/* * Copyright (C) 2015, 2016 "IoT.bzh" * Author "Romain Forlot" <romain.forlot@iot.bzh> * * 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. */ #pragma once #include "can-utils.hpp" class decoder_t { private: public: /* Public: Parse the signal's bitfield from the given data and return the raw * value. * * signal - The signal to parse from the data. * data - The data to parse the signal from. * length - The length of the data array. * * Returns the raw value of the signal parsed as a bitfield from the given byte * array. */ float parseSignalBitfield(const CanSignal& signal, const can_message_t& message); /* Public: Find and return the corresponding string state for a CAN signal's * raw integer value. * * This is an implementation of the SignalDecoder type signature, and can be * used directly in the CanSignal.decoder field. * * signal - The details of the signal that contains the state mapping. * signals - The list of all signals. * signalCount - the length of the signals array. * value - The numerical value that should map to a state. * send - An output argument that will be set to false if the value should * not be sent for any reason. * * Returns a DynamicField with a string value if a matching state is found in * the signal. If an equivalent isn't found, send is sent to false and the * return value is undefined. */ openxc_DynamicField stateDecoder(const CanSignal& signal, const CanSignal& signals, float value, bool* send); /* Public: Coerces a numerical value to a boolean. * * This is an implementation of the SignalDecoder type signature, and can be * used directly in the CanSignal.decoder field. * * signal - The details of the signal that contains the state mapping. * signals - The list of all signals * signalCount - The length of the signals array * value - The numerical value that will be converted to a boolean. * send - An output argument that will be set to false if the value should * not be sent for any reason. * * Returns a DynamicField with a boolean value of false if the raw signal value * is 0.0, otherwise true. The 'send' argument will not be modified as this * decoder always succeeds. */ openxc_DynamicField booleanDecoder(const CanSignal& signal, const CanSignal& signals, float value, bool* send); /* Public: Update the metadata for a signal and the newly received value. * * This is an implementation of the SignalDecoder type signature, and can be * used directly in the CanSignal.decoder field. * * This function always flips 'send' to false. * * signal - The details of the signal that contains the state mapping. * signals - The list of all signals. * signalCount - The length of the signals array. * value - The numerical value that will be converted to a boolean. * send - This output argument will always be set to false, so the caller will * know not to publish this value to the pipeline. * * The return value is undefined. */ openxc_DynamicField ignoreDecoder(const CanSignal& signal, const CanSignal& signals, float value, bool* send); /* Public: Wrap a raw CAN signal value in a DynamicField without modification. * * This is an implementation of the SignalDecoder type signature, and can be * used directly in the CanSignal.decoder field. * * signal - The details of the signal that contains the state mapping. * signals - The list of all signals * signalCount - The length of the signals array * value - The numerical value that will be wrapped in a DynamicField. * send - An output argument that will be set to false if the value should * not be sent for any reason. * * Returns a DynamicField with the original, unmodified raw CAN signal value as * its numeric value. The 'send' argument will not be modified as this decoder * always succeeds. */ openxc_DynamicField noopDecoder(const CanSignal& signal, const CanSignal& signals, float value, bool* send); /* Public: Parse a signal from a CAN message and apply any required * transforations to get a human readable value. * * If the CanSignal has a non-NULL 'decoder' field, the raw CAN signal value * will be passed to the decoder before returning. * * signal - The details of the signal to decode and forward. * message - The CAN message that contains the signal. * signals - an array of all active signals. * signalCount - The length of the signals array. * send - An output parameter that will be flipped to false if the value could * not be decoded. * * The decoder returns an openxc_DynamicField, which may contain a number, * string or boolean. If 'send' is false, the return value is undefined. */ openxc_DynamicField decodeSignal(const CanSignal& signal, const can_message_t& message, const std::vector<CanSignal>& signals, bool* send); /* Public: Decode a transformed, human readable value from an raw CAN signal * already parsed from a CAN message. * * This is the same as decodeSignal(const CanSignal&, CanMessage*, const CanSignal&, int, * bool*) but you must parse the bitfield value of the signal from the CAN * message yourself. This is useful if you need that raw value for something * else. */ openxc_DynamicField decodeSignal(const CanSignal& signal, float value, const std::vector<CanSignal>& signals, bool* send); };