Adding KVStore api from mbedos: interface

Author: andreagilardoni

libraries/KVStore/KVStore.h

@@ -0,0 +1,230 @@
+/*
+ * Copyright (c) 2018 ARM Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ * 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 MBED_KVSTORE_H
+#define MBED_KVSTORE_H
+
+#include <stdint.h>
+#include <string.h>
+
+// FIXME define mbed errors adequately
+#define KVSTORE_SUCCESS                        0
+#define KVSTORE_ERROR_READ_FAILED              283
+#define KVSTORE_ERROR_WRITE_FAILED             284
+#define KVSTORE_ERROR_INVALID_DATA_DETECTED    258
+#define KVSTORE_ERROR_INVALID_SIZE             261
+#define KVSTORE_ERROR_INVALID_ARGUMENT         257
+#define KVSTORE_ERROR_ITEM_NOT_FOUND           263
+#define KVSTORE_ERROR_MEDIA_FULL               267
+#define KVSTORE_ERROR_WRITE_PROTECTED          274
+#define KVSTORE_ERROR_OUT_OF_RESOURCES         288
+#define KVSTORE_ERROR_NOT_READY                270
+#define KVSTORE_ERROR_FAILED_OPERATION         271
+
+namespace mbed {
+
+/** KVStore class
+ *
+ *  Interface class for Key Value Storage
+ */
+class KVStore {
+public:
+    enum create_flags {
+        WRITE_ONCE_FLAG                     = (1 << 0),
+        REQUIRE_CONFIDENTIALITY_FLAG        = (1 << 1),
+        RESERVED_FLAG                       = (1 << 2),
+        REQUIRE_REPLAY_PROTECTION_FLAG      = (1 << 3),
+    };
+
+    static const uint32_t MAX_KEY_SIZE = 128;
+
+    typedef struct _opaque_set_handle *set_handle_t;
+
+    typedef struct _opaque_key_iterator *iterator_t;
+
+    /**
+     * Holds key information
+     */
+    typedef struct info {
+        /**
+         * The key size
+         */
+        size_t size;
+        /*
+         * The Key flags, possible flags combination:
+         * WRITE_ONCE_FLAG,
+         * REQUIRE_CONFIDENTIALITY_FLAG,
+         * REQUIRE_REPLAY_PROTECTION_FLAG
+         */
+        uint32_t flags;
+    } info_t;
+
+    virtual ~KVStore() {};
+
+    /**
+     * @brief Initialize KVStore
+     *
+     * @returns KVSTORE_SUCCESS on success or an error code on failure
+     */
+    virtual int init() = 0;
+
+    /**
+     * @brief Deinitialize KVStore
+     *
+     * @returns KVSTORE_SUCCESS on success or an error code on failure
+     */
+    virtual int deinit() = 0;
+
+
+    /**
+     * @brief Reset KVStore contents (clear all keys)
+     *
+     * @returns KVSTORE_SUCCESS on success or an error code on failure
+     */
+    virtual int reset() = 0;
+
+    /**
+     * @brief Set one KVStore item, given key and value.
+     *
+     * @param[in]  key                  Key - must not include '*' '/' '?' ':' ';' '\' '"' '|' ' ' '<' '>' '\'.
+     * @param[in]  buffer               Value data buffer.
+     * @param[in]  size                 Value data size.
+     * @param[in]  create_flags         Flag mask.
+     *
+     * @returns KVSTORE_SUCCESS on success or an error code on failure
+     */
+    virtual int set(const char *key, const void *buffer, size_t size, uint32_t create_flags) = 0;
+
+    /**
+     * @brief Get one KVStore item, given key.
+     *
+     * @param[in]  key                  Key - must not include '*' '/' '?' ':' ';' '\' '"' '|' ' ' '<' '>' '\'.
+     * @param[in]  buffer               Value data buffer.
+     * @param[in]  buffer_size          Value data buffer size.
+     * @param[out] actual_size          Actual read size (NULL to pass nothing).
+     * @param[in]  offset               Offset to read from in data.
+     *
+     * @returns KVSTORE_SUCCESS on success or an error code on failure
+     */
+    virtual int get(const char *key, void *buffer, size_t buffer_size, size_t *actual_size = NULL, size_t offset = 0) = 0;
+
+    /**
+     * @brief Get information of a given key.
+     *
+     * @param[in]  key                  Key - must not include '*' '/' '?' ':' ';' '\' '"' '|' ' ' '<' '>' '\'.
+     * @param[out] info                 Returned information structure (NULL to pass nothing).
+     *
+     * @returns KVSTORE_SUCCESS on success or an error code on failure
+     */
+    virtual int get_info(const char *key, info_t *info = NULL) = 0;
+
+    /**
+     * @brief Remove a KVStore item, given key.
+     *
+     * @param[in]  key                  Key - must not include '*' '/' '?' ':' ';' '\' '"' '|' ' ' '<' '>' '\'.
+     *
+     * @returns KVSTORE_SUCCESS on success or an error code on failure
+     */
+    virtual int remove(const char *key) = 0;
+
+
+    /**
+     * @brief Start an incremental KVStore set sequence.
+     *
+     * @param[out] handle               Returned incremental set handle.
+     * @param[in]  key                  Key - must not include '*' '/' '?' ':' ';' '\' '"' '|' ' ' '<' '>' '\'.
+     * @param[in]  final_data_size      Final value data size.
+     * @param[in]  create_flags         Flag mask.
+     *
+     * @returns KVSTORE_SUCCESS on success or an error code on failure
+     */
+    virtual int set_start(set_handle_t *handle, const char *key, size_t final_data_size, uint32_t create_flags) = 0;
+
+    /**
+     * @brief Add data to incremental KVStore set sequence.
+     *
+     * @param[in]  handle               Incremental set handle.
+     * @param[in]  value_data           Value data to add.
+     * @param[in]  data_size            Value data size.
+     *
+     * @returns KVSTORE_SUCCESS on success or an error code on failure
+     */
+    virtual int set_add_data(set_handle_t handle, const void *value_data, size_t data_size) = 0;
+
+    /**
+     * @brief Finalize an incremental KVStore set sequence.
+     *
+     * @param[in]  handle               Incremental set handle.
+     *
+     * @returns KVSTORE_SUCCESS on success or an error code on failure
+     */
+    virtual int set_finalize(set_handle_t handle) = 0;
+
+    /**
+     * @brief Start an iteration over KVStore keys.
+     *
+     * @param[out] it                   Returned iterator handle.
+     * @param[in]  prefix               Key prefix (null for all keys).
+     *
+     * @returns KVSTORE_SUCCESS on success or an error code on failure
+     */
+    virtual int iterator_open(iterator_t *it, const char *prefix = NULL) = 0;
+
+    /**
+     * @brief Get next key in iteration.
+     *
+     * @param[in]  it                   Iterator handle.
+     * @param[in]  key                  Buffer for returned key.
+     * @param[in]  key_size             Key buffer size.
+     *
+     * @returns KVSTORE_SUCCESS on success or an error code on failure
+     */
+    virtual int iterator_next(iterator_t it, char *key, size_t key_size) = 0;
+
+    /**
+     * @brief Close iteration.
+     *
+     * @param[in]  it                   Iterator handle.
+     *
+     * @returns KVSTORE_SUCCESS on success or an error code on failure
+     */
+    virtual int iterator_close(iterator_t it) = 0;
+
+    /** Convenience function for checking key validity.
+     *  Key must not include '*' '/' '?' ':' ';' '\' '"' '|' ' ' '<' '>' '\'.
+     *
+     * @param[in]  key                  Key buffer.
+     *
+     * @returns KVSTORE_SUCCESS on success or an error code on failure
+     */
+    bool is_valid_key(const char *key) const
+    {
+        if (!key || !strlen(key) || (strlen(key) > MAX_KEY_SIZE)) {
+            return false;
+        }
+
+        if (strpbrk(key, " */?:;\"|<>\\")) {
+            return false;
+        }
+        return true;
+    }
+
+};
+/** @}*/
+
+} // namespace mbed
+
+#endif