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Re: How to copy ONLY the updated data from a large file?

khan++27-Jun-05 1:29

khan++

27-Jun-05 1:29

When you are making changes to the file, make another file (changes-file) also, with your own file format:
Repeat (1) below for every change:
1- The size of data in four bytes (long int) then four bytes (long int) for offset into the file for the data, then the data. Write this into your "changes-file".

Then when you need to update the destination file, repeat (2) below until the end of the file.
2- Read the "changes-file", and correctly read the length of data, offset of data, and the data. Then open the destination file in update mode, move into it at the correct offset, and write out the data you read from the "changes-file".

Does that solve the problem?

this is this.

Re: How to copy ONLY the updated data from a large file?

jahfer27-Jun-05 2:19

jahfer

27-Jun-05 2:19

Dear khan++,

That doesn't solve my problem, because I am not the person going to update the file. More over, the file may get updated not only at its end but anywhere in it.

Any other idea?

regards,
Jahfer V P.

Re: How to copy ONLY the updated data from a large file?

khan++27-Jun-05 2:59

khan++

27-Jun-05 2:59

jahfer wrote:
because I am not the person going to update the file

I don't get it.
The technique I gave can update the file anywhere in it, not just the end, that is why I asked for an offset field.
I hope someone else can help as I am about to logout for the day.

this is this.

Re: How to copy ONLY the updated data from a large file?

John M. Drescher1-Jul-05 8:00

John M. Drescher

1-Jul-05 8:00

Here are a few links to tools that do this by sending only the differences between the two files. They both use the same rsync algorithm to determine what to send:

http://samba.anu.edu.au/rsync/features.html[^]

http://www.cis.upenn.edu/~bcpierce/unison/[^]

John

Image Transformation

ThatsAlok26-Jun-05 20:12

ThatsAlok

26-Jun-05 20:12

Could any body provide me basic algorithms for Fading IN or Fading Out of the Image and other related EFFECT.

Thanks

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta

Re: Image Transformation

FlyingTinman26-Jun-05 21:50

FlyingTinman

26-Jun-05 21:50

I haven't done such a fade in filter but for a smooth
transition--one image fading to another--I'd guess you
just need to scale each pixel's R,G & B values in the
'old' image toward the R,G & B values of the corresponding
pixels in the new image.

e.g if you want to do a full fade from old image to identically
sized new image in 10 steps :

for ( each pixel position in the image(s) ){
<font color=#FBEDB5>__<font color=#000000>for (Step = 1; Step<=10; Step++){
<font color=#FBEDB5>____<font color=#000000>IntermediateR = OldR + (NewR-OldR)/10 * Step;
<font color=#FBEDB5>____<font color=#000000>IntermediateG = OldG + (NewG-OldG)/!0 * Step;
<font color=#FBEDB5>____<font color=#000000>IntermediateB = OldB + (NewB-OldB)/10 * Step;
<font color=#FBEDB5>__<font color=#000000>}
}

(Be sure to use signed types for the RGB values so that
the scaling will correctly handle the cases where R, G or B
in the old image are larger than the corresponding R, G or B
value in the new image.)

If you want to fade to (or from) a 'blank' screen just substitute
the constant 'blank' RGB values for the new (or old) image pixel
position RGB values as required.

Steve T

Re: Image Transformation

ThatsAlok26-Jun-05 22:47

ThatsAlok

26-Jun-05 22:47

Thanks I will try it Smile | :)

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta

Using databases in vc++

smartymanav26-Jun-05 20:06

smartymanav

26-Jun-05 20:06

hi i am making a appliocation which facialates the procedure of student admission in a college...

i hav made a database name "Students" which has 3 tables "student","fees","course" the objective of each table is clear by its name i suppose...

now i have made a odbc object to link the databse in my mfc project...
i want to know that how i use the data of all the 3 tables at the same time...
ie i have designed 3 forms in the same project for each of the 3 tables...now i want to link the tables with the forms...how to do so???please help....

i wud b thankful...this is my first question...so please sorry for making it a long one!!!!

thanks manav