Hello,
2009/8/12 Tamas Szekeres :
>
>
> 2009/8/12 Jorge Arévalo
>>
>> >> I'm afraid I have not quite followed the discussion of the IRasterIO
>> >> implementation, but I find the above statement quite alarming. It is
>> >> imperative that we *not* end up reading back all blocks if only a few
>> >
2009/8/12 Jorge Arévalo
>
> >> I'm afraid I have not quite followed the discussion of the IRasterIO
> >> implementation, but I find the above statement quite alarming. It is
> >> imperative that we *not* end up reading back all blocks if only a few
> >> are requested. Imagine a 100GB image split
Jorge Arévalo wrote:
> Hello,
>
> 2009/8/12 Mateusz Loskot :
>> Frank Warmerdam wrote:
>>> 2009/8/9 Jorge Arévalo :
Then, my point could be, when creating the dataset (Open static
method), perform a query to get all the blocks that cover the
extent of the raster (the extent is in RA
Hello,
2009/8/12 Mateusz Loskot :
> Frank Warmerdam wrote:
>> 2009/8/9 Jorge Arévalo :
>>> Then, my point could be, when creating the dataset (Open static
>>> method), perform a query to get all the blocks that cover the
>>> extent of the raster (the extent is in RASTER_COLUMNS table) and
>>> stor
Frank Warmerdam wrote:
> 2009/8/9 Jorge Arévalo :
>> Then, my point could be, when creating the dataset (Open static
>> method), perform a query to get all the blocks that cover the
>> extent of the raster (the extent is in RASTER_COLUMNS table) and
>> store them in any place (A new class attribut
2009/8/9 Jorge Arévalo :
> Then, my point could be, when creating the dataset (Open static
> method), perform a query to get all the blocks that cover the extent
> of the raster (the extent is in RASTER_COLUMNS table) and store them
> in any place (A new class attribute?, flush the data on a tmp fi
Hello Tamas,
2009/8/8 Tamas Szekeres :
> Hi Jorge,
>
> What I have in my mind is something like the DirectRasterIO implementation
> in WCSDataset / WCSRasterBand (see wcsdataset.cpp). It appears that this
> driver is suffering from the same issue, and intend to minimize the
> roundtrips to the se
2009/8/7 Even Rouault :
>
> - Original Message - From: "Jorge Arévalo"
> To: "Tamas Szekeres"
> Cc: "gdal-dev"
> Sent: Friday, August 07, 2009 7:43 PM
> Subject: Re: [gdal-dev] Overriding IRasterIO in class derived from
> GDALRasterBan
Hi Jorge,
What I have in my mind is something like the DirectRasterIO implementation
in WCSDataset / WCSRasterBand (see wcsdataset.cpp). It appears that this
driver is suffering from the same issue, and intend to minimize the
roundtrips to the server as much as possible. It looks like this direct
Hello,
2009/8/7 Tamas Szekeres :
> Just thinking out loadly;
>
> Wouldn't it be easier to implement that cache at the driver level, just by
> composing the raster in a temp image buffer and feed that image in the
> subsequent IReadBlock calls? I think we should also think about the non
> regular a
Just thinking out loadly;
Wouldn't it be easier to implement that cache at the driver level, just by
composing the raster in a temp image buffer and feed that image in the
subsequent IReadBlock calls? I think we should also think about the non
regular and overlapping blocks which should also be co
- Original Message -
From: "Jorge Arévalo"
To: "Tamas Szekeres"
Cc: "gdal-dev"
Sent: Friday, August 07, 2009 7:43 PM
Subject: Re: [gdal-dev] Overriding IRasterIO in class derived from
GDALRasterBand
OK, I commented this part during tests, -1 for
2009/8/7 Jorge Arévalo
>
> > One issue with this concept would be related to the limited memory size
> of
> > the particular machine, it may be more reasonable to copy the retrieved
> > blocks directly onto the output buffer if possible. In this case you
> cannot
> > much rely on the base RasterI
2009/8/7 Tamas Szekeres :
> Jorge,
>
> Did you call DropLock() right after copying the data on the newly allocated
> block? This assertion shows the raster block have remained in locked state.
>
OK, I commented this part during tests, -1 for me. The assertion
disappeared. Many thanks.
And about t
Jorge,
Did you call DropLock() right after copying the data on the newly allocated
block? This assertion shows the raster block have remained in locked state.
It's quite annoying if you find long executing times somewhere. Did you know
how much time required to fetch the data and place that into
Hello,
Context: GDAL WKT Raster driver
In my class derived from GDALRasterBand, I've overrided the methods:
- IReadBlock: Fetch a block from database
- IRasterIO: Should fetch several blocks, that cover an area, and add
them to papoBlocks (cache). The idea is to avoid rounds in the server
AFAIK
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