SF: Introduce LayerTraceGenerator

Generates layer traces from transaction traces. The tool is a custom
surface flinger build that mocks out most everything else apart from
the front end logic. Transaction traces are written when the
transaction is applied, along with a timestamp and vsync id. The
transactions are parsed from proto, and applied to recreate the
layer state and output the result into a layer trace.

Test: presubmit
Bug: 200284593

Change-Id: If90a23b9310dbafbdca597b7f5178e40c8b86022
diff --git a/services/surfaceflinger/Tracing/tools/main.cpp b/services/surfaceflinger/Tracing/tools/main.cpp
new file mode 100644
index 0000000..f3cf42d
--- /dev/null
+++ b/services/surfaceflinger/Tracing/tools/main.cpp
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2022 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.
+ */
+
+#undef LOG_TAG
+#define LOG_TAG "LayerTraceGenerator"
+
+#include <fstream>
+#include <iostream>
+#include <string>
+
+#include "LayerTraceGenerator.h"
+
+using namespace android;
+
+int main(int argc, char** argv) {
+    if (argc > 3) {
+        std::cout << "Usage: " << argv[0]
+                  << " [transaction-trace-path] [output-layers-trace-path]\n";
+        return -1;
+    }
+
+    const char* transactionTracePath =
+            (argc > 1) ? argv[1] : "/data/misc/wmtrace/transactions_trace.winscope";
+    std::cout << "Parsing " << transactionTracePath << "\n";
+    std::fstream input(transactionTracePath, std::ios::in | std::ios::binary);
+    if (!input) {
+        std::cout << "Error: Could not open " << transactionTracePath;
+        return -1;
+    }
+
+    proto::TransactionTraceFile transactionTraceFile;
+    if (!transactionTraceFile.ParseFromIstream(&input)) {
+        std::cout << "Error: Failed to parse " << transactionTracePath;
+        return -1;
+    }
+
+    const char* outputLayersTracePath =
+            (argc == 3) ? argv[2] : "/data/misc/wmtrace/layers_trace.winscope";
+    ;
+    ALOGD("Generating %s...", outputLayersTracePath);
+    std::cout << "Generating " << outputLayersTracePath << "\n";
+    if (!LayerTraceGenerator().generate(transactionTraceFile, outputLayersTracePath)) {
+        std::cout << "Error: Failed to generate layers trace " << outputLayersTracePath;
+        return -1;
+    }
+    return 0;
+}
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