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authorHenrik Rydberg <rydberg@euromail.se>2010-06-17 18:12:58 +0200
committerHenrik Rydberg <rydberg@euromail.se>2010-06-17 18:12:58 +0200
commit66e5de9eaefc33ffa6af3617f9ec7a50f10af50d (patch)
tree66535311e0b9c422b30341237fd596fb9ebbdd75 /src/iobuf.c
Initial load of mtdev project
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Diffstat (limited to 'src/iobuf.c')
-rw-r--r--src/iobuf.c69
1 files changed, 69 insertions, 0 deletions
diff --git a/src/iobuf.c b/src/iobuf.c
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1/*****************************************************************************
2 *
3 * mtdev - MT device event converter (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
32int mtdev_fetch(struct mtdev *dev, struct input_event *ev, int fd)
33{
34 struct mtdev_iobuf *buf = &dev->state->iobuf;
35 int n = buf->head - buf->tail;
36 if (n < EVENT_SIZE) {
37 if (buf->tail && n > 0)
38 memmove(buf->data, buf->data + buf->tail, n);
39 buf->head = n;
40 buf->tail = 0;
41 SYSCALL(n = read(fd, buf->data + buf->head,
42 DIM_BUFFER - buf->head));
43 if (n <= 0)
44 return n;
45 buf->head += n;
46 }
47 if (buf->head - buf->tail < EVENT_SIZE)
48 return 0;
49 memcpy(ev, buf->data + buf->tail, EVENT_SIZE);
50 buf->tail += EVENT_SIZE;
51 return 1;
52}
53
54int mtdev_pull(struct mtdev *dev, int fd, int max_events)
55{
56 struct mtdev_state *state = dev->state;
57 struct input_event ev;
58 int ret, count = 0;
59 while (max_events-- && !evbuf_full(&state->inbuf)) {
60 ret = mtdev_fetch(dev, &ev, fd);
61 if (ret < 0)
62 return ret;
63 if (ret == 0)
64 break;
65 mtdev_put(dev, &ev);
66 count++;
67 }
68 return count;
69}