问题
I'm executing 4 startup commands and also expecting to receive 4 responses. The server is already implemented and another dev who is developing android, is able to receive those 4 separate responses, however, I'm getting 2 good responses (separate) and then 3rd and 4th responses come as one response. I'v placed NSLog of NSData result in completeCurrentRead, and it outputs me merged packet "0106000000000b0600000000" instead of separate packets "010600000000" and "0b0600000000". I'v also tested those 3rd and 4th commands separatedly (only one at a time) and everything is OK with the server, it sends them separately, however there occurs merge (with 3rd and 4th) if all four commands are executed in a line. Any ideas?
UPDATE: I think I'v traced to the problem roots. There's a call that reads packet data from a stream in doBytesAvailable method:
CFIndex result = [self readIntoBuffer:subBuffer maxLength:bytesToRead];
And in readIntoBuffer:maxLength, there's a call (length == 256) :
return CFReadStreamRead(theReadStream, (UInt8 *)buffer, length);
So, CFReadStreamRead returns incorrect length of packet - it return length of 12 (instead of 6), and also grabs merged data. Hm, what might causing CFReadStreamRead to read two packets into one, instead of reading them separately...
UPDATE2: I'm using onSocket:didReadData:withTag: delegate method and expecting to receive response data with the tag of request I performed. I have realized recently, streams are streams, not packets but how I can solve that? Server responses does not have terminating chars at start and end of response, just response size, that comes as 2 - 5 bytes. I can cut the first part of response (first packet) and ignore the second part but how AsyncSocket will make another callback with the second part of the response (second packet)? If I will cut only the first parts and ignore the second then IMHO the second "packet" will be lost...
How to cut the first part of response and tell AsyncSocket to make another callback with tag and the second part of response as separate callback?
UPDATE3: In onSocket:didReadData:withTag:, I manually cut merged response, handle the first part (first packet) and then at the end, throwing a call to onSocket:didReadData:withTag: again:
if (isMergedPacket) {
...
[self onSocket:sock didReadData:restPartOfTheResponse withTag:myCommandTag];
}
However, it looks like AsyncSocket itself pairs every request packet with its response packet (via AsyncReadPacket class) using tags. So, my manual cutting works, but AsyncSocket does not know that I already handled both packets, and it still tries to read the second packet. So, I'm getting sock:shouldTimeoutReadWithTag:... callback which is called when a read operation has reached its timeout without completing.
回答1:
Found solution. It's not necessary to change and dig into AsyncSocket. You just need to define the length of each response - how much bytes are you interested in reading and getting your callback. More info you can on other post here
来源：https://stackoverflow.com/questions/9359391/asyncsocket-getting-merged-two-packets-instead-of-separate-two-packets