1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
/*
* Copyright (C) 2008 The Android Open Source Project
*
* 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 <stdint.h>
#include <errno.h>
#include <unistd.h>
#include <poll.h>
#include <sys/cdefs.h>
#include <sys/types.h>
#include <linux/input.h>
#include <cutils/log.h>
#include "InputEventReader.h"
/*****************************************************************************/
template <typename T>
static inline T min(T a, T b) {
return a<b ? a : b;
}
struct input_event;
InputEventCircularReader::InputEventCircularReader(size_t numEvents)
: mBuffer(new input_event[numEvents]),
mBufferEnd(mBuffer + numEvents),
mHead(mBuffer),
mCurr(mBuffer),
mEvents(numEvents),
mFreeSpace(numEvents)
{
}
InputEventCircularReader::~InputEventCircularReader()
{
delete [] mBuffer;
}
ssize_t InputEventCircularReader::fill(int fd)
{
size_t numEventsRead = 0;
if (mFreeSpace) {
struct iovec iov[2];
const size_t numFirst = min(mFreeSpace, (size_t)(mBufferEnd - mHead));
const size_t numSecond = mFreeSpace - numFirst;
int iovcnt = 1;
iov[0].iov_base = mHead;
iov[0].iov_len = numFirst * sizeof(input_event);
if (numSecond > 0)
{
iovcnt++;
iov[1].iov_base = mBuffer;
iov[1].iov_len = numSecond * sizeof(input_event);
}
const ssize_t nread = readv(fd, iov, iovcnt);
if (nread < 0 || nread % sizeof(input_event)) {
// we got a partial event!!
return nread < 0 ? -errno : -EINVAL;
}
numEventsRead = nread / sizeof(input_event);
if (numEventsRead) {
mHead += numEventsRead;
mFreeSpace -= numEventsRead;
if (mHead >= mBufferEnd)
mHead -= mBufferEnd - mBuffer;
}
}
return numEventsRead;
}
bool InputEventCircularReader::readEvent(int fd, input_event const** events)
{
if (mFreeSpace >= mEvents) {
ssize_t eventCount = fill(fd);
if (eventCount <= 0)
return false;
}
*events = mCurr;
return true;
}
void InputEventCircularReader::next()
{
mCurr++;
mFreeSpace++;
if (mCurr >= mBufferEnd) {
mCurr = mBuffer;
}
}
|
