#3996 closed enhancement (fixed)
Defer RPC/IMD loading for GeoTiff
Reported by: | kellison | Owned by: | Even Rouault |
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Priority: | normal | Milestone: | 1.9.0 |
Component: | GDAL_Raster | Version: | 1.8.0 |
Severity: | normal | Keywords: | RPC IMD Network Metadata |
Cc: |
Description
Need better performance opening GeoTiff files when there are thousands of files on a network share. In a previous version of GDAL (1.6.0), setting GDAL_DISABLE_READDIR_ON_OPEN resulted in very good performance for this scenario. In 1.8.0 setting this variable made matters worse. It was determined that searching for the various metadata files on Open was causing the slow-down. Even Rouault provided a patch that deferred loading of RPC and IMD until necessary (that is to say when GetMetadata() or GetMetadataItem() is called with "RPC" or "IMD" metadata domain, or when GetFileList() is called. I tested this patch in 1.8.0 and got satisfactory results. Please add this patch to the 1.8.0 tree and future versions of GDAL. I will try to attach the patch. Thanks.
Attachments (1)
Change History (5)
by , 13 years ago
Attachment: | differ_reading_rpc_and_imd.patch added |
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comment:1 by , 13 years ago
Keywords: | Metadata added |
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comment:2 by , 13 years ago
Milestone: | 1.8.1 → 1.9.0 |
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Owner: | changed from | to
Priority: | high → normal |
follow-up: 4 comment:3 by , 13 years ago
Resolution: | → fixed |
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Status: | new → closed |
comment:4 by , 13 years ago
Thanks Even for putting this in. Not sure what to say about the file loading on previous versions since I was working with binaries only at that time. But, it's fast again with this change. Thanks again. Kyle Replying to rouault:
r21963 /trunk/ (autotest/gcore/tiff_write.py gdal/frmts/gtiff/geotiff.cpp): GTiff: defer loading of RPC/RPB/IMD files (#3996)
I'm not sure this is really material for the 1.8.x series. More an improvement than anything else : RPC and IMD files were loaded at opening time in 1.6.
geotiff.cpp patch that fixed the problem.