Make a common interface for different versions of the BlockHeader arising from different evio versions. More...

#include <IBlockHeader.h>

Public Member Functions
virtual uint32_t	getSize ()=0
	Get the size of the block (record) in 32 bit words. More...

virtual uint32_t	getNumber ()=0
	Get the block number for this block (record). More...

virtual uint32_t	getHeaderWords ()=0
	Get the block (record) header length, in 32 bit words. More...

virtual uint32_t	getSourceId ()=0
	Get the source ID number if in CODA online context and data is coming from ROC. More...

virtual bool	hasFirstEvent ()=0
	Does this block/record contain the "first event" (first event to be written to each file split)? More...

virtual uint32_t	getEventType ()=0
	Get the type of events in block/record (see values of DataType. More...

virtual uint32_t	getVersion ()=0
	Get the evio version of the block (record) header. More...

virtual uint32_t	getMagicNumber ()=0
	Get the magic number the block (record) header which should be 0xc0da0100. More...

virtual ByteOrder &	getByteOrder ()=0
	Get the byte order of the data being read. More...

virtual size_t	getBufferEndingPosition ()=0
	Get the position in the buffer (bytes) of this block's last data word. More...

virtual size_t	getBufferStartingPosition ()=0
	Get the starting position in the buffer (bytes) from which this header was read–if that happened. More...

virtual void	setBufferStartingPosition (size_t pos)=0
	Set the starting position in the buffer (bytes) from which this header was read–if that happened. More...

virtual size_t	nextBufferStartingPosition ()=0
	Determines where the start of the next block (record) header in some buffer is located (bytes). More...

virtual size_t	firstEventStartingPosition ()=0
	Determines where the start of the first event in this block (record) is located (bytes). More...

virtual size_t	bytesRemaining (size_t position)=0
	Gives the bytes remaining in this block (record) given a buffer position. More...

virtual bool	hasDictionary ()=0
	Does this block contain an evio dictionary? More...

virtual bool	isLastBlock ()=0
	Is this the last block in the file or being sent over the network? More...

virtual bool	isCompressed ()=0
	Is this the data in this block compressed? More...

virtual Compressor::CompressionType	getCompressionType ()=0
	Get the type of data compression used. More...

virtual size_t	write (ByteBuffer &byteBuffer)=0
	Write myself out into a byte buffer. More...

virtual std::string	toString ()=0
	Get the string representation of the block (record) header. More...

Static Public Attributes
static const uint32_t	MAGIC_NUMBER = 0xc0da0100
	The magic number, should be the value of `magicNumber`. More...

static const uint32_t	MAGIC_OFFSET = 28
	Byte offset from beginning of header to the magic number. More...

static const uint32_t	BIT_INFO_OFFSET = 20
	Byte offset from beginning of header to bit info word. More...

static const uint32_t	VERSION_MASK = 0xff
	Mask to get version number from bitinfo word in header. More...

Detailed Description

Make a common interface for different versions of the BlockHeader arising from different evio versions.

In evio version 4 and later, blocks are called records.

Date: 06/5/2020

Author: timmer

Member Function Documentation

virtual size_t evio::IBlockHeader::bytesRemaining ( size_t position )

pure virtual

Gives the bytes remaining in this block (record) given a buffer position.

The position is an absolute position in a byte buffer. This assumes that the absolute position in bufferStartingPosition is being maintained properly by the reader.

Parameters

position the absolute current position in a byte buffer.

Returns: the number of bytes remaining in this block (record).

Exceptions

EvioException if position out of bounds

Implemented in evio::BlockHeaderV4, evio::RecordHeader, and evio::BlockHeaderV2.

virtual size_t evio::IBlockHeader::firstEventStartingPosition ( )

pure virtual

Determines where the start of the first event in this block (record) is located (bytes).

This assumes the start position has been maintained by the object performing the buffer read.

Returns: where the start of the first event in this block (record) is located (bytes). In evio format version 2, returns 0 if start is 0, signaling that this entire record is part of a logical record that spans at least three physical records.

Implemented in evio::BlockHeaderV4, evio::RecordHeader, and evio::BlockHeaderV2.

virtual size_t evio::IBlockHeader::getBufferEndingPosition ( )

pure virtual

Get the position in the buffer (bytes) of this block's last data word.

Returns: position in the buffer (bytes) of this block's last data word.

Implemented in evio::BlockHeaderV4, evio::RecordHeader, and evio::BlockHeaderV2.

virtual size_t evio::IBlockHeader::getBufferStartingPosition ( )

pure virtual

Get the starting position in the buffer (bytes) from which this header was read–if that happened.

This is not part of the block header proper. It is a position in a memory buffer of the start of the block (record). It is kept for convenience. It is up to the reader to set it.

Returns: starting position in buffer (bytes) from which this header was read–if that happened.

Implemented in evio::BlockHeaderV4, evio::RecordHeader, and evio::BlockHeaderV2.

virtual ByteOrder& evio::IBlockHeader::getByteOrder ( )

pure virtual

Get the byte order of the data being read.

Returns: byte order of the data being read.

Implemented in evio::BlockHeaderV4, evio::RecordHeader, and evio::BlockHeaderV2.

virtual Compressor::CompressionType evio::IBlockHeader::getCompressionType ( )

pure virtual

Get the type of data compression used.

Returns: type of data compression used.

Implemented in evio::RecordHeader, evio::BlockHeaderV4, and evio::BlockHeaderV2.

virtual uint32_t evio::IBlockHeader::getEventType ( )

pure virtual

Get the type of events in block/record (see values of DataType.

This is not supported by versions 1-3 which returns 0.

Returns: type of events in block/record, or 0 if evio version 1-3.

Implemented in evio::RecordHeader, evio::BlockHeaderV4, and evio::BlockHeaderV2.

virtual uint32_t evio::IBlockHeader::getHeaderWords ( )

pure virtual

Get the block (record) header length, in 32 bit words.

Returns: block (record) header length, in 32 bit words.

Implemented in evio::RecordHeader, evio::BlockHeaderV2, and evio::BlockHeaderV4.

virtual uint32_t evio::IBlockHeader::getMagicNumber ( )

pure virtual

Get the magic number the block (record) header which should be 0xc0da0100.

Returns: magic number in the block (record).

Implemented in evio::BlockHeaderV4, evio::RecordHeader, and evio::BlockHeaderV2.

virtual uint32_t evio::IBlockHeader::getNumber ( )

pure virtual

Get the block number for this block (record).

In a file, this is usually sequential, starting at 1.

Returns: the block number for this block (record).

Implemented in evio::RecordHeader, evio::BlockHeaderV2, and evio::BlockHeaderV4.

virtual uint32_t evio::IBlockHeader::getSize ( )

pure virtual

Get the size of the block (record) in 32 bit words.

Returns: size of the block (record) in 32 bit words.

Implemented in evio::RecordHeader, evio::BlockHeaderV4, and evio::BlockHeaderV2.

virtual uint32_t evio::IBlockHeader::getSourceId ( )

pure virtual

Get the source ID number if in CODA online context and data is coming from ROC.

Returns: source ID number if in CODA online context and data is coming from ROC.

Implemented in evio::BlockHeaderV4, evio::RecordHeader, and evio::BlockHeaderV2.

virtual uint32_t evio::IBlockHeader::getVersion ( )

pure virtual

Get the evio version of the block (record) header.

Returns: evio version of the block (record) header.

Implemented in evio::RecordHeader, evio::BlockHeaderV2, and evio::BlockHeaderV4.

virtual bool evio::IBlockHeader::hasDictionary ( )

pure virtual

Does this block contain an evio dictionary?

Returns: true if this block contains an evio dictionary, else false. Always returns false for versions 1-3 (not implemented).

Implemented in evio::RecordHeader, evio::BlockHeaderV4, and evio::BlockHeaderV2.

virtual bool evio::IBlockHeader::hasFirstEvent ( )

pure virtual

Does this block/record contain the "first event" (first event to be written to each file split)?

Returns: true if this record has the first event, else false. Evio versions 1-3 always return false.

Implemented in evio::RecordHeader, evio::BlockHeaderV4, and evio::BlockHeaderV2.

virtual bool evio::IBlockHeader::isCompressed ( )

pure virtual

Is this the data in this block compressed?

Returns: true if the data in this block is compressed, else false.

Implemented in evio::RecordHeader, evio::BlockHeaderV4, and evio::BlockHeaderV2.

virtual bool evio::IBlockHeader::isLastBlock ( )

pure virtual

Is this the last block in the file or being sent over the network?

Returns: true if this is the last block in the file or being sent over the network, else false. Always returns false for versions 1-3 (not implemented).

Implemented in evio::RecordHeader, evio::BlockHeaderV4, and evio::BlockHeaderV2.

virtual size_t evio::IBlockHeader::nextBufferStartingPosition ( )

pure virtual

Determines where the start of the next block (record) header in some buffer is located (bytes).

This assumes the start position has been maintained by the object performing the buffer read.

Returns: the start of the next block (record) header in some buffer is located (bytes).

Implemented in evio::BlockHeaderV4, evio::RecordHeader, and evio::BlockHeaderV2.

virtual void evio::IBlockHeader::setBufferStartingPosition ( size_t pos )

pure virtual

Set the starting position in the buffer (bytes) from which this header was read–if that happened.

This is not part of the block header proper. It is a position in a memory buffer of the start of the block (record). It is kept for convenience. It is up to the reader to set it.

Parameters