A generic class to read a file containing an ASDM table as a stream. More...

#include <TableStreamReader.h>

Public Member Functions
	TableStreamReader ()
	An empty constructor. More...

virtual	~TableStreamReader ()
	The destructor. More...

void	open (const std::string &directory)
	Opens a file expected to contain an ASDM table of type T with rows of type R. More...

void	reset ()
	Repositions the read head to the beginning of the table. More...

const std::vector< R * > &	nextNRows (unsigned int nRows)
	Reads at most n rows in the file, creates as many memory representations of these rows and return the reference of a vector of pointers on these representations. More...

const std::vector< R * > &	untilNBytes (unsigned int nBytes)
	Reads as many rows as possible in the file, keeps their in memory representation until the number of read bytes is greater or equal a number of bytes, n, passed as a parameter to the method. More...

bool	hasRows ()
	Returns true if the end of the file has not been reached. More...

void	close ()
	Releases all the resources allocated to the instance which can be reused with another file. More...

Private Types
enum	State { S_CLOSED, S_OPENED }

enum	Transition { T_OPEN, T_CHECK, T_RESET, T_READ, T_CLOSE }

Private Member Functions
void	checkState (Transition t, const std::string &methodName) const

void	clear ()
	Empty the local storage containing the rows obtained during the last read operation. More...

void	skipUntilEmptyLine (int maxSkips)

std::string	nextLine ()

std::pair< std::string, std::string >	headerField2Pair (const std::string &hf)

std::string	requireMIMEHeader ()

std::pair< std::string, std::string >	requireHeaderField (const std::string &hf)

void	requireBoundary (const std::string &boundary, int maxLines)

std::string	accumulateUntilBoundary (const std::string &boundary, int maxLines)

std::string	requireBoundaryInCT (const std::string &ctValue)

std::string	unquote (const std::string &s, std::string &unquoted)

Private Attributes
std::string	tablePath

std::ifstream	tableFile

std::string	currentLine

std::string	boundary_1

off_t	fileSizeInBytes

off_t	endBoundarySizeInBytes

asdm::EndianIFStream	eifs

std::vector< std::string >	attributesSeq

asdm::ASDM	asdm

std::vector< R * >	rows

char *	readBuffer

std::streampos	whereRowsStart

State	currentState

Detailed Description

template<class T, class R>
class asdm::TableStreamReader< T, R >

A generic class to read a file containing an ASDM table as a stream.

The purpose of this class is to provide the programmer with a way to read a file containing an ASDM table by successive slices. Each slice is transformed into the in memory representation of the rows which have been read. A slice can be specified in two ways :

a number of rows. See methods nextNRows.
a number of bytes. See methods untilNBytes.

Remarks

This class has been meant as an alternative to the historical ASDM methods getXXXX (e.g. getAntenna of getPointing) which load entirely the tables into memory.
This class allows to read a table completely independantly of the ASDM it belongs to and of the other tables of the ASDM.

Parameters

T	The parameter T must be the type of one of the tables which can be found in an ASDM (e.g. AntennaTable)
R	The parameter R must be the type of the rows which make the content of a table of type T (e.g. AntennaRow is T is AntennaTable).

Definition at line 39 of file TableStreamReader.h.

Member Enumeration Documentation

template<class T , class R >

enum asdm::TableStreamReader::State

private

Enumerator
S_CLOSED
S_OPENED

Definition at line 265 of file TableStreamReader.h.

template<class T , class R >

enum asdm::TableStreamReader::Transition

private

Enumerator
T_OPEN
T_CHECK
T_RESET
T_READ
T_CLOSE

Definition at line 266 of file TableStreamReader.h.

Constructor & Destructor Documentation

template<class T , class R >

asdm::TableStreamReader< T, R >::TableStreamReader ( )

inline

An empty constructor.

Definition at line 44 of file TableStreamReader.h.

References asdm::TableStreamReader< T, R >::boundary_1, asdm::TableStreamReader< T, R >::currentState, asdm::TableStreamReader< T, R >::readBuffer, READBUFFERSIZE, and asdm::TableStreamReader< T, R >::S_CLOSED.

template<class T , class R >

virtual asdm::TableStreamReader< T, R >::~TableStreamReader ( )

inlinevirtual

The destructor.

Definition at line 49 of file TableStreamReader.h.

Member Function Documentation

template<class T , class R >

std::string asdm::TableStreamReader< T, R >::accumulateUntilBoundary	(	const std::string &	boundary,
		int	maxLines
	)

inlineprivate

cout << "Entering accumulateUntilBoundary with maxLines = " << maxLines << std::endl;

not sure where this trim is coming from

Definition at line 415 of file TableStreamReader.h.

References casa::name(), asdm::TableStreamReader< T, R >::nextLine(), and casacore::trim().

Referenced by asdm::TableStreamReader< T, R >::open().

template<class T , class R >

void asdm::TableStreamReader< T, R >::checkState	(	Transition	t,
		const std::string &	methodName
	)		const

inlineprivate

Definition at line 269 of file TableStreamReader.h.

References asdm::TableStreamReader< T, R >::currentState, casa::name(), asdm::TableStreamReader< T, R >::S_CLOSED, asdm::TableStreamReader< T, R >::S_OPENED, asdm::TableStreamReader< T, R >::T_CHECK, asdm::TableStreamReader< T, R >::T_CLOSE, asdm::TableStreamReader< T, R >::T_OPEN, asdm::TableStreamReader< T, R >::T_READ, and asdm::TableStreamReader< T, R >::T_RESET.

Referenced by asdm::TableStreamReader< T, R >::close(), asdm::TableStreamReader< T, R >::hasRows(), asdm::TableStreamReader< T, R >::nextNRows(), asdm::TableStreamReader< T, R >::open(), asdm::TableStreamReader< T, R >::reset(), and asdm::TableStreamReader< T, R >::untilNBytes().

template<class T , class R >

void asdm::TableStreamReader< T, R >::clear ( )

inlineprivate

Empty the local storage containing the rows obtained during the last read operation.

Definition at line 282 of file TableStreamReader.h.

References asdm::TableStreamReader< T, R >::rows.

Referenced by asdm::TableStreamReader< T, R >::close(), asdm::TableStreamReader< T, R >::nextNRows(), asdm::TableStreamReader< T, R >::reset(), and asdm::TableStreamReader< T, R >::untilNBytes().

template<class T , class R >

void asdm::TableStreamReader< T, R >::close ( )

inline

Releases all the resources allocated to the instance which can be reused with another file.

Update the state.

Definition at line 239 of file TableStreamReader.h.

References asdm::TableStreamReader< T, R >::checkState(), asdm::TableStreamReader< T, R >::clear(), asdm::TableStreamReader< T, R >::currentState, free(), asdm::TableStreamReader< T, R >::readBuffer, asdm::TableStreamReader< T, R >::S_CLOSED, asdm::TableStreamReader< T, R >::T_CLOSE, and asdm::TableStreamReader< T, R >::tableFile.

template<class T , class R >

bool asdm::TableStreamReader< T, R >::hasRows ( )

inline

Returns true if the end of the file has not been reached.

Definition at line 231 of file TableStreamReader.h.

References asdm::TableStreamReader< T, R >::checkState(), asdm::TableStreamReader< T, R >::endBoundarySizeInBytes, asdm::TableStreamReader< T, R >::fileSizeInBytes, asdm::TableStreamReader< T, R >::T_CHECK, and asdm::TableStreamReader< T, R >::tableFile.

Referenced by asdm::TableStreamReader< T, R >::nextNRows(), and asdm::TableStreamReader< T, R >::untilNBytes().

template<class T , class R >

std::pair<std::string, std::string> asdm::TableStreamReader< T, R >::headerField2Pair ( const std::string & hf )

inlineprivate

Definition at line 324 of file TableStreamReader.h.

References casa::name(), casacore::trim(), and casacore::value().

Referenced by asdm::TableStreamReader< T, R >::requireHeaderField(), and asdm::TableStreamReader< T, R >::requireMIMEHeader().

template<class T , class R >

std::string asdm::TableStreamReader< T, R >::nextLine ( )

inlineprivate

cout << "nextLine has read '" << currentLine << "'" << std::endl;

Definition at line 312 of file TableStreamReader.h.

References asdm::TableStreamReader< T, R >::currentLine, casa::name(), asdm::TableStreamReader< T, R >::tableFile, and asdm::TableStreamReader< T, R >::tablePath.

Referenced by asdm::TableStreamReader< T, R >::accumulateUntilBoundary(), asdm::TableStreamReader< T, R >::requireBoundary(), asdm::TableStreamReader< T, R >::requireHeaderField(), asdm::TableStreamReader< T, R >::requireMIMEHeader(), and asdm::TableStreamReader< T, R >::skipUntilEmptyLine().

template<class T , class R >

const std::vector<R*>& asdm::TableStreamReader< T, R >::nextNRows ( unsigned int nRows )

inline

Reads at most n rows in the file, creates as many memory representations of these rows and return the reference of a vector of pointers on these representations.

Parameters

nRows the maximum number of rows to read.

Returns: a constant reference to a vector of pointers on instances of R.

Definition at line 194 of file TableStreamReader.h.

References asdm::TableStreamReader< T, R >::asdm, asdm::TableStreamReader< T, R >::attributesSeq, asdm::TableStreamReader< T, R >::checkState(), asdm::TableStreamReader< T, R >::clear(), asdm::TableStreamReader< T, R >::eifs, asdm::ASDM::getTable(), asdm::TableStreamReader< T, R >::hasRows(), casa::name(), asdm::TableStreamReader< T, R >::rows, and asdm::TableStreamReader< T, R >::T_READ.

template<class T , class R >

void asdm::TableStreamReader< T, R >::open ( const std::string & directory )

inline

Opens a file expected to contain an ASDM table of type T with rows of type R.

Parameters

directory the path to the directory containing the file.

Open the file.

Determine the size of the file.

And start parsing the content.

cout << "boundary_1 = " << boundary_1 << std::endl;

We have the xmlHeader, let's parse it.

Then it's an "old fashioned" MIME file for tables. Just try to deserialize it with Big_Endian for the bytes ordering.

It's a new (and correct) MIME file for tables.

1st) Look for a BulkStoreRef element with an attribute byteOrder.

Skip the two first children (Entity and ContainerEntity).

We found BulkStoreRef, now look for its attribute byteOrder.

2nd) Look for the Attributes element and grab the names of the elements it contains.

Create an EndianIFStream from the substring containing the binary part.

We do nothing with that but we have to read it.

Let's read numRows but ignore it and rely on the value specified in the ASDM.xml file.

Memorize the starting point of rows.

find where the rows end, seek to near the end

the accumulateUntilBoundary looks at "lines", but it may be starting from inside the binary part where null values might be found At most, there might be 100 bytes of null, or 100 lines. So limit the search to 100 lines before giving up.

the full size of the boundary and anything after it

reset back to start of rows

Update the state

Definition at line 58 of file TableStreamReader.h.

template<class T , class R >

void asdm::TableStreamReader< T, R >::requireBoundary	(	const std::string &	boundary,
		int	maxLines
	)

inlineprivate

cout << "Entering require boundary with boundary == '" << boundary << "' and maxLines = " << maxLines << std::endl;

Definition at line 398 of file TableStreamReader.h.

References casa::name(), and asdm::TableStreamReader< T, R >::nextLine().

Referenced by asdm::TableStreamReader< T, R >::open().

template<class T , class R >

std::string asdm::TableStreamReader< T, R >::requireBoundaryInCT ( const std::string & ctValue )

inlineprivate

Definition at line 449 of file TableStreamReader.h.

References casa::name(), casa::utilj::split(), and asdm::TableStreamReader< T, R >::unquote().

Referenced by asdm::TableStreamReader< T, R >::requireMIMEHeader().

template<class T , class R >

std::pair<std::string, std::string> asdm::TableStreamReader< T, R >::requireHeaderField ( const std::string & hf )

inlineprivate

Definition at line 373 of file TableStreamReader.h.

References asdm::TableStreamReader< T, R >::currentLine, asdm::TableStreamReader< T, R >::headerField2Pair(), casa::name(), and asdm::TableStreamReader< T, R >::nextLine().

Referenced by asdm::TableStreamReader< T, R >::requireMIMEHeader().

template<class T , class R >

std::string asdm::TableStreamReader< T, R >::requireMIMEHeader ( )

inlineprivate

MIME-Version

cout << name_value.first << "=" << name_value.second << std::endl; if (currentLine != "MIME-Version: 1.0") // a work around for the case when the very first character is not the expected "M" (happened with some corrupted data).

Content-Type

cout << "boundary_1 =" << boundary_1 << std::endl;

Content-Description name_value = requireHeaderField("CONTENT-DESCRIPTION");

Content-Location name_value = requireHeaderField("CONTENT-LOCATION");

Look for an empty line in the at most 10 subsequent lines.

Definition at line 343 of file TableStreamReader.h.

References asdm::TableStreamReader< T, R >::boundary_1, asdm::TableStreamReader< T, R >::currentLine, asdm::TableStreamReader< T, R >::headerField2Pair(), casa::name(), asdm::TableStreamReader< T, R >::nextLine(), asdm::TableStreamReader< T, R >::requireBoundaryInCT(), asdm::TableStreamReader< T, R >::requireHeaderField(), casacore::C::second, asdm::TableStreamReader< T, R >::skipUntilEmptyLine(), and asdm::TableStreamReader< T, R >::tablePath.

Referenced by asdm::TableStreamReader< T, R >::open().

template<class T , class R >

void asdm::TableStreamReader< T, R >::reset ( )

inline

Repositions the read head to the beginning of the table.

The internal storage containing the result of the last read operation is cleared.

Definition at line 182 of file TableStreamReader.h.

References asdm::TableStreamReader< T, R >::checkState(), asdm::TableStreamReader< T, R >::clear(), asdm::TableStreamReader< T, R >::T_RESET, asdm::TableStreamReader< T, R >::tableFile, and asdm::TableStreamReader< T, R >::whereRowsStart.

template<class T , class R >

void asdm::TableStreamReader< T, R >::skipUntilEmptyLine ( int maxSkips )

inlineprivate

cout << "Entering skipUntilEmptyLine" << std::endl;

not sure where this trim is coming from

cout << "Exiting skipUntilEmptyLine" << std::endl;

Definition at line 288 of file TableStreamReader.h.

References casa::name(), asdm::TableStreamReader< T, R >::nextLine(), and casacore::trim().

Referenced by asdm::TableStreamReader< T, R >::open(), and asdm::TableStreamReader< T, R >::requireMIMEHeader().

template<class T , class R >

std::string asdm::TableStreamReader< T, R >::unquote	(	const std::string &	s,
		std::string &	unquoted
	)

inlineprivate

Definition at line 475 of file TableStreamReader.h.

Referenced by asdm::TableStreamReader< T, R >::requireBoundaryInCT().

template<class T , class R >

const std::vector<R*>& asdm::TableStreamReader< T, R >::untilNBytes ( unsigned int nBytes )

inline

Reads as many rows as possible in the file, keeps their in memory representation until the number of read bytes is greater or equal a number of bytes, n, passed as a parameter to the method.

Parameters