Add statsd.

It doesn't start yet by default. When you start it manually, it sets
itself up as a binder system service and starts a thread to read the
event log.

Test: Run statsd, observe output. also run stats_test
Change-Id: If435d6a80fef3c1d957aedb61699bf5e9aae7e56
diff --git a/cmds/statsd/src/LogEntryPrinter.cpp b/cmds/statsd/src/LogEntryPrinter.cpp
new file mode 100644
index 0000000..ba07308
--- /dev/null
+++ b/cmds/statsd/src/LogEntryPrinter.cpp
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+#include <LogEntryPrinter.h>
+
+#include <log/event_tag_map.h>
+#include <log/logprint.h>
+#include <utils/Errors.h>
+
+using namespace android;
+
+LogEntryPrinter::LogEntryPrinter(int out)
+    :m_out(out)
+{
+    // Initialize the EventTagMap, which is how we know the names of the numeric event tags.
+    // If this fails, we can't print well, but something will print.
+    m_tags = android_openEventTagMap(NULL);
+
+    // Printing format
+    m_format = android_log_format_new();
+    android_log_setPrintFormat(m_format, FORMAT_THREADTIME);
+}
+
+LogEntryPrinter::~LogEntryPrinter()
+{
+    if (m_tags != NULL) {
+        android_closeEventTagMap(m_tags);
+    }
+    android_log_format_free(m_format);
+}
+
+void
+LogEntryPrinter::OnLogEvent(const log_msg& msg)
+{
+    status_t err;
+    AndroidLogEntry entry;
+    char buf[1024];
+
+    err = android_log_processBinaryLogBuffer(&(const_cast<log_msg*>(&msg)->entry_v1),
+                &entry, m_tags, buf, sizeof(buf));
+    if (err == NO_ERROR) {
+        android_log_printLogLine(m_format, m_out, &entry);
+    } else {
+        printf("log entry: %s\n", buf);
+        fflush(stdout);
+    }
+}
+