recovery: Implement a volume manager

This is a copy of the pre-binderized vold which has been converted to
use direct calls instead of sockets and stripped down to only what is
needed to support recovery.

Change-Id: Ic82d929e052b5ba70ecf7b475e0a223d77d9687e
diff --git a/volclient.cpp b/volclient.cpp
new file mode 100644
index 0000000..7399b7f
--- /dev/null
+++ b/volclient.cpp
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2019 The LineageOS 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 "volclient.h"
+#include "volume_manager/ResponseCode.h"
+
+void VolumeClient::handleEvent(int code, const std::vector<std::string>& argv) {
+  // This client is only interested in volume addition/deletion
+  if (code != ResponseCode::VolumeDestroyed &&
+      code != ResponseCode::DiskScanned)
+    return;
+
+  printf("VolumeClient::handleEvent: code=%d, argv=<", code);
+  for (auto& arg : argv) {
+    printf("%s,", arg.c_str());
+  }
+  printf(">\n");
+
+  mDevice->handleVolumeChanged();
+}