summaryrefslogtreecommitdiffstats
path: root/src/can-decoder.hpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/can-decoder.hpp')
-rw-r--r--src/can-decoder.hpp146
1 files changed, 146 insertions, 0 deletions
diff --git a/src/can-decoder.hpp b/src/can-decoder.hpp
new file mode 100644
index 0000000..b6234b5
--- /dev/null
+++ b/src/can-decoder.hpp
@@ -0,0 +1,146 @@
+/*
+ * 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
+
+
+class decoder_t
+{
+ private:
+ openxc_DynamicField decoded_value;
+
+ 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 CanMessage& 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 CanMessage& message, const 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 CanSignal& signals, bool* send);
+} \ No newline at end of file