Hello. I've build a "download manager" module for my application arround THttpCli and I'm making use of ContentRangeBegin to resume failed downloads. It all works very nice and smooth, and all my downloads resume fine. Unfortunately my downloads only fail when I unplug the network cable from my computer OR when I disable my network adapter... and I don't think those are the most common causes of disconnections for the average user! So I'll have to ask about "abnormal" situations, just to make sure I'm getting things right:
(1) What happens if I use ContnetRangeBegin and the server doesn't support ranges (ex: if I'm downloading the results of a script)? Will I end up with the whole document append to the already downloaded portion of the document? (2) I noticed there's a AcceptRanges property that's set up by THttpCli from the headers it receives while processing a request. I supose this is server-dependent. Can I make use of this to determine if ranges are supported? (3) In the code running after a failed download I'm removing the last portion of the received data, just in case it's corrupted. I noticed this behavior in a freeware download manager I used to use some time ago. But now I'm asking: is this really necessary? HTTP traffic travels over TCP and TCP is supposed to be an checksummed, reliable protocol. Is the probability of receiving corrupt data high enough to make such radical surgery useful? If so, is tail-trimming the best solution, or should I implement some other kind of checksumming to make sure no portion of the code is actually corrupt (after all, corruption might occur anywhere in the document, not just in the last received portion). Thanks, Cosmin Prund -- To unsubscribe or change your settings for TWSocket mailing list please goto http://www.elists.org/mailman/listinfo/twsocket Visit our website at http://www.overbyte.be
