sf-latency: Write a benchmark for RenderEngine

Bug: 193240340
Test: mmma -j frameworks/native/libs/renderengine/bench/
      && adb push out/.../librenderengine_bench
                  /data/.../librenderengine_bench
      && adb shell /data/.../librenderengine_bench

Write a benchmark using Google-Benchmark to track the performance of
RenderEngine.

RenderEngineBench.cpp:
- Contains the benchmarks to run.
- Write a helper function that times calls to RenderEngine::drawLayers.
- Write a single benchmark that times drawing a mock homescreen plus a
  blur layer, using a blur radius used in practice.
  Decode the homescreen into a buffer with CPU support, and then copy it
  to one without, which better represents actual use.
- Use RenderEngineType to determine which subclass to benchmark. The
  only existing benchmark uses SKIA_GL, since we intend to time just
  drawLayers, but future benchmarks will want to time threading aspects
  with SKIA_GL_THREADED, and we may add more RenderEngineTypes in the
  future.

Codec.cpp:
- Write methods for decoding and encoding a buffer.

Flags.cpp:
- Extra flags that can be passed to the executable.
- --save allows encoding the result to a file to verify it looks as
  intended.
- parse --help to describe --save and any future flags specific to
  RenderEngineBench.

RenderEngineBench.h:
- header file for methods used across cpp files. Use a single common
  header since otherwise we would have several small headers.

homescreen.png:
- Mock homescreen to draw in drawLayers

Change-Id: I81a1a8a30a1c20985bbf066d2ba4d5f1fd1f6dc3
diff --git a/libs/renderengine/benchmark/Codec.cpp b/libs/renderengine/benchmark/Codec.cpp
new file mode 100644
index 0000000..80e4fc4
--- /dev/null
+++ b/libs/renderengine/benchmark/Codec.cpp
@@ -0,0 +1,136 @@
+/*
+ * Copyright 2021 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 <RenderEngineBench.h>
+#include <android/bitmap.h>
+#include <android/data_space.h>
+#include <android/imagedecoder.h>
+#include <log/log.h>
+#include <renderengine/ExternalTexture.h>
+#include <renderengine/RenderEngine.h>
+#include <sys/types.h>
+
+using namespace android;
+using namespace android::renderengine;
+
+namespace {
+struct DecoderDeleter {
+    void operator()(AImageDecoder* decoder) { AImageDecoder_delete(decoder); }
+};
+
+using AutoDecoderDeleter = std::unique_ptr<AImageDecoder, DecoderDeleter>;
+
+bool ok(int aImageDecoderResult, const char* path, const char* method) {
+    if (aImageDecoderResult == ANDROID_IMAGE_DECODER_SUCCESS) {
+        return true;
+    }
+
+    ALOGE("Failed AImageDecoder_%s on '%s' with error '%s'", method, path,
+          AImageDecoder_resultToString(aImageDecoderResult));
+    return false;
+}
+} // namespace
+
+namespace renderenginebench {
+
+void decode(const char* path, const sp<GraphicBuffer>& buffer) {
+    base::unique_fd fd{open(path, O_RDONLY)};
+    if (fd.get() < 0) {
+        ALOGE("Failed to open %s", path);
+        return;
+    }
+
+    AImageDecoder* decoder{nullptr};
+    auto result = AImageDecoder_createFromFd(fd.get(), &decoder);
+    if (!ok(result, path, "createFromFd")) {
+        return;
+    }
+
+    AutoDecoderDeleter deleter(decoder);
+
+    LOG_ALWAYS_FATAL_IF(buffer->getWidth() <= 0 || buffer->getHeight() <= 0,
+                        "Impossible buffer size!");
+    auto width = static_cast<int32_t>(buffer->getWidth());
+    auto height = static_cast<int32_t>(buffer->getHeight());
+    result = AImageDecoder_setTargetSize(decoder, width, height);
+    if (!ok(result, path, "setTargetSize")) {
+        return;
+    }
+
+    void* pixels{nullptr};
+    int32_t stride{0};
+    if (auto status = buffer->lock(GRALLOC_USAGE_SW_WRITE_OFTEN, &pixels,
+                                   nullptr /*outBytesPerPixel*/, &stride);
+        status < 0) {
+        ALOGE("Failed to lock pixels!");
+        return;
+    }
+
+    result = AImageDecoder_decodeImage(decoder, pixels, static_cast<size_t>(stride),
+                                       static_cast<size_t>(stride * height));
+    if (auto status = buffer->unlock(); status < 0) {
+        ALOGE("Failed to unlock pixels!");
+    }
+
+    // For the side effect of logging.
+    (void)ok(result, path, "decodeImage");
+}
+
+void encodeToJpeg(const char* path, const sp<GraphicBuffer>& buffer) {
+    base::unique_fd fd{open(path, O_WRONLY | O_CREAT, S_IWUSR)};
+    if (fd.get() < 0) {
+        ALOGE("Failed to open %s", path);
+        return;
+    }
+
+    void* pixels{nullptr};
+    int32_t stride{0};
+    if (auto status = buffer->lock(GRALLOC_USAGE_SW_READ_OFTEN, &pixels,
+                                   nullptr /*outBytesPerPixel*/, &stride);
+        status < 0) {
+        ALOGE("Failed to lock pixels!");
+        return;
+    }
+
+    AndroidBitmapInfo info{
+            .width = buffer->getWidth(),
+            .height = buffer->getHeight(),
+            .stride = static_cast<uint32_t>(stride),
+            .format = ANDROID_BITMAP_FORMAT_RGBA_8888,
+            .flags = ANDROID_BITMAP_FLAGS_ALPHA_OPAQUE,
+    };
+    int result = AndroidBitmap_compress(&info, ADATASPACE_SRGB, pixels,
+                                        ANDROID_BITMAP_COMPRESS_FORMAT_JPEG, 80, &fd,
+                                        [](void* fdPtr, const void* data, size_t size) -> bool {
+                                            const ssize_t bytesWritten =
+                                                    write(reinterpret_cast<base::unique_fd*>(fdPtr)
+                                                                  ->get(),
+                                                          data, size);
+                                            return bytesWritten > 0 &&
+                                                    static_cast<size_t>(bytesWritten) == size;
+                                        });
+    if (result == ANDROID_BITMAP_RESULT_SUCCESS) {
+        ALOGD("Successfully encoded to '%s'", path);
+    } else {
+        ALOGE("Failed to encode to %s with error %d", path, result);
+    }
+
+    if (auto status = buffer->unlock(); status < 0) {
+        ALOGE("Failed to unlock pixels!");
+    }
+}
+
+} // namespace renderenginebench