many brute-force attacks... I didn't say that it makes encryption obsolete... Nothing does, but its another security measure.

ShacharK 21-Oct-11 7:52am View

I am using a queue of messages.

ShacharK 20-Oct-11 6:54am View

Do you mean extracting the text in the address bar from your web browser (lets say Firefox) and use it in your application?

ShacharK 20-Oct-11 4:50am View

According to what you're saying, there shouldn't be any problem with the DROP, but what about the creation? Can I create "randomly" my tables, with my foreign key constraints turned off, and only eventually, after the whole database is built, to actually turn them on (without the SQL telling me that it couldn't find the column that I was referring to)

ShacharK 19-Oct-11 23:13pm View

Maybe, I don't know. I don't have a good reason to implement it right away, nothing to do with table-return values right away at this moment. Thank you very much anyway, I'll look at it whenever I would actually need that.

ShacharK 19-Oct-11 3:44am View

I know the purpose of course of every one of the "components" in the deal.
I just didn't realize how the specific is done... All my SELECTS so far were direct queries, I wanted to have the possibility to combine the two.

You say that I could be having an OUTPUT Parameter that is simply assigned with multiple data? I just couldn't find a good example how to combine that with data selection, could you maybe post some pseudo?

ShacharK 17-Oct-11 21:41pm View

I have written a module that helps me create the procedures in code and then install them query-like... I think it would be sufficient (for now). Thanks anyway :)

ShacharK 17-Oct-11 11:34am View

Its problematic, because I might be connecting to a remote database and won't have access to it...

My alternative solution is to create the procedures by query during the setup, which is not very pretty because it would be simply a string and can cause troubles in later changes...

The optimal solution would be if I could write the methods as if they were written in the dll, and transform them into SQL query form or something like that...

ShacharK 17-Oct-11 9:44am View

Found it by myself eventually, thanks a lot anyway :)

ShacharK 16-Oct-11 10:03am View

Make them anyway, an extra opinion is always welcome...

ShacharK 16-Oct-11 10:02am View

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Make them anyway, an extra opinion is always welcome...

ShacharK 16-Oct-11 9:43am View

Of course, Every inherited Command builds the abstract Command base with different type, that's how I know what I'm building when deserializing them, and what are the values that I'm expecting.
The issue is the possible lack of Encapsulation, and not how to apply the Polymorphism. Whether I should just build an InheritedCommand and hide it behind a regular Command pointer. and then call command.Handle(All The Modules That Handle Might Require);
which of course would be much more aesthetic than a notorious switch-statement. A switch statement on the type would be followed by a cast to the actual command, and a set of operations in the module (Reply, Database Access, etc.) according to the specific properties of the message and state - decent encapsulation... but not very pretty.

ShacharK 16-Oct-11 9:10am View

Nah, I'm satisfied with my own serialization... Its still not what I was asking.

My switch statement is applied when I'm willing to handle the received message within the handle thread. According to that design, my commands are nothing but structures that organize my data.

My question was whether I should be using virtual Handle methods, that would need some inputs that would contradict the program's logic, and its encapsulation, by giving the method access to many other modules. My "handler" is kind of a main module which operates the Socket modules and Database module. Don't you think that it would be weird?

ShacharK 11-Oct-11 3:37am View

Are you saying that I should execute the queries by myself when receiving them, instead of letting the SQL to do the job for me?

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