Implement Sensors NDK Filtering
Implements the Sensors NDK filtering to only deliver
ASENSOR_TYPE_ADDITIONAL_INFO sensor events to clients who have
requested the events.
Bug: 77276247
Test: Unit tests pass
Test: Verified NDK clients only receive additional info sensor events
if they have been explicitly requested
Change-Id: I951ab65b19eafad16d18afb795fbb19fd5f95589
diff --git a/libs/sensor/SensorEventQueue.cpp b/libs/sensor/SensorEventQueue.cpp
index 46ba7c6..4438d45 100644
--- a/libs/sensor/SensorEventQueue.cpp
+++ b/libs/sensor/SensorEventQueue.cpp
@@ -29,6 +29,7 @@
#include <sensor/ISensorEventConnection.h>
#include <android/sensor.h>
+#include <hardware/sensors-base.h>
using std::min;
@@ -188,6 +189,52 @@
return;
}
+ssize_t SensorEventQueue::filterEvents(ASensorEvent* events, size_t count) const {
+ // Check if this Sensor Event Queue is registered to receive each type of event. If it is not,
+ // then do not copy the event into the final buffer. Minimize the number of copy operations by
+ // finding consecutive sequences of events that the Sensor Event Queue should receive and only
+ // copying the events once an unregistered event type is reached.
+ bool intervalStartLocSet = false;
+ size_t intervalStartLoc = 0;
+ size_t eventsInInterval = 0;
+ ssize_t eventsCopied = 0;
+
+ for (size_t i = 0; i < count; i++) {
+ bool includeEvent =
+ (events[i].type != SENSOR_TYPE_ADDITIONAL_INFO || requestAdditionalInfo);
+
+ if (includeEvent) {
+ // Do not copy events yet since there may be more consecutive events that should be
+ // copied together. Track the start location and number of events in the current
+ // sequence.
+ if (!intervalStartLocSet) {
+ intervalStartLoc = i;
+ intervalStartLocSet = true;
+ eventsInInterval = 0;
+ }
+ eventsInInterval++;
+ }
+
+ // Shift the events from the already processed interval once an event that should not be
+ // included is reached or if this is the final event to be processed.
+ if (!includeEvent || (i + 1 == count)) {
+ // Only shift the events if the interval did not start with the first event. If the
+ // interval started with the first event, the events are already in their correct
+ // location.
+ if (intervalStartLoc > 0) {
+ memmove(&events[eventsCopied], &events[intervalStartLoc],
+ eventsInInterval * sizeof(ASensorEvent));
+ }
+ eventsCopied += eventsInInterval;
+
+ // Reset the interval information
+ eventsInInterval = 0;
+ intervalStartLocSet = false;
+ }
+ }
+ return eventsCopied;
+}
+
// ----------------------------------------------------------------------------
}; // namespace android