Marshaller that knows how to marshal/serialize dap data objects to a C++ iostream using DAP4's receiver-makes-right scheme. This code adds checksums to the stream and uses the xdr library to encode real values if the underlying representation is not IEEE 754. It also supports computing the checksum only. More...

#include <D4StreamMarshaller.h>

Inheritance diagram for libdap::D4StreamMarshaller:

Public Member Functions
virtual void	checksum_update (const void *data, unsigned long len)

	D4StreamMarshaller (std::ostream &out, bool write_data=true)

virtual void	dump (std::ostream &strm) const
	dump the contents of this object to the specified ostream More...

virtual string	get_checksum ()

virtual void	put_byte (dods_byte val)

virtual void	put_checksum ()
	Write the checksum Write the checksum for the data sent since the last call to reset_checksum() to the I/O stream associated with this marshaller. Use this to send the checksum, not get_checksum(). More...

virtual void	put_count (int64_t count)

virtual void	put_float32 (dods_float32 val)

virtual void	put_float64 (dods_float64 val)

virtual void	put_int (int)

virtual void	put_int16 (dods_int16 val)

virtual void	put_int32 (dods_int32 val)

virtual void	put_int64 (dods_int64 val)

virtual void	put_int8 (dods_int8 val)

virtual void	put_opaque (char *, unsigned int)

virtual void	put_opaque_dap4 (const char *val, int64_t len)

virtual void	put_str (const string &val)

virtual void	put_uint16 (dods_uint16 val)

virtual void	put_uint32 (dods_uint32 val)

virtual void	put_uint64 (dods_uint64 val)

virtual void	put_url (const string &val)

virtual void	put_vector (char *val, int64_t num_bytes)
	Write a fixed size vector. More...

virtual void	put_vector (char *val, int64_t num_elem, int elem_size)

virtual void	put_vector (char *, int, Vector &)

virtual void	put_vector (char *, int, int, Vector &)

virtual void	put_vector_end ()

virtual void	put_vector_float32 (char *val, int64_t num_elem)
	Write a fixed size vector. More...

virtual void	put_vector_float64 (char *val, int64_t num_elem)
	Write a fixed size vector of float64s. More...

virtual void	put_vector_part (char *, unsigned int, int, Type)

virtual void	put_vector_start (int)

virtual void	reset_checksum ()

Detailed Description

Marshaller that knows how to marshal/serialize dap data objects to a C++ iostream using DAP4's receiver-makes-right scheme. This code adds checksums to the stream and uses the xdr library to encode real values if the underlying representation is not IEEE 754. It also supports computing the checksum only.

Note: This class uses the Marshaller interface; it could be rewritten to use far fewer methods since all of the put_*() methods take different types.

Definition at line 71 of file D4StreamMarshaller.h.

Constructor & Destructor Documentation

◆ D4StreamMarshaller()

libdap::D4StreamMarshaller::D4StreamMarshaller	(	std::ostream &	out,
		bool	write_data = `true`
	)

Build an instance of D4StreamMarshaller. Bind the C++ stream out to this instance. If the write_data parameter is true, write the data in addition to computing and sending the checksum.

Parameters

out	Write to this stream object.
write_data	If true, write data values. True by default

Definition at line 201 of file D4StreamMarshaller.cc.

Member Function Documentation

◆ checksum_update()

void libdap::D4StreamMarshaller::checksum_update	(	const void *	data,
		unsigned long	len
	)

virtual

Update the current CRC 32 checksum value. Calling this with len equal to zero has no effect on the checksum value.

Definition at line 276 of file D4StreamMarshaller.cc.

◆ dump()

void libdap::D4StreamMarshaller::dump ( std::ostream & strm ) const

virtual

dump the contents of this object to the specified ostream

This method is implemented by all derived classes to dump their contents, in other words, any state they might have, private variables, etc...

Parameters

strm	C++ i/o stream to dump the object to

Implements libdap::Marshaller.

Definition at line 820 of file D4StreamMarshaller.cc.

◆ get_checksum()

string libdap::D4StreamMarshaller::get_checksum ( )

virtual

Get the current checksum. It is not possible to continue computing the checksum once this has been called.

Note: This method is not intended to be called often or for inserting the checksum into an I/O stream; see put_checksum(). This is intended for instrumentation code.

Returns: The checksum in a string object that always has eight characters.

Definition at line 248 of file D4StreamMarshaller.cc.

◆ put_checksum()

void libdap::D4StreamMarshaller::put_checksum ( )

virtual

Write the checksum Write the checksum for the data sent since the last call to reset_checksum() to the I/O stream associated with this marshaller. Use this to send the checksum, not get_checksum().

Definition at line 263 of file D4StreamMarshaller.cc.

◆ put_count()

void libdap::D4StreamMarshaller::put_count ( int64_t count )

virtual

Used only for Sequences, where the count must be added to the stream and then the fields sent using separate calls to methods here. The methods put_opaque_dap4(), ..., that need counts sent as prefixes to their data handle it themselves.

Parameters

count How many elements follow.

Definition at line 489 of file D4StreamMarshaller.cc.

◆ put_vector()

void libdap::D4StreamMarshaller::put_vector	(	char *	val,
		int64_t	num_bytes
	)

virtual

Write a fixed size vector.

Parameters

val	Pointer to the data
num	Number of bytes to write

Definition at line 546 of file D4StreamMarshaller.cc.

◆ put_vector_end()

virtual void libdap::D4StreamMarshaller::put_vector_end ( )

inlinevirtual

Close a vector when its values are written using put_vector_part(). In DAP4 this does nothing because arrays are serialized using the server's binary representation (i.e., using 'reader make right').

See also: put_vector_start(); put_vector_part()

Reimplemented from libdap::Marshaller.

Definition at line 170 of file D4StreamMarshaller.h.

◆ put_vector_float32()

void libdap::D4StreamMarshaller::put_vector_float32	(	char *	val,
		int64_t	num_elem
	)

virtual

Write a fixed size vector.

Note: This method and its companion for float64 exists in case we need to support machine that do not use IEEE754 for their floating point representation.

Parameters

val	Pointer to the data
num	Number of elements
width	Size of a single element
type	DAP variable type; used to handle float32 and float64 types correctly

Definition at line 625 of file D4StreamMarshaller.cc.

◆ put_vector_float64()

void libdap::D4StreamMarshaller::put_vector_float64	(	char *	val,
		int64_t	num_elem
	)

virtual

Write a fixed size vector of float64s.

Parameters

val	Pointer to the data
num	Number of elements
width	Size of a single element
type	DAP variable type; used to handle float32 and float64 types correctly

Definition at line 699 of file D4StreamMarshaller.cc.

◆ put_vector_part()

void libdap::D4StreamMarshaller::put_vector_part	(	char *	,
		unsigned int	,
		int	,
		Type
	)

virtual

Write one part of a vector's contents.

Parameters

val	Pointer to the part's values
num	The number of values in this part
width	The number of bytes per value
type	The DAP2 data type for each value

Reimplemented from libdap::Marshaller.

Definition at line 762 of file D4StreamMarshaller.cc.

◆ put_vector_start()

virtual void libdap::D4StreamMarshaller::put_vector_start ( int )

inlinevirtual

Prepare to send a single array/vector using a series of 'put' calls. In DAP4 this does nothing because arrays are serialized using the server's binary representation (i.e., using 'reader make right').

Parameters

num Ignored

See also: put_vector_part(); put_vector_end()

Reimplemented from libdap::Marshaller.

Definition at line 157 of file D4StreamMarshaller.h.

◆ reset_checksum()

void libdap::D4StreamMarshaller::reset_checksum ( )

virtual

Initialize the checksum buffer. This resets the checksum calculation.

Definition at line 233 of file D4StreamMarshaller.cc.

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

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ D4StreamMarshaller()

Member Function Documentation

◆ checksum_update()

◆ dump()

◆ get_checksum()

◆ put_checksum()

◆ put_count()

◆ put_vector()

◆ put_vector_end()

◆ put_vector_float32()

◆ put_vector_float64()

◆ put_vector_part()

◆ put_vector_start()

◆ reset_checksum()