Files
pvData/src/misc/pv/serialize.h
2016-07-22 15:56:43 +01:00

254 lines
8.4 KiB
C++

/* serialize.h */
/*
* Copyright information and license terms for this software can be
* found in the file LICENSE that is included with the distribution
*/
/**
* @author mrk
*/
#ifndef SERIALIZE_H
#define SERIALIZE_H
#include <epicsTypes.h>
#include <pv/byteBuffer.h>
#include <pv/sharedPtr.h>
#include <shareLib.h>
namespace epics { namespace pvData {
class SerializableControl;
class DeserializableControl;
class Serializable;
class BitSetSerializable;
class SerializableArray;
class BitSet;
class Field;
/**
* @brief Callback class for serialization.
*
* This must be provided by code that calls serialize.
*/
class epicsShareClass SerializableControl {
public:
/**
* Destructor.
*/
virtual ~SerializableControl(){}
/**
* Done with this buffer. Flush it.
*/
virtual void flushSerializeBuffer() =0;
/**
* Make sure buffer has at least size bytes remaining.
* If not flush existing buffer and provide a new one.
* @param size The number of bytes.
*/
virtual void ensureBuffer(std::size_t size) =0;
/**
* Add pad bytes to buffer.
* @param alignment alignment required.
*/
virtual void alignBuffer(std::size_t alignment) =0;
/**
* Method for serializing primitive array data.
* Hook for supplying custom serialization implementation.
* The serialization implementation need not be provided.
* Returns true if method performs serialization, false otherwise.
* This should only be used for arrays of primitive types,
* i. e. boolean, byte,..., double.
* It cannot be called for string, structure, or union arrays.
* @param existingBuffer the existing buffer from the caller.
* @param toSerialize location of data to be put into buffer.
* @param elementCount number of elements.
* @param elementSize element size.
* @returns true if serialization performed, else false.
*/
virtual bool directSerialize(
ByteBuffer *existingBuffer,
const char* toSerialize,
std::size_t elementCount,
std::size_t elementSize) = 0;
/**
* serialize via cache
* @param field instance to be serialized
* @param buffer buffer to be serialized to
*/
virtual void cachedSerialize(
std::tr1::shared_ptr<const Field> const & field,
ByteBuffer* buffer) = 0;
};
/**
* @brief Callback class for deserialization.
*
* This must be provided by code that calls deserialize.
*/
class epicsShareClass DeserializableControl {
public:
/**
* Destructor.
*/
virtual ~DeserializableControl(){}
/**
* Helper method.
* Ensures specified size of bytes, provides it if necessary.
* @param size The number of bytes.
*/
virtual void ensureData(std::size_t size) =0;
/**
* Align buffer.
* Note that this takes care only current buffer alignment.
* If streaming protocol is used,
* care must be taken that entire stream is aligned.
* @param alignment size in bytes, must be power of two.
*/
virtual void alignData(std::size_t alignment) =0;
/**
* Method for deserializing array data.
* Hook for supplying custom deserialization implementation.
* The deserialization implementation need not be provided.
* Returns true if method performs deserialization, false otherwise.
* This should only be used for arrays of primitive types.
* i.e. boolean, byte,..., double.
* It cannot be called for string, structure, or union arrays.
* @param existingBuffer the existing buffer from the caller.
* @param deserializeTo location of data.
* @param elementCount number of elements.
* @param elementSize element size.
* @returns true if deserialization performed, else false.
*/
virtual bool directDeserialize(
ByteBuffer *existingBuffer,
char* deserializeTo,
std::size_t elementCount,
std::size_t elementSize) = 0;
/**
* deserialize via cache
* @param buffer buffer to be deserialized from
*/
virtual std::tr1::shared_ptr<const Field> cachedDeserialize(
ByteBuffer* buffer) = 0;
};
/**
* @brief Base class for serialization.
*
*/
class epicsShareClass Serializable {
public:
/**
* Destructor.
*/
virtual ~Serializable(){}
/**
* Serialize field into given buffer.
* @param buffer serialization buffer.
* @param flusher flush interface.
*/
virtual void serialize(ByteBuffer *buffer,
SerializableControl *flusher) const = 0;
/**
* Deserialize buffer.
* @param buffer serialization buffer.
* @param flusher deserialization control.
*/
virtual void deserialize(ByteBuffer *buffer,
DeserializableControl *flusher) = 0;
};
/**
* @brief Push serialize and append to the provided byte vector.
* No caching is done. Only complete serialization.
*
* @param S A Serializable object
* @param byteOrder Byte order to write (EPICS_ENDIAN_LITTLE or EPICS_ENDIAN_BIG)
* @param out The output vector. Results are appended
*/
void epicsShareFunc serializeToVector(const Serializable *S,
int byteOrder,
std::vector<epicsUInt8>& out);
/**
* @brief deserializeFromBuffer Deserialize into S from provided vector
* @param S A Serializeable object. The current contents will be replaced
* @param in The input buffer (byte order of this buffer is used)
* @throws std::logic_error if input buffer is too small. State of S is then undefined.
*/
void epicsShareFunc deserializeFromBuffer(Serializable *S,
ByteBuffer& in);
/**
* @brief deserializeFromBuffer Deserialize into S from provided vector
* @param S A Serializeable object. The current contents will be replaced
* @param byteOrder Byte order to write (EPICS_ENDIAN_LITTLE or EPICS_ENDIAN_BIG)
* @param in The input vector
* @throws std::logic_error if input buffer is too small. State of S is then undefined.
*/
inline void deserializeFromVector(Serializable *S,
int byteOrder,
const std::vector<epicsUInt8>& in)
{
ByteBuffer B((char*)&in[0], in.size(), byteOrder); // we promise not the modify 'in'
deserializeFromBuffer(S, B);
}
/**
* @brief Class for serializing bitSets.
*
*/
class epicsShareClass BitSetSerializable {
public:
/**
* Destructor.
*/
virtual ~BitSetSerializable(){}
/**
* Serialize field into given buffer.
* @param buffer serialization buffer.
* @param flusher flush interface.
* @param bitSet The bitSet to serialize.
*/
virtual void serialize(ByteBuffer *buffer,
SerializableControl *flusher,BitSet *bitSet) const = 0;
/**
* Deserialize buffer.
* @param buffer serialization buffer.
* @param flusher deserialization control.
* @param bitSet The bitSet to deserialize.
*/
virtual void deserialize(ByteBuffer *buffer,
DeserializableControl *flusher,BitSet *bitSet) = 0;
};
/**
* @brief Class for serializing arrays.
*
*/
class epicsShareClass SerializableArray : public virtual Serializable {
public:
/**
* Destructor.
*/
virtual ~SerializableArray(){}
using Serializable::serialize;
/**
* Serialize field into given buffer.
* @param buffer serialization buffer.
* @param flusher flush interface.
* @param offset offset in elements.
* @param count number of elements
*/
virtual void serialize(
ByteBuffer *buffer,
SerializableControl *flusher,
std::size_t offset,
std::size_t count) const = 0;
};
}}
#endif /* SERIALIZE_H */