Question

I have a class with a couple static arrays:

an int[] with 17,720 elements
a string[] with 17,720 elements

I noticed when I first access this class it takes almost 2 seconds to initialize, which causes a pause in the GUI that’s accessing it.

Specifically, it’s a lookup for Unicode character names. The first array is an index into the second array.

static readonly int[] NAME_INDEX = {
0x0000, 0x0001, 0x0005, 0x002C, 0x003B, ...

static readonly string[] NAMES = {
"Exclamation Mark", "Digit Three", "Semicolon", "Question Mark", ...


The following code is how the arrays are used (given a character code). [Note: This code isn’t a performance problem]

int nameIndex = Array.BinarySearch<int>(NAME_INDEX, code);
if (nameIndex > 0)
{
return NAMES[nameIndex];
}

I guess I’m looking at other options on how to structure the data so that 1) The class is quickly loaded, and 2) I can quickly get the “name” for a given character code.

Should I not be storing all these thousands of elements in static arrays?

Update
Thanks for all the suggestions. I’ve tested out a Dictionary approach and the performance of adding all the entries seems to be really poor.

Here is some code with the Unicode data to test out Arrays vs Dictionaries
http://drop.io/fontspace/asset/fontspace-unicodesupport-zip

Solution Update
I tested out my original dual arrays (which are faster than both dictionary options) with a background thread to initialize and that helped performance a bit.

However, the real surprise is how well the binary files in resource streams works. It is the fastest solution discussed in this thread. Thanks everyone for your answers!

Answer 1

“Should I not be storing all these thousands of elements in static arrays?”

A much better way would be to store your data as binary stream in resources in the assembly and then load from the resources. Will be some more programming overhead but therefore doesn’t need any object initialization.

Basic idea would be (no real code):

// Load data (two streams):
indices = ResourceManager.GetStream ("indexData");
strings = ResourceManager.GetStream ("stringData");

// Retrieving an entry:
stringIndex = indices.GetIndexAtPosition (char);
string = strings.GetStringFromPosition (stringIndex);

If you want a really good solution (for even some more work) look into using memmapped data files.