The default implementation for the generic reader. It constructs new .NET objects for avro objects on the stream and returns the .NET object. Users can directly use this class or, if they want to customize the object types for differnt Avro schema types, can derive from this class. There are enough hooks in this class to allow customization. More...

Inheritance diagram for Avro::Generic::DefaultReader:

Public Member Functions
	DefaultReader (Schema writerSchema, Schema readerSchema)
	Constructs the default reader for the given schemas using the DefaultReader. If the reader's and writer's schemas are different this class performs the resolution. This default implemenation maps Avro types to .NET types as follows:
T	Read< T > (T reuse, Decoder decoder)
	Reads an object off the stream.
object	Read (object reuse, Schema writerSchema, Schema readerSchema, Decoder d)
Protected Member Functions
virtual object	ReadNull (Schema readerSchema, Decoder d)
	Deserializes a null from the stream.
S	Read< S > (Schema.Type tag, Schema readerSchema, Reader< S > reader)
	A generic function to read primitive types.
virtual object	ReadRecord (object reuse, RecordSchema writerSchema, Schema readerSchema, Decoder dec)
	Deserializes a record from the stream.
virtual object	CreateRecord (object reuse, RecordSchema readerSchema)
	Creates a new record object. Derived classes can override this to return an object of their choice.
virtual bool	TryGetField (object record, string fieldName, int fieldPos, out object value)
	Used by the default implementation of ReadRecord() to get the existing field of a record object. The derived classes can override this to make their own interpretation of the record object.
virtual void	AddField (object record, string fieldName, int fieldPos, object fieldValue)
	Used by the default implementation of ReadRecord() to add a field to a record object. The derived classes can override this to suit their own implementation of the record object.
virtual object	ReadEnum (object reuse, EnumSchema writerSchema, Schema readerSchema, Decoder d)
	Deserializes a enum. Uses CreateEnum to construct the new enum object.
virtual object	CreateEnum (object reuse, EnumSchema es, string symbol)
	Used by the default implementation of ReadEnum to construct a new enum object.
virtual object	ReadArray (object reuse, ArraySchema writerSchema, Schema readerSchema, Decoder d)
	Deserializes an array and returns an array object. It uses CreateArray() and works on it before returning it. It also uses GetArraySize(), ResizeArray(), SetArrayElement() and GetArrayElement() methods. Derived classes can override these methods to customize their behavior.
virtual object	CreateArray (object reuse, ArraySchema rs)
	Creates a new array object. The initial size of the object could be anything. The users should use GetArraySize() to determine the size. The default implementation creates an `object[]`.
virtual int	GetArraySize (object array)
	Returns the size of the given array object.
virtual void	ResizeArray (ref object array, int n)
	Resizes the array to the new value.
virtual void	SetArrayElement (object array, int index, object value)
	Assigns a new value to the object at the given index.
virtual object	GetArrayElement (object array, int index)
	Returns the element at the given index.
virtual object	ReadMap (object reuse, MapSchema writerSchema, Schema readerSchema, Decoder d)
	Deserialized an avro map. The default implemenation creats a new map using CreateMap() and then adds elements to the map using AddMapEntry().
virtual object	CreateMap (object reuse, MapSchema ms)
	Used by the default implementation of ReadMap() to create a fresh map object. The default implementaion of this method returns a IDictionary<string, map>.
virtual void	AddMapEntry (object map, string key, object value)
	Adds an entry to the map.
virtual object	ReadUnion (object reuse, UnionSchema writerSchema, Schema readerSchema, Decoder d)
	Deserialized an object based on the writer's uninon schema.
virtual object	ReadFixed (object reuse, FixedSchema writerSchema, Schema readerSchema, Decoder d)
	Deserializes a fixed object and returns the object. The default implementation uses CreateFixed() and GetFixedBuffer() and returns what CreateFixed() returned.
virtual object	CreateFixed (object reuse, FixedSchema rs)
	Returns a fixed object.
virtual byte[]	GetFixedBuffer (object f)
	Returns a buffer of appropriate size to read data into.
virtual void	Skip (Schema writerSchema, Decoder d)
Static Protected Member Functions
static Schema	findBranch (UnionSchema us, Schema s)
Properties
Schema	ReaderSchema `[get, set]`
Schema	WriterSchema `[get, set]`

Detailed Description

The default implementation for the generic reader. It constructs new .NET objects for avro objects on the stream and returns the .NET object. Users can directly use this class or, if they want to customize the object types for differnt Avro schema types, can derive from this class. There are enough hooks in this class to allow customization.

Avro Type	.NET Type
null	null reference

Constructor & Destructor Documentation

Avro::Generic::DefaultReader::DefaultReader	(	Schema	writerSchema,
		Schema	readerSchema
	)			`[inline]`

Constructs the default reader for the given schemas using the DefaultReader. If the reader's and writer's schemas are different this class performs the resolution. This default implemenation maps Avro types to .NET types as follows:

Parameters:

	writerSchema	The schema used while generating the data
	readerSchema	The schema desired by the reader

Member Function Documentation

virtual void Avro::Generic::DefaultReader::AddField	(	object	record,
		string	fieldName,
		int	fieldPos,
		object	fieldValue
	)			`[inline, protected, virtual]`

Used by the default implementation of ReadRecord() to add a field to a record object. The derived classes can override this to suit their own implementation of the record object.

Parameters:

	record	The record object to be probed into. This is guaranteed to be one that was returned by a previous call to CreateRecord.
	fieldName	The name of the field to probe.
	fieldValue	The value to be added for the field

virtual void Avro::Generic::DefaultReader::AddMapEntry	(	object	map,
		string	key,
		object	value
	)			`[inline, protected, virtual]`

Adds an entry to the map.

Parameters:

	map	A map object, which is guaranteed to be one returned by a previous call to CreateMap().
	key	The key to add.
	value	The value to add.

virtual object Avro::Generic::DefaultReader::CreateArray	(	object	reuse,
		ArraySchema	rs
	)			`[inline, protected, virtual]`

Creates a new array object. The initial size of the object could be anything. The users should use GetArraySize() to determine the size. The default implementation creates an object[].

Parameters:

reuse

If appropriate use this instead of creating a new one.

Returns:: An object suitable to deserialize an avro array

virtual object Avro::Generic::DefaultReader::CreateEnum	(	object	reuse,
		EnumSchema	es,
		string	symbol
	)			`[inline, protected, virtual]`

Used by the default implementation of ReadEnum to construct a new enum object.

Parameters:

	reuse	If appropriate, use this enum object instead of a new one.
	es	The enum schema used by the reader.
	symbol	The symbol that needs to be used.

Returns:: The default implemenation returns a GenericEnum.

virtual object Avro::Generic::DefaultReader::CreateFixed	(	object	reuse,
		FixedSchema	rs
	)			`[inline, protected, virtual]`

Returns a fixed object.

Parameters:

	reuse	If appropriate, uses this object instead of creating a new one.
	rs	The reader's FixedSchema.

Returns:: A fixed object with an appropriate buffer.

virtual object Avro::Generic::DefaultReader::CreateMap	(	object	reuse,
		MapSchema	ms
	)			`[inline, protected, virtual]`

Used by the default implementation of ReadMap() to create a fresh map object. The default implementaion of this method returns a IDictionary<string, map>.

Parameters:

reuse

If appropriate, use this map object instead of creating a new one.

Returns:: An empty map object.

virtual object Avro::Generic::DefaultReader::CreateRecord	(	object	reuse,
		RecordSchema	readerSchema
	)			`[inline, protected, virtual]`

Creates a new record object. Derived classes can override this to return an object of their choice.

Parameters:

	reuse	If appropriate, will reuse this object instead of constructing a new one
	readerSchema	The schema the reader is using

Returns:

virtual object Avro::Generic::DefaultReader::GetArrayElement	(	object	array,
		int	index
	)			`[inline, protected, virtual]`

Returns the element at the given index.

Parameters:

	array	Array object whose size is required. This is guaranteed to be somthing returned by a previous call to CreateArray().
	index	The index to look into.

Returns:: The object the given index. Null if no object has been assigned to that index.

virtual int Avro::Generic::DefaultReader::GetArraySize ( object array ) [inline, protected, virtual]

Returns the size of the given array object.

Parameters:

array

Array object whose size is required. This is guaranteed to be somthing returned by a previous call to CreateArray().

Returns:: The size of the array

virtual byte [] Avro::Generic::DefaultReader::GetFixedBuffer ( object f ) [inline, protected, virtual]

Returns a buffer of appropriate size to read data into.

Parameters:

f

The fixed object. It is guaranteed that this is something that has been previously returned by CreateFixed

Returns:: A byte buffer of fixed's size.

S Avro::Generic::DefaultReader::Read< S >	(	Schema.Type	tag,
		Schema	readerSchema,
		Reader< S >	reader
	)			`[inline, protected]`

A generic function to read primitive types.

Template Parameters:

S

The .NET type to read

Parameters:

	tag	The Avro type tag for the object on the stream
	readerSchema	A schema compatible to the Avro type
	reader	A function that can read the avro type from the stream

Returns:: The primitive type just read

T Avro::Generic::DefaultReader::Read< T >	(	T	reuse,
		Decoder	decoder
	)			`[inline]`

Reads an object off the stream.

Template Parameters:

T

The type of object to read. A single schema typically returns an object of a single .NET class. The only exception is UnionSchema, which can return a object of different types based on the branch selected.

Parameters:

	reuse	If not null, the implemenation will try to use to return the object
	decoder	The decoder for deserialization

Returns:

virtual object Avro::Generic::DefaultReader::ReadArray	(	object	reuse,
		ArraySchema	writerSchema,
		Schema	readerSchema,
		Decoder	d
	)			`[inline, protected, virtual]`

Deserializes an array and returns an array object. It uses CreateArray() and works on it before returning it. It also uses GetArraySize(), ResizeArray(), SetArrayElement() and GetArrayElement() methods. Derived classes can override these methods to customize their behavior.

Parameters:

	reuse	If appropriate, uses this instead of creating a new array object.
	writerSchema	The schema used by the writer.
	readerSchema	The schema that the reader uses.
	d	The decoder for deserialization.

Returns:: The deserialized array object.

Reimplemented in Avro::Specific::SpecificDefaultReader.

virtual object Avro::Generic::DefaultReader::ReadEnum	(	object	reuse,
		EnumSchema	writerSchema,
		Schema	readerSchema,
		Decoder	d
	)			`[inline, protected, virtual]`

Deserializes a enum. Uses CreateEnum to construct the new enum object.

Parameters:

	reuse	If appropirate, uses this instead of creating a new enum object.
	writerSchema	The schema the writer used while writing the enum
	readerSchema	The schema the reader is using
	d	The decoder for deserialization.

Returns:: An enum object.

Reimplemented in Avro::Specific::SpecificDefaultReader.

virtual object Avro::Generic::DefaultReader::ReadFixed	(	object	reuse,
		FixedSchema	writerSchema,
		Schema	readerSchema,
		Decoder	d
	)			`[inline, protected, virtual]`

Deserializes a fixed object and returns the object. The default implementation uses CreateFixed() and GetFixedBuffer() and returns what CreateFixed() returned.

Parameters:

	reuse	If appropriate, uses this object instead of creating a new one.
	writerSchema	The FixedSchema the writer used during serialization.
	readerSchema	The schema that the readr uses. Must be a FixedSchema with the same size as the writerSchema.
	d	The decoder for deserialization.

Returns:: The deserilized object.

Reimplemented in Avro::Specific::SpecificDefaultReader.

virtual object Avro::Generic::DefaultReader::ReadMap	(	object	reuse,
		MapSchema	writerSchema,
		Schema	readerSchema,
		Decoder	d
	)			`[inline, protected, virtual]`

Deserialized an avro map. The default implemenation creats a new map using CreateMap() and then adds elements to the map using AddMapEntry().

Parameters:

	reuse	If appropriate, use this instead of creating a new map object.
	writerSchema	The schema the writer used to write the map.
	readerSchema	The schema the reader is using.
	d	The decoder for serialization.

Returns:: The deserialized map object.

Reimplemented in Avro::Specific::SpecificDefaultReader.

virtual object Avro::Generic::DefaultReader::ReadNull	(	Schema	readerSchema,
		Decoder	d
	)			`[inline, protected, virtual]`

Deserializes a null from the stream.

Parameters:

	readerSchema	Reader's schema, which should be a NullSchema
	d	The decoder for deserialization

Returns:

virtual object Avro::Generic::DefaultReader::ReadRecord	(	object	reuse,
		RecordSchema	writerSchema,
		Schema	readerSchema,
		Decoder	dec
	)			`[inline, protected, virtual]`

Deserializes a record from the stream.

Parameters:

	reuse	If not null, a record object that could be reused for returning the result
	writerSchema	The writer's RecordSchema
	readerSchema	The reader's schema, must be RecordSchema too.
	dec	The decoder for deserialization

Returns:: The record object just read

Reimplemented in Avro::Specific::SpecificDefaultReader.

virtual object Avro::Generic::DefaultReader::ReadUnion	(	object	reuse,
		UnionSchema	writerSchema,
		Schema	readerSchema,
		Decoder	d
	)			`[inline, protected, virtual]`

Deserialized an object based on the writer's uninon schema.

Parameters:

	reuse	If appropriate, uses this object instead of creating a new one.
	writerSchema	The UnionSchema that the writer used.
	readerSchema	The schema the reader uses.
	d	The decoder for serialization.

Returns:: The deserialized object.

virtual void Avro::Generic::DefaultReader::ResizeArray	(	ref object	array,
		int	n
	)			`[inline, protected, virtual]`

Resizes the array to the new value.

Parameters:

	array	Array object whose size is required. This is guaranteed to be somthing returned by a previous call to CreateArray().
	n	The new size.

virtual void Avro::Generic::DefaultReader::SetArrayElement	(	object	array,
		int	index,
		object	value
	)			`[inline, protected, virtual]`

Assigns a new value to the object at the given index.

Parameters:

	array	Array object whose size is required. This is guaranteed to be somthing returned by a previous call to CreateArray().
	index	The index to reassign to.
	value	The value to assign.

virtual bool Avro::Generic::DefaultReader::TryGetField	(	object	record,
		string	fieldName,
		int	fieldPos,
		out object	value
	)			`[inline, protected, virtual]`

Used by the default implementation of ReadRecord() to get the existing field of a record object. The derived classes can override this to make their own interpretation of the record object.

Parameters:

	record	The record object to be probed into. This is guaranteed to be one that was returned by a previous call to CreateRecord.
	fieldName	The name of the field to probe.
	value	The value of the field, if found. Null otherwise.

Returns:: True if and only if a field with the given name is found.

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

src/apache/main/Generic/GenericReader.cs

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Avro::Generic::DefaultReader Class Reference

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Properties

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation