C++ CFSetGetValues函数代码示例

CFMutableSetRef
CFSetCreateMutableCopy (CFAllocatorRef allocator, CFIndex capacity,
                        CFSetRef set)
{
  if (CF_IS_OBJC (_kCFSetTypeID, set))
    {
      CFMutableSetRef result;
      const CFIndex count = CFSetGetCount (set);
      void **values =
        (void **) CFAllocatorAllocate (allocator, sizeof (void *) * count, 0);
      CFIndex i;

      CFSetGetValues (set, (const void **) values);
      result = CFSetCreateMutable (allocator, count, &kCFTypeSetCallBacks);

      for (i = 0; i < count; i++)
        GSHashTableAddValue ((GSHashTableRef) result, values[i], values[i]);

      CFAllocatorDeallocate (allocator, (void *) values);
      return result;
    }

  return (CFMutableSetRef) GSHashTableCreateMutableCopy (allocator,
                                                         (GSHashTableRef) set,
                                                         capacity);
}

CFSetRef CFSetCreateCopy(CFAllocatorRef allocator, CFSetRef set) {
    CFSetRef result;
    const CFSetCallBacks *cb;
    CFIndex numValues = CFSetGetCount(set);
    const void **list, *buffer[256];
    list = (numValues <= 256) ? buffer : CFAllocatorAllocate(allocator, numValues * sizeof(void *), 0);
    if (list != buffer && __CFOASafe) __CFSetLastAllocationEventName(list, "CFSet (temp)");
    CFSetGetValues(set, list);
    cb = CF_IS_OBJC(__kCFSetTypeID, set) ? &kCFTypeSetCallBacks : __CFSetGetCallBacks(set);
    result = CFSetCreate(allocator, list, numValues, cb);
    if (list != buffer) CFAllocatorDeallocate(allocator, list);
    return result;
}

bool HIDDeviceManager::Enumerate(HIDEnumerateVisitor* enumVisitor)
{
    if (!initializeManager())
    {
        return false;
    }
    

	CFSetRef deviceSet = IOHIDManagerCopyDevices(HIDManager);
	CFIndex deviceCount = CFSetGetCount(deviceSet);
    
    // Allocate a block of memory and read the set into it.
    IOHIDDeviceRef* devices = (IOHIDDeviceRef*) OVR_ALLOC(sizeof(IOHIDDeviceRef) * deviceCount);
    CFSetGetValues(deviceSet, (const void **) devices);
    

    // Iterate over devices.
    for (CFIndex deviceIndex = 0; deviceIndex < deviceCount; deviceIndex++)
    {
        IOHIDDeviceRef hidDev = devices[deviceIndex];
        
        if (!hidDev)
        {
            continue;
        }
        
        HIDDeviceDesc devDesc;
                
        if (getPath(hidDev, &(devDesc.Path)) &&
            initVendorProductVersion(hidDev, &devDesc) &&
            enumVisitor->MatchVendorProduct(devDesc.VendorId, devDesc.ProductId) &&
            initUsage(hidDev, &devDesc))
        {
            initStrings(hidDev, &devDesc);
            initSerialNumber(hidDev, &devDesc);

            // Construct minimal device that the visitor callback can get feature reports from.
            OSX::HIDDevice device(this, hidDev);
            
            enumVisitor->Visit(device, devDesc);
        }
    }
    
    OVR_FREE(devices);
    CFRelease(deviceSet);
    
    return true;
}

IOHIDDeviceRef FindDevice(IOHIDManagerRef manager, long vendorId, long productId)
{
    IOHIDDeviceRef theDevice = NULL;

    // setup dictionary

    CFMutableDictionaryRef dictionary = CFDictionaryCreateMutable(
                                              kCFAllocatorDefault, 
                                              2, 
                                              &kCFTypeDictionaryKeyCallBacks, 
                                              &kCFTypeDictionaryValueCallBacks);

    CFNumberRef cfVendorId = CFNumberCreate(kCFAllocatorDefault, kCFNumberLongType, &vendorId);
    CFStringRef cfVendorSt = CFStringCreateWithCString(kCFAllocatorDefault, kIOHIDVendorIDKey, kCFStringEncodingUTF8);
    CFDictionaryAddValue(dictionary, cfVendorSt, cfVendorId);
    CFRelease(cfVendorId);
    CFRelease(cfVendorSt);

    CFNumberRef cfProductId = CFNumberCreate(kCFAllocatorDefault, kCFNumberLongType, &productId);
    CFStringRef cfProductSt = CFStringCreateWithCString(kCFAllocatorDefault, kIOHIDProductIDKey, kCFStringEncodingUTF8);
    CFDictionaryAddValue(dictionary, cfProductSt, cfProductId);
    CFRelease(cfProductId);
    CFRelease(cfProductSt);

    // look for devices matching criteria

    IOHIDManagerSetDeviceMatching(manager, dictionary);
    CFSetRef foundDevices = IOHIDManagerCopyDevices(manager);
    CFIndex foundCount = foundDevices ? CFSetGetCount(foundDevices) : 0; // what the API does not say is that it could be null
    if(foundCount > 0) 
    {
        CFTypeRef* array = new CFTypeRef[foundCount]; // array of IOHIDDeviceRef
        CFSetGetValues(foundDevices, array);
        // get first matching device
        theDevice = (IOHIDDeviceRef)array[0];
        CFRetain(theDevice);
        delete [] array;
    }

    if(foundDevices)
    {
        CFRelease(foundDevices);
    }
    CFRelease(dictionary);

    return theDevice;
}

CFMutableSetRef CFSetCreateMutableCopy(CFAllocatorRef allocator, CFIndex capacity, CFSetRef set) {
    CFMutableSetRef result;
    const CFSetCallBacks *cb;
    CFIndex idx, numValues = CFSetGetCount(set);
    const void **list, *buffer[256];
    CFAssert3(0 == capacity || numValues <= capacity, __kCFLogAssertion, "%s(): for fixed-mutable sets, capacity (%d) must be greater than or equal to initial number of values (%d)", __PRETTY_FUNCTION__, capacity, numValues);
    list = (numValues <= 256) ? buffer : CFAllocatorAllocate(allocator, numValues * sizeof(void *), 0);
    if (list != buffer && __CFOASafe) __CFSetLastAllocationEventName(list, "CFSet (temp)");
    CFSetGetValues(set, list);
    cb = CF_IS_OBJC(__kCFSetTypeID, set) ? &kCFTypeSetCallBacks : __CFSetGetCallBacks(set);
    result = CFSetCreateMutable(allocator, capacity, cb);
    if (0 == capacity) _CFSetSetCapacity(result, numValues);
    for (idx = 0; idx < numValues; idx++) {
	CFSetAddValue(result, list[idx]);
    }
    if (list != buffer) CFAllocatorDeallocate(allocator, list);
    return result;
}

void
CFSetApplyFunction (CFSetRef set, CFSetApplierFunction applier, void *context)
{
  // TODO: could be made more efficient by providing a specialized
  // implementation for the CF_IS_OBJC case

  const CFIndex count = CFSetGetCount (set);
  void **values =
    (void **) CFAllocatorAllocate (NULL, sizeof (void *) * count, 0);
  CFIndex i;

  CFSetGetValues (set, (const void **) values);

  for (i = 0; i < count; i++)
    {
      applier (values[i], context);
    }

  CFAllocatorDeallocate (NULL, (void *) values);
}

static IOHIDDeviceRef* getDevRef(OSX_HID_REF *hid, CFIndex *deviceCount)
{

    CFSetRef        deviceCFSetRef;
    IOHIDDeviceRef  *dev_refs=NULL;

    *deviceCount = 0;

    yEnterCriticalSection(&hid->hidMCS);
    deviceCFSetRef = IOHIDManagerCopyDevices(hid->manager);
    yLeaveCriticalSection(&hid->hidMCS);
    if (deviceCFSetRef!= NULL) {
        // how many devices in the set?
        *deviceCount = CFSetGetCount( deviceCFSetRef );
        dev_refs = yMalloc( sizeof(IOHIDDeviceRef) * (u32)*deviceCount );
        // now extract the device ref's from the set
        CFSetGetValues( deviceCFSetRef, (const void **) dev_refs );
    }
    return dev_refs;
}

void setAllKeyboards(LedState changes[])
{
    IOHIDManagerRef manager = IOHIDManagerCreate(kCFAllocatorDefault, kIOHIDOptionsTypeNone);
    if (!manager) {
        fprintf(stderr, "Failed to create IOHID manager.\n");
        return;
    }
    
    CFDictionaryRef keyboard = getKeyboardDictionary();
    if (!keyboard) {
        fprintf(stderr, "Failed to get dictionary usage page for kHIDUsage_GD_Keyboard.\n");
        return;
    }
    
    IOHIDManagerOpen(manager, kIOHIDOptionsTypeNone);
    IOHIDManagerSetDeviceMatching(manager, keyboard);
    
    CFSetRef devices = IOHIDManagerCopyDevices(manager);
    if (devices) {
        CFIndex deviceCount = CFSetGetCount(devices);
        if (deviceCount == 0) {
            fprintf(stderr, "Could not find any keyboard devices.\n");
        }
        else {
            // Loop through all keyboards attempting to get or display led state
            IOHIDDeviceRef *deviceRefs = malloc(sizeof(IOHIDDeviceRef) * deviceCount);
            if (deviceRefs) {
                CFSetGetValues(devices, (const void **) deviceRefs);
                for (CFIndex deviceIndex = 0; deviceIndex < deviceCount; deviceIndex++)
                    if (isKeyboardDevice(deviceRefs[deviceIndex]))
                        setKeyboard(deviceRefs[deviceIndex], keyboard, changes);
                
                free(deviceRefs);
            }
        }
        
        CFRelease(devices);
    }
    
    CFRelease(keyboard);
}

CFSetRef
CFSetCreateCopy (CFAllocatorRef allocator, CFSetRef set)
{
  if (CF_IS_OBJC (_kCFSetTypeID, set))
    {
      CFSetRef result;
      const CFIndex count = CFSetGetCount (set);
      void **values =
        (void **) CFAllocatorAllocate (allocator, sizeof (void *) * count, 0);

      CFSetGetValues (set, (const void **) values);
      result =
        CFSetCreate (allocator, (const void **) values, count,
                     &kCFTypeSetCallBacks);

      CFAllocatorDeallocate (allocator, (void *) values);
      return result;
    }

  return (CFSetRef) GSHashTableCreateCopy (allocator, (GSHashTableRef) set);
}

int main(void)
{
	IOHIDManagerRef mgr;
	int i;

	mgr = IOHIDManagerCreate(kCFAllocatorDefault, kIOHIDOptionsTypeNone);
	IOHIDManagerSetDeviceMatching(mgr, NULL);
	IOHIDManagerOpen(mgr, kIOHIDOptionsTypeNone);

	CFSetRef device_set = IOHIDManagerCopyDevices(mgr);
    if (device_set==NULL) {
        return 0;
    }

	CFIndex num_devices = CFSetGetCount(device_set);
	IOHIDDeviceRef *device_array = calloc(num_devices, sizeof(IOHIDDeviceRef));
	CFSetGetValues(device_set, (const void **) device_array);

	for (i = 0; i < num_devices; i++) {
		IOHIDDeviceRef dev = device_array[i];
		printf("Device: %p\n", dev);
		printf("  %04hx %04hx\n", get_vendor_id(dev), get_product_id(dev));

		wchar_t serial[256], buf[256];
		char cbuf[256];
		get_serial_number(dev, serial, 256);


		printf("  Serial: %ls\n", serial);
		printf("  Loc: %ld\n", get_location_id(dev));
		get_transport(dev, buf, 256);
		printf("  Trans: %ls\n", buf);
		make_path(dev, cbuf, 256);
		printf("  Path: %s\n", cbuf);

	}

	return 0;
}

CFArrayRef CFLocaleCopyAvailableLocaleIdentifiers(void) {
    int32_t locale, localeCount = uloc_countAvailable();
    CFMutableSetRef working = CFSetCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeSetCallBacks);
    for (locale = 0; locale < localeCount; ++locale) {
        const char *localeID = uloc_getAvailable(locale);
        CFStringRef string1 = CFStringCreateWithCString(kCFAllocatorSystemDefault, localeID, kCFStringEncodingASCII);
	CFStringRef string2 = CFLocaleCreateCanonicalLocaleIdentifierFromString(kCFAllocatorSystemDefault, string1);
	CFSetAddValue(working, string1);
	// do not include canonicalized version as IntlFormats cannot cope with that in its popup
        CFRelease(string1);
        CFRelease(string2);
    }
    CFIndex cnt = CFSetGetCount(working);
#if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_LINUX || (DEPLOYMENT_TARGET_WINDOWS && __GNUC__)
    STACK_BUFFER_DECL(const void *, buffer, cnt);
#else
    const void* buffer[BUFFER_SIZE];
#endif
    CFSetGetValues(working, buffer);
    CFArrayRef result = CFArrayCreate(kCFAllocatorSystemDefault, buffer, cnt, &kCFTypeArrayCallBacks);
    CFRelease(working);
    return result;
}

bool JoystickImpl::open(unsigned int index)
{
    m_index = index;
    Location deviceLoc = m_locationIDs[index]; // The device we need to load

    // Get all devices
    CFSetRef devices = HIDJoystickManager::getInstance().copyJoysticks();
    if (devices == NULL)
        return false;

    // Get a usable copy of the joysticks devices.
    CFIndex joysticksCount = CFSetGetCount(devices);
    CFTypeRef devicesArray[joysticksCount];
    CFSetGetValues(devices, devicesArray);

    // Get the desired joystick.
    IOHIDDeviceRef self = 0;
    for (CFIndex i(0); i < joysticksCount; ++i)
    {
        IOHIDDeviceRef d = (IOHIDDeviceRef)devicesArray[i];
        if (deviceLoc == HIDInputManager::getLocationID(d))
        {
            self = d;
            break; // We found it so we stop looping.
        }
    }

    if (self == 0)
    {
        // This shouldn't happen!
        CFRelease(devices);
        return false;
    }

    m_identification.name      = getDeviceString(self, CFSTR(kIOHIDProductKey), m_index);
    m_identification.vendorId  = getDeviceUint(self, CFSTR(kIOHIDVendorIDKey), m_index);
    m_identification.productId = getDeviceUint(self, CFSTR(kIOHIDProductIDKey), m_index);

    // Get a list of all elements attached to the device.
    CFArrayRef elements = IOHIDDeviceCopyMatchingElements(self, NULL, kIOHIDOptionsTypeNone);

    if (elements == NULL)
    {
        CFRelease(devices);
        return false;
    }

    // How many elements are there?
    CFIndex elementsCount = CFArrayGetCount(elements);

    if (elementsCount == 0)
    {
        // What is a joystick with no element?
        CFRelease(elements);
        CFRelease(devices);
        return false;
    }

    // Go through all connected elements.
    for (int i = 0; i < elementsCount; ++i)
    {
        IOHIDElementRef element = (IOHIDElementRef) CFArrayGetValueAtIndex(elements, i);
        switch (IOHIDElementGetType(element))
        {
            case kIOHIDElementTypeInput_Misc:
                switch (IOHIDElementGetUsage(element))
                {
                    case kHIDUsage_GD_X:  m_axis[Joystick::X] = element; break;
                    case kHIDUsage_GD_Y:  m_axis[Joystick::Y] = element; break;
                    case kHIDUsage_GD_Z:  m_axis[Joystick::Z] = element; break;
                    case kHIDUsage_GD_Rx: m_axis[Joystick::U] = element; break;
                    case kHIDUsage_GD_Ry: m_axis[Joystick::V] = element; break;
                    case kHIDUsage_GD_Rz: m_axis[Joystick::R] = element; break;
                    // kHIDUsage_GD_Vx, kHIDUsage_GD_Vy, kHIDUsage_GD_Vz are ignored.
                }
                break;

            case kIOHIDElementTypeInput_Button:
                if (m_buttons.size() < Joystick::ButtonCount) // If we have free slot...
                    m_buttons.push_back(element); // ...we add this element to the list
                // Else: too many buttons. We ignore this one.
                break;

            default: // Make compiler happy
                break;
        }
    }

    // Ensure that the buttons will be indexed in the same order as their
    // HID Usage (assigned by manufacturer and/or a driver).
    std::sort(m_buttons.begin(), m_buttons.end(), JoystickButtonSortPredicate);

    // Note: Joy::AxisPovX/Y are not supported (yet).
    // Maybe kIOHIDElementTypeInput_Axis is the corresponding type but I can't test.

    // Retain all these objects for personal use
    for (ButtonsVector::iterator it(m_buttons.begin()); it != m_buttons.end(); ++it)
        CFRetain(*it);
    for (AxisMap::iterator it(m_axis.begin()); it != m_axis.end(); ++it)
        CFRetain(it->second);
//.........这里部分代码省略.........

int main( int argc, const char * argv[] )
{
	Boolean initialized = FALSE;
	
	if (( argc != 4 ) && ( argc != 5 ))  {
		printf ( "usage: Dream Cheeky Notifier R G B [A]\n\tRGB values should be 0-31.  A is an optional parameter on whether to do the LED activation sequence.  Anything larger than 0 is YES, default is 0 (activate).\n\n");
		exit ( -1 );
	}
	
	char r = (int)strtol ( argv[1], NULL, 10 );
	char g = (int)strtol ( argv[2], NULL, 10 );
	char b = (int)strtol ( argv[3], NULL, 10 );
	if ( argc == 5 ) {
		initialized = TRUE;
	}
	
	if ((r < 0) || (r > 31) || (g < 0) || (g > 31) || (b < 0) || (b > 31)) {
		printf("RGB values must be within 0-31.");
		exit -1;
	}
	
	// create a IO HID Manager reference
	IOHIDManagerRef tIOHIDManagerRef = IOHIDManagerCreate( kCFAllocatorDefault, kIOHIDOptionsTypeNone );
	// Create a device matching dictionary
	CFDictionaryRef matchingCFDictRef = hu_CreateMatchingDictionaryUsagePageUsage( TRUE,
																				  kHIDPage_GenericDesktop,
																				  0x10 );
	// set the HID device matching dictionary
	IOHIDManagerSetDeviceMatching( tIOHIDManagerRef, matchingCFDictRef );
	if ( matchingCFDictRef ) {
		CFRelease( matchingCFDictRef );
	}
	
	// Now open the IO HID Manager reference
	IOReturn tIOReturn = IOHIDManagerOpen( tIOHIDManagerRef, kIOHIDOptionsTypeNone );
	
	// and copy out its devices
	CFSetRef deviceCFSetRef = IOHIDManagerCopyDevices( tIOHIDManagerRef );
	
	// how many devices in the set?
	CFIndex deviceIndex, deviceCount = CFSetGetCount( deviceCFSetRef );
	
	// allocate a block of memory to extact the device ref's from the set into
	IOHIDDeviceRef * tIOHIDDeviceRefs = malloc( sizeof( IOHIDDeviceRef ) * deviceCount );
	
	// now extract the device ref's from the set
	CFSetGetValues( deviceCFSetRef, (const void **) tIOHIDDeviceRefs );
	
	// before we get into the device loop we'll setup our element matching dictionary (Note: we don't do element matching anymore)
	matchingCFDictRef = hu_CreateMatchingDictionaryUsagePageUsage( FALSE, 0, 0 );
	
	for ( deviceIndex = 0; deviceIndex < deviceCount; deviceIndex++ ) {
		
		// if this isn't the notifier device...  TODO: let's detect via vendor/product ids instead
		long vendor_id = 0;
		IOHIDDevice_GetLongProperty(tIOHIDDeviceRefs[deviceIndex], CFSTR(kIOHIDVendorIDKey), &vendor_id);
		long product_id = 0;
		IOHIDDevice_GetLongProperty(tIOHIDDeviceRefs[deviceIndex], CFSTR(kIOHIDProductIDKey), &product_id);
		if ((vendor_id != 0x1D34 ) || (product_id != 0x0004 )) {
			printf("	skipping device %p.\n", tIOHIDDeviceRefs[deviceIndex] );
			continue;	// ...skip it
		}
		
		printf( "	 device = %p.\n", tIOHIDDeviceRefs[deviceIndex] );
		
		unsigned char report[8];
		if (initialized == FALSE) {
			report[0] = 0x1F; // turn on LEDs
			report[1] = 0x02;
			report[2] = 0x00;
			report[3] = 0x5F;
			report[4] = 0x00;
			report[5] = 0x00;
			report[6] = 0x1A;
			report[7] = 0x03;
			
            // Note: We don't use the returned value here, so the compiler might throw a warning.
			IOReturn  tIOReturn = IOHIDDeviceSetReport(
													   tIOHIDDeviceRefs[deviceIndex],          // IOHIDDeviceRef for the HID device
													   kIOHIDReportTypeInput,   // IOHIDReportType for the report (input, output, feature)
													   0,           // CFIndex for the report ID
													   report,             // address of report buffer
													   8);      // length of the report
			initialized = TRUE;
		}
		
		report[0] = r; // set brightness on LEDs to r, g, & b
		report[1] = g;
		report[2] = b;
		report[3] = 0x00;
		report[4] = 0x00;
		report[5] = 0x00;
		report[6] = 0x1A;
		report[7] = 0x05;
		
		tIOReturn = IOHIDDeviceSetReport(
										 tIOHIDDeviceRefs[deviceIndex],          // IOHIDDeviceRef for the HID device
										 kIOHIDReportTypeInput,   // IOHIDReportType for the report (input, output, feature)
										 0,           // CFIndex for the report ID
										 report,             // address of report buffer
//.........这里部分代码省略.........

bool HIDDevice::openDevice()
{
    
    // Have to iterate through devices again to generate paths.
	CFSetRef deviceSet = IOHIDManagerCopyDevices(HIDManager->HIDManager);
	CFIndex deviceCount = CFSetGetCount(deviceSet);
    
    // Allocate a block of memory and read the set into it.
    IOHIDDeviceRef* devices = (IOHIDDeviceRef*) OVR_ALLOC(sizeof(IOHIDDeviceRef) * deviceCount);
    CFSetGetValues(deviceSet, (const void **) devices);
    
    
    // Iterate over devices.
    IOHIDDeviceRef device = NULL;

    for (CFIndex deviceIndex = 0; deviceIndex < deviceCount; deviceIndex++)
    {
        IOHIDDeviceRef tmpDevice = devices[deviceIndex];
        
        if (!tmpDevice)
        {
            continue;
        }
        
        String path;
        if (!HIDManager->getPath(tmpDevice, &path))
        {
            continue;
        }
        
        if (path == DevDesc.Path)
        {
            device = tmpDevice;
            break;
        }
    }
    
    
    OVR_FREE(devices);
    
    if (!device)
    {
        CFRelease(deviceSet);
        return false;
    }
    
    // Attempt to open device.
    if (IOHIDDeviceOpen(device, kIOHIDOptionsTypeSeizeDevice)
        != kIOReturnSuccess)
    {
        CFRelease(deviceSet);
        return false;
    }

    // Retain the device before we release the set.
    CFRetain(device);
    CFRelease(deviceSet);
    
    
    Device = device;

    
    if (!initInfo())
    {
        IOHIDDeviceClose(Device, kIOHIDOptionsTypeSeizeDevice);
        CFRelease(Device);
        Device = NULL;
        return false;
    }
    
    
    // Setup the Run Loop and callbacks.
    IOHIDDeviceScheduleWithRunLoop(Device,
                                   HIDManager->getRunLoop(),
                                   kCFRunLoopDefaultMode);
    
    IOHIDDeviceRegisterInputReportCallback(Device,
                                           ReadBuffer,
                                           ReadBufferSize,
                                           staticHIDReportCallback,
                                           this);

    IOHIDDeviceRegisterRemovalCallback(Device,
                                       staticDeviceRemovedCallback,
                                       this);
    
    return true;
}

struct hid_device_info  HID_API_EXPORT *hid_enumerate(unsigned short vendor_id, unsigned short product_id)
{
	struct hid_device_info *root = NULL; /* return object */
	struct hid_device_info *cur_dev = NULL;
	CFIndex num_devices;
	int i;

	/* Set up the HID Manager if it hasn't been done */
	if (hid_init() < 0)
		return NULL;

	/* give the IOHIDManager a chance to update itself */
	process_pending_events();

	/* Get a list of the Devices */
	IOHIDManagerSetDeviceMatching(hid_mgr, NULL);
	CFSetRef device_set = IOHIDManagerCopyDevices(hid_mgr);

	/* Convert the list into a C array so we can iterate easily. */
	num_devices = CFSetGetCount(device_set);
	IOHIDDeviceRef *device_array = calloc(num_devices, sizeof(IOHIDDeviceRef));
	CFSetGetValues(device_set, (const void **) device_array);

	/* Iterate over each device, making an entry for it. */
	for (i = 0; i < num_devices; i++) {
		unsigned short dev_vid;
		unsigned short dev_pid;
		#define BUF_LEN 256
		wchar_t buf[BUF_LEN];

		IOHIDDeviceRef dev = device_array[i];

        if (!dev) {
            continue;
        }
		dev_vid = get_vendor_id(dev);
		dev_pid = get_product_id(dev);

		/* Check the VID/PID against the arguments */
		if ((vendor_id == 0x0 || vendor_id == dev_vid) &&
		    (product_id == 0x0 || product_id == dev_pid)) {
			struct hid_device_info *tmp;
			io_object_t iokit_dev;
			kern_return_t res;
			io_string_t path;

			/* VID/PID match. Create the record. */
			tmp = malloc(sizeof(struct hid_device_info));
			if (cur_dev) {
				cur_dev->next = tmp;
			}
			else {
				root = tmp;
			}
			cur_dev = tmp;

			/* Get the Usage Page and Usage for this device. */
			cur_dev->usage_page = get_int_property(dev, CFSTR(kIOHIDPrimaryUsagePageKey));
			cur_dev->usage = get_int_property(dev, CFSTR(kIOHIDPrimaryUsageKey));

			/* Fill out the record */
			cur_dev->next = NULL;

			/* Fill in the path (IOService plane) */
			iokit_dev = hidapi_IOHIDDeviceGetService(dev);
			res = IORegistryEntryGetPath(iokit_dev, kIOServicePlane, path);
			if (res == KERN_SUCCESS)
				cur_dev->path = strdup(path);
			else
				cur_dev->path = strdup("");

			/* Serial Number */
			get_serial_number(dev, buf, BUF_LEN);
			cur_dev->serial_number = dup_wcs(buf);

			/* Manufacturer and Product strings */
			get_manufacturer_string(dev, buf, BUF_LEN);
			cur_dev->manufacturer_string = dup_wcs(buf);
			get_product_string(dev, buf, BUF_LEN);
			cur_dev->product_string = dup_wcs(buf);

			/* VID/PID */
			cur_dev->vendor_id = dev_vid;
			cur_dev->product_id = dev_pid;

			/* Release Number */
			cur_dev->release_number = get_int_property(dev, CFSTR(kIOHIDVersionNumberKey));

			/* Interface Number (Unsupported on Mac)*/
			cur_dev->interface_number = -1;
		}
	}

	free(device_array);
	CFRelease(device_set);

	return root;
}