Implement audio devices and streams HAL delegating to legacy HAL

Changes made to the .hal definition:

  - introduce Effect ID returned by the IEffectsFactory that
    needs to be passed to IStream.{add|remove}Effect; otherwise
    it's impossible to retrieve the underlying HAL effect handle;

  - change "bus address" in DeviceAddress to "string" type;

  - fix signature of some methods w.r.t. returning Result;

  - remove unused "struct AudioPatch".

Bug: 30222631
Test: make
Change-Id: Icb51729ef57bb2a5b0b78609735e7481bc04f95c
diff --git a/audio/common/2.0/default/EffectMap.h b/audio/common/2.0/default/EffectMap.h
new file mode 100644
index 0000000..82bbb1f
--- /dev/null
+++ b/audio/common/2.0/default/EffectMap.h
@@ -0,0 +1,46 @@
+/*
+ * 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.
+ */
+
+#ifndef android_hardware_audio_V2_0_EffectMap_H_
+#define android_hardware_audio_V2_0_EffectMap_H_
+
+#include <mutex>
+
+#include <hardware/audio_effect.h>
+#include <utils/KeyedVector.h>
+#include <utils/Singleton.h>
+
+namespace android {
+
+// This class needs to be in 'android' ns because Singleton macros require that.
+class EffectMap : public Singleton<EffectMap> {
+  public:
+    static const uint64_t INVALID_ID;
+
+    uint64_t add(effect_handle_t handle);
+    effect_handle_t get(const uint64_t& id);
+    void remove(effect_handle_t handle);
+
+  private:
+    static uint64_t makeUniqueId();
+
+    std::mutex mLock;
+    KeyedVector<uint64_t, effect_handle_t> mEffects;
+};
+
+}  // namespace android
+
+#endif  // android_hardware_audio_V2_0_EffectMap_H_