aws_iot_shadow_json_data.h

00001 /*
00002  * Copyright 2010-2015 Amazon.com, Inc. or its affiliates. All Rights Reserved.
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License").
00005  * You may not use this file except in compliance with the License.
00006  * A copy of the License is located at
00007  *
00008  *  http://aws.amazon.com/apache2.0
00009  *
00010  * or in the "license" file accompanying this file. This file is distributed
00011  * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
00012  * express or implied. See the License for the specific language governing
00013  * permissions and limitations under the License.
00014  */
00015 
00016 #ifndef SRC_SHADOW_AWS_IOT_SHADOW_JSON_DATA_H_
00017 #define SRC_SHADOW_AWS_IOT_SHADOW_JSON_DATA_H_
00018 
00019 /**
00020  * @file aws_iot_shadow_json_data.h
00021  * @brief This file is the interface for all the Shadow related JSON functions.
00022  */
00023 
00024 #include <stddef.h>
00025 
00026 /**
00027  * @brief This is a static JSON object that could be used in code
00028  *
00029  */
00030 typedef struct jsonStruct jsonStruct_t;
00031 /**
00032  * @brief Every JSON name value can have a callback. The callback should follow this signature
00033  */
00034 typedef void (*jsonStructCallback_t)(const char *pJsonValueBuffer, uint32_t valueLength, jsonStruct_t *pJsonStruct_t);
00035 
00036 /**
00037  * @brief All the JSON object types enum
00038  *
00039  * JSON number types need to be split into proper integer / floating point data types and sizes on embedded platforms.
00040  */
00041 typedef enum {
00042     SHADOW_JSON_INT32,
00043     SHADOW_JSON_INT16,
00044     SHADOW_JSON_INT8,
00045     SHADOW_JSON_UINT32,
00046     SHADOW_JSON_UINT16,
00047     SHADOW_JSON_UINT8,
00048     SHADOW_JSON_FLOAT,
00049     SHADOW_JSON_DOUBLE,
00050     SHADOW_JSON_BOOL,
00051     SHADOW_JSON_STRING,
00052     SHADOW_JSON_OBJECT
00053 } JsonPrimitiveType;
00054 
00055 /**
00056  * @brief This is the struct form of a JSON Key value pair
00057  */
00058 struct jsonStruct {
00059     const char *pKey; ///< JSON key
00060     void *pData; ///< pointer to the data (JSON value)
00061     JsonPrimitiveType type; ///< type of JSON
00062     jsonStructCallback_t cb; ///< callback to be executed on receiving the Key value pair
00063 };
00064 
00065 /**
00066  * @brief Initialize the JSON document with Shadow expected name/value
00067  *
00068  * This Function will fill the JSON Buffer with a null terminated string. Internally it uses snprintf
00069  * This function should always be used First, followed by iot_shadow_add_reported and/or iot_shadow_add_desired.
00070  * Always finish the call sequence with iot_finalize_json_document
00071  *
00072  * @note Ensure the size of the Buffer is enough to hold the entire JSON Document.
00073  *
00074  *
00075  * @param pJsonDocument The JSON Document filled in this char buffer
00076  * @param maxSizeOfJsonDocument maximum size of the pJsonDocument that can be used to fill the JSON document
00077  * @return An IoT Error Type defining if the buffer was null or the entire string was not filled up
00078  */
00079 IoT_Error_t aws_iot_shadow_init_json_document(char *pJsonDocument, size_t maxSizeOfJsonDocument);
00080 
00081 /**
00082  * @brief Add the reported section of the JSON document of jsonStruct_t
00083  *
00084  * This is a variadic function and please be careful with the usage. count is the number of jsonStruct_t types that you would like to add in the reported section
00085  * This function will add "reported":{<all the values that needs to be added>}
00086  *
00087  * @note Ensure the size of the Buffer is enough to hold the reported section + the init section. Always use the same JSON document buffer used in the iot_shadow_init_json_document function. This function will accommodate the size of previous null terminated string, so pass teh max size of the buffer
00088  *
00089  *
00090  * @param pJsonDocument The JSON Document filled in this char buffer
00091  * @param maxSizeOfJsonDocument maximum size of the pJsonDocument that can be used to fill the JSON document
00092  * @param count total number of arguments(jsonStruct_t object) passed in the arguments
00093  * @return An IoT Error Type defining if the buffer was null or the entire string was not filled up
00094  */
00095 IoT_Error_t aws_iot_shadow_add_reported(char *pJsonDocument, size_t maxSizeOfJsonDocument, uint8_t count, ...);
00096 
00097 /**
00098  * @brief Add the desired section of the JSON document of jsonStruct_t
00099  *
00100  * This is a variadic function and please be careful with the usage. count is the number of jsonStruct_t types that you would like to add in the reported section
00101  * This function will add "desired":{<all the values that needs to be added>}
00102  *
00103  * @note Ensure the size of the Buffer is enough to hold the reported section + the init section. Always use the same JSON document buffer used in the iot_shadow_init_json_document function. This function will accommodate the size of previous null terminated string, so pass the max size of the buffer
00104  *
00105  *
00106  * @param pJsonDocument The JSON Document filled in this char buffer
00107  * @param maxSizeOfJsonDocument maximum size of the pJsonDocument that can be used to fill the JSON document
00108  * @param count total number of arguments(jsonStruct_t object) passed in the arguments
00109  * @return An IoT Error Type defining if the buffer was null or the entire string was not filled up
00110  */
00111 IoT_Error_t aws_iot_shadow_add_desired(char *pJsonDocument, size_t maxSizeOfJsonDocument, uint8_t count, ...);
00112 
00113 /**
00114  * @brief Finalize the JSON document with Shadow expected client Token.
00115  *
00116  * This function will automatically increment the client token every time this function is called.
00117  *
00118  * @note Ensure the size of the Buffer is enough to hold the entire JSON Document. If the finalized section is not invoked then the JSON doucment will not be valid
00119  *
00120  *
00121  * @param pJsonDocument The JSON Document filled in this char buffer
00122  * @param maxSizeOfJsonDocument maximum size of the pJsonDocument that can be used to fill the JSON document
00123  * @return An IoT Error Type defining if the buffer was null or the entire string was not filled up
00124  */
00125 IoT_Error_t aws_iot_finalize_json_document(char *pJsonDocument, size_t maxSizeOfJsonDocument);
00126 
00127 /**
00128  * @brief Fill the given buffer with client token for tracking the Repsonse.
00129  *
00130  * This function will add the AWS_IOT_MQTT_CLIENT_ID with a sequence number. Every time this function is used the sequence number gets incremented
00131  *
00132  *
00133  * @param pBufferToBeUpdatedWithClientToken buffer to be updated with the client token string
00134  * @param maxSizeOfJsonDocument maximum size of the pBufferToBeUpdatedWithClientToken that can be used
00135  * @return An IoT Error Type defining if the buffer was null or the entire string was not filled up
00136  */
00137 
00138 IoT_Error_t aws_iot_fill_with_client_token(char *pBufferToBeUpdatedWithClientToken, size_t maxSizeOfJsonDocument);
00139 
00140 #endif /* SRC_SHADOW_AWS_IOT_SHADOW_JSON_DATA_H_ */
00141