Software structure advice

I have posted a question on here previously asking similar advise, but this project has evolved significantly, so I would like to ask for advice on how the experts would tackle this problem.

First, I will describe what the problem is, then how I have currently looked at it. Please, I want to learn - so do critise my approach/tell me what I can/should do better!

Requirements: I have a log file decoder. I have three different systems generating log files. Each system is slightly different. There are seven different types of log files. Each log file can be in either ASCII format (human readable) or binary format (not human readable). So there are a lot of different logs - but many are similar. For example, for most, the binary and ascii is the same info in a different form. There is also one log type which is in a totally different structure, i.e., if a, b and c are different values - each stored 6 times, most logs are type 1. One log is type 2. type 1: abcabcabcabcabcabc type 2: aaaaaabbbbbbcccccc

On top of this, each system has a status register. The three systems are all different in this respect. i.e. 7 * 8 bit registers, 3 * 32 bit registers... These need processing after the log is decoded (for the logs that contain the info) and then a chart needs to be plotted for other info (where required).

So, my solution so far:

I have a LogFile struct. This contains a DataTable to contain all the data. Also contains a few strings, such as serial numbers which are read from the log files and some Enums (log type, system type, encoding format)

I have a Parser class. This has some static methods : to Identify what logs are contained within a log file (An ASCII file can contain several different ones - the GUI will find out what is in there, ask the user which one they want and then decode it. Another static method to act as a factory and give back an instantiation of the Parser class - there are 3 types. One generic. One for binary of the (type 2, above) and one for ascii of the (type 2, above).

I have a SystemType class. This contains info such as status register meanings, log structures for each type. I.e. when decoding a type, the GUI will call the 'GetTable, which will give back a DataTable with columns of the fields to read from the file. The Parser can then just cycle through the columns, which will allow it to know what type of variable to read from the file (Int, Single, String, etc).

I have a Reader class. This is abstract and has two child classes - one for ascii, one for binary. So, I can call reader.ReadInt and it will handle appropriately.

There is also a class to generate charts and decode the status register. Status registers are just an array of array of strings, giving name and description of each bit. Perhaps this could be a struct - but does it make a difference? There is also a further class which analyses 3 values in one particular log and if they are present, will insert a column with a value calculated from them (they are strings).

The whole things just isn't very flexible, but I didn't want to write a different class for each of (3*7*2 =) 42 log types! They are too similar, yet different so I think that they开发者_JAVA技巧 would have resulted in a lot of duplicate code. This is why I came up with the idea of the DataTable and a generic Parser.

So, sorry for the long text!

I have a few other questions - I have used a DataTable for the data because I use a DataGridView in the GUI to display all of this to the user. I assumed this would simplify this, but is there a better way of doing this? When I bind the DataTable to the DataGridView, I have to go through each one looking for a particular row to highlight, adding tooltips and setting various column widths, which actually takes as long as the whole decoding process. So if there is a more efficient way of doing this, it would be great!

Thanks for any feedback!! Please, I can not have too much advice here as I have been playing around, rearranging for ages trying to get it in a way that I think is a nice solution, but it always seems clunky and very tightly coupled, espcially with the GUI.

You probably want a class instead of a struct.

I wouldn't use a DataTable unless I had to. I would instead use a List or something similar, you can still bind this to your DataGridView. For formatting the grid, if this is an option, buy a UI control library that will give you more options than the DataGridView does. My favorite is Telerik, but there are a bunch of them. If that isn't an option, then you'll have some custom UI logic (either JavaScript or row binding code behind) that will look at the record your binding and make decisions based on the properties of the class.

As far as the 42 different classes, all with similar code, create an abstract base class with the reusable code, and derive from this class in your different logtype classes, overriding the base functionality where needed.

Use interfaces to separate functionality that must be implemented by the logtype, and implement those interfaces. That way when you are iterating through a list of these classes, you know what functionality will be implemented based interface.

It sounds like you would greatly benefit from using interfaces to separate contract from implementation, and code to the contract to decouple your classes.

Hope this helps.

The only thing that pops out at me is this

I have a LogFile struct

Are you actually getting a benefit from it being a struct that outway the potential pitfalls?

From the guidelines

CONSIDER defining a struct instead of a class if instances of the type are small and commonly short-lived or are commonly embedded in other objects.

DO NOT define a struct unless the type has all of the following characteristics:

• It logically represents a single value, similar to primitive types (int, double, etc.).
• It has an instance size under 16 bytes.
• It is immutable.
• It will not have to be boxed frequently.