You can read for x characters then check the result for empty. So no you do not need to read the entire file into memory.
Bob S > On May 10, 2022, at 12:14 , Mark Clark via use-livecode > <[email protected]> wrote: > > Thanks Tom, Mike and Craig. Sorry for the late response, I’m on the digest > version. > > My thought was that an open file for read does not require placing the whole > file into memory. Am I mistaken in that assumption? Seems like it would be > nice to not use all of the available memory to run the decrypt. Results below > seem to confirm this... > > I worked up a quick stack using the chunking notion I referenced in the > original post and this seems to work fine. I compressed the Mac system folder > on an old SSD. That directory was 8.9GB on disk. Compressing it with the > Finder took about 28 minutes. Compressed size was 5.9GB. > > Using a byte range of 1048576 (1MB—small but useful for testing), I was able > to read the source compressed file, encrypt and write to the new (encrypted) > file in about 2 minutes. Decrypt took a little longer (less than 3 min). > Memory utilization (I did a quick build of the stack) was 44-45MB during both > operations. I’ll bump up the byte range and see how that compares. > > > > Thanks, > Mark > > >> On May 10, 2022, at 11:00 AM, [email protected] >> <mailto:[email protected]> wrote: >> >> there is no way to decrypt something that does not fit in memory. with 64 >> bit builds the limit is whatever the motherboard supports. on 32 bit >> builds the limit is whatever the os will allow 1 process to have, >> but then u need memory to store the decrypted data too. >> you can use a command line program to outsource that work and memory >> management. > _______________________________________________ > use-livecode mailing list > [email protected] > Please visit this url to subscribe, unsubscribe and manage your subscription > preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode _______________________________________________ use-livecode mailing list [email protected] Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
