1 /*
2 * Copyright (C) 2012 Invensense, Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #define LOG_NDEBUG 0
18
19 #include <stdint.h>
20 #include <errno.h>
21 #include <unistd.h>
22 #include <poll.h>
23
24 #include <sys/cdefs.h>
25 #include <sys/types.h>
26
27 #include <linux/input.h>
28
29 #include <cutils/log.h>
30
31 #include "InputEventReader.h"
32 #include "local_log_def.h"
33
34 /*****************************************************************************/
35
36 struct input_event;
37
InputEventCircularReader(size_t numEvents)38 InputEventCircularReader::InputEventCircularReader(size_t numEvents)
39 : mBuffer(new input_event[numEvents * 2]),
40 mBufferEnd(mBuffer + numEvents),
41 mHead(mBuffer),
42 mCurr(mBuffer),
43 mFreeSpace(numEvents)
44 {
45 }
46
~InputEventCircularReader()47 InputEventCircularReader::~InputEventCircularReader()
48 {
49 delete [] mBuffer;
50 }
51
52 #define INPUT_EVENT_DEBUG (0)
fill(int fd)53 ssize_t InputEventCircularReader::fill(int fd)
54 {
55 size_t numEventsRead = 0;
56 LOGV_IF(INPUT_EVENT_DEBUG,
57 "DEBUG:%s enter, fd=%d\n", __PRETTY_FUNCTION__, fd);
58 if (mFreeSpace) {
59 const ssize_t nread = read(fd, mHead, mFreeSpace * sizeof(input_event));
60 if (nread < 0 || nread % sizeof(input_event)) {
61 //LOGE("Partial event received nread=%d, required=%d",
62 // nread, sizeof(input_event));
63 //LOGE("FD trying to read is: %d");
64 // we got a partial event!!
65 if (INPUT_EVENT_DEBUG) {
66 LOGV_IF(nread < 0, "DEBUG:%s exit nread < 0\n",
67 __PRETTY_FUNCTION__);
68 LOGV_IF(nread % sizeof(input_event),
69 "DEBUG:%s exit nread %% sizeof(input_event)\n",
70 __PRETTY_FUNCTION__);
71 }
72 return (nread < 0 ? -errno : -EINVAL);
73 }
74
75 numEventsRead = nread / sizeof(input_event);
76 if (numEventsRead) {
77 mHead += numEventsRead;
78 mFreeSpace -= numEventsRead;
79 if (mHead > mBufferEnd) {
80 size_t s = mHead - mBufferEnd;
81 memcpy(mBuffer, mBufferEnd, s * sizeof(input_event));
82 mHead = mBuffer + s;
83 }
84 }
85 }
86
87 LOGV_IF(INPUT_EVENT_DEBUG, "DEBUG:%s exit\n", __PRETTY_FUNCTION__);
88 return numEventsRead;
89 }
90
readEvent(input_event const ** events)91 ssize_t InputEventCircularReader::readEvent(input_event const** events)
92 {
93 *events = mCurr;
94 ssize_t available = (mBufferEnd - mBuffer) - mFreeSpace;
95 return available ? 1 : 0;
96 }
97
next()98 void InputEventCircularReader::next()
99 {
100 mCurr++;
101 mFreeSpace++;
102 if (mCurr >= mBufferEnd) {
103 mCurr = mBuffer;
104 }
105 }
106