Beginning of work on obd2 object and

files reorganization.

Change-Id: Idaa7ad05c45d734ce771506fd6e41f1a09a6ac66
Signed-off-by: Romain Forlot <romain.forlot@iot.bzh>

1 files changed, 161 insertions, 0 deletions

diff --git a/src/can/can-decoder.hpp b/src/can/can-decoder.hpp
new file mode 100644
index 0000000..e7dfff8
--- /dev/null
+++ b/src/can/can-decoder.hpp
@@ -0,0 +1,161 @@
+/*
+ * 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-bus.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(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.
+		*/
+		static openxc_DynamicField stateDecoder(CanSignal& signal, const std::vector<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.
+		*/
+		static openxc_DynamicField booleanDecoder(CanSignal& signal, const std::vector<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(CanSignal& signal, const std::vector<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.
+		*/
+		static openxc_DynamicField noopDecoder(CanSignal& signal, const std::vector<CanSignal>& signals,
+				float value, bool* send);
+
+
+		/* Public: 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 CanSignal has a non-NULL 'decoder' field, the raw CAN signal value
+		* will be passed to the decoder before publishing.
+		*
+		* signal - The details of the signal to decode and forward.
+		* message   - The received CAN message that should contain this signal.
+		* signals - an array of all active signals.
+		*
+		* The decoder returns an openxc_DynamicField, which may contain a number,
+		* string or boolean.
+		*/
+		openxc_DynamicField translateSignal(CanSignal& signal, can_message_t& message,
+			const std::vector<CanSignal>& signals);
+		
+		/* 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.
+		* 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(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(CanSignal& signal, float value,
+			const std::vector<CanSignal>& signals, bool* send);
+};
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