The KPN SenML library helps you create and parse senml documents in both json and cbor format. The library can be used for sending sensor data and receiving actuator commands.
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senml_pack.h
- Committer:
- kpniot
- Date:
- 2018-05-27
- Revision:
- 2:9b44be6e79ac
- Parent:
- 0:a9259748d982
File content as of revision 2:9b44be6e79ac:
/* _ __ ____ _ _ * | |/ / | _ \ | \ | | * | ' / | |_) | | \| | * | . \ | __/ | |\ | * |_|\_\ |_| |_| \_| * * (c) 2018 KPN * License: MIT License. * Author: Jan Bogaerts * * pack (document) without base values headers */ #ifndef SENMLPACK #define SENMLPACK #ifdef __MBED__ #include "mbed.h" #include <string> using namespace std; #define String string #endif #include <senml_base.h> #define PACK_ACTUATOR_SIGNATURE void (*callback)(const char*, const char*, const void*, int, SenMLDataType) /** * SenMLPack represents a single senml document that can be sent or received. * * A senmlPack object has SenMLRecords and/or other SenMLPack objects as children. These * represent the data that the object contains. * A SenMLRecord represents a single value, while child SenMLPacks represent data of other * devices. When a SenMLPack contains other SenMLPack objects, the root object represents a * gateway. * * A SenMLPack object is able to render and parse the data to/from a json string or to/from binary * CBOR data. Both rendering and parsing can be done either directly from a stream (like an UART * connected to a modem), or from a memory buffer. * Rendering to and parsing from a stream is useful for devices that have extreme low memory available. * Almost no buffers are used in this case. Error handling is limited in this case though. * The parser and generator are able to render in the native format (strings for json, binary data for * cbor) and as a hex string. This is especially useful when directly working on a stream: some modems * (ex lora) accept instructions with data in HEX format. * * example: * * @code * #include <kpn_senml.h> * * SenMLPack doc("device_name"); * * void setup(){ * Serial.begin(57600); * senMLSetLogger(&Serial); * delay(1000); * Serial.println("start"); * } * void loop(){ * int val = 10; //just give it some value * SenMLFloatRecord rec("temp", SENML_UNIT_DEGREES_CELSIUS, val); * doc.add(&rec); * doc.toJson(&Serial); //as text * Serial.println(); * doc.toJson(&Serial, SENML_HEX); //in hex format (often used in communication with lora modems) * Serial.println(); * delay(1000); * } * @endcode * */ class SenMLPack: public SenMLBase { friend class SenMLJsonListener; friend class SenMLCborParser; friend class SenMLBase; public: /** * create a SenMLPack object. */ SenMLPack(): _bu(SENML_UNIT_NONE), _bt(NAN), _end(NULL) {}; /** * create a SenMLPack object. * @param baseName the string that will be prepended to all records in this pack. * Is used to represent the name of the device. */ SenMLPack(const char* baseName): _bn(baseName), //mbed compiler doesnt support delegating constructors _bu(SENML_UNIT_NONE), _bt(NAN), _end(NULL) {}; /** * create a SenMLPack object. * @param baseName the string that will be prepended to all records in this pack. * Is used to represent the name of the device. * @param baseUnit the unit name that will be used by default if the record doesnt * not define one. */ SenMLPack(const char* baseName, SenMLUnit baseUnit): _bn(baseName), _bu(baseUnit), _bt(NAN), _end(NULL) {}; /** * create a SenMLPack object. * @param baseName the string that will be prepended to all records in this pack. * Is used to represent the name of the device. * @param baseUnit the unit name that will be used by default if the record doesnt * not define one. * @param baseTime the time that will be added to each record. When specified, each * record that does not specify a time, will receive this time. When * the record does have a time, the baseTime of the pack is added to it, * so the time of the record becomes relative to that of the pack. */ SenMLPack(const char* baseName, SenMLUnit baseUnit, double baseTime): _bn(baseName), _bu(baseUnit), _bt(baseTime), _end(NULL) {}; /** * create a SenMLPack object. * @param callback a function that will be called while parsing incomming data, when no * record can be found that matches any of the defined ones in the object. * The parameters of the callback must be: * const char* packName the name of the pack that the record belongs to. * The data is for a child SenMLPack when this * field is different then the name of the root pack. * const char* recordName the name of the record * const void* value a pointer to the memory blob that contains the actual value. * int size the size of the memory blobl * SenMLDataType dataType: defines how to interprete the memory blob (ex: pointer to integer,..) */ SenMLPack(PACK_ACTUATOR_SIGNATURE): _bn(""), _bu(SENML_UNIT_NONE), _bt(NAN), _end(NULL), callback(callback) {}; /** * create a SenMLPack object. * @param baseName the string that will be prepended to all records in this pack. * Is used to represent the name of the device. * @param callback a function that will be called while parsing incomming data, when no * record can be found that matches any of the defined ones in the object. * The parameters of the callback must be: * const char* packName the name of the pack that the record belongs to. * The data is for a child SenMLPack when this * field is different then the name of the root pack. * const char* recordName the name of the record * const void* value a pointer to the memory blob that contains the actual value. * int size the size of the memory blobl * SenMLDataType dataType: defines how to interprete the memory blob (ex: pointer to integer,..) */ SenMLPack(const char* baseName, PACK_ACTUATOR_SIGNATURE): _bn(baseName), _bu(SENML_UNIT_NONE), _bt(NAN), _end(NULL), callback(callback) {}; /** * create a SenMLPack object. * @param baseName the string that will be prepended to all records in this pack. * Is used to represent the name of the device. * @param baseUnit the unit name that will be used by default if the record doesnt * not define one. * @param callback a function that will be called while parsing incomming data, when no * record can be found that matches any of the defined ones in the object. * The parameters of the callback must be: * const char* packName the name of the pack that the record belongs to. * The data is for a child SenMLPack when this * field is different then the name of the root pack. * const char* recordName the name of the record * const void* value a pointer to the memory blob that contains the actual value. * int size the size of the memory blobl * SenMLDataType dataType: defines how to interprete the memory blob (ex: pointer to integer,..) */ SenMLPack(const char* baseName, SenMLUnit baseUnit, PACK_ACTUATOR_SIGNATURE): _bn(baseName), _bu(baseUnit), _bt(NAN), _end(NULL), callback(callback) {}; /** * create a SenMLPack object. * @param baseName the string that will be prepended to all records in this pack. * Is used to represent the name of the device. * @param baseUnit the unit name that will be used by default if the record doesnt * not define one. * @param baseTime the time that will be added to each record. When specified, each * record that does not specify a time, will receive this time. When * the record does have a time, the baseTime of the pack is added to it, * so the time of the record becomes relative to that of the pack. * @param callback a function that will be called while parsing incomming data, when no * record can be found that matches any of the defined ones in the object. * The parameters of the callback must be: * const char* packName the name of the pack that the record belongs to. * The data is for a child SenMLPack when this * field is different then the name of the root pack. * const char* recordName the name of the record * const void* value a pointer to the memory blob that contains the actual value. * int size the size of the memory blobl * SenMLDataType dataType: defines how to interprete the memory blob (ex: pointer to integer,..) */ SenMLPack(const char* baseName, SenMLUnit baseUnit, double baseTime, PACK_ACTUATOR_SIGNATURE): _bn(baseName), _bu(baseUnit), _bt(baseTime), _end(NULL), callback(callback) {}; /** * destroys the SenMLPack object. */ ~SenMLPack(){}; /** * render the content of the current object to json data (string). * This function is ideal for devices with low memory usage but offers less control over the rendering process. * @param dest the destination stream to where the data will be rendered without buffering it in memory * @param format determins how the data will be rendered. See SenMLStreamMethod for possible methods. * @returns none */ void toJson(Stream* dest, SenMLStreamMethod format=SENML_RAW); /** * render the content of the current object to json data (string). * This function renders the data to a memory buffer. If the buffer is full before the entire object is * rendered, an error will be written to the debug stream. * @param dest a memory buffer to which the data will be rendred. * @param length the length of the memory buffer. * @param format determins how the data will be rendered. See SenMLStreamMethod for possible methods. * @returns none */ void toJson(char *dest, int length, SenMLStreamMethod format=SENML_RAW); /** * render the content of the current object to cbor data (binary). * This function is ideal for devices with low memory usage but offers less control over the rendering process. * @param dest the destination stream to where the data will be rendered without buffering it in memory * @param format determins how the data will be rendered. See SenMLStreamMethod for possible methods. * @returns nr of bytes that were rendered */ int toCbor(Stream* dest, SenMLStreamMethod format=SENML_RAW); /** * render the content of the current object to cbor data (binary). * This function renders the data to a memory buffer. If the buffer is full before the entire object is * rendered, an error will be written to the debug stream. * @param dest a memory buffer to which the data will be rendred. * @param length the length of the memory buffer. * @param format determins how the data will be rendered. See SenMLStreamMethod for possible methods. * @returns nr of bytes that were rendered */ int toCbor(char *dest, int length, SenMLStreamMethod format=SENML_RAW); /** * read and parse a senml json string from the specified source and, for each registered actuator, call the * appropriate event on the actuator itself, for others, the callback function PACK_ACTUATOR_SIGNATURE * will be called, if present. * This method is ideal for devices with very littel ram memory. It will block on most devices if there is * no more input to be read from the stream and the end of the json structure is not yet reached. * Note: on mbed systems, the blocking nature is not garanteed. Instead, if no more data is available before * the end is reached, parsing will fail. * @param source the source stream to read the data from. * @param format determins how the data will be read (ex: as normal text or in HEX format). * See SenMLStreamMethod for possible methods. * @returns none */ void fromJson(Stream* source, SenMLStreamMethod format=SENML_RAW); /** * parse a senml json string from the specified source and, for each registered actuator, call the * appropriate event on the actuator itself, for others, the callback function PACK_ACTUATOR_SIGNATURE * will be called, if present. * This method takes a string stored in memory as input. The json must be fully defined. It is up to the * caller to transform it to a regular text string, if needed (ex: lora devices might send it in hex format). * @param source the source string to use as input. This must be null terminated. * @returns none */ void fromJson(const char* source); /** * read and parse senml cbor from the specified source and, for each registered actuator, call the * appropriate event on the actuator itself, for others, the callback function PACK_ACTUATOR_SIGNATURE * will be called, if present. * This method is ideal for devices with very littel ram memory. It will block on most decices if there is no * more input to be read from the stream and the end of the cbor structure is not yet reached. * Note: on mbed systems, the blocking nature is not garanteed. Instead, if no more data is available before * the end is reached, parsing will fail. * @param source the source stream to read the data from. * @param format determins how the data will be read (ex: as normal binary or in HEX format). * See SenMLStreamMethod for possible methods. * @returns none */ void fromCbor(Stream* source, SenMLStreamMethod format=SENML_RAW); /** * parse senml cbor from the specified memory and, for each registered actuator, call the * appropriate event on the actuator itself, for others, the callback function PACK_ACTUATOR_SIGNATURE * will be called, if present. * This method takes a memory blob as input. The data must be fully defined. * @param source the source data to use as input. * @param length the length of the source data. * @param format determins how the data will be read (ex: as normal binary or in HEX format). * See SenMLStreamMethod for possible methods. * @returns none */ void fromCbor(char* source, int length, SenMLStreamMethod format); /** * assign a basename to the SenMLPack object. This represents the name of the device. * see the spec on [base fields](https://tools.ietf.org/html/draft-ietf-core-senml-13#section-4.1) for more info. * Every SenMLPack object must have a basename. This field will always be rendered in the output, even if the * string is empty. * @param name an immutable string that will be used to represent the name of the device. An internal * copy of the value will be made. * @returns none */ void setBaseName(const char* name); /** * Get the base name. see the spec on [base fields](https://tools.ietf.org/html/draft-ietf-core-senml-13#section-4.1) for more info. * @returns the name of the device as an immutable string. */ const char* getBaseName(); /** * Set the base unit that will be used as the default unit for all records that don't define their own unit. * see the spec on [base fields](https://tools.ietf.org/html/draft-ietf-core-senml-13#section-4.1) for more info. * Set to SENML_UNIT_NONE for ommiting the base unit from the output (default). * @param unit the unit to use as default. See SenMLUnit for all supported unit names. * @returns none */ void setBaseUnit(SenMLUnit unit); /** * Get the base unit. see the spec on [base fields](https://tools.ietf.org/html/draft-ietf-core-senml-13#section-4.1) for more info. * @returns a SenMLUnit enum value that is used as the default unit for records that don't define a unit of their own. */ inline SenMLUnit getBaseUnit() { return this->_bu; }; /** * Set the base time. see the spec on [base fields](https://tools.ietf.org/html/draft-ietf-core-senml-13#section-4.1) for more info. * @param time the value to use as base time. set bt to NaN if the field should not be included in the output. * @returns none */ void setBaseTime(double time); /** * Get the base time. see the spec on [base fields](https://tools.ietf.org/html/draft-ietf-core-senml-13#section-4.1) for more info. * @returns a double value that is used as the default unit for records that don't define a unit of their own. * if no base time is set, NaN will be returned. */ inline double getBaseTime() { return this->_bt; }; /** * Adds the specified SenML object to the document. The item will be appended to the end of the linked list. * The item being added, can be a regular SenMLRecord or another SenMLPack object if you want to send data * for multiple devices in 1 SenML message. * Check the result of the function to see if the operation was successful or not. Possible reasons for failure: * - if the item being added is already part of a document. * @param item a pointer to a SenMlRecord or SenMLPack that needs to be added to the document. * @returns true upon success, otherwise false. */ bool add(SenMLBase* item); /** * Clear out the document and remove all the children. Children aren't destroyed, this is up to the developer. * @returns true (at the moment, the function does not yet return false as it doesn't detect any errors) */ bool clear(); /** * get the first recrod of in this pack element. * @returns null when this object is empty (has no children), otherwise, the first item (SenMLRecord or SenMLPack) * of the list. */ inline SenMLBase* getFirst() { return this->_start; }; /** * renders all the fields to json, without the starting and ending brackets. * Inheriters can extend this function if they want to add extra fields to the json output * note: this is public so that custom implementations for the record object can use other objects * internally and render to json using this function (ex: coordinatesRecord using 3 floatRecrods for lat, lon & alt. * @returns: None */ virtual void fieldsToJson(); /** * renders all the fields to cbor format. renders all the fields of the object without the length info * at the beginning * note: this is public so that custom implementations for the record object can use other objects * internally and render to json using this function (ex: coordinatesRecord using 3 floatRecrods for * lat, lon & alt. * @returns: The number of bytes that were written. */ virtual int fieldsToCbor(); protected: //derived classes can use this function to see if the root object (getRoot) is a SenMLPack //class or not. virtual bool isPack() { return true; } //when the user did not register a specific record actuator, this will be called. inline void actuate(const char* pack, const char* record, const void* value, int valueLength, SenMLDataType dataType) { if(this->callback) this->callback(pack, record, value, valueLength, dataType); }; //store a ref to the last item in the list for quick link operations void setLast(SenMLBase* value); //renders the content of the pack object without [] virtual int contentToCbor(); //calculates the nr of items that there will be in the json array in senml representation //this is used for rendering cbor which needs to declare the nr of elements in an array. virtual int getArrayLength(); virtual void setupStreamCtx(char *dest, int length, SenMLStreamMethod format); virtual void setupStreamCtx(Stream *dest, SenMLStreamMethod format); private: String _bn; SenMLUnit _bu; double _bt; SenMLBase *_end; //keeps track of the end of the list SenMLBase *_start; //keeps track of the start of the list PACK_ACTUATOR_SIGNATURE; //for registering actuator callbacks. //renders the content of the pack object without [] virtual void contentToJson(); //calculates the nr of json fields that this object uses in a senml structure virtual int getFieldLength(); void internalToJson(); inline char readHexChar(Stream *source){ #ifdef __MBED__ unsigned char first = source->getc(); unsigned char second = source->getc(); #else unsigned char first = source->read(); unsigned char second = source->read(); #endif first = (first < '9') ? first - '0' : first - '7'; second = (second < '9') ? second - '0' : second - '7'; return (16 * first) + second; }; }; #endif // SENMLPACK