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+/*
+ * 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.
+ */
+
+#include "can-decoder.hpp"
+
+#include "canutil/read.h"
+#include "../utils/openxc-utils.hpp"
+#include "can-message-definition.hpp"
+#include "../binding/low-can-hat.hpp"
+
+/// @brief Parse the signal's bitfield from the given data and return the raw
+/// value.
+///
+/// @param[in] signal - The signal to parse from the data.
+/// @param[in] message - can_message_t to parse
+///
+/// @return Returns the raw value of the signal parsed as a bitfield from the given byte
+/// array.
+///
+float decoder_t::parseSignalBitfield(can_signal_t& signal, const can_message_t& message)
+{
+ return bitfield_parse_float(message.get_data(), CAN_MESSAGE_SIZE,
+ signal.get_bit_position(), signal.get_bit_size(), signal.get_factor(),
+ signal.get_offset());
+}
+
+/// @brief 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 can_signal_t.decoder field.
+///
+/// @param[in] signal - The details of the signal that contains the state mapping.
+/// @param[in] signals - The list of all signals
+/// @param[in] value - The numerical value that will be wrapped in a DynamicField.
+/// @param[out] send - An output argument that will be set to false if the value should
+/// not be sent for any reason.
+///
+/// @return 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 decoder_t::noopDecoder(can_signal_t& signal,
+ const std::vector<std::shared_ptr<can_signal_t> >& signals, float value, bool* send)
+{
+ openxc_DynamicField decoded_value = build_DynamicField(value);
+
+ return decoded_value;
+}
+/// @brief Coerces a numerical value to a boolean.
+///
+/// This is an implementation of the SignalDecoder type signature, and can be
+/// used directly in the can_signal_t.decoder field.
+///
+/// @param[in] signal - The details of the signal that contains the state mapping.
+/// @param[in] signals - The list of all signals
+/// @param[in] value - The numerical value that will be converted to a boolean.
+/// @param[out] send - An output argument that will be set to false if the value should
+/// not be sent for any reason.
+///
+/// @return 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 decoder_t::booleanDecoder(can_signal_t& signal,
+ const std::vector<std::shared_ptr<can_signal_t> >& signals, float value, bool* send)
+{
+ openxc_DynamicField decoded_value = build_DynamicField(value == 0.0 ? false : true);
+
+ return decoded_value;
+}
+/// @brief 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 can_signal_t.decoder field.
+///
+/// This function always flips 'send' to false.
+///
+/// @param[in] signal - The details of the signal that contains the state mapping.
+/// @param[in] signals - The list of all signals.
+/// @param[in] value - The numerical value that will be converted to a boolean.
+/// @param[out] send - This output argument will always be set to false, so the caller will
+/// know not to publish this value to the pipeline.
+///
+/// @return Return value is undefined.
+///
+openxc_DynamicField decoder_t::ignoreDecoder(can_signal_t& signal,
+ const std::vector<std::shared_ptr<can_signal_t> >& signals, float value, bool* send)
+{
+ if(send)
+ *send = false;
+
+ openxc_DynamicField decoded_value;
+
+ return decoded_value;
+}
+
+/// @brief 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 can_signal_t.decoder field.
+///
+/// @param[in] signal - The details of the signal that contains the state mapping.
+/// @param[in] signals - The list of all signals.
+/// @param[in] value - The numerical value that should map to a state.
+/// @param[out] send - An output argument that will be set to false if the value should
+/// not be sent for any reason.
+///
+/// @return 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 decoder_t::stateDecoder(can_signal_t& signal,
+ const std::vector<std::shared_ptr<can_signal_t> >& signals, float value, bool* send)
+{
+ const std::string signal_state = signal.get_states((uint8_t)value);
+ openxc_DynamicField decoded_value = build_DynamicField(signal_state);
+ if(signal_state.size() <= 0)
+ {
+ *send = false;
+ ERROR("No state found with index: %d", (int)value);
+ }
+ return decoded_value;
+}
+
+
+/// @brief Parse a signal from a CAN message, apply any required transforations
+/// to get a human readable value and public the result to the pipeline.
+///
+/// If the can_signal_t has a non-NULL 'decoder' field, the raw CAN signal value
+/// will be passed to the decoder before publishing.
+///
+/// @param[in] signal - The details of the signal to decode and forward.
+/// @param[in] message - The received CAN message that should contain this signal.
+/// @param[in] signals - an array of all active signals.
+/// @param[out] 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.
+///
+openxc_DynamicField decoder_t::translateSignal(can_signal_t& signal, const can_message_t& message,
+ const std::vector<std::shared_ptr<can_signal_t> >& signals, bool* send)
+{
+ float value = decoder_t::parseSignalBitfield(signal, message);
+ DEBUG("Decoded message from parseSignalBitfield: %f", value);
+
+ // Must call the decoders every time, regardless of if we are going to
+ // decide to send the signal or not.
+ openxc_DynamicField decoded_value = decoder_t::decodeSignal(signal,
+ value, signals, send);
+
+ signal.set_received(true);
+
+ // Don't send if they is no changes
+ if ((signal.get_last_value() == value && !signal.get_send_same()) || !*send )
+ {
+ *send = false;
+ }
+ signal.set_last_value(value);
+ signal.set_timestamp(message.get_timestamp());
+ signal.get_message()->set_last_value(message);
+ return decoded_value;
+}
+
+/// @brief Parse a signal from a CAN message and apply any required
+/// transforations to get a human readable value.
+///
+/// If the can_signal_t has a non-NULL 'decoder' field, the raw CAN signal value
+/// will be passed to the decoder before returning.
+///
+/// @param[in] signal - The details of the signal to decode and forward.
+/// @param[in] value - The numerical value that will be converted to a boolean.
+/// @param[in] signals - an array of all active signals.
+/// @param[out] send - An output parameter that will be flipped to false if the value could
+/// not be decoded.
+///
+/// @return 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 decoder_t::decodeSignal( can_signal_t& signal,
+ float value, const std::vector<std::shared_ptr<can_signal_t> >& signals, bool* send)
+{
+ SignalDecoder decoder = signal.get_decoder() == nullptr ?
+ noopDecoder : signal.get_decoder();
+ openxc_DynamicField decoded_value = decoder(signal, signals,
+ value, send);
+ return decoded_value;
+}
+
+/// @brief Decode a transformed, human readable value from an raw CAN signal
+/// already parsed from a CAN message.
+///
+/// This is the same as decodeSignal 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.
+///
+/// @param[in] signal - The details of the signal to decode and forward.
+/// @param[in] message - Raw CAN message to decode
+/// @param[in] signals - an array of all active signals.
+/// @param[out] send - An output parameter that will be flipped to false if the value could
+/// not be decoded.
+///
+openxc_DynamicField decoder_t::decodeSignal( can_signal_t& signal,
+ const can_message_t& message, const std::vector<std::shared_ptr<can_signal_t> >& signals, bool* send)
+{
+ float value = parseSignalBitfield(signal, message);
+ return decodeSignal(signal, value, signals, send);
+}
+
+
+///
+/// @brief Decode the payload of an OBD-II PID.
+///
+/// This function matches the type signature for a DiagnosticResponseDecoder, so
+/// it can be used as the decoder for a DiagnosticRequest. It returns the decoded
+/// value of the PID, using the standard formulas (see
+/// http://en.wikipedia.org/wiki/OBD-II_PIDs#Mode_01).
+///
+/// @param[in] response - the received DiagnosticResponse (the data is in response.payload,
+/// a byte array). This is most often used when the byte order is
+/// signiticant, i.e. with many OBD-II PID formulas.
+/// @param[in] parsed_payload - the entire payload of the response parsed as an int.
+///
+/// @return Float decoded value.
+///
+float decoder_t::decode_obd2_response(const DiagnosticResponse* response, float parsed_payload)
+{
+ return diagnostic_decode_obd2_pid(response);
+} \ No newline at end of file