cm: add storage interface

Signed-off-by: Mykola Kobets <[email protected]>
Reviewed-by: Mykhailo Lohvynenko <[email protected]>
Reviewed-by: Oleksandr Grytsov <[email protected]>
Reviewed-by: Mykola Solianko <[email protected]>

Author: mykola-kobets-epam

include/aos/cm/storage.hpp

@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2025 EPAM Systems, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef AOS_CM_STORAGE_HPP_
+#define AOS_CM_STORAGE_HPP_
+
+#include <aos/common/types.hpp>
+
+namespace aos::cm::storage {
+
+/** @addtogroup CM Storage
+ *  @{
+ */
+
+/**
+ * Instance state type.
+ */
+class InstanceStateType {
+public:
+    enum class Enum {
+        eActive,
+        eCached,
+        ePending,
+    };
+
+    static const Array<const char* const> GetStrings()
+    {
+        static const char* const sStateStrings[] = {
+            "active",
+            "cached",
+        };
+
+        return Array<const char* const>(sStateStrings, ArraySize(sStateStrings));
+    };
+};
+
+using InstanceStateEnum = InstanceStateType::Enum;
+using InstanceState     = EnumStringer<InstanceStateType>;
+
+/**
+ * Represents information about a service instance.
+ */
+struct InstanceInfo {
+    /**
+     * Instance identifier.
+     */
+    InstanceIdent mInstanceID;
+
+    /**
+     * Node identifier.
+     */
+    StaticString<cNodeIDLen> mNodeID;
+
+    /**
+     * Previous node identifier, it's used for node balancing.
+     */
+    StaticString<cNodeIDLen> mPrevNodeID;
+
+    /**
+     * User ID.
+     */
+    uint32_t mUID = 0;
+
+    /**
+     * Timestamp.
+     */
+    Time mTimestamp;
+
+    /**
+     * Instance state.
+     */
+    InstanceStateType state;
+};
+
+/**
+ * Interface for service instance storage.
+ */
+class StorageItf {
+public:
+    /**
+     * Destructor.
+     */
+    virtual ~StorageItf() = default;
+
+    /**
+     * Adds a new instance to the storage.
+     *
+     * @param info instance information.
+     * @return Error.
+     */
+    virtual Error AddInstance(const InstanceInfo& info) = 0;
+
+    /**
+     * Updates an existing instance in the storage.
+     *
+     * @param info updated instance information.
+     * @return Error.
+     */
+    virtual Error UpdateInstance(const InstanceInfo& info) = 0;
+
+    /**
+     * Removes an instance from the storage.
+     *
+     * @param instanceID instance identifier.
+     * @return Error.
+     */
+    virtual Error RemoveInstance(const InstanceIdent& instanceID) = 0;
+
+    /**
+     * Get information about a stored instance.
+     *
+     * @param instanceID instance identifier.
+     * @param[out] info instance info.
+     * @return Error.
+     */
+    virtual Error GetInstance(const InstanceIdent& instanceID, InstanceInfo& info) const = 0;
+
+    /**
+     * Get all stored instances.
+     *
+     * @param[out] instances all stored instances.
+     * @return Error.
+     */
+    virtual Error GetInstances(Array<InstanceInfo>& instances) const = 0;
+};
+
+/** @}*/
+
+} // namespace aos::cm::storage
+
+#endif