Plugin development: How to use the buffer suite?

Hello,

I am developing a Photoshop Filter plugin and I try to figure out how to update the deprecated buffer procs (gFilterRecord->bufferProcs) to the non-deprecated buffer suite.

I made a small test plugin, but it doesn't work as expected.

What am I doing wrong?

DLLEXPORT MACPASCAL
void ENTRYPOINT(short selector, FilterRecordPtr pb, intptr_t *data, short *result){
......

	if (selector != filterSelectorAbout) {
		char* xx = (char*)malloc(200);

		// ======== 32 Bit ========
		PSBufferSuite1* gPSBufferSuite32 = NULL;
		if (pb->sSPBasic->AcquireSuite(kPSBufferSuite, kPSBufferSuiteVersion1, (const void**)&gPSBufferSuite32)) {
			simplealert("no buffer suite 32"); // does not happen in Photoshop 7 and Photoshop CS 2
			*result = errPlugInHostInsufficient;
			return;
		}
		// Photoshop 7   on a 16GB system => 844,238,416 = 805 MiB?!
		// Photoshop CS2 on a 16GB system => 1,600,846,272 = 1.53 GiB
		unsigned32 free32 = gPSBufferSuite32->GetSpace();
		sprintf(xx, "Space32 = %u", free32); simplealert(xx);
		pb->sSPBasic->ReleaseSuite(kPSBufferSuite, kPSBufferSuiteVersion1);

		// ======== 64 Bit ========
		PSBufferSuite2* gPSBufferSuite64 = NULL;
		if (pb->sSPBasic->AcquireSuite(kPSBufferSuite, kPSBufferSuiteVersion2, (const void**)&gPSBufferSuite64)) {
			simplealert("no buffer suite 64"); // does not happen in Photoshop 7 and Photoshop CS 2
			*result = errPlugInHostInsufficient;
			return;
		}
		// Photoshop 7 on a 16GB system => 19,216,129 = 18 MiB?!
		// Photoshop CS2 => Crash
		unsigned64 free64 = gPSBufferSuite64->GetSpace();
		sprintf(xx, "Space64 = %llu", free64); simplealert(xx);
		pb->sSPBasic->ReleaseSuite(kPSBufferSuite, kPSBufferSuiteVersion2);
	}

...........................

The 64 bit suite crashes with Photoshop CS2, and outputs a very low value on Photoshop 7.

I wonder why CS2/7 have the 64 bit suites at all, since they are 32 bit apps.

The SDK does not state the Unit-Of-Measure for the Space methods. I guess the result is measured in bytes?

 Thank you for your help!