1 /*****************************************************************************
2 *
3 * mtdev - Multitouch Protocol Translation Library (MIT license)
4 *
5 * Copyright (C) 2010 Henrik Rydberg <rydberg@euromail.se>
6 * Copyright (C) 2010 Canonical Ltd.
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a
9 * copy of this software and associated documentation files (the "Software"),
10 * to deal in the Software without restriction, including without limitation
11 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
12 * and/or sell copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice (including the next
16 * paragraph) shall be included in all copies or substantial portions of the
17 * Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
24 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
25 * DEALINGS IN THE SOFTWARE.
26 *
27 ****************************************************************************/
28
29 #include "iobuf.h"
30 #include "state.h"
31 #include <unistd.h>
32 #include <poll.h>
33
mtdev_idle(struct mtdev * dev,int fd,int ms)34 int mtdev_idle(struct mtdev *dev, int fd, int ms)
35 {
36 struct mtdev_iobuf *buf = &dev->state->iobuf;
37 struct pollfd fds = { fd, POLLIN, 0 };
38 return buf->head == buf->tail && poll(&fds, 1, ms) <= 0;
39 }
40
mtdev_fetch_event(struct mtdev * dev,int fd,struct input_event * ev)41 int mtdev_fetch_event(struct mtdev *dev, int fd, struct input_event *ev)
42 {
43 struct mtdev_iobuf *buf = &dev->state->iobuf;
44 int n = buf->head - buf->tail;
45 if (n < EVENT_SIZE) {
46 if (buf->tail && n > 0)
47 memmove(buf->data, buf->data + buf->tail, n);
48 buf->head = n;
49 buf->tail = 0;
50 SYSCALL(n = read(fd, buf->data + buf->head,
51 DIM_BUFFER - buf->head));
52 if (n <= 0)
53 return n;
54 buf->head += n;
55 }
56 if (buf->head - buf->tail < EVENT_SIZE)
57 return 0;
58 memcpy(ev, buf->data + buf->tail, EVENT_SIZE);
59 buf->tail += EVENT_SIZE;
60 return 1;
61 }
62
mtdev_empty(struct mtdev * dev)63 int mtdev_empty(struct mtdev *dev)
64 {
65 return evbuf_empty(&dev->state->outbuf);
66 }
67
mtdev_get_event(struct mtdev * dev,struct input_event * ev)68 void mtdev_get_event(struct mtdev *dev, struct input_event* ev)
69 {
70 evbuf_get(&dev->state->outbuf, ev);
71 }
72
mtdev_get(struct mtdev * dev,int fd,struct input_event * ev,int ev_max)73 int mtdev_get(struct mtdev *dev, int fd, struct input_event* ev, int ev_max)
74 {
75 struct input_event kev;
76 int ret, count = 0;
77 while (count < ev_max) {
78 while (mtdev_empty(dev)) {
79 ret = mtdev_fetch_event(dev, fd, &kev);
80 if (ret <= 0)
81 return count > 0 ? count : ret;
82 mtdev_put_event(dev, &kev);
83 }
84 mtdev_get_event(dev, &ev[count++]);
85 }
86 return count;
87 }
88