Issue setting caller ID in a TSP - tapi

Question

I have developed a TSP to talk to a CTI server. In the most part it works, but when setting the caller/called ID parties, in
function TSPI_lineGetCallInfo(
hdCall : HDRVCALL;
lpCallInfo : LPLINECALLINFO
) : LONG;
I am finding the offsets are all corrects but the size fields are NOT. At the end of the function I output (to debugger) the size and offsets of each field and they are what I expect them to be. But when I inspect the values using a TAPI program the sizes are different, (but the offsets are EXACTLY the same as per the debug statements) in fact the size field 5 regardless of what is actually there, whereas the debug statements at the end of the code below shows the correct values...
Any help greatly appreciated.
lpCallInfo^.dwCallerIDOffset := 0;
lpCallInfo^.dwCallerIDSize := 0;
lpCallInfo^.dwCalledIDOffset := 0;
lpCallInfo^.dwCalledIDSize := 0;
lpCallInfo^.dwConnectedIDOffset := 0;
lpCallInfo^.dwConnectedIDSize := 0;
extnid := thiscall.CallItem.ExtnId;
phoneno := thiscall.CallItem.DialNum;
extnid_size := (Length(extnid) + 1) * sizeof(WCHAR);
phoneno_size := (Length(phoneno) + 1) * sizeof(WCHAR);
extnidw := StringToWideStringEx(extnid, CP_ACP);
phonenow := StringToWideStringEx(phoneno, CP_ACP);
if lpCallInfo^.dwOrigin = LINECALLORIGIN_INTERNAL then
begin
{me}
lpCallInfo^.dwCallerIDOffset := sizeof(TLINECALLINFO);
lpCallInfo^.dwCallerIDSize := extnid_size;
Move(ExtnIdw[1], ptr^, extnid_size * 2);
ptr := Pointer(integer(ptr) + lpCallInfo^.dwCallerIDSize);
{other party}
if phoneno <> '' then
begin
lpCallInfo^.dwCalledIDOffset :=
sizeof(TLINECALLINFO) + lpCallInfo^.dwCallerIDSize;
lpCallInfo^.dwCalledIDSize := phoneno_size;
Move(phonenow[1], ptr^, phoneno_size * 2);
end;
end
else
begin
if thiscall.CallItem.CallType = 1 then
begin {incoming call}
{agent is the called party}
lpCallInfo^.dwCalledIDOffset := sizeof(TLINECALLINFO);
lpCallInfo^.dwCalledIDSize := extnid_size;
Move(ExtnIdw[1], ptr^, extnid_size);
ptr := Pointer(integer(ptr) + lpCallInfo^.dwCalledIDSize);
{other party is the caller}
if phoneno <> '' then
begin
lpCallInfo^.dwCallerIDOffset :=
sizeof(TLINECALLINFO) + lpCallInfo^.dwCalledIDSize;
lpCallInfo^.dwCallerIDSize := phoneno_size;
Move(phonenow[1], ptr^, phoneno_size);
ptr := Pointer(integer(ptr) + lpCallInfo^.dwCallerIDSize);
end;
end
else
begin
{agnet is the caller}
lpCallInfo^.dwCallerIDOffset := sizeof(TLINECALLINFO);
lpCallInfo^.dwCallerIDSize := extnid_size;
Move(ExtnIdw[1], ptr^, extnid_size);
ptr := Pointer(integer(ptr) + lpCallInfo^.dwCallerIDSize);
{dialed number is the called party}
if phoneno <> '' then
begin
lpCallInfo^.dwCalledIDOffset :=
sizeof(TLINECALLINFO) + lpCallInfo^.dwCallerIDSize;
lpCallInfo^.dwCalledIDSize := phoneno_size;
Move(phonenow[1], ptr^, phoneno_size);
ptr := Pointer(integer(ptr) + lpCallInfo^.dwCalledIDSize);
end;
end;
if (thiscall.CallItem.CallState = cs_Connected) and
(phoneno <> '') then
begin
lpCallInfo^.dwConnectedIDOffset := sizeof(TLINECALLINFO) +
lpCallInfo^.dwCallerIDSize + lpCallInfo^.dwCalledIDSize;
lpCallInfo^.dwConnectedIDSize := phoneno_size;
Move(phonenow[1], ptr^, phoneno_size);
ptr := Pointer(integer(ptr) + lpCallInfo^.dwConnectedIDSize);
end;
end;
end;
DEBUG('TSPI_lineGetCallInfo::dwCallerIDOffset=' + intToStr(lpCallInfo^.dwCallerIDOffset));
DEBUG('TSPI_lineGetCallInfo::dwCallerIDSize=' + intToStr(lpCallInfo^.dwCallerIDSize));
DEBUG('TSPI_lineGetCallInfo::dwCalledIDOffset=' + intToStr(lpCallInfo^.dwCalledIDOffset));
DEBUG('TSPI_lineGetCallInfo::dwCalledIDSize=' + intToStr(lpCallInfo^.dwCalledIDSize));
DEBUG('TSPI_lineGetCallInfo::dwConnectedIDOffset=' + intToStr(lpCallInfo^.dwConnectedIDOffset));
DEBUG('TSPI_lineGetCallInfo::dwConnectedIDSize=' + intToStr(lpCallInfo^.dwConnectedIDSize));

Answer 1

These are strange results. Your code seems to check out. It may be a longshot but the result could be caused by too few memory reserved for the lpCallInfo structure. What tapi program do you use? Most programs just reserve a large surplus beforehand. However, another commonly used approach is to 'ask' the TSP the exact amount needed by first calling TSPI_lineGetCallInfo and then reserving the exact amount after you set the dwNeededSize and returning LINEERR_STRUCTURETOOSMALL. You don't seem to check the dwTotalSize or set the dwNeededSize and dwUsedSize fields (which is dangerous).
Please look at the : LINEERR constants
and let me know if it solves the issue. If it doesn't, I would be curious to see the structure log from the Tapi Browser, but let's hope it works. Good luck!