Changes between Initial Version and Version 2 of Ticket #2883


Ignore:
Timestamp:
Dec 21, 2011, 10:38:11 AM (12 years ago)
Author:
warmerdam
Comment:

removing milestone.

Legend:

Unmodified
Added
Removed
Modified

  • Ticket #2883

    • Property Milestone 1.6.4

  • Ticket #2883 – Description

    initial v2  
    1 ==================================Description=================================
     1
    22I'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.
    33
    44When 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;
    55
    6 =================================My Analysis===============================
     6My Analysis
    77
    88I found that: in GDALOpen() function, it first create an GDALOpenInfo object;
    99in the GDALOpenInfo constructor, there is one statement like this:
    10 
     10{{{
    1111 papszSiblingFiles = VSIReadDir( osDir );
    12 
     12}}}
    1313when the doDir has many files, VSIReadDir() will be very slow.
    1414Now I just change the statement to:
    15 
     15{{{
    1616   papszSiblingFiles = NULL;
    17 
     17}}}
    1818Is there any better solution?
    1919