system/core: Add initial implementation of the bootstat command.
The bootstat command enables the measurement and logging of boot time
metrics
for GMS devices.
BUG:21724738
Change-Id: I331456dd38a60fb4ef24a4d5320909dbad30db66
diff --git a/bootstat/event_log_list_builder.cpp b/bootstat/event_log_list_builder.cpp
new file mode 100644
index 0000000..017a7c5
--- /dev/null
+++ b/bootstat/event_log_list_builder.cpp
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2016 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 "event_log_list_builder.h"
+
+#include <cinttypes>
+#include <string>
+#include <base/logging.h>
+#include <log/log.h>
+
+namespace {
+
+const size_t MAX_EVENT_PAYLOAD_SIZE = 512 - 1; // Leave room for final '\n'.
+const size_t EVENT_TYPE_SIZE = 1; // Size in bytes of the event type marker.
+
+} // namespace
+
+EventLogListBuilder::EventLogListBuilder()
+ : payload_count_(0),
+ payload_size_(0),
+ payload_(std::make_unique<uint8_t[]>(MAX_EVENT_PAYLOAD_SIZE)) {
+ memset(payload_.get(), 0, MAX_EVENT_PAYLOAD_SIZE);
+
+ // Set up the top-level EventLog data type.
+ AppendByte(EVENT_TYPE_LIST);
+
+ // Skip over the byte prepresenting the number of items in the list. This
+ // value is set in Release().
+ payload_size_++;
+}
+
+bool EventLogListBuilder::Append(int value) {
+ DCHECK_NE(static_cast<uint8_t*>(nullptr), payload_.get());
+
+ if (!IsSpaceAvailable(sizeof(value) + EVENT_TYPE_SIZE)) {
+ return false;
+ }
+
+ AppendByte(EVENT_TYPE_INT);
+ AppendData(&value, sizeof(value));
+
+ payload_count_++;
+ return true;
+}
+
+bool EventLogListBuilder::Append(const std::string& value) {
+ DCHECK_NE(static_cast<uint8_t*>(nullptr), payload_.get());
+
+ int len = value.length();
+ if (!IsSpaceAvailable(sizeof(len) + len)) {
+ return false;
+ }
+
+ AppendByte(EVENT_TYPE_STRING);
+ AppendData(&len, sizeof(len));
+ AppendData(value.c_str(), len);
+
+ payload_count_++;
+ return true;
+}
+
+void EventLogListBuilder::Release(std::unique_ptr<uint8_t[]>* log,
+ size_t* size) {
+ // Finalize the log payload.
+ payload_[1] = payload_count_;
+
+ // Return the log payload.
+ *size = payload_size_;
+ *log = std::move(payload_);
+}
+
+void EventLogListBuilder::AppendData(const void* data, size_t size) {
+ DCHECK_LT(payload_size_ + size, MAX_EVENT_PAYLOAD_SIZE);
+ memcpy(&payload_[payload_size_], data, size);
+ payload_size_ += size;
+}
+
+void EventLogListBuilder::AppendByte(uint8_t byte) {
+ DCHECK_LT(payload_size_ + sizeof(byte), MAX_EVENT_PAYLOAD_SIZE);
+ payload_[payload_size_++] = byte;
+}
+
+bool EventLogListBuilder::IsSpaceAvailable(size_t value_size) {
+ size_t space_needed = value_size + EVENT_TYPE_SIZE;
+ if (payload_size_ + space_needed > MAX_EVENT_PAYLOAD_SIZE) {
+ size_t remaining = MAX_EVENT_PAYLOAD_SIZE - payload_size_;
+ LOG(WARNING) << "Not enough space for value. remain=" <<
+ remaining << "; needed=" << space_needed;
+ return false;
+ }
+
+ return true;
+}