fsfw/datapool/PoolVariable.h

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/*
* \file PoolVariable.h
*
* \brief This file contains the PoolVariable class, which locally represents a non-array data pool variable.
*
* \date 10/17/2012
*
* \author Bastian Baetz
*/
#ifndef POOLVARIABLE_H_
#define POOLVARIABLE_H_
#include <framework/datapool/DataSetIF.h>
#include <framework/datapool/PoolEntry.h>
#include <framework/datapool/PoolVariableIF.h>
#include <framework/serialize/SerializeAdapter.h>
#include <framework/serviceinterface/ServiceInterfaceStream.h>
template<typename T, uint8_t n_var> class PoolVarList;
/**
* \brief This is the access class for non-array data pool entries.
*
* \details To ensure safe usage of the data pool, operation is not done directly on the data pool
* entries, but on local copies. This class provides simple type-safe access to single
* data pool entries (i.e. entries with length = 1).
* The class can be instantiated as read-write and read only.
* It provides a commit-and-roll-back semantic, which means that the variable's value in
* the data pool is not changed until the commit call is executed.
* \tparam T The template parameter sets the type of the variable. Currently, all plain data types
* are supported, but in principle any type is possible.
* \ingroup data_pool
*/
template<typename T>
class PoolVariable: public PoolVariableIF {
template<typename U, uint8_t n_var> friend class PoolVarList;
protected:
/**
* \brief To access the correct data pool entry on read and commit calls, the data pool id
* is stored.
*/
uint32_t dataPoolId;
/**
* \brief The valid information as it was stored in the data pool is copied to this attribute.
*/
uint8_t valid;
/**
* \brief The information whether the class is read-write or read-only is stored here.
*/
ReadWriteMode_t readWriteMode;
/**
* \brief This is a call to read the value from the global data pool.
* \details When executed, this operation tries to fetch the pool entry with matching
* data pool id from the global data pool and copies the value and the valid
* information to its local attributes. In case of a failure (wrong type or
* pool id not found), the variable is set to zero and invalid.
* The operation does NOT provide any mutual exclusive protection by itself.
*/
ReturnValue_t read() {
PoolEntry<T>* read_out = ::dataPool.getData<T>(dataPoolId, 1);
if (read_out != NULL) {
valid = read_out->valid;
value = *(read_out->address);
return HasReturnvaluesIF::RETURN_OK;
} else {
value = 0;
valid = false;
error << "PoolVariable: read of DP Variable 0x" << std::hex
<< dataPoolId << std::dec << " failed." << std::endl;
return HasReturnvaluesIF::RETURN_FAILED;
}
}
/**
* \brief The commit call writes back the variable's value to the data pool.
* \details It checks type and size, as well as if the variable is writable. If so,
* the value is copied and the valid flag is automatically set to "valid".
* The operation does NOT provide any mutual exclusive protection by itself.
*
*/
ReturnValue_t commit() {
PoolEntry<T>* write_back = ::dataPool.getData<T>(dataPoolId, 1);
if ((write_back != NULL) && (readWriteMode != VAR_READ)) {
write_back->valid = valid;
*(write_back->address) = value;
return HasReturnvaluesIF::RETURN_OK;
} else {
return HasReturnvaluesIF::RETURN_FAILED;
}
}
/**
* Empty ctor for List initialization
*/
PoolVariable() :
dataPoolId(PoolVariableIF::NO_PARAMETER), valid(
PoolVariableIF::INVALID), readWriteMode(VAR_READ), value(0) {
}
public:
/**
* \brief This is the local copy of the data pool entry.
* \details The user can work on this attribute
* just like he would on a simple local variable.
*/
T value;
/**
* \brief In the constructor, the variable can register itself in a DataSet (if not NULL is
* passed).
* \details It DOES NOT fetch the current value from the data pool, but sets the value
* attribute to default (0). The value is fetched within the read() operation.
* \param set_id This is the id in the global data pool this instance of the access class
* corresponds to.
* \param dataSet The data set in which the variable shall register itself. If NULL,
* the variable is not registered.
* \param setReadWriteMode
*/
PoolVariable(uint32_t set_id, DataSetIF* dataSet,
ReadWriteMode_t setReadWriteMode) :
dataPoolId(set_id), valid(PoolVariableIF::INVALID), readWriteMode(
setReadWriteMode), value(0) {
if (dataSet != NULL) {
dataSet->registerVariable(this);
}
}
/**
* Copy ctor to copy classes containing Pool Variables.
*/
PoolVariable(const PoolVariable& rhs) :
dataPoolId(rhs.dataPoolId), valid(rhs.valid), readWriteMode(
rhs.readWriteMode), value(rhs.value) {
}
/**
* \brief The classes destructor is empty.
* \details If commit() was not called, the local value is
* discarded and not written back to the data pool.
*/
~PoolVariable() {
}
/**
* \brief This operation returns the data pool id of the variable.
*/
uint32_t getDataPoolId() const {
return dataPoolId;
}
/**
* This operation sets the data pool id of the variable.
* The method is necessary to set id's of data pool member variables with bad initialization.
*/
void setDataPoolId(uint32_t poolId) {
dataPoolId = poolId;
}
/**
* This method returns if the variable is write-only, read-write or read-only.
*/
ReadWriteMode_t getReadWriteMode() const {
return readWriteMode;
}
/**
* \brief With this call, the valid information of the variable is returned.
*/
bool isValid() const {
if (valid)
return true;
else
return false;
}
uint8_t getValid() {
return valid;
}
void setValid(uint8_t valid) {
this->valid = valid;
}
operator T() {
return value;
}
operator T() const {
return value;
}
PoolVariable<T> &operator=(T newValue) {
value = newValue;
return *this;
}
PoolVariable<T> &operator=(PoolVariable<T> newPoolVariable) {
value = newPoolVariable.value;
return *this;
}
virtual ReturnValue_t serialize(uint8_t** buffer, size_t* size,
const size_t max_size, bool bigEndian) const {
return SerializeAdapter<T>::serialize(&value, buffer, size, max_size,
bigEndian);
}
virtual size_t getSerializedSize() const {
return SerializeAdapter<T>::getSerializedSize(&value);
}
virtual ReturnValue_t deSerialize(const uint8_t** buffer, size_t* size,
bool bigEndian) {
return SerializeAdapter<T>::deSerialize(&value, buffer, size, bigEndian);
}
};
typedef PoolVariable<uint8_t> db_uint8_t;
typedef PoolVariable<uint16_t> db_uint16_t;
typedef PoolVariable<uint32_t> db_uint32_t;
typedef PoolVariable<int8_t> db_int8_t;
typedef PoolVariable<int16_t> db_int16_t;
typedef PoolVariable<int32_t> db_int32_t;
typedef PoolVariable<uint8_t> db_bool_t;
typedef PoolVariable<float> db_float_t;
typedef PoolVariable<double> db_double_t;
//Alternative (but I thing this is not as useful: code duplication, differences too small):
//template <typename T>
//class PoolReader : public PoolVariableIF {
//private:
// uint32_t parameter_id;
// uint8_t valid;
//public:
// T value;
// PoolReader( uint32_t set_id, DataSetIF* set ) : parameter_id(set_id), valid(false), value(0) {
// set->registerVariable( this );
// }
//
// ~PoolReader() {};
//
// uint8_t commit() {
// return HasReturnvaluesIF::RETURN_OK;
// }
//
// uint8_t read() {
// PoolEntry<T>* read_out = ::dataPool.getData<T>( parameter_id, 1 );
// if ( read_out != NULL ) {
// valid = read_out->valid;
// value = *(read_out->address);
// return HasReturnvaluesIF::RETURN_OK;
// } else {
// value = 0;
// valid = false;
// return CHECKOUT_FAILED;
// }
// }
// uint32_t getParameterId() { return parameter_id; }
// bool isWritable() { return false; };
// bool isValid() { if (valid) return true; else return false; }
//};
//
//template <typename T>
//class PoolWriter : public PoolVariableIF {
//private:
// uint32_t parameter_id;
//public:
// T value;
// PoolWriter( uint32_t set_id, DataSetIF* set ) : parameter_id(set_id), value(0) {
// set->registerVariable( this );
// }
//
// ~PoolWriter() {};
//
// uint8_t commit() {
// PoolEntry<T>* write_back = ::dataPool.getData<T>( parameter_id, 1 );
// if ( write_back != NULL ) {
// write_back->valid = true;
// *(write_back->address) = value;
// return HasReturnvaluesIF::RETURN_OK;
// } else {
// return CHECKOUT_FAILED;
// }
// }
// uint8_t read() {
// PoolEntry<T>* read_out = ::dataPool.getData<T>( parameter_id, 1 );
// if ( read_out != NULL ) {
// value = *(read_out->address);
// return HasReturnvaluesIF::RETURN_OK;
// } else {
// value = 0;
// return CHECKOUT_FAILED;
// }
// }
// uint32_t getParameterId() { return parameter_id; }
// bool isWritable() { return true; };
// bool isValid() { return false; }
//};
#endif /* POOLVARIABLE_H_ */