Reading multiple HID reports

I set my report size to 64 bytes and want to stream single reports (say 2 for now) to the host. My understanding is that there is a ReadFile buffer where these reports can sit. At the host, I have a 64 byte buffer that I use to read single reports. If I send one report from the device, the host reads it fine. If I use two ReadFiles in a loop, the second ReadFile times out. The device is sending two reports. I don't know if they're getting on the ReadFile buffer at the same time, so when the host reads the end point for the first report, the buffer gets purged and I lose the second report? If there are indeed 2 reports on the ReadFile buffer, do I need to read them both at once? How would I know how many 开发者_如何学Goreports are on the buffer?

ReadFile reads as many reports as there are in the HID driver's ring buffer up to the numberOfBytesToRead parameter.

The respective HID driver will implement everything as needed. You need not worry about whether those packets arrive "simultaneously". They won't.

The first packet should tell you the length of the report (i.e. a collection of packets), which in turn should allow you to figure out whether you have the full report, yet.

Of course you will have to keep an internal representation of the data from the report, because the packet buffers can only be at most 64 byte in size according to the specification. So to collect a full report you will have to handle that yourself or use the Hid_* routines described in the WDK.