Maybe I should clairfy a little. I think using the NULL variable speeds things
up in the development environment because VEE isn't storing lots of data on the
output pin of the From File.
It might be cleverer than that, but someone from Agilent would know for sure.
--
Graeme Hilton
R&D Engineer
Schlumberger Sensa
Allan (home) wrote the following on 23/11/2005 21:09:
> My files are wav files of 16 channel data , generally of about 600MB size; I
> will give the NULL variable a try, should be signiificantly quicker than
> reading chunks of data untill you reach the desired location.
>
> Thanks, all.
>
> Allan Thomson
> allan.strathardo@virgin.net
> www.strathardo.com
>
>
>
> ----- Original Message -----
> From: "Graeme Hilton" <GHilton@slb.com>
> To: "VRF" <vrf@agilent.com>
> Sent: Wednesday, November 23, 2005 9:21 AM
> Subject: Re: [vrf] Text files - delete processed lines
>
>
>> Shawn Fessenden wrote the following on 22/11/2005 19:10:
>>>> I was thinking of marking the last
>>>> processed line, but if I can not
>>>> jump to the "mark", then it does
>>>> not make sense.
>>> No problem at all. Simply save the byte offset of the last processed
> cr/lf.
>>> When you reopen the file, simply skip ahead that many bytes.
>> I find that reading the file into the NULL variable speeds things up a
> little,
>> especially on slower PCs.
>>
>> Read Text NULL Char ARRAY 1D Size: A
>> where A is the offset.
>>
>> Then carry on reading as normal.
>>
>> --
>> Graeme Hilton
>> R&D Engineer
>>
>> Schlumberger Sensa
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up in the development environment because VEE isn't storing lots of data on the
output pin of the From File.
It might be cleverer than that, but someone from Agilent would know for sure.
--
Graeme Hilton
R&D Engineer
Schlumberger Sensa
Allan (home) wrote the following on 23/11/2005 21:09:
> My files are wav files of 16 channel data , generally of about 600MB size; I
> will give the NULL variable a try, should be signiificantly quicker than
> reading chunks of data untill you reach the desired location.
>
> Thanks, all.
>
> Allan Thomson
> allan.strathardo@virgin.net
> www.strathardo.com
>
>
>
> ----- Original Message -----
> From: "Graeme Hilton" <GHilton@slb.com>
> To: "VRF" <vrf@agilent.com>
> Sent: Wednesday, November 23, 2005 9:21 AM
> Subject: Re: [vrf] Text files - delete processed lines
>
>
>> Shawn Fessenden wrote the following on 22/11/2005 19:10:
>>>> I was thinking of marking the last
>>>> processed line, but if I can not
>>>> jump to the "mark", then it does
>>>> not make sense.
>>> No problem at all. Simply save the byte offset of the last processed
> cr/lf.
>>> When you reopen the file, simply skip ahead that many bytes.
>> I find that reading the file into the NULL variable speeds things up a
> little,
>> especially on slower PCs.
>>
>> Read Text NULL Char ARRAY 1D Size: A
>> where A is the offset.
>>
>> Then carry on reading as normal.
>>
>> --
>> Graeme Hilton
>> R&D Engineer
>>
>> Schlumberger Sensa
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> - jump to location" there is no way to
> jump to a specified location in a file,
> knowing the offset.
Well sure there is! What Stan was saying is that there are no inherently
"random access" file systems. That's true, but it doesn't stop you from
moving the file pointer.
If you'd like to avoid doing actual file input to skip bytes (say for
performance reasons or something), use CreateFile/SetFilePointer/ReadFile.
> I was thinking of marking the last
> processed line, but if I can not
> jump to the "mark", then it does
> not make sense.
No problem at all. Simply save the byte offset of the last processed cr/lf.
When you reopen the file, simply skip ahead that many bytes.
> Is it possible to delete the
> processed lines of the original
> file?
Not directly. You have to open a temporary file for writing and copy the
information you want to keep.
-SHAWN-
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