IBlockHeader

All Known Implementing Classes:

BlockHeaderV2, BlockHeaderV4
```
public interface IBlockHeader
```
Make a common interface for different versions of the BlockHeader.

Author:

timmer

Field Summary

Fields
Modifier and Type Field and Description

static int MAGIC_NUMBER
The magic number, should be the value of magicNumber.

Fields
Modifier and Type	Field and Description
`static int`	`MAGIC_NUMBER` The magic number, should be the value of `magicNumber`.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`int`	`bytesRemaining(long position)` Gives the bytes remaining in this block (physical record) given a buffer position.
`long`	`firstEventStartingPosition()` Determines where the start of the first event (logical record) in this block (physical record) is located (in bytes).
`long`	`getBufferEndingPosition()` Get the position in the buffer (in bytes) of this block's last data word.
`long`	`getBufferStartingPosition()` Get the starting position in the buffer (in bytes) from which this header was read--if that happened. This is not part of the block header proper.
`java.nio.ByteOrder`	`getByteOrder()` Get the byte order of the data being read.
`int`	`getHeaderLength()` Get the block header length, in ints.
`int`	`getMagicNumber()` Get the magic number the block (physical record) header which should be 0xc0da0100.
`int`	`getNumber()` Get the block number for this block (physical record).
`int`	`getSize()` Get the size of the block (physical record).
`int`	`getVersion()` Get the evio version of the block (physical record) header.
`boolean`	`hasDictionary()` Is this block's first event is an evio dictionary?
`boolean`	`isLastBlock()` Is this the last block in the file or being sent over the network?
`long`	`nextBufferStartingPosition()` Determines where the start of the next block (physical record) header in some buffer is located (in bytes).
`void`	`setBufferStartingPosition(long bufferStartingPosition)` Set the starting position in the buffer (in bytes) from which this header was read--if that happened. This is not part of the block header proper.
`java.lang.String`	`toString()` Obtain a string representation of the block (physical record) header.
`int`	`write(java.nio.ByteBuffer byteBuffer)` Write myself out a byte buffer.

- Field Detail
  - MAGIC_NUMBER
```
static final int MAGIC_NUMBER
```
    The magic number, should be the value of magicNumber.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - getSize
```
int getSize()
```
    Get the size of the block (physical record).
    
    Returns:
    
    the size of the block (physical record) in ints.
  - getNumber
```
int getNumber()
```
    Get the block number for this block (physical record). In a file, this is usually sequential.
    
    Returns:
    
    the block number for this block (physical record).
  - getHeaderLength
```
int getHeaderLength()
```
    Get the block header length, in ints. This should be 8.
    
    Returns:
    
    the block header length. This should be 8.
  - getVersion
```
int getVersion()
```
    Get the evio version of the block (physical record) header.
    
    Returns:
    
    the evio version of the block (physical record) header.
  - getMagicNumber
```
int getMagicNumber()
```
    Get the magic number the block (physical record) header which should be 0xc0da0100.
    
    Returns:
    
    the magic number in the block (physical record).
  - getByteOrder
```
java.nio.ByteOrder getByteOrder()
```
    Get the byte order of the data being read.
    
    Returns:
    
    the byte order of the data being read.
  - getBufferEndingPosition
```
long getBufferEndingPosition()
```
    Get the position in the buffer (in bytes) of this block's last data word.
    
    Returns:
    
    the position in the buffer (in bytes) of this block's last data word.
  - getBufferStartingPosition
```
long getBufferStartingPosition()
```
    Get the starting position in the buffer (in 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 (physical record). It is kept for convenience. It is up to the reader to set it.
    
    Returns:
    
    the starting position in the buffer (in bytes) from which this header was read--if that happened.
  - setBufferStartingPosition
```
void setBufferStartingPosition(long bufferStartingPosition)
```
    Set the starting position in the buffer (in 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 (physical record). It is kept for convenience. It is up to the reader to set it.
    
    Parameters:
    
    bufferStartingPosition - the starting position in the buffer from which this header was read--if that happened.
  - nextBufferStartingPosition
```
long nextBufferStartingPosition()
```
    Determines where the start of the next block (physical record) header in some buffer is located (in bytes). This assumes the start position has been maintained by the object performing the buffer read.
    
    Returns:
    
    the start of the next block (physical record) header in some buffer is located (in bytes).
  - firstEventStartingPosition
```
long firstEventStartingPosition()
```
    Determines where the start of the first event (logical record) in this block (physical record) is located (in bytes). This assumes the start position has been maintained by the object performing the buffer read.
    
    Returns:
    
    where the start of the first event (logical record) in this block (physical record) is located (in bytes). Returns 0 if start is 0, signaling that this entire physical record is part of a logical record that spans at least three physical records.
  - bytesRemaining
```
int bytesRemaining(long position)
            throws EvioException
```
    Gives the bytes remaining in this block (physical 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. No block is longer than 2.1GB - 31 bits of length. This is for practical reasons - so a block can be read into a single byte array.
    
    Parameters:
    
    position - the absolute current position is a byte buffer.
    
    Returns:
    
    the number of bytes remaining in this block (physical record.)
    
    Throws:
    
    EvioException - if position out of bounds
  - hasDictionary
```
boolean hasDictionary()
```
    Is this block's first event is an evio dictionary?
    
    Returns:
    
    true if this block's first event is an evio dictionary, else false
  - isLastBlock
```
boolean isLastBlock()
```
    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
  - write
```
int write(java.nio.ByteBuffer byteBuffer)
```
    Write myself out a byte buffer. This write is relative--i.e., it uses the current position of the buffer.
    
    Parameters:
    
    byteBuffer - the byteBuffer to write to.
    
    Returns:
    
    the number of bytes written, which for a BlockHeader is 32.
  - toString
```
java.lang.String toString()
```
    Obtain a string representation of the block (physical record) header.
    
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    a string representation of the block (physical record) header.

Interface IBlockHeader

Field Summary

Method Summary

Field Detail

MAGIC_NUMBER

Method Detail

getSize

getNumber

getHeaderLength

getVersion

getMagicNumber

getByteOrder

getBufferEndingPosition

getBufferStartingPosition

setBufferStartingPosition

nextBufferStartingPosition

firstEventStartingPosition

bytesRemaining

hasDictionary

isLastBlock

write

toString