C interface to MediaMetrics
C interface is more stable across upgrades than C++
and simplifies cross-package interfaces in upgradeable components.
Bug: 119675363
Test: parallel metrics generation from nuplayer
Change-Id: I36beeade82a208be64af0860eb6f175a2801b27f
diff --git a/media/libmediametrics/include/MediaMetrics.h b/media/libmediametrics/include/MediaMetrics.h
new file mode 100644
index 0000000..4d2f352
--- /dev/null
+++ b/media/libmediametrics/include/MediaMetrics.h
@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2018 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_MEDIA_MEDIAMETRICS_H
+#define ANDROID_MEDIA_MEDIAMETRICS_H
+
+//
+// define a C interface to the media metrics functionality
+//
+// All functions that return a char * or const char * also give responsibility
+// for that string to the caller. The caller is responsible for calling free()
+// on that pointer when done using the value.
+
+__BEGIN_DECLS
+
+// internally re-cast to the behind-the-scenes C++ class instance
+typedef int64_t mediametrics_handle_t;
+typedef const char *mediametricskey_t;
+typedef const char *attr_t;
+
+mediametrics_handle_t mediametrics_create(mediametricskey_t key);
+void mediametrics_delete(mediametrics_handle_t handle);
+
+mediametricskey_t mediametrics_getKey(mediametrics_handle_t handle);
+
+
+// set
+void mediametrics_setInt32(mediametrics_handle_t handle, attr_t attr,
+ int32_t value);
+void mediametrics_setInt64(mediametrics_handle_t handle, attr_t attr,
+ int64_t value);
+void mediametrics_setDouble(mediametrics_handle_t handle, attr_t attr,
+ double value);
+void mediametrics_setRate(mediametrics_handle_t handle, attr_t attr,
+ int64_t count, int64_t duration);
+void mediametrics_setCString(mediametrics_handle_t handle, attr_t attr,
+ const char * value);
+
+// fused get/add/set; if attr wasn't there, it's a simple set.
+// these do not provide atomicity or mutual exclusion, only simpler code sequences.
+void mediametrics_addInt32(mediametrics_handle_t handle, attr_t attr,
+ int32_t value);
+void mediametrics_addInt64(mediametrics_handle_t handle, attr_t attr,
+ int64_t value);
+void mediametrics_addDouble(mediametrics_handle_t handle, attr_t attr,
+ double value);
+void mediametrics_addRate(mediametrics_handle_t handle, attr_t attr,
+ int64_t count, int64_t duration);
+
+// find & extract values
+// return indicates whether attr exists (and thus whether value filled in)
+// NULL parameter value suppresses storage of value.
+bool mediametrics_getInt32(mediametrics_handle_t handle, attr_t attr,
+ int32_t * value);
+bool mediametrics_getInt64(mediametrics_handle_t handle, attr_t attr,
+ int64_t * value);
+bool mediametrics_getDouble(mediametrics_handle_t handle, attr_t attr,
+ double *value);
+bool mediametrics_getRate(mediametrics_handle_t handle, attr_t attr,
+ int64_t * count, int64_t * duration, double *rate);
+bool mediametrics_getCString(mediametrics_handle_t handle, attr_t attr,
+ char **value);
+// to release strings returned via getCString()
+void mediametrics_freeCString(char *value);
+
+// # of attributes set within this record.
+int32_t mediametrics_count(mediametrics_handle_t handle);
+
+bool mediametrics_selfRecord(mediametrics_handle_t handle);
+
+const char *mediametrics_readable(mediametrics_handle_t handle);
+void mediametrics_setUid(mediametrics_handle_t handle, uid_t uid);
+bool mediametrics_isEnabled();
+
+#if 0
+// do not expose this as is.
+// need to revisit (or redefine) how the android::Parcel parameter is handled
+// so that it meets the stable-API criteria for updateable components.
+//
+int32_t mediametrics_writeToParcel(mediametrics_handle_t handle, android::Parcel *parcel);
+#endif
+
+__END_DECLS
+
+#endif