MediaMetrics: Minor logging fixes

Remove extraneous right brace in Time Machine dump.
Do not suppress repeated EVENT properties in the Time Machine.
Use "--" prefix instead of "-" for long dumpsys argv options.

Test: atest mediametrics_tests
Test: adb shell dumpsys media.metrics
Bug: 138583596
Change-Id: I874be909ac08641b14dd12fb2c83de7a276a1796

media/libmediametrics/include/MediaMetricsConstants.h

@@ -70,14 +70,21 @@
 // Underscores after the AMEDIAMETRICS_PROP_* prefix indicate
 // a "dot" in the property name. For example AMEDIAMETRICS_PROP_VOLUME_LEFT
 // corresponds to "volume.left".
-
+//
+// The property names are camel case, typically a lowercase letter [a-z]
+// followed by one or more characters in the range [a-zA-Z0-9_.].
+// Special symbols such as !@#$%^&*()[]{}<>,:;'"\/?|+-=~ are reserved.
+//
+// A property that ends with a ! will have duplicate values listed instead
+// of suppressed in the Time Machine.
+//
 #define AMEDIAMETRICS_PROP_AUXEFFECTID    "auxEffectId"    // int32 (AudioTrack)
 #define AMEDIAMETRICS_PROP_CHANNELCOUNT   "channelCount"   // int32
 #define AMEDIAMETRICS_PROP_CHANNELMASK    "channelMask"    // int32
 #define AMEDIAMETRICS_PROP_CONTENTTYPE    "contentType"    // string attributes (AudioTrack)
 #define AMEDIAMETRICS_PROP_DURATIONNS     "durationNs"     // int64 duration time span
 #define AMEDIAMETRICS_PROP_ENCODING       "encoding"       // string value of format
-#define AMEDIAMETRICS_PROP_EVENT          "event"          // string value (often func name)
+#define AMEDIAMETRICS_PROP_EVENT          "event!"         // string value (often func name)
 
 // TODO: fix inconsistency in flags: AudioRecord / AudioTrack int32,  AudioThread string
 #define AMEDIAMETRICS_PROP_FLAGS          "flags"

services/mediametrics/MediaMetricsService.cpp

@@ -204,13 +204,13 @@ status_t MediaMetricsService::dump(int fd, const Vector<String16>& args)
     }
 
     // crack any parameters
-    const String16 protoOption("-proto");
-    const String16 clearOption("-clear");
+    const String16 protoOption("--proto");
+    const String16 clearOption("--clear");
     bool clear = false;
-    const String16 sinceOption("-since");
+    const String16 sinceOption("--since");
     nsecs_t ts_since = 0;
-    const String16 helpOption("-help");
-    const String16 onlyOption("-only");
+    const String16 helpOption("--help");
+    const String16 onlyOption("--only");
     std::string only;
     const int n = args.size();
     for (int i = 0; i < n; i++) {
@@ -250,11 +250,11 @@ status_t MediaMetricsService::dump(int fd, const Vector<String16>& args)
             // or dumpsys media.metrics audiotrack codec
 
             result.append("Recognized parameters:\n");
-            result.append("-help        this help message\n");
-            result.append("-proto #     dump using protocol #");
-            result.append("-clear       clears out saved records\n");
-            result.append("-only X      process records for component X\n");
-            result.append("-since X     include records since X\n");
+            result.append("--help        this help message\n");
+            result.append("--proto #     dump using protocol #");
+            result.append("--clear       clears out saved records\n");
+            result.append("--only X      process records for component X\n");
+            result.append("--since X     include records since X\n");
             result.append("             (X is milliseconds since the UNIX epoch)\n");
             write(fd, result.string(), result.size());
             return NO_ERROR;

services/mediametrics/TimeMachine.h

@@ -168,7 +168,6 @@ private:
                 ss << "(" << (offset == 0 ? "" : "~") << &timestring.time[offset]
                     << ") " << eptr->second;
                 if (++eptr == timeSequence.end()) {
-                    ss << "}";
                     break;
                 }
                 ss << ", ";