Hello David, Thanks for feedback. That is indeed the right way to do it. Remember that Receive() may return -1, and in that case you dont want to substrackt it from BytesRemaining, so something like this:
Count := TWSocket(Sender).Receive(Buf, Min(BufSize, BytesRemaining)); if Count <= 0 then Exit; Dec(BytesRemaining, Count); ... --- Rgds, Wilfried [TeamICS] http://www.overbyte.be/eng/overbyte/teamics.html http://www.mestdagh.biz Sunday, October 30, 2005, 08:28, Kei wrote: > Hi Everyone > I've solved this problem.. what I do is make a count of "How many bytes > remaining". Everytime the value returned by Receive() will be subtracted > from the "BytesRemaining". When OnDataAvailable is repeatedly called, a > buffer is kept being ReAlloc()'ed . When "ByteRemaining" reaches zero, > then a WriteFile will be performed, so that the buffer is written to disk.. > Thanks! > David > Wilfried Mestdagh wrote: >>Hello David, >> >> >> >>>How do I know the maximum size possible? >>> >>> >> >>at receiving side, specially depending on the speed of your own program >>you mostly never get above 8 kb. However I have seen receiving packets >>10 time as high. But you dont have to care mutch, if you receive not >>all, then OnDataAvailable is immediatly called again, meaning if you >>have a temporary buffer that is to small, however if you receive on the >>stack then you can make him (almost) as large you wants. >> >> >> >>>I certainly don't want to malloc 100KB for a TCP packet... >>> >>> >> >>See above, you dont need to. >> >>--- >>Rgds, Wilfried [TeamICS] >>http://www.overbyte.be/eng/overbyte/teamics.html >>http://www.mestdagh.biz >> >>Saturday, October 29, 2005, 20:25, Kei wrote: >> >> >> >>>Hi! >>> >>> >> >> >> >>>I think I'm going to accept the reality that... TCP packets are splitted >>>into arbitrary sizes.. but!!! >>>How do I know the maximum size possible? What is the maximum size that a >>>packet can be? I certainly don't want to malloc 100KB for a TCP packet... >>> >>> >> >> >> >>>Thanks! >>> >>> >> >> >> >>>David >>> >>> >> >> >> >>>Wilfried Mestdagh wrote: >>> >>> >> >> >> >>>>Hello David, >>>> >>>> >>>> >>>> >>>> >>>>>Hi! I'm new to ICS! >>>>> >>>>> >>>>> >>>>> >>>>Welcome to the group :) >>>> >>>> >>>> >>>> >>>> >>>>>A->>B: msg hello >>>>>B->>A: msg yo! how's it going? >>>>> >>>>> >>>>> >>>>> >>>>Yes that's the way to go. Design a user made proto for what you intend >>>>to do. >>>> >>>> >>>> >>>> >>>> >>>>>If A is larger than the default buffer size (256 chars) then the A >>>>>(sender) will warn B in advance >>>>> >>>>> >>>>> >>>>> >>>>You can do that, but is not nececary. Also you will maybe have a very >>>>mutch allocation / deallocation of memory and you can eventually end up >>>>with fragmented memory where you have not a nice large block in it at >>>>the moment you need it. But it can work, just think over carefully. A >>>>better idea is often to make a receive buffer that grows automatically >>>>if (and only if) needed, and then just reuse that buffer over and over >>>>again. Then you have some (re)allocation in begin but then stable. >>>> >>>> >>>> >>>> >>>> >>>>>TWSocket will automatically split it into packets, >>>>> >>>>> >>>>> >>>>> >>>>Winsock will split in packets as large as the MTU (around 1500 bytes). >>>>Eventually data can (and will if high speed) arrive as 1 large packet >>>>but not necacarely. >>>> >>>> >>>> >>>> >>>> >>>>>I really want the sender side to send the 1MB file all at once, since I >>>>>do the FileWrite() right after Receive().... >>>>> >>>>> >>>>> >>>>> >>>>No you cannot. Winsock does not respect packet boundaries, but (see >>>>prior paragraph) there are no megabytes TCP packets. >>>> >>>>You have to receive all data chuncks into a buffer, and when you >>>>received them all then you save to file (or save every packet direct to >>>>disk). There is no problem to know the moment of close the file because >>>>you know the length of the data from your protocol. >>>> >>>>--- >>>>Rgds, Wilfried [TeamICS] >>>>http://www.overbyte.be/eng/overbyte/teamics.html >>>>http://www.mestdagh.biz >>>> >>>>Saturday, October 29, 2005, 11:01, Kei wrote: >>>> >>>> >>>> >>>> >>>> >>>>>Hi! I'm new to ICS! >>>>> >>>>> >>>>> >>>>> >>>> >>>> >>>> >>>> >>>>>I am designing a simple protocol that will be mainly used locally (as a >>>>>database server backend)..so I'm guessing I could send up to 2GB of >>>>>stuff without hassle (BLOBs, for example). Right now I'm just >>>>>experimenting with the facility for two parties to effectively "talk" to >>>>>each other, even with long long messages, and with binary data transfer. >>>>>For example, for sending a message, the command is "msg [text]" >>>>> >>>>> >>>>> >>>>> >>>>A->>B: msg hello >>>>B->>A: msg yo! how's it going? >>>> >>>> >>>> >>>> >>>> >>>>>If A is larger than the default buffer size (256 chars) then the A >>>>>(sender) will warn B in advance, like this: "hey! I'm gonna send you >>>>>10000 bytes of text" >>>>> >>>>> >>>>> >>>>> >>>>A->>B: longmsg 10000 >>>>B->>A: ready msg >>>>A->>B: msg blahblahblah...........blah! >>>> >>>> >>>> >>>> >>>> >>>>>In this case, B will be notified of the text size, then when >>>>>OnClientDataAvailable() event comes, it will malloc a bigger buffer, >>>>>then Receive(CustomSized_Buffer, SizeHeToldMe). Similarly Im considering >>>>>the same mechanism to send binary data. But if the file is slightly >>>>> >>>>> >>>>> >>>>> >>>>larger (>>10KB) then TWSocket will automatically split it into packets, >>>> >>>> >>>> >>>> >>>>>which I don't want it to do: >>>>> >>>>> >>>>> >>>>> >>>>A->>B: upload 1048576 picture.jpg >>>>B->>A: ready upload >>>>A->>B: 01001010101010.. (10720 bytes) >>>>A->>B: 11111010101012.. (10720 bytes) >>>> >>>> >>>> >>>> >>>>>: >>>>>: >>>>> >>>>> >>>>> >>>>> >>>>A->>B: 01001010101010.. (4023 bytes) >>>> >>>> >>>> >>>> >>>> >>>>>I really want the sender side to send the 1MB file all at once, since I >>>>>do the FileWrite() right after Receive().... >>>>> >>>>> >>>>> >>>>> >>>> >>>> >>>> >>>> >>>>>Could anybody please help me on this issue? >>>>> >>>>> >>>>> >>>>> >>>> >>>> >>>> >>>> >>>>>Thanks! >>>>> >>>>> >>>>> >>>>> >>>> >>>> >>>> >>>> >>>>>David >>>>> >>>>> >>>>> >>>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >> >> >> >> -- 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
