Basic binary event-log helpers
EventLog can be used from SurfaceFlinger to log jank
statistics events to the binary event log.
Change-Id: If0fbbe7d7111f10957697166d37fd0c3418109bb
diff --git a/services/surfaceflinger/EventLog/EventLog.cpp b/services/surfaceflinger/EventLog/EventLog.cpp
new file mode 100644
index 0000000..815242b
--- /dev/null
+++ b/services/surfaceflinger/EventLog/EventLog.cpp
@@ -0,0 +1,128 @@
+/*
+ * Copyright 2013 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 <stdio.h>
+#include <stdlib.h>
+#include <cutils/log.h>
+#include <utils/String8.h>
+
+#include "EventLog.h"
+
+// ---------------------------------------------------------------------------
+namespace android {
+// ---------------------------------------------------------------------------
+
+ANDROID_SINGLETON_STATIC_INSTANCE(EventLog)
+
+
+EventLog::EventLog() {
+}
+
+void EventLog::doLogJank(const String8& window, int32_t value) {
+ EventLog::TagBuffer buffer(LOGTAG_SF_JANK);
+ buffer.startList(2);
+ buffer.writeString8(window);
+ buffer.writeInt32(value);
+ buffer.endList();
+ buffer.log();
+}
+
+void EventLog::logJank(const String8& window, int32_t value) {
+ EventLog::getInstance().doLogJank(window, value);
+}
+
+// ---------------------------------------------------------------------------
+
+EventLog::TagBuffer::TagBuffer(int32_t tag)
+ : mPos(0), mTag(tag), mOverflow(false) {
+}
+
+void EventLog::TagBuffer::log() {
+ if (mOverflow) {
+ ALOGW("couldn't log to binary event log: overflow.");
+ } else if (android_bWriteLog(mTag, mStorage, mPos) < 0) {
+ ALOGE("couldn't log to EventLog: %s", strerror(errno));
+ }
+ // purge the buffer
+ mPos = 0;
+ mOverflow = false;
+}
+
+void EventLog::TagBuffer::startList(int8_t count) {
+ if (mOverflow) return;
+ const size_t needed = 1 + sizeof(count);
+ if (mPos + needed > STORAGE_MAX_SIZE) {
+ mOverflow = true;
+ return;
+ }
+ mStorage[mPos + 0] = EVENT_TYPE_LIST;
+ mStorage[mPos + 1] = count;
+ mPos += needed;
+}
+
+void EventLog::TagBuffer::endList() {
+ if (mOverflow) return;
+ const size_t needed = 1;
+ if (mPos + needed > STORAGE_MAX_SIZE) {
+ mOverflow = true;
+ return;
+ }
+ mStorage[mPos + 0] = '\n';
+ mPos += needed;
+}
+
+void EventLog::TagBuffer::writeInt32(int32_t value) {
+ if (mOverflow) return;
+ const size_t needed = 1 + sizeof(value);
+ if (mPos + needed > STORAGE_MAX_SIZE) {
+ mOverflow = true;
+ return;
+ }
+ mStorage[mPos + 0] = EVENT_TYPE_INT;
+ memcpy(&mStorage[mPos + 1], &value, sizeof(value));
+ mPos += needed;
+}
+
+void EventLog::TagBuffer::writeInt64(int64_t value) {
+ if (mOverflow) return;
+ const size_t needed = 1 + sizeof(value);
+ if (mPos + needed > STORAGE_MAX_SIZE) {
+ mOverflow = true;
+ return;
+ }
+ mStorage[mPos + 0] = EVENT_TYPE_LONG;
+ memcpy(&mStorage[mPos + 1], &value, sizeof(value));
+ mPos += needed;
+}
+
+void EventLog::TagBuffer::writeString8(const String8& value) {
+ if (mOverflow) return;
+ const int32_t stringLen = value.length();
+ const size_t needed = 1 + sizeof(int32_t) + stringLen;
+ if (mPos + needed > STORAGE_MAX_SIZE) {
+ mOverflow = true;
+ return;
+ }
+ mStorage[mPos + 0] = EVENT_TYPE_STRING;
+ memcpy(&mStorage[mPos + 1], &stringLen, sizeof(int32_t));
+ memcpy(&mStorage[mPos + 5], value.string(), stringLen);
+ mPos += needed;
+}
+
+// ---------------------------------------------------------------------------
+}// namespace android
+
+// ---------------------------------------------------------------------------