libaudiohal: Implement simple HIDL client

This client requires both HIDL client and server to be of the same
ABI version (e.g. 32-bit).

EffectHalHidl::process and EffectHalHidl::processReverse are stubs.

Some extra warnings are logged due to unimplemented functions
in the legacy HAL.

Bug: 30222631
Change-Id: Id074131dec6d6c4f1031695abcf3ea066e92a5af
Test: Play Music (play / EQ), YouTube, Loopback RTLT, Ok Google on N5X
diff --git a/media/libaudiohal/ConversionHelperHidl.cpp b/media/libaudiohal/ConversionHelperHidl.cpp
new file mode 100644
index 0000000..ebbc02c
--- /dev/null
+++ b/media/libaudiohal/ConversionHelperHidl.cpp
@@ -0,0 +1,99 @@
+/*
+ * 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.
+ */
+
+#include <string.h>
+
+#define LOG_TAG "HalHidl"
+#include <media/AudioParameter.h>
+#include <utils/Log.h>
+
+#include "ConversionHelperHidl.h"
+
+using ::android::hardware::audio::V2_0::Result;
+
+namespace android {
+
+// static
+status_t ConversionHelperHidl::keysFromHal(const String8& keys, hidl_vec<hidl_string> *hidlKeys) {
+    AudioParameter halKeys(keys);
+    if (halKeys.size() == 0) return BAD_VALUE;
+    hidlKeys->resize(halKeys.size());
+    for (size_t i = 0; i < halKeys.size(); ++i) {
+        String8 key;
+        status_t status = halKeys.getAt(i, key);
+        if (status != OK) return status;
+        (*hidlKeys)[i] = key.string();
+    }
+    return OK;
+}
+
+// static
+status_t ConversionHelperHidl::parametersFromHal(
+        const String8& kvPairs, hidl_vec<ParameterValue> *hidlParams) {
+    AudioParameter params(kvPairs);
+    if (params.size() == 0) return BAD_VALUE;
+    hidlParams->resize(params.size());
+    for (size_t i = 0; i < params.size(); ++i) {
+        String8 key, value;
+        status_t status = params.getAt(i, key, value);
+        if (status != OK) return status;
+        (*hidlParams)[i].key = key.string();
+        (*hidlParams)[i].value = value.string();
+    }
+    return OK;
+}
+
+// static
+void ConversionHelperHidl::parametersToHal(
+        const hidl_vec<ParameterValue>& parameters, String8 *values) {
+    AudioParameter params;
+    for (size_t i = 0; i < parameters.size(); ++i) {
+        params.add(String8(parameters[i].key.c_str()), String8(parameters[i].value.c_str()));
+    }
+    values->setTo(params.toString());
+}
+
+ConversionHelperHidl::ConversionHelperHidl(const char* className)
+        : mClassName(className) {
+}
+
+// static
+status_t ConversionHelperHidl::analyzeResult(const Result& result) {
+    switch (result) {
+        case Result::OK: return OK;
+        case Result::INVALID_ARGUMENTS: return BAD_VALUE;
+        case Result::INVALID_STATE: return NOT_ENOUGH_DATA;
+        case Result::NOT_INITIALIZED: return NO_INIT;
+        case Result::NOT_SUPPORTED: return INVALID_OPERATION;
+        default: return NO_INIT;
+    }
+}
+
+status_t ConversionHelperHidl::processReturn(const char* funcName, const Status& status) {
+    const status_t st = status.transactionError();
+    ALOGE_IF(st, "%s %p %s: %s (from rpc)", mClassName, this, funcName, strerror(-st));
+    return st;
+}
+
+status_t ConversionHelperHidl::processReturn(
+        const char* funcName, const Status& status, hardware::audio::V2_0::Result retval) {
+    const status_t st = status.isOk() ? analyzeResult(retval) : status.transactionError();
+    ALOGE_IF(st, "%s %p %s: %s (from %s)",
+            mClassName, this, funcName, strerror(-st), status.isOk() ? "hal" : "rpc");
+    return st;
+}
+
+}  // namespace android