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-rw-r--r--libsensors/InputEventReader.cpp89
1 files changed, 89 insertions, 0 deletions
diff --git a/libsensors/InputEventReader.cpp b/libsensors/InputEventReader.cpp
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--- /dev/null
+++ b/libsensors/InputEventReader.cpp
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+/*
+ * 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 <cstring>
+
+#include <linux/input.h>
+
+#include <cutils/log.h>
+
+#include "InputEventReader.h"
+
+/*****************************************************************************/
+
+struct input_event;
+
+InputEventCircularReader::InputEventCircularReader(size_t numEvents)
+ : mBuffer(new input_event[numEvents * 2]),
+ mBufferEnd(mBuffer + numEvents),
+ mHead(mBuffer),
+ mCurr(mBuffer),
+ mFreeSpace(numEvents)
+{
+}
+
+InputEventCircularReader::~InputEventCircularReader()
+{
+ delete [] mBuffer;
+}
+
+ssize_t InputEventCircularReader::fill(int fd)
+{
+ size_t numEventsRead = 0;
+ if (mFreeSpace) {
+ const ssize_t nread = read(fd, mHead, mFreeSpace * sizeof(input_event));
+ 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) {
+ size_t s = mHead - mBufferEnd;
+ memcpy(mBuffer, mBufferEnd, s * sizeof(input_event));
+ mHead = mBuffer + s;
+ }
+ }
+ }
+
+ return numEventsRead;
+}
+
+ssize_t InputEventCircularReader::readEvent(input_event const** events)
+{
+ *events = mCurr;
+ ssize_t available = (mBufferEnd - mBuffer) - mFreeSpace;
+ return available ? 1 : 0;
+}
+
+void InputEventCircularReader::next()
+{
+ mCurr++;
+ mFreeSpace++;
+ if (mCurr >= mBufferEnd) {
+ mCurr = mBuffer;
+ }
+}