Use and test patch utilities from system/audio.h

Use `audio_patch_is_valid` function.

Add basic tests for the following functions:
  audio_patch_is_valid
  audio_port_config_has_hw_av_sync
  audio_patches_are_equal

Bug: 63901775
Test: systemaudio_tests
Change-Id: I378ab544e4148fda0dd7b9520d6fd57ff01cb34b
diff --git a/services/audiopolicy/tests/systemaudio_tests.cpp b/services/audiopolicy/tests/systemaudio_tests.cpp
new file mode 100644
index 0000000..abaae52
--- /dev/null
+++ b/services/audiopolicy/tests/systemaudio_tests.cpp
@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2018 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 <gtest/gtest.h>
+
+#define LOG_TAG "SysAudio_Test"
+#include <log/log.h>
+#include <media/PatchBuilder.h>
+#include <system/audio.h>
+
+using namespace android;
+
+TEST(SystemAudioTest, PatchInvalid) {
+    audio_patch patch{};
+    ASSERT_FALSE(audio_patch_is_valid(&patch));
+    patch.num_sources = AUDIO_PATCH_PORTS_MAX + 1;
+    patch.num_sinks = 1;
+    ASSERT_FALSE(audio_patch_is_valid(&patch));
+    patch.num_sources = 1;
+    patch.num_sinks = AUDIO_PATCH_PORTS_MAX + 1;
+    ASSERT_FALSE(audio_patch_is_valid(&patch));
+    patch.num_sources = 0;
+    patch.num_sinks = 1;
+    ASSERT_FALSE(audio_patch_is_valid(&patch));
+}
+
+TEST(SystemAudioTest, PatchValid) {
+    const audio_port_config src = {
+        .id = 1, .role = AUDIO_PORT_ROLE_SOURCE, .type = AUDIO_PORT_TYPE_DEVICE };
+    // It's OK not to have sinks.
+    ASSERT_TRUE(audio_patch_is_valid((PatchBuilder{}).addSource(src).patch()));
+    const audio_port_config sink = {
+        .id = 2, .role = AUDIO_PORT_ROLE_SINK, .type = AUDIO_PORT_TYPE_DEVICE };
+    ASSERT_TRUE(audio_patch_is_valid((PatchBuilder{}).addSource(src).addSink(sink).patch()));
+    ASSERT_TRUE(audio_patch_is_valid(
+                    (PatchBuilder{}).addSource(src).addSource(src).addSink(sink).patch()));
+    ASSERT_TRUE(audio_patch_is_valid(
+                    (PatchBuilder{}).addSource(src).addSink(sink).addSink(sink).patch()));
+    ASSERT_TRUE(audio_patch_is_valid(
+                    (PatchBuilder{}).addSource(src).addSource(src).
+                    addSink(sink).addSink(sink).patch()));
+}
+
+TEST(SystemAudioTest, PatchHwAvSync) {
+    audio_port_config device_src_cfg = {
+        .id = 1, .role = AUDIO_PORT_ROLE_SOURCE, .type = AUDIO_PORT_TYPE_DEVICE };
+    ASSERT_FALSE(audio_port_config_has_hw_av_sync(&device_src_cfg));
+    device_src_cfg.config_mask |= AUDIO_PORT_CONFIG_FLAGS;
+    ASSERT_FALSE(audio_port_config_has_hw_av_sync(&device_src_cfg));
+    device_src_cfg.flags.input = AUDIO_INPUT_FLAG_HW_AV_SYNC;
+    ASSERT_TRUE(audio_port_config_has_hw_av_sync(&device_src_cfg));
+
+    audio_port_config device_sink_cfg = {
+        .id = 1, .role = AUDIO_PORT_ROLE_SINK, .type = AUDIO_PORT_TYPE_DEVICE };
+    ASSERT_FALSE(audio_port_config_has_hw_av_sync(&device_sink_cfg));
+    device_sink_cfg.config_mask |= AUDIO_PORT_CONFIG_FLAGS;
+    ASSERT_FALSE(audio_port_config_has_hw_av_sync(&device_sink_cfg));
+    device_sink_cfg.flags.output = AUDIO_OUTPUT_FLAG_HW_AV_SYNC;
+    ASSERT_TRUE(audio_port_config_has_hw_av_sync(&device_sink_cfg));
+
+    audio_port_config mix_sink_cfg = {
+        .id = 1, .role = AUDIO_PORT_ROLE_SINK, .type = AUDIO_PORT_TYPE_MIX };
+    ASSERT_FALSE(audio_port_config_has_hw_av_sync(&mix_sink_cfg));
+    mix_sink_cfg.config_mask |= AUDIO_PORT_CONFIG_FLAGS;
+    ASSERT_FALSE(audio_port_config_has_hw_av_sync(&mix_sink_cfg));
+    mix_sink_cfg.flags.input = AUDIO_INPUT_FLAG_HW_AV_SYNC;
+    ASSERT_TRUE(audio_port_config_has_hw_av_sync(&mix_sink_cfg));
+
+    audio_port_config mix_src_cfg = {
+        .id = 1, .role = AUDIO_PORT_ROLE_SOURCE, .type = AUDIO_PORT_TYPE_MIX };
+    ASSERT_FALSE(audio_port_config_has_hw_av_sync(&mix_src_cfg));
+    mix_src_cfg.config_mask |= AUDIO_PORT_CONFIG_FLAGS;
+    ASSERT_FALSE(audio_port_config_has_hw_av_sync(&mix_src_cfg));
+    mix_src_cfg.flags.output = AUDIO_OUTPUT_FLAG_HW_AV_SYNC;
+    ASSERT_TRUE(audio_port_config_has_hw_av_sync(&mix_src_cfg));
+}
+
+TEST(SystemAudioTest, PatchEqual) {
+    const audio_patch patch1{}, patch2{};
+    // Invalid patches are not equal.
+    ASSERT_FALSE(audio_patches_are_equal(&patch1, &patch2));
+    const audio_port_config src = {
+        .id = 1, .role = AUDIO_PORT_ROLE_SOURCE, .type = AUDIO_PORT_TYPE_DEVICE };
+    const audio_port_config sink = {
+        .id = 2, .role = AUDIO_PORT_ROLE_SINK, .type = AUDIO_PORT_TYPE_DEVICE };
+    ASSERT_FALSE(audio_patches_are_equal(
+                    (PatchBuilder{}).addSource(src).patch(),
+                    (PatchBuilder{}).addSource(src).addSink(sink).patch()));
+    ASSERT_TRUE(audio_patches_are_equal(
+                    (PatchBuilder{}).addSource(src).addSink(sink).patch(),
+                    (PatchBuilder{}).addSource(src).addSink(sink).patch()));
+    ASSERT_FALSE(audio_patches_are_equal(
+                    (PatchBuilder{}).addSource(src).addSink(sink).patch(),
+                    (PatchBuilder{}).addSource(src).addSource(src).addSink(sink).patch()));
+    audio_port_config sink_hw_av_sync = sink;
+    sink_hw_av_sync.config_mask |= AUDIO_PORT_CONFIG_FLAGS;
+    sink_hw_av_sync.flags.output = AUDIO_OUTPUT_FLAG_HW_AV_SYNC;
+    ASSERT_FALSE(audio_patches_are_equal(
+                    (PatchBuilder{}).addSource(src).addSink(sink).patch(),
+                    (PatchBuilder{}).addSource(src).addSink(sink_hw_av_sync).patch()));
+    ASSERT_TRUE(audio_patches_are_equal(
+                    (PatchBuilder{}).addSource(src).addSink(sink_hw_av_sync).patch(),
+                    (PatchBuilder{}).addSource(src).addSink(sink_hw_av_sync).patch()));
+}