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// Copyright 2013 Google Inc. All rights reserved.
// Copyright 2016 the gousb Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <libusb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void print_xfer(struct libusb_transfer *xfer);
void xferCallback(struct libusb_transfer*);
int submit(struct libusb_transfer *xfer) {
xfer->callback = (libusb_transfer_cb_fn)(&xferCallback);
xfer->status = -1;
return libusb_submit_transfer(xfer);
}
void print_xfer(struct libusb_transfer *xfer) {
int i;
printf("Transfer:\n");
printf(" dev_handle: %p\n", xfer->dev_handle);
printf(" flags: %08x\n", xfer->flags);
printf(" endpoint: %x\n", xfer->endpoint);
printf(" type: %x\n", xfer->type);
printf(" timeout: %dms\n", xfer->timeout);
printf(" status: %x\n", xfer->status);
printf(" length: %d (act: %d)\n", xfer->length, xfer->actual_length);
printf(" callback: %p\n", xfer->callback);
printf(" user_data: %p\n", xfer->user_data);
printf(" buffer: %p\n", xfer->buffer);
printf(" num_iso_pkts: %d\n", xfer->num_iso_packets);
printf(" packets:\n");
for (i = 0; i < xfer->num_iso_packets; i++) {
printf(" [%04d] %d (act: %d) %x\n", i,
xfer->iso_packet_desc[i].length,
xfer->iso_packet_desc[i].actual_length,
xfer->iso_packet_desc[i].status);
}
}
// compact the data in an isochronous transfer. The contents of individual
// iso packets are shifted left, so that no gaps are left between them.
// Status is set to the first non-zero status of an iso packet.
int gousb_compact_iso_data(struct libusb_transfer *xfer, unsigned char *status) {
int i;
int sum = 0;
unsigned char *in = xfer->buffer;
unsigned char *out = xfer->buffer;
for (i = 0; i < xfer->num_iso_packets; i++) {
struct libusb_iso_packet_descriptor pkt = xfer->iso_packet_desc[i];
if (pkt.status != 0) {
*status = pkt.status;
break;
}
// Copy the data
int len = pkt.actual_length;
memmove(out, in, len);
// Increment offsets
sum += len;
in += pkt.length;
out += len;
}
return sum;
}
// allocates a libusb transfer and a buffer for packet data.
struct libusb_transfer *gousb_alloc_transfer_and_buffer(int bufLen, int isoPackets) {
struct libusb_transfer *xfer = libusb_alloc_transfer(isoPackets);
if (xfer == NULL) {
return NULL;
}
xfer->buffer = (unsigned char*)malloc(bufLen);
if (xfer->buffer == NULL) {
libusb_free_transfer(xfer);
return NULL;
}
xfer->length = bufLen;
return xfer;
}
// frees a libusb transfer and its buffer. The buffer of the given
// libusb_transfer must have been allocated with alloc_transfer_and_buffer.
void gousb_free_transfer_and_buffer(struct libusb_transfer *xfer) {
free(xfer->buffer);
xfer->length = 0;
libusb_free_transfer(xfer);
}
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