Public StatsLog API for generic mainline logging.

Sets up a public api for logging atoms to statsd. The API excepts a
buffer which is already encoded in the proper format for the socket, as
well as the number of bytes of the buffer to write. It performs a JNI
call to perform the socket write. Autogenerated app code will be built
for each mainline module that needs to use this API to log.

Test: builds
Test: existing logs flow properly
Bug: 126134616
Change-Id: I8a9a91e638d730e3ff69cb9345692e49e0db3c96

api/system-current.txt

@@ -9471,6 +9471,10 @@ package android.util {
     method public int getUid();
   }
 
+  public final class StatsLog {
+    method public static void writeRaw(@NonNull byte[], int);
+  }
+
   public class StatsLogAtoms {
     field public static final int PERMISSION_GRANT_REQUEST_RESULT_REPORTED = 170; // 0xaa
     field public static final int PERMISSION_GRANT_REQUEST_RESULT_REPORTED__RESULT__AUTO_DENIED = 8; // 0x8

core/java/android/util/StatsLog.java

@@ -22,6 +22,7 @@ import static android.Manifest.permission.PACKAGE_USAGE_STATS;
 import android.Manifest;
 import android.annotation.NonNull;
 import android.annotation.RequiresPermission;
+import android.annotation.SystemApi;
 import android.app.IActivityManager;
 import android.content.Context;
 import android.os.IStatsManager;
@@ -199,6 +200,16 @@ public final class StatsLog extends StatsLogInternal {
         }
     }
 
+    /**
+     * Write an event to stats log using the raw format.
+     *
+     * @param buffer    The encoded buffer of data to write..
+     * @param size      The number of bytes from the buffer to write.
+     * @hide
+     */
+    @SystemApi
+    public static native void writeRaw(@NonNull byte[] buffer, int size);
+
     private static void enforceDumpCallingPermission(Context context) {
         context.enforceCallingPermission(android.Manifest.permission.DUMP, "Need DUMP permission.");
     }

core/jni/Android.bp

@@ -1,10 +1,10 @@
 
 genrule {
-    name: "android_util_StatsLog.cpp",
+    name: "android_util_StatsLogInternal.cpp",
     tools: ["stats-log-api-gen"],
-    cmd: "$(location stats-log-api-gen) --jni $(genDir)/android_util_StatsLog.cpp",
+    cmd: "$(location stats-log-api-gen) --jni $(genDir)/android_util_StatsLogInternal.cpp",
     out: [
-        "android_util_StatsLog.cpp",
+        "android_util_StatsLogInternal.cpp",
     ],
 }
 
@@ -111,6 +111,7 @@ cc_library_shared {
         "android_util_Binder.cpp",
         "android_util_EventLog.cpp",
         "android_util_Log.cpp",
+        "android_util_StatsLog.cpp",
         "android_util_MemoryIntArray.cpp",
         "android_util_PathParser.cpp",
         "android_util_Process.cpp",
@@ -306,7 +307,7 @@ cc_library_shared {
         "server_configurable_flags",
     ],
 
-    generated_sources: ["android_util_StatsLog.cpp"],
+    generated_sources: ["android_util_StatsLogInternal.cpp"],
 
     local_include_dirs: ["android/graphics"],
     export_include_dirs: [

core/jni/AndroidRuntime.cpp

@@ -127,6 +127,7 @@ extern int register_android_app_admin_SecurityLog(JNIEnv* env);
 extern int register_android_content_AssetManager(JNIEnv* env);
 extern int register_android_util_EventLog(JNIEnv* env);
 extern int register_android_util_StatsLog(JNIEnv* env);
+extern int register_android_util_StatsLogInternal(JNIEnv* env);
 extern int register_android_util_Log(JNIEnv* env);
 extern int register_android_util_MemoryIntArray(JNIEnv* env);
 extern int register_android_util_PathParser(JNIEnv* env);
@@ -1394,6 +1395,7 @@ static const RegJNIRec gRegJNI[] = {
     REG_JNI(register_android_util_MemoryIntArray),
     REG_JNI(register_android_util_PathParser),
     REG_JNI(register_android_util_StatsLog),
+    REG_JNI(register_android_util_StatsLogInternal),
     REG_JNI(register_android_app_admin_SecurityLog),
     REG_JNI(register_android_content_AssetManager),
     REG_JNI(register_android_content_StringBlock),

core/jni/android_util_StatsLog.cpp

@@ -0,0 +1,69 @@
+/*
+ * 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.
+ */
+
+#define LOG_NAMESPACE "StatsLog.tag."
+#define LOG_TAG "StatsLog_println"
+
+#include <assert.h>
+#include <cutils/properties.h>
+
+#include "jni.h"
+#include <nativehelper/JNIHelp.h>
+#include "utils/misc.h"
+#include "core_jni_helpers.h"
+#include "stats_event_list.h"
+
+namespace android {
+
+static void android_util_StatsLog_writeRaw(JNIEnv* env, jobject clazz, jbyteArray buf, jint size)
+{
+    if (buf == NULL) {
+        return;
+    }
+    jint actualSize = env->GetArrayLength(buf);
+    if (actualSize < size) {
+        return;
+    }
+
+    jbyte* bufferArray = env->GetByteArrayElements(buf, NULL);
+    if (bufferArray == NULL) {
+        return;
+    }
+    const uint32_t statsEventTag = 1937006964;
+    struct iovec vec[2];
+    vec[0].iov_base = (void*) &statsEventTag;
+    vec[0].iov_len = sizeof(statsEventTag);
+    vec[1].iov_base = (void*) bufferArray;
+    vec[1].iov_len = size;
+    write_to_statsd(vec, 2);
+
+    env->ReleaseByteArrayElements(buf, bufferArray, 0);
+}
+
+/*
+ * JNI registration.
+ */
+static const JNINativeMethod gMethods[] = {
+    /* name, signature, funcPtr */
+    { "writeRaw", "([BI)V", (void*) android_util_StatsLog_writeRaw },
+};
+
+int register_android_util_StatsLog(JNIEnv* env)
+{
+    return RegisterMethodsOrDie(env, "android/util/StatsLog", gMethods, NELEM(gMethods));
+}
+
+}; // namespace android

tools/stats_log_api_gen/main.cpp

@@ -1403,10 +1403,10 @@ write_stats_log_jni(FILE* out, const Atoms& atoms, const AtomDecl &attributionDe
     fprintf(out, "\n");
 
     // Print registration function
-    fprintf(out, "int register_android_util_StatsLog(JNIEnv* env) {\n");
+    fprintf(out, "int register_android_util_StatsLogInternal(JNIEnv* env) {\n");
     fprintf(out, "    return RegisterMethodsOrDie(\n");
     fprintf(out, "            env,\n");
-    fprintf(out, "            \"android/util/StatsLog\",\n");
+    fprintf(out, "            \"android/util/StatsLogInternal\",\n");
     fprintf(out, "            gRegisterMethods, NELEM(gRegisterMethods));\n");
     fprintf(out, "}\n");