Support atom-level annotations within AStatsEvent
Refactors implementation details to allow for atom-level annotations.
This CL does not change the API surface. addBoolAnnotation and
addInt32Annotation work for both atom-level and proto field annotations.
Test: bit libstatssocket_test:*
Bug: 151158794
Change-Id: I2c340b201aeb3bcddd5cfde171b7c4df1d8d69a4
diff --git a/libstats/socket/include/stats_event.h b/libstats/socket/include/stats_event.h
index ff84283..3576298 100644
--- a/libstats/socket/include/stats_event.h
+++ b/libstats/socket/include/stats_event.h
@@ -29,8 +29,9 @@
* AStatsEvent* event = AStatsEvent_obtain();
*
* AStatsEvent_setAtomId(event, atomId);
+ * AStatsEvent_addBoolAnnotation(event, 5, false); // atom-level annotation
* AStatsEvent_writeInt32(event, 24);
- * AStatsEvent_addBoolAnnotation(event, 1, true); // annotations apply to the previous field
+ * AStatsEvent_addBoolAnnotation(event, 1, true); // annotation for preceding atom field
* AStatsEvent_addInt32Annotation(event, 2, 128);
* AStatsEvent_writeFloat(event, 2.0);
*
@@ -38,13 +39,8 @@
* AStatsEvent_write(event);
* AStatsEvent_release(event);
*
- * Notes:
- * (a) write_<type>() and add_<type>_annotation() should be called in the order that fields
- * and annotations are defined in the atom.
- * (b) set_atom_id() can be called anytime before stats_event_write().
- * (c) add_<type>_annotation() calls apply to the previous field.
- * (d) If errors occur, stats_event_write() will write a bitmask of the errors to the socket.
- * (e) All strings should be encoded using UTF8.
+ * Note that calls to add atom fields and annotations should be made in the
+ * order that they are defined in the atom.
*/
#ifdef __cplusplus
@@ -84,7 +80,7 @@
int AStatsEvent_write(AStatsEvent* event);
/**
- * Frees the memory held by this StatsEvent
+ * Frees the memory held by this StatsEvent.
*
* After calling this, the StatsEvent must not be used or modified in any way.
*/
@@ -92,6 +88,8 @@
/**
* Sets the atom id for this StatsEvent.
+ *
+ * This function should be called immediately after AStatsEvent_obtain.
**/
void AStatsEvent_setAtomId(AStatsEvent* event, uint32_t atomId);
diff --git a/libstats/socket/stats_event.c b/libstats/socket/stats_event.c
index b045d93..24d2ea8 100644
--- a/libstats/socket/stats_event.c
+++ b/libstats/socket/stats_event.c
@@ -29,7 +29,6 @@
#define POS_NUM_ELEMENTS 1
#define POS_TIMESTAMP (POS_NUM_ELEMENTS + sizeof(uint8_t))
#define POS_ATOM_ID (POS_TIMESTAMP + sizeof(uint8_t) + sizeof(uint64_t))
-#define POS_FIRST_FIELD (POS_ATOM_ID + sizeof(uint8_t) + sizeof(uint32_t))
/* LIMITS */
#define MAX_ANNOTATION_COUNT 15
@@ -66,8 +65,11 @@
// within a buf. Also includes other required fields.
struct AStatsEvent {
uint8_t* buf;
- size_t lastFieldPos; // location of last field within the buf
- size_t size; // number of valid bytes within buffer
+ // Location of last field within the buf. Here, field denotes either a
+ // metadata field (e.g. timestamp) or an atom field.
+ size_t lastFieldPos;
+ // Number of valid bytes within the buffer.
+ size_t size;
uint32_t numElements;
uint32_t atomId;
uint32_t errors;
@@ -85,20 +87,21 @@
AStatsEvent* AStatsEvent_obtain() {
AStatsEvent* event = malloc(sizeof(AStatsEvent));
event->buf = (uint8_t*)calloc(MAX_EVENT_PAYLOAD, 1);
- event->buf[0] = OBJECT_TYPE;
+ event->lastFieldPos = 0;
+ event->size = 2; // reserve first two bytes for outer event type and number of elements
+ event->numElements = 0;
event->atomId = 0;
event->errors = 0;
event->truncate = true; // truncate for both pulled and pushed atoms
event->built = false;
- // place the timestamp
- uint64_t timestampNs = get_elapsed_realtime_ns();
- event->buf[POS_TIMESTAMP] = INT64_TYPE;
- memcpy(&event->buf[POS_TIMESTAMP + sizeof(uint8_t)], ×tampNs, sizeof(timestampNs));
+ event->buf[0] = OBJECT_TYPE;
+ AStatsEvent_writeInt64(event, get_elapsed_realtime_ns()); // write the timestamp
- event->numElements = 1;
- event->lastFieldPos = 0; // 0 since we haven't written a field yet
- event->size = POS_FIRST_FIELD;
+ // Force client to set atom id immediately (this is required for atom-level
+ // annotations to be written correctly). All atom field and annotation
+ // writes will fail until the atom id is set because event->errors != 0.
+ event->errors |= ERROR_NO_ATOM_ID;
return event;
}
@@ -109,10 +112,12 @@
}
void AStatsEvent_setAtomId(AStatsEvent* event, uint32_t atomId) {
+ if ((event->errors & ERROR_NO_ATOM_ID) == 0) return;
+
+ // Clear the ERROR_NO_ATOM_ID bit.
+ event->errors &= ~ERROR_NO_ATOM_ID;
event->atomId = atomId;
- event->buf[POS_ATOM_ID] = INT32_TYPE;
- memcpy(&event->buf[POS_ATOM_ID + sizeof(uint8_t)], &atomId, sizeof(atomId));
- event->numElements++;
+ AStatsEvent_writeInt32(event, atomId);
}
// Overwrites the timestamp populated in AStatsEvent_obtain with a custom
@@ -306,23 +311,23 @@
void AStatsEvent_build(AStatsEvent* event) {
if (event->built) return;
- if (event->atomId == 0) event->errors |= ERROR_NO_ATOM_ID;
-
- if (event->numElements > MAX_BYTE_VALUE) {
- event->errors |= ERROR_TOO_MANY_FIELDS;
- } else {
- event->buf[POS_NUM_ELEMENTS] = event->numElements;
- }
+ if (event->numElements > MAX_BYTE_VALUE) event->errors |= ERROR_TOO_MANY_FIELDS;
// If there are errors, rewrite buffer.
if (event->errors) {
- event->buf[POS_NUM_ELEMENTS] = 3;
- event->buf[POS_FIRST_FIELD] = ERROR_TYPE;
- memcpy(&event->buf[POS_FIRST_FIELD + sizeof(uint8_t)], &event->errors,
- sizeof(event->errors));
- event->size = POS_FIRST_FIELD + sizeof(uint8_t) + sizeof(uint32_t);
+ // Discard everything after the atom id (including atom-level
+ // annotations). This leaves only two elements (timestamp and atom id).
+ event->numElements = 2;
+ // Reset number of atom-level annotations to 0.
+ event->buf[POS_ATOM_ID] = INT32_TYPE;
+ // Now, write errors to the buffer immediately after the atom id.
+ event->size = POS_ATOM_ID + sizeof(uint8_t) + sizeof(uint32_t);
+ start_field(event, ERROR_TYPE);
+ append_int32(event, event->errors);
}
+ event->buf[POS_NUM_ELEMENTS] = event->numElements;
+
// Truncate the buffer to the appropriate length in order to limit our
// memory usage.
if (event->truncate) event->buf = (uint8_t*)realloc(event->buf, event->size);
diff --git a/libstats/socket/tests/stats_event_test.cpp b/libstats/socket/tests/stats_event_test.cpp
index 69d0a9b..04eff36 100644
--- a/libstats/socket/tests/stats_event_test.cpp
+++ b/libstats/socket/tests/stats_event_test.cpp
@@ -89,7 +89,7 @@
}
void checkMetadata(uint8_t** buffer, uint8_t numElements, int64_t startTime, int64_t endTime,
- uint32_t atomId) {
+ uint32_t atomId, uint8_t numAtomLevelAnnotations = 0) {
// All events start with OBJECT_TYPE id.
checkTypeHeader(buffer, OBJECT_TYPE);
@@ -104,7 +104,7 @@
EXPECT_LE(timestamp, endTime);
// Check atom id
- checkTypeHeader(buffer, INT32_TYPE);
+ checkTypeHeader(buffer, INT32_TYPE, numAtomLevelAnnotations);
checkScalar(buffer, atomId);
}
@@ -240,7 +240,7 @@
AStatsEvent_release(event);
}
-TEST(StatsEventTest, TestAnnotations) {
+TEST(StatsEventTest, TestFieldAnnotations) {
uint32_t atomId = 100;
// first element information
@@ -259,7 +259,7 @@
int64_t startTime = android::elapsedRealtimeNano();
AStatsEvent* event = AStatsEvent_obtain();
- AStatsEvent_setAtomId(event, 100);
+ AStatsEvent_setAtomId(event, atomId);
AStatsEvent_writeBool(event, boolValue);
AStatsEvent_addBoolAnnotation(event, boolAnnotation1Id, boolAnnotation1Value);
AStatsEvent_addInt32Annotation(event, boolAnnotation2Id, boolAnnotation2Value);
@@ -292,6 +292,45 @@
AStatsEvent_release(event);
}
+TEST(StatsEventTest, TestAtomLevelAnnotations) {
+ uint32_t atomId = 100;
+ // atom-level annotation information
+ uint8_t boolAnnotationId = 1;
+ uint8_t int32AnnotationId = 2;
+ bool boolAnnotationValue = false;
+ int32_t int32AnnotationValue = 5;
+
+ float fieldValue = -3.5;
+
+ int64_t startTime = android::elapsedRealtimeNano();
+ AStatsEvent* event = AStatsEvent_obtain();
+ AStatsEvent_setAtomId(event, atomId);
+ AStatsEvent_addBoolAnnotation(event, boolAnnotationId, boolAnnotationValue);
+ AStatsEvent_addInt32Annotation(event, int32AnnotationId, int32AnnotationValue);
+ AStatsEvent_writeFloat(event, fieldValue);
+ AStatsEvent_build(event);
+ int64_t endTime = android::elapsedRealtimeNano();
+
+ size_t bufferSize;
+ uint8_t* buffer = AStatsEvent_getBuffer(event, &bufferSize);
+ uint8_t* bufferEnd = buffer + bufferSize;
+
+ checkMetadata(&buffer, /*numElements=*/1, startTime, endTime, atomId,
+ /*numAtomLevelAnnotations=*/2);
+
+ // check atom-level annotations
+ checkAnnotation(&buffer, boolAnnotationId, BOOL_TYPE, boolAnnotationValue);
+ checkAnnotation(&buffer, int32AnnotationId, INT32_TYPE, int32AnnotationValue);
+
+ // check first element
+ checkTypeHeader(&buffer, FLOAT_TYPE);
+ checkScalar(&buffer, fieldValue);
+
+ EXPECT_EQ(buffer, bufferEnd); // ensure that we have read the entire buffer
+ EXPECT_EQ(AStatsEvent_getErrors(event), 0);
+ AStatsEvent_release(event);
+}
+
TEST(StatsEventTest, TestNoAtomIdError) {
AStatsEvent* event = AStatsEvent_obtain();
// Don't set the atom id in order to trigger the error.