From 8e6f9983009eadf32d05ad65e38906d3985bc9ba Mon Sep 17 00:00:00 2001
From: Yao Chen <yaochen@google.com>
Date: Thu, 29 Nov 2018 09:39:45 -0800
Subject: [PATCH] Skip writing message field in an atom if it's empty

Test: unit test added
Change-Id: I825b1ce526944a20fe65705508ad180ece37492c
---
 cmds/statsd/src/logd/LogEvent.cpp   |  2 +-
 cmds/statsd/src/stats_log_util.cpp  |  8 ++++---
 cmds/statsd/tests/LogEvent_test.cpp | 37 +++++++++++++++++++++++++++++
 tools/stats_log_api_gen/main.cpp    |  5 +++-
 4 files changed, 47 insertions(+), 5 deletions(-)

diff --git a/cmds/statsd/src/logd/LogEvent.cpp b/cmds/statsd/src/logd/LogEvent.cpp
index 625294ce5e49a..e1490da041f06 100644
--- a/cmds/statsd/src/logd/LogEvent.cpp
+++ b/cmds/statsd/src/logd/LogEvent.cpp
@@ -653,7 +653,7 @@ float LogEvent::GetFloat(size_t key, status_t* err) const {
 
 string LogEvent::ToString() const {
     string result;
-    result += StringPrintf("{ %lld %lld (%d)", (long long)mLogdTimestampNs,
+    result += StringPrintf("{ uid(%d) %lld %lld (%d)", mLogUid, (long long)mLogdTimestampNs,
                            (long long)mElapsedTimestampNs, mTagId);
     for (const auto& value : mValues) {
         result +=
diff --git a/cmds/statsd/src/stats_log_util.cpp b/cmds/statsd/src/stats_log_util.cpp
index 504c5864f2ec3..f1310db03d458 100644
--- a/cmds/statsd/src/stats_log_util.cpp
+++ b/cmds/statsd/src/stats_log_util.cpp
@@ -343,9 +343,11 @@ void writeFieldValueTreeToStreamHelper(int tagId, const std::vector<FieldValue>&
                         }
                     }
                     if (isBytesField) {
-                        protoOutput->write(FIELD_TYPE_MESSAGE | fieldNum,
-                                           (const char*)dim.mValue.str_value.c_str(),
-                                           dim.mValue.str_value.length());
+                        if (dim.mValue.str_value.length() > 0) {
+                            protoOutput->write(FIELD_TYPE_MESSAGE | fieldNum,
+                                               (const char*)dim.mValue.str_value.c_str(),
+                                               dim.mValue.str_value.length());
+                        }
                     } else {
                         protoOutput->write(FIELD_TYPE_STRING | fieldNum, dim.mValue.str_value);
                     }
diff --git a/cmds/statsd/tests/LogEvent_test.cpp b/cmds/statsd/tests/LogEvent_test.cpp
index 6384757b7fc8a..fdc792a48e0ab 100644
--- a/cmds/statsd/tests/LogEvent_test.cpp
+++ b/cmds/statsd/tests/LogEvent_test.cpp
@@ -444,7 +444,44 @@ TEST(LogEventTest, TestBinaryFieldAtom) {
     EXPECT_EQ(orig_str, result_str);
 }
 
+TEST(LogEventTest, TestBinaryFieldAtom_empty) {
+    Atom launcherAtom;
+    auto launcher_event = launcherAtom.mutable_launcher_event();
+    launcher_event->set_action(stats::launcher::LauncherAction::LONGPRESS);
+    launcher_event->set_src_state(stats::launcher::LauncherState::OVERVIEW);
+    launcher_event->set_dst_state(stats::launcher::LauncherState::ALLAPPS);
 
+    // empty string.
+    string extension_str;
+
+    LogEvent event1(Atom::kLauncherEventFieldNumber, 1000);
+
+    event1.write((int32_t)stats::launcher::LauncherAction::LONGPRESS);
+    event1.write((int32_t)stats::launcher::LauncherState::OVERVIEW);
+    event1.write((int64_t)stats::launcher::LauncherState::ALLAPPS);
+    event1.write(extension_str);
+    event1.init();
+
+    ProtoOutputStream proto;
+    event1.ToProto(proto);
+
+    std::vector<uint8_t> outData;
+    outData.resize(proto.size());
+    size_t pos = 0;
+    auto iter = proto.data();
+    while (iter.readBuffer() != NULL) {
+        size_t toRead = iter.currentToRead();
+        std::memcpy(&(outData[pos]), iter.readBuffer(), toRead);
+        pos += toRead;
+        iter.rp()->move(toRead);
+    }
+
+    std::string result_str(outData.begin(), outData.end());
+    std::string orig_str;
+    launcherAtom.SerializeToString(&orig_str);
+
+    EXPECT_EQ(orig_str, result_str);
+}
 
 }  // namespace statsd
 }  // namespace os
diff --git a/tools/stats_log_api_gen/main.cpp b/tools/stats_log_api_gen/main.cpp
index 8585ae9f3f611..88b7e2e9de211 100644
--- a/tools/stats_log_api_gen/main.cpp
+++ b/tools/stats_log_api_gen/main.cpp
@@ -1128,7 +1128,10 @@ write_stats_log_jni(FILE* out, const string& java_method_name, const string& cpp
                 hadStringOrChain = true;
                 fprintf(out, "    jbyte* jbyte_array%d;\n", argIndex);
                 fprintf(out, "    const char* str%d;\n", argIndex);
-                fprintf(out, "    if (arg%d != NULL) {\n", argIndex);
+                fprintf(out,
+                        "    if (arg%d != NULL && env->GetArrayLength(arg%d) > "
+                        "0) {\n",
+                        argIndex, argIndex);
                 fprintf(out,
                         "        jbyte_array%d = "
                         "env->GetByteArrayElements(arg%d, NULL);\n",