GDALOpen() is too slow when the direcotry containing the file to open has many files

[Kasulle]

==================================Description================================= I'm using GDAL to access Tile Pyramid. Each Tile is a single file, so when the image is very large, like (100,000 * 100,000), there are many files in the direcotry storing the whole Tile Pyramid. In this case, the source image is 100,000*300,000 ,and the tile size is 512*512, so there are about 160,000 files in the direcotry.

When i use GDALOpen() to open one file, it takes about 0.6s; then i copy the file to an empty directory, this time it just takes about 0.02s;

=================================My Analysis===============================

I found that: in GDALOpen() function, it first create an GDALOpenInfo object; in the GDALOpenInfo constructor, there is one statement like this:

papszSiblingFiles = VSIReadDir( osDir );

when the doDir has many files, VSIReadDir() will be very slow. Now I just change the statement to:

papszSiblingFiles = NULL;

Is there any better solution?