Checksum via FTP???
ambassador at fourthworld.com
Sun Sep 11 15:48:55 EDT 2011
Roger Eller wrote:
> On Sun, Sep 11, 2011 at 2:22 PM, Richard Gaskin wrote:
>> Databases are handy for working with very large data stores, esp. where you
>> need relationality but for simple things like a checksum value for a file,
>> Mark Weider's suggestion is probably the simplest and most efficient, to
>> just store a checksum file with the actual file,
> Richard, would you have the same reservations about database usage overhead
> if a standalone or revlet were used as the client? There are over 100,000
> files pre-existing, so an initial creation of a server-side md5digest for
> every file would be a challenge in itself. How about a standalone which
> lives on the server-side (always running - kinda cgi-like) which accepts
> requests for a files md5digest and returns that string to the client
> standalone/revlet before starting the download.
If the checksums are pre-calculated I don't know that it would make much
practical difference either way. With so many files in that directory,
offhand I see no practical detriment with adding a few thousand more. ;)
You might see a minor performance improvement if you split the files
into sub-directories of <32k files each, but I'm not sure it would
amount to much.
If the values are to be calculated on the fly then a DB may not help
much anyway. Writing a CGI to do that on demand would be a snap,
provided the files are of a reasonable size to be loaded into RAM and
run through md5Digest (or sha1Digest, which is said to be theoretically
slightly more reliable).
I believe there's a limit to the size of files that can be run through
LiveCode's checksum functions - anyone here know what that limit is offhand?
If your file sizes exceed LC's limit you could use a shell call for that
from your CGI.
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