Avro C#
Public Member Functions | Protected Member Functions | Properties
Avro::Generic::DefaultWriter Class Reference

A General purpose writer for serializing objects into a Stream using Avro. This class implements a default way of serializing objects. But one can derive a class from this and override different methods to acheive results that are different from the default implementation. More...

Inheritance diagram for Avro::Generic::DefaultWriter:
Avro::Specific::SpecificDefaultWriter

List of all members.

Public Member Functions

 DefaultWriter (Schema schema)
 Constructs a generic writer for the given schema.
void Write< T > (T value, Encoder encoder)
virtual void Write (Schema schema, object value, Encoder encoder)
 Examines the schema and dispatches the actual work to one of the other methods of this class. This allows the derived classes to override specific methods and get custom results.

Protected Member Functions

virtual void WriteNull (object value, Encoder encoder)
 Serializes a "null".
virtual void Write< S > (object value, Schema.Type tag, Writer< S > writer)
 A generic method to serialize primitive Avro types.
virtual void WriteRecord (RecordSchema schema, object value, Encoder encoder)
 Serialized a record using the given RecordSchema. It uses GetField method to extract the field value from the given object.
virtual void EnsureRecordObject (RecordSchema s, object value)
virtual object GetField (object value, string fieldName, int fieldPos)
 Extracts the field value from the given object. In this default implementation, value should be of type GenericRecord.
virtual void WriteEnum (EnumSchema es, object value, Encoder encoder)
 Serializes an enumeration. The default implementation expectes the value to be string whose value is the name of the enumeration.
virtual void WriteArray (ArraySchema schema, object value, Encoder encoder)
 Serialized an array. The default implementation calls EnsureArrayObject() to ascertain that the given value is an array. It then calls GetArrayLength() and GetArrayElement() to access the members of the array and then serialize them.
virtual void EnsureArrayObject (object value)
 Checks if the given object is an array. If it is a valid array, this function returns normally. Otherwise, it throws an exception. The default implementation checks if the value is an array.
virtual long GetArrayLength (object value)
 Returns the length of an array. The default implementation requires the object to be an array of objects and returns its length. The defaul implementation gurantees that EnsureArrayObject() has been called on the value before this function is called.
virtual object GetArrayElement (object value, long index)
 Returns the element at the given index from the given array object. The default implementation requires that the value is an object array and returns the element in that array. The defaul implementation gurantees that EnsureArrayObject() has been called on the value before this function is called.
virtual void WriteMap (MapSchema schema, object value, Encoder encoder)
 Serialized a map. The default implementation first ensure that the value is indeed a map and then uses GetMapSize() and GetMapElements() to access the contents of the map.
virtual void EnsureMapObject (object value)
 Checks if the given object is a map. If it is a valid map, this function returns normally. Otherwise, it throws an exception. The default implementation checks if the value is an IDictionary<string, object>.
virtual long GetMapSize (object value)
 Returns the size of the map object. The default implementation gurantees that EnsureMapObject has been successfully called with the given value. The default implementation requires the value to be an IDictionary<string, object> and returns the number of elements in it.
virtual IEnumerable
< KeyValuePair< string, object > > 
GetMapValues (object value)
 Returns the contents of the given map object. The default implementation guarantees that EnsureMapObject has been called with the given value. The defualt implementation of this method requires that the value is an IDictionary<string, object> and returns its contents.
virtual void WriteUnion (UnionSchema us, object value, Encoder encoder)
 Resolves the given value against the given UnionSchema and serializes the object against the resolved schema member. The default implementation of this method uses ResolveUnion to find the member schema within the UnionSchema.
virtual int ResolveUnion (UnionSchema us, object obj)
 Finds the branch within the given UnionSchema that matches the given object. The default implementation calls Matches() method in the order of branches within the UnionSchema. If nothing matches, throws an exception.
virtual void WriteFixed (FixedSchema es, object value, Encoder encoder)
 Serialized a fixed object. The default implementation requires that the value is a GenericFixed object with an identical schema as es.
AvroException TypeMismatch (object obj, string schemaType, string type)
virtual bool Matches (Schema sc, object obj)

Properties

Schema Schema [get, set]

Detailed Description

A General purpose writer for serializing objects into a Stream using Avro. This class implements a default way of serializing objects. But one can derive a class from this and override different methods to acheive results that are different from the default implementation.


Constructor & Destructor Documentation

Avro::Generic::DefaultWriter::DefaultWriter ( Schema  schema) [inline]

Constructs a generic writer for the given schema.

Parameters:
schemaThe schema for the object to be serialized

Member Function Documentation

virtual void Avro::Generic::DefaultWriter::EnsureArrayObject ( object  value) [inline, protected, virtual]

Checks if the given object is an array. If it is a valid array, this function returns normally. Otherwise, it throws an exception. The default implementation checks if the value is an array.

Parameters:
value
virtual void Avro::Generic::DefaultWriter::EnsureMapObject ( object  value) [inline, protected, virtual]

Checks if the given object is a map. If it is a valid map, this function returns normally. Otherwise, it throws an exception. The default implementation checks if the value is an IDictionary<string, object>.

Parameters:
value
virtual object Avro::Generic::DefaultWriter::GetArrayElement ( object  value,
long  index 
) [inline, protected, virtual]

Returns the element at the given index from the given array object. The default implementation requires that the value is an object array and returns the element in that array. The defaul implementation gurantees that EnsureArrayObject() has been called on the value before this function is called.

Parameters:
valueThe array object
indexThe index to look for
Returns:
The array element at the index
virtual long Avro::Generic::DefaultWriter::GetArrayLength ( object  value) [inline, protected, virtual]

Returns the length of an array. The default implementation requires the object to be an array of objects and returns its length. The defaul implementation gurantees that EnsureArrayObject() has been called on the value before this function is called.

Parameters:
valueThe object whose array length is required
Returns:
The array length of the given object
virtual object Avro::Generic::DefaultWriter::GetField ( object  value,
string  fieldName,
int  fieldPos 
) [inline, protected, virtual]

Extracts the field value from the given object. In this default implementation, value should be of type GenericRecord.

Parameters:
valueThe record value from which the field needs to be extracted
fieldNameThe name of the field in the record
fieldPosThe position of field in the record
Returns:
virtual long Avro::Generic::DefaultWriter::GetMapSize ( object  value) [inline, protected, virtual]

Returns the size of the map object. The default implementation gurantees that EnsureMapObject has been successfully called with the given value. The default implementation requires the value to be an IDictionary<string, object> and returns the number of elements in it.

Parameters:
valueThe map object whose size is desired
Returns:
The size of the given map object
virtual IEnumerable<KeyValuePair<string, object> > Avro::Generic::DefaultWriter::GetMapValues ( object  value) [inline, protected, virtual]

Returns the contents of the given map object. The default implementation guarantees that EnsureMapObject has been called with the given value. The defualt implementation of this method requires that the value is an IDictionary<string, object> and returns its contents.

Parameters:
valueThe map object whose size is desired
Returns:
The contents of the given map object
virtual int Avro::Generic::DefaultWriter::ResolveUnion ( UnionSchema  us,
object  obj 
) [inline, protected, virtual]

Finds the branch within the given UnionSchema that matches the given object. The default implementation calls Matches() method in the order of branches within the UnionSchema. If nothing matches, throws an exception.

Parameters:
usThe UnionSchema to resolve against
objThe object that should be used in matching
Returns:
virtual void Avro::Generic::DefaultWriter::Write ( Schema  schema,
object  value,
Encoder  encoder 
) [inline, virtual]

Examines the schema and dispatches the actual work to one of the other methods of this class. This allows the derived classes to override specific methods and get custom results.

Parameters:
schemaThe schema to use for serializing
valueThe value to be serialized
encoderThe encoder to use during serialization
virtual void Avro::Generic::DefaultWriter::Write< S > ( object  value,
Schema.Type  tag,
Writer< S >  writer 
) [inline, protected, virtual]

A generic method to serialize primitive Avro types.

Template Parameters:
SType of the C# type to be serialized
Parameters:
valueThe value to be serialized
tagThe schema type tag
writerThe writer which should be used to write the given type.
virtual void Avro::Generic::DefaultWriter::WriteArray ( ArraySchema  schema,
object  value,
Encoder  encoder 
) [inline, protected, virtual]

Serialized an array. The default implementation calls EnsureArrayObject() to ascertain that the given value is an array. It then calls GetArrayLength() and GetArrayElement() to access the members of the array and then serialize them.

Parameters:
schemaThe ArraySchema for serialization
valueThe value being serialized
encoderThe encoder for serialization

Reimplemented in Avro::Specific::SpecificDefaultWriter.

virtual void Avro::Generic::DefaultWriter::WriteEnum ( EnumSchema  es,
object  value,
Encoder  encoder 
) [inline, protected, virtual]

Serializes an enumeration. The default implementation expectes the value to be string whose value is the name of the enumeration.

Parameters:
esThe EnumSchema for serialization
valueValue to be written
encoderEncoder for serialization

Reimplemented in Avro::Specific::SpecificDefaultWriter.

virtual void Avro::Generic::DefaultWriter::WriteFixed ( FixedSchema  es,
object  value,
Encoder  encoder 
) [inline, protected, virtual]

Serialized a fixed object. The default implementation requires that the value is a GenericFixed object with an identical schema as es.

Parameters:
esThe schema for serialization
valueThe value to be serialized
encoderThe encoder for serialization

Reimplemented in Avro::Specific::SpecificDefaultWriter.

virtual void Avro::Generic::DefaultWriter::WriteMap ( MapSchema  schema,
object  value,
Encoder  encoder 
) [inline, protected, virtual]

Serialized a map. The default implementation first ensure that the value is indeed a map and then uses GetMapSize() and GetMapElements() to access the contents of the map.

Parameters:
schemaThe MapSchema for serialization
valueThe value to be serialized
encoderThe encoder for serialization

Reimplemented in Avro::Specific::SpecificDefaultWriter.

virtual void Avro::Generic::DefaultWriter::WriteNull ( object  value,
Encoder  encoder 
) [inline, protected, virtual]

Serializes a "null".

Parameters:
valueThe object to be serialized using null schema
encoderThe encoder to use while serialization
virtual void Avro::Generic::DefaultWriter::WriteRecord ( RecordSchema  schema,
object  value,
Encoder  encoder 
) [inline, protected, virtual]

Serialized a record using the given RecordSchema. It uses GetField method to extract the field value from the given object.

Parameters:
schemaThe RecordSchema to use for serialization
valueThe value to be serialized
encoderThe Encoder for serialization

Reimplemented in Avro::Specific::SpecificDefaultWriter.

virtual void Avro::Generic::DefaultWriter::WriteUnion ( UnionSchema  us,
object  value,
Encoder  encoder 
) [inline, protected, virtual]

Resolves the given value against the given UnionSchema and serializes the object against the resolved schema member. The default implementation of this method uses ResolveUnion to find the member schema within the UnionSchema.

Parameters:
usThe UnionSchema to resolve against
valueThe value to be serialized
encoderThe encoder for serialization

Reimplemented in Avro::Specific::SpecificDefaultWriter.


The documentation for this class was generated from the following file:
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