Added needed functions for basics decode needs.

Change-Id: Ic6202927058ff693c7c5c9b04e25b7be2fba340c
Signed-off-by: Romain Forlot <romain.forlot@iot.bzh>

4 files changed, 256 insertions, 23 deletions

diff --git a/can-decoder.cpp b/can-decoder.cpp
new file mode 100644
index 0000000..000db2a
--- /dev/null
+++ b/can-decoder.cpp
@@ -0,0 +1,93 @@
+/*
+ * 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.
+ */
+
+Decoder::Decoder
+{
+	decoded_value = { .has_type = false,
+					.has_numeric_value = false,
+					.has_boolean_value = false,
+					.has_string_value = false };
+}
+
+float Decoder::parseSignalBitfield(CanSignal* signal, const CanMessage* message)
+{
+	 return bitfield_parse_float(message->data, CAN_MESSAGE_SIZE,
+			signal->bitPosition, signal->bitSize, signal->factor,
+			signal->offset);
+}
+
+openxc_DynamicField Decoder::noopDecoder(CanSignal* signal,
+        CanSignal* signals, int signalCount, float value, bool* send)
+{
+	decoded_value = { .has_type = true,
+					.type = openxc_DynamicField_Type_NUM,
+					.has_numeric_value = true,
+					.numeric_value = value };
+    return decoded_value;
+}
+
+openxc_DynamicField Decoder::booleanDecoder(CanSignal* signal,
+        CanSignal* signals, int signalCount, float value, bool* send)
+{
+	decoded_value = { .has_type = true,
+					.type = openxc_DynamicField_Type_BOOL,
+					.has_boolean_value = true,
+					.numeric_value = value == 0.0 ? false : true };
+	return decoded_value;
+}
+
+openxc_DynamicField Decoder::ignoreDecoder(CanSignal* signal,
+        CanSignal* signals, int signalCount, float value, bool* send)
+{
+    *send = false;
+    openxc_DynamicField decoded_value = {0};
+    return decoded_value;
+}
+
+openxc_DynamicField Decoder::stateDecoder(CanSignal* signal,
+        CanSignal* signals, int signalCount, float value, bool* send)
+{
+    openxc_DynamicField decoded_value = {0};
+    decoded_value.has_type = true;
+    decoded_value.type = openxc_DynamicField_Type_STRING;
+    decoded_value.has_string_value = true;
+
+    const CanSignalState* signalState = lookupSignalState(value, signal);
+    if(signalState != NULL) {
+        strcpy(decoded_value.string_value, signalState->name);
+    } else {
+        *send = false;
+    }
+    return decoded_value;
+}
+
+openxc_DynamicField Decoder::decodeSignal(CanSignal* signal,
+        float value, CanSignal* signals, int signalCount, bool* send)
+{
+    SignalDecoder decoder = signal->decoder == NULL ?
+				            noopDecoder : signal->decoder;
+    openxc_DynamicField decoded_value = decoder(signal, signals,
+            signalCount, value, send);
+    return decoded_value;
+}
+
+openxc_DynamicField Decoder::decodeSignal(CanSignal* signal,
+        const CanMessage* message, CanSignal* signals, int signalCount,
+        bool* send) {
+    float value = parseSignalBitfield(signal, message);
+    return decodeSignal(signal, value, signals, signalCount, send);
+}
\ No newline at end of file
diff --git a/can-decoder.h b/can-decoder.h
new file mode 100644
index 0000000..249d5b0
--- /dev/null
+++ b/can-decoder.h
@@ -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_c
+{
+	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(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(CanSignal* signal, CanSignal* signals,
+				int signalCount, 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(CanSignal* signal, CanSignal* signals,
+				int signalCount, 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, CanSignal* signals,
+				int signalCount, 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(CanSignal* signal, CanSignal* signals,
+				int signalCount, 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(CanSignal* signal,
+				const CanMessage* message, CanSignal* signals, int signalCount,
+				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(CanSignal*, CanMessage*, 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,
+		CanSignal* signals, int signalCount, bool* send);
+}
\ No newline at end of file
diff --git a/low-can-binding.cpp b/low-can-binding.cpp
index b523e9d..bb219be 100644
--- a/low-can-binding.cpp
+++ b/low-can-binding.cpp
@@ -7,7 +7,7 @@
  * 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
+ *	 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,
@@ -44,7 +44,7 @@
 #include "obd2.h"
 
 /*
- *   Interface between the daemon and the binding
+ *	 Interface between the daemon and the binding
  */
 static const struct afb_binding_interface *interface;
 
@@ -84,11 +84,12 @@ static int on_event(sd_event_source *s, int fd, uint32_t revents, void *userdata
 }
 
 /*
+ * USELESS SINCE THREADS SEPARATION
+ *
  * Get the event loop running.
  * Will trigger on_event function on EPOLLIN event on socket
  *
  * Return 0 or positive value on success. Else negative value for failure.
- */
 static int connect_to_event_loop(CanBus &CanBus_handler)
 {
 	sd_event *event_loop;
@@ -113,6 +114,7 @@ static int connect_to_event_loop(CanBus &CanBus_handler)
 
 	return rc;
 }
+ */
 
 /********************************************************************************
 *
@@ -156,7 +158,7 @@ static int subscribe_unsubscribe_name(struct afb_req request, int subscribe, con
 	if (0 == strcmp(name, "*"))
 		return subscribe_unsubscribe_all(request, subscribe);
 
-	sig = getsig(name);
+	sig = getSignal(name);
 	if (sig == NULL) {
 		return 0;
 	}
@@ -204,8 +206,8 @@ static void unsubscribe(struct afb_req request)
 }
 static const struct afb_verb_desc_v1 verbs[]=
 {
-  { .name= "subscribe",    .session= AFB_SESSION_NONE, .callback= subscribe,    .info= "subscribe to notification of CAN bus messages." },
-  { .name= "unsubscribe",  .session= AFB_SESSION_NONE, .callback= unsubscribe,  .info= "unsubscribe a previous subscription." },
+  { .name= "subscribe",    .session= AFB_SESSION_NONE, .callback= subscribe,	.info= "subscribe to notification of CAN bus messages." },
+  { .name= "unsubscribe",  .session= AFB_SESSION_NONE, .callback= unsubscribe,	.info= "unsubscribe a previous subscription." },
 	{NULL}
 };
 
@@ -230,9 +232,7 @@ int afbBindingV1ServiceInit(struct afb_service service)
 	/* Open JSON conf file */
 
 	/* Open CAN socket */
-	CanBus_t CanBus_handler;
+	CanBus_c CanBus_handler(interface);
 	CanBus_handler.open();
-    CanBus_handler.start_threads();
-
-	return connect_to_event_loop(CanBus_handler);
-}
\ No newline at end of file
+	CanBus_handler.start_threads();
+}
diff --git a/timer.h b/timer.h
index fa329eb..76eb51d 100644
--- a/timer.h
+++ b/timer.h
@@ -6,7 +6,7 @@
  * 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
+ *	 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,
@@ -23,17 +23,11 @@
  *
  * frequency - the clock frequency in Hz.
  * last_time - the last time (in milliseconds since startup) that the clock
- *  ticked.
+ *	ticked.
  * time_function - a function returning current time in ms
-typedef struct {
-	    float frequency;
-	        unsigned long lastTick;
-		    TimeFunction timeFunction;
-} FrequencyClock;
  */
-
-class FrequencyClock_c {
-	private:
+typedef struct {
 		float frequency;
-		unsigned long last_tick;
-}
\ No newline at end of file
+		unsigned long lastTick;
+		TimeFunction timeFunction;
+} FrequencyClock;