audio: Generalize stream implementations

This allows for more code reuse and composability when
implementing streams for a particular audio "backend."

The existing "stub" code has been moved to StreamStub* files.

Bug: 264712385
Test: atest VtsHalAudioCoreTargetTest
Change-Id: I97fd41f87eb6d01e1d57f0d70a86d3b2b3555837
diff --git a/audio/aidl/default/StreamStub.cpp b/audio/aidl/default/StreamStub.cpp
new file mode 100644
index 0000000..5442179
--- /dev/null
+++ b/audio/aidl/default/StreamStub.cpp
@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#define LOG_TAG "AHAL_Stream"
+#include <android-base/logging.h>
+
+#include "core-impl/Module.h"
+#include "core-impl/StreamStub.h"
+
+using aidl::android::hardware::audio::common::SinkMetadata;
+using aidl::android::hardware::audio::common::SourceMetadata;
+using aidl::android::media::audio::common::AudioOffloadInfo;
+
+namespace aidl::android::hardware::audio::core {
+
+DriverStub::DriverStub(const StreamContext& context, bool isInput)
+    : mFrameSizeBytes(context.getFrameSize()), mIsInput(isInput) {}
+
+::android::status_t DriverStub::init() {
+    usleep(1000);
+    return ::android::OK;
+}
+
+::android::status_t DriverStub::drain(StreamDescriptor::DrainMode) {
+    usleep(1000);
+    return ::android::OK;
+}
+
+::android::status_t DriverStub::flush() {
+    usleep(1000);
+    return ::android::OK;
+}
+
+::android::status_t DriverStub::pause() {
+    usleep(1000);
+    return ::android::OK;
+}
+
+::android::status_t DriverStub::transfer(void* buffer, size_t frameCount, size_t* actualFrameCount,
+                                         int32_t* latencyMs) {
+    usleep(3000);
+    if (mIsInput) {
+        uint8_t* byteBuffer = static_cast<uint8_t*>(buffer);
+        for (size_t i = 0; i < frameCount * mFrameSizeBytes; ++i) {
+            byteBuffer[i] = std::rand() % 255;
+        }
+    }
+    *actualFrameCount = frameCount;
+    *latencyMs = Module::kLatencyMs;
+    return ::android::OK;
+}
+
+::android::status_t DriverStub::standby() {
+    usleep(1000);
+    return ::android::OK;
+}
+
+// static
+ndk::ScopedAStatus StreamInStub::createInstance(const SinkMetadata& sinkMetadata,
+                                                StreamContext&& context,
+                                                const std::vector<MicrophoneInfo>& microphones,
+                                                std::shared_ptr<StreamIn>* result) {
+    std::shared_ptr<StreamIn> stream =
+            ndk::SharedRefBase::make<StreamInStub>(sinkMetadata, std::move(context), microphones);
+    if (auto status = initInstance(stream); !status.isOk()) {
+        return status;
+    }
+    *result = std::move(stream);
+    return ndk::ScopedAStatus::ok();
+}
+
+StreamInStub::StreamInStub(const SinkMetadata& sinkMetadata, StreamContext&& context,
+                           const std::vector<MicrophoneInfo>& microphones)
+    : StreamIn(
+              sinkMetadata, std::move(context),
+              [](const StreamContext& ctx) -> DriverInterface* {
+                  return new DriverStub(ctx, true /*isInput*/);
+              },
+              [](const StreamContext& ctx, DriverInterface* driver) -> StreamWorkerInterface* {
+                  // The default worker implementation is used.
+                  return new StreamInWorker(ctx, driver);
+              },
+              microphones) {}
+
+// static
+ndk::ScopedAStatus StreamOutStub::createInstance(const SourceMetadata& sourceMetadata,
+                                                 StreamContext&& context,
+                                                 const std::optional<AudioOffloadInfo>& offloadInfo,
+                                                 std::shared_ptr<StreamOut>* result) {
+    std::shared_ptr<StreamOut> stream = ndk::SharedRefBase::make<StreamOutStub>(
+            sourceMetadata, std::move(context), offloadInfo);
+    if (auto status = initInstance(stream); !status.isOk()) {
+        return status;
+    }
+    *result = std::move(stream);
+    return ndk::ScopedAStatus::ok();
+}
+
+StreamOutStub::StreamOutStub(const SourceMetadata& sourceMetadata, StreamContext&& context,
+                             const std::optional<AudioOffloadInfo>& offloadInfo)
+    : StreamOut(
+              sourceMetadata, std::move(context),
+              [](const StreamContext& ctx) -> DriverInterface* {
+                  return new DriverStub(ctx, false /*isInput*/);
+              },
+              [](const StreamContext& ctx, DriverInterface* driver) -> StreamWorkerInterface* {
+                  // The default worker implementation is used.
+                  return new StreamOutWorker(ctx, driver);
+              },
+              offloadInfo) {}
+
+}  // namespace aidl::android::hardware::audio::core