1 files changed, 89 insertions, 0 deletions
diff --git a/libsensors/InputEventReader.cpp b/libsensors/InputEventReader.cpp
new file mode 100644
index 0000000..ab23a22
--- /dev/null
+++ b/libsensors/InputEventReader.cpp
@@ -0,0 +1,89 @@
+/*
+ * 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;
+    }
+}