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#include <string.h>
24
25#include <sys/cdefs.h>
26#include <sys/types.h>
27
28#include <linux/input.h>
29
30#include <cutils/log.h>
31
32#include "InputEventReader.h"
33
34/*****************************************************************************/
35
36struct input_event;
37
38InputEventCircularReader::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    mLastFd = -1;
46}
47
48InputEventCircularReader::~InputEventCircularReader()
49{
50    delete [] mBuffer;
51}
52
53#define INPUT_EVENT_DEBUG (0)
54ssize_t InputEventCircularReader::fill(int fd)
55{
56    size_t numEventsRead = 0;
57    mLastFd = fd;
58
59    LOGV_IF(INPUT_EVENT_DEBUG,
60            "DEBUG:%s enter, fd=%d\n", __PRETTY_FUNCTION__, fd);
61    if (mFreeSpace) {
62        const ssize_t nread = read(fd, mHead, mFreeSpace * sizeof(input_event));
63        if (nread < 0 || nread % sizeof(input_event)) {
64            //LOGE("Partial event received nread=%d, required=%d",
65            //     nread, sizeof(input_event));
66            //LOGE("FD trying to read is: %d");
67            // we got a partial event!!
68            if (INPUT_EVENT_DEBUG) {
69                LOGV_IF(nread < 0, "DEBUG:%s exit nread < 0\n",
70                        __PRETTY_FUNCTION__);
71                LOGV_IF(nread % sizeof(input_event),
72                        "DEBUG:%s exit nread %% sizeof(input_event)\n",
73                        __PRETTY_FUNCTION__);
74            }
75            return (nread < 0 ? -errno : -EINVAL);
76        }
77
78        numEventsRead = nread / sizeof(input_event);
79        if (numEventsRead) {
80            mHead += numEventsRead;
81            mFreeSpace -= numEventsRead;
82            if (mHead > mBufferEnd) {
83                size_t s = mHead - mBufferEnd;
84                memcpy(mBuffer, mBufferEnd, s * sizeof(input_event));
85                mHead = mBuffer + s;
86            }
87        }
88    }
89
90    LOGV_IF(INPUT_EVENT_DEBUG, "DEBUG:%s exit, numEventsRead:%d\n",
91            __PRETTY_FUNCTION__, numEventsRead);
92    return numEventsRead;
93}
94
95ssize_t InputEventCircularReader::readEvent(input_event const** events)
96{
97    *events = mCurr;
98    ssize_t available = (mBufferEnd - mBuffer) - mFreeSpace;
99    LOGV_IF(INPUT_EVENT_DEBUG, "DEBUG:%s fd:%d, available:%d\n",
100            __PRETTY_FUNCTION__, mLastFd, (int)available);
101    return (available ? 1 : 0);
102}
103
104void InputEventCircularReader::next()
105{
106    mCurr++;
107    mFreeSpace++;
108    if (mCurr >= mBufferEnd) {
109        mCurr = mBuffer;
110    }
111    ssize_t available = (mBufferEnd - mBuffer) - mFreeSpace;
112    LOGV_IF(INPUT_EVENT_DEBUG, "DEBUG:%s fd:%d, still available:%d\n",
113            __PRETTY_FUNCTION__, mLastFd, (int)available);
114}
115
116