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Calling a C++ dll with ColdFusion, ColdFusion cannot pass pointers as required

We have an existing C++ dll for processing data the has been used for a few years in our products. We are not develolping a web based SAAS version of our product, and need to integrate ColdFusion in with the .dll. The trouble is the C++ dll expects an array of data, passed as a pointer to the start of the array, but ColdFusion cannot deal with pointers.
The dll function prototype is
void SpeechAnalyseRT::storeAndAnalyseChunk(short int* data, unsigned long dataLength)
and has virtual function
virtual void CALL storeAndAnalyseChunk(short int* data, unsigned long dataLength) = 0;
How do we change this to pass by value? it has been suggested that we use a struct with an array inside. What is the syntax to make this work, i.e. declaring the struct etc?
Is this the right thing to do?
Thanks
Thor

jkr

The easiest way would be to pass an array of size 1:

data Data;

// fill struct

storeAndAnalyseChunk(&Data,1);

jkr

...or

data Data[1];

// fill struct

storeAndAnalyseChunk(Data,1);

respectively.

jkr

um, make the last one
data Data[1];

// fill struct
Data[0].nSampleMember = 42;

storeAndAnalyseChunk(Data,1);

ThorRussell

ASKER

The array needs to be of size somewhere between 44,100 to 441,000 size 1 definitely wont do!

jkr

If you cannot supply such aq range, there definitely is a problem... a conceptional one. Pointers and arrays are interchangeable in C/C++, so you should be fine with both. Changing an existing function is out of question, unfortunately.

ThorRussell

ASKER

Are you trying to say it cant be done? There must be a way to let coldfusion call a C++ dll.
What do you mean by changing an existing function is out of the question? The dll is mine, so I can change it how I like. I want it to accept the array by value rather than pointer.

ASKER CERTIFIED SOLUTION

jkr

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SidFishes

"There must be a way to let coldfusion call a C++ dll. "

i'm not familiar with the internals of c++ but i do know how to use them with cf...

just register a cfx custom tag

cfadmin -> cfx tags -> Register C++ CFX -> name tag cfx_yourDLLName -> choose path to dll

note that if your dll is called foo you need to name the tag cfx_foo

then call the dll like so

<cfx_foo expectedInputparameter1="#somevar1#"
expectedInputparameter2="#somevar2#">

then the output would be something like

<cfoutput>
#outputParamStuct.outputParam1#
</cfoutput>

where outputParamStruct is the struct containing value or values returned by the dll and outputParam1 is the value itself.

SidFishes

"note that if your dll is called foo you need to name the tag cfx_foo"

to be more specific

note that if your dll is called FOO.DLL you need to name the tag CFX_FOO (no extension)

jkr

I'd say http:#20423624 clears up the issue, so I tend to object to a delete.