First draft of native StatsEvent API
Test: m -j libstatssocket compiles
Change-Id: I0da9740d29749d79d14be39e5949b98c58df704d
diff --git a/libstats/stats_event.h b/libstats/stats_event.h
new file mode 100644
index 0000000..16a04f8
--- /dev/null
+++ b/libstats/stats_event.h
@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#ifndef ANDROID_STATS_LOG_STATS_EVENT_H
+#define ANDROID_STATS_LOG_STATS_EVENT_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+/*
+ * Functionality to build and store the buffer sent over the statsd socket.
+ * This code defines and encapsulates the socket protocol.
+ *
+ * Usage:
+ * struct stats_event* event = stats_event_obtain();
+ *
+ * stats_event_set_timestamp_ns(event, timestampNs);
+ * stats_event_set_atom_id(event, atomId);
+ * stats_event_write_int32(event, 24);
+ * stats_event_add_bool_annotation(event, 1, true); // annotations apply to the previous field
+ * stats_event_add_int32_annotation(event, 2, 128);
+ * stats_event_write_float(event, 2.0);
+ *
+ * stats_event_write(event);
+ * stats_event_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_timestamp_ns() and 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) Strings should be encoded using UTF8 and written using stats_event_write_string8().
+ */
+
+struct stats_event;
+
+/* ERRORS */
+#define ERROR_NO_TIMESTAMP 0x1
+#define ERROR_NO_ATOM_ID 0x2
+#define ERROR_OVERFLOW 0x4
+#define ERROR_ATTRIBUTION_CHAIN_TOO_LONG 0x8
+#define ERROR_ANNOTATION_DOES_NOT_FOLLOW_FIELD 0x10
+#define ERROR_INVALID_ANNOTATION_ID 0x20
+#define ERROR_ANNOTATION_ID_TOO_LARGE 0x40
+#define ERROR_TOO_MANY_ANNOTATIONS 0x80
+#define ERROR_TOO_MANY_FIELDS 0x100
+
+/* System API */
+struct stats_event* stats_event_obtain();
+void stats_event_write(struct stats_event* event);
+void stats_event_release(struct stats_event* event);
+
+void stats_event_set_atom_id(struct stats_event* event, const uint32_t atomId);
+void stats_event_set_timestamp_ns(struct stats_event* event, const uint64_t timestampNs);
+
+void stats_event_write_int32(struct stats_event* event, int32_t value);
+void stats_event_write_int64(struct stats_event* event, int64_t value);
+void stats_event_write_float(struct stats_event* event, float value);
+void stats_event_write_bool(struct stats_event* event, bool value);
+void stats_event_write_byte_array(struct stats_event* event, uint8_t* buf, uint32_t numBytes);
+void stats_event_write_string8(struct stats_event* event, char* buf, uint32_t numBytes);
+void stats_event_write_attribution_chain(struct stats_event* event, uint32_t* uids, char** tags,
+ uint32_t* tagLengths, uint32_t numNodes);
+
+void stats_event_add_bool_annotation(struct stats_event* event, uint32_t annotationId, bool value);
+void stats_event_add_int32_annotation(struct stats_event* event, uint32_t annotationId,
+ int32_t value);
+
+uint32_t stats_event_get_errors(struct stats_event* event);
+
+#endif // ANDROID_STATS_LOG_STATS_EVENT_H