FileHeader

java.lang.Object
- org.jlab.coda.hipo.FileHeader

All Implemented Interfaces:: java.lang.Cloneable

public class FileHeader
extends java.lang.Object
implements java.lang.Cloneable

This class represents the file header of an evio or hipo format file.



 FILE HEADER STRUCTURE ( 56 bytes, 14 integers (32 bit) )

    +----------------------------------+
  1 |              ID                  | // HIPO: 0x43455248, Evio: 0x4556494F
    +----------------------------------+
  2 +          File Number             | // split file #
    +----------------------------------+
  3 +         Header Length            | // 14 (words)
    +----------------------------------+
  4 +      Record (Index) Count        |
    +----------------------------------+
  5 +      Index Array Length          | // bytes
    +-----------------------+----------+
  6 +       Bit Info        | Version  | // version (8 bits)
    +-----------------------+----------+
  7 +      User Header Length          | // bytes
    +----------------------------------+
  8 +          Magic Number            | // 0xc0da0100
    +----------------------------------+
  9 +          User Register           | 
    +--                              --+
 10 +                                  |
    +----------------------------------+
 11 +         Trailer Position         | // File offset to trailer head (64 bits).
    +--                              --+ // 0 = no offset available or no trailer exists.
 12 +                                  |
    +----------------------------------+
 13 +          User Integer 1          |
    +----------------------------------+
 14 +          User Integer 2          |
    +----------------------------------+

 -------------------
   Bit Info Word
 -------------------
     0-7  = version
     8    = true if dictionary is included (relevant for first record only)
     9    = true if this file has "first" event (in every split file)
    10    = File trailer with index array of record lengths exists
    11-19 = reserved
    20-21 = pad 1
    22-23 = pad 2
    24-25 = pad 3 (always 0)
    26-27 = reserved
    28-31 = general header type: 1 = Evio file
                                 2 = Evio extended file
                                 5 = HIPO file
                                 6 = HIPO extended file

Since:: 6.0 9/6/17
Version:: 6.0
Author:: gavalian, timmer

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`BIT_INFO_OFFSET` Byte offset from beginning of header to bit info word.
`static int`	`EVIO_FILE_UNIQUE_WORD` First word in every Evio file for identification purposes.
`static int`	`FILE_ID_OFFSET` Byte offset from beginning of header to the file id.
`static int`	`FILE_NUMBER_OFFSET` Byte offset from beginning of header to the file number.
`static int`	`HEADER_LENGTH_OFFSET` Byte offset from beginning of header to the header length.
`static int`	`HEADER_MAGIC` Magic number used to track endianness.
`static int`	`HEADER_SIZE_BYTES` Number of bytes in a normal sized header.
`static int`	`HEADER_SIZE_WORDS` Number of 32-bit words in a normal sized header.
`static int`	`HIPO_FILE_UNIQUE_WORD` First word in every HIPO file for identification purposes.
`static int`	`INDEX_ARRAY_OFFSET` Byte offset from beginning of header to the index array length.
`static int`	`INT1_OFFSET` Byte offset from beginning of header to the user integer #1.
`static int`	`INT2_OFFSET` Byte offset from beginning of header to the user integer #2.
`static int`	`MAGIC_OFFSET` Byte offset from beginning of header to the record length.
`static int`	`RECORD_COUNT_OFFSET` Byte offset from beginning of header to the record count.
`static int`	`REGISTER1_OFFSET` Byte offset from beginning of header to the user register #1.
`static int`	`TRAILER_POSITION_OFFSET` Byte offset from beginning of header to write trailer position.
`static int`	`USER_LENGTH_OFFSET` Byte offset from beginning of header to the user header length.

Constructor Summary

Constructors
Constructor and Description

FileHeader()
Default, no-arg constructor.

FileHeader(boolean isEvio)
Constructor which sets the type of header this is and file id.

Constructors
Constructor and Description
`FileHeader()` Default, no-arg constructor.
`FileHeader(boolean isEvio)` Constructor which sets the type of header this is and file id.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static void`	`byteBufferBinaryString(java.nio.ByteBuffer buffer)` Print out each word of the given buffer as binary, hex, and decimal.
`java.lang.Object`	`clone()`
`void`	`copy(FileHeader head)` Copy the contents of the arg into this object.
`int`	`getBitInfoWord()` Get the bit info word.
`java.nio.ByteOrder`	`getByteOrder()` Get the byte order of the file this header was read from.
`int`	`getEntries()` Get the number of events or entries in index.
`int`	`getFileId()` Get the file id.
`int`	`getFileNumber()` Get the file number or split number.
`HeaderType`	`getFileType()` Get the file's type.
`static HeaderType`	`getFileType(int word)` Get the file's type from the bit info word.
`int`	`getHeaderLength()` Get the length of this header data in bytes.
`HeaderType`	`getHeaderType()` Get the type of header this is.
`int`	`getIndexLength()` Get the length of the index array in bytes.
`int`	`getLength()` Get the total length of header + index + user header (including padding) in bytes.
`long`	`getPosition()` Get the position of this record in a file.
`long`	`getTrailerPosition()` Get the trailer's (trailing header's) file position in bytes.
`int`	`getUserHeaderLength()` Get the length of the user-defined header in bytes.
`int`	`getUserHeaderLengthPadding()` Get the user header's padding - the number of bytes required to bring uncompressed user header to 4-byte boundary.
`int`	`getUserHeaderLengthWords()` Get the length of the user-defined header in words.
`int`	`getUserIntFirst()` Get the first user integer value.
`int`	`getUserIntSecond()` Get the second user integer value.
`long`	`getUserRegister()` Get the user register value.
`int`	`getVersion()` Get the Evio format version number.
`boolean`	`hasDictionary()` Does this header have a dictionary in the file header?
`int`	`hasDictionary(boolean hasDictionary)` Set the bit in the file header which says there is a dictionary.
`static boolean`	`hasDictionary(int bitInfo)` Does this bitInfo arg indicate the existence of a dictionary in the file header?
`boolean`	`hasFirstEvent()` Does this header have a first event in the file header?
`int`	`hasFirstEvent(boolean hasFirst)` Set the bit which says file has a first event.
`static boolean`	`hasFirstEvent(int bitInfo)` Does this bitInfo arg indicate the existence of a first event in the file header?
`boolean`	`hasIndex()` Does this file have a valid index of record lengths immediately following header? There should be at least one integer for valid index.
`boolean`	`hasTrailerWithIndex()` Does this file have a trailer with a record length index?
`int`	`hasTrailerWithIndex(boolean hasTrailerWithIndex)` Set the bit in the file header which says there is a trailer with a record length index.
`static boolean`	`hasTrailerWithIndex(int bitInfo)` Does this bitInfo arg indicate the existence of a trailer with a record length index?
`boolean`	`hasUserHeader()` Is this header followed by a user header?
`static void`	`main(java.lang.String[] args)` Run this class as an executable which tests the writing and reading of a record.
`void`	`readHeader(java.nio.ByteBuffer buffer)` Reads the file header information from a byte buffer and validates it by checking the magic word (8th word).
`void`	`readHeader(java.nio.ByteBuffer buffer, int offset)` Reads the file header information from a byte buffer and validates it by checking the magic word (8th word).
`void`	`reset()` Reset most internal variables (not file id and header type).
`int`	`setBitInfo(boolean haveFirst, boolean haveDictionary, boolean haveTrailerWithIndex)` Set the bit info word for a file header.
`FileHeader`	`setEntries(int n)` Set the number of record entries.
`FileHeader`	`setFileNumber(int num)` Set the file number which is the split number starting at 1.
`FileHeader`	`setHeaderLength(int length)` Set the this header's length in bytes and words.
`FileHeader`	`setIndexLength(int length)` Set the length of the index array in bytes.
`FileHeader`	`setLength(int length)` Set the total length in bytes, header + index + user header.
`FileHeader`	`setPosition(long pos)` Set the position of this record in a file.
`FileHeader`	`setUserHeaderLength(int length)` Set the user-defined header's length in bytes and words and the padding.
`FileHeader`	`setUserIntFirst(int val)` Set the first user integer.
`FileHeader`	`setUserIntSecond(int val)` Set the second user integer.
`FileHeader`	`setUserRegister(long val)` Set the first user register.
`java.lang.String`	`toString()` Returns a string representation of the record.
`void`	`writeHeader(java.nio.ByteBuffer buffer)` Writes the file (not record!) header into the given byte buffer starting at beginning.
`void`	`writeHeader(java.nio.ByteBuffer buf, int off)` Writes the file (not record!) header into the given byte buffer.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - HIPO_FILE_UNIQUE_WORD
```
public static final int HIPO_FILE_UNIQUE_WORD
```
    First word in every HIPO file for identification purposes.
    
    See Also:
    
    Constant Field Values
  - EVIO_FILE_UNIQUE_WORD
```
public static final int EVIO_FILE_UNIQUE_WORD
```
    First word in every Evio file for identification purposes.
    
    See Also:
    
    Constant Field Values
  - HEADER_SIZE_WORDS
```
public static final int HEADER_SIZE_WORDS
```
    Number of 32-bit words in a normal sized header.
    
    See Also:
    
    Constant Field Values
  - HEADER_SIZE_BYTES
```
public static final int HEADER_SIZE_BYTES
```
    Number of bytes in a normal sized header.
    
    See Also:
    
    Constant Field Values
  - HEADER_MAGIC
```
public static final int HEADER_MAGIC
```
    Magic number used to track endianness.
    
    See Also:
    
    Constant Field Values
  - FILE_ID_OFFSET
```
public static final int FILE_ID_OFFSET
```
    Byte offset from beginning of header to the file id.
    
    See Also:
    
    Constant Field Values
  - FILE_NUMBER_OFFSET
```
public static final int FILE_NUMBER_OFFSET
```
    Byte offset from beginning of header to the file number.
    
    See Also:
    
    Constant Field Values
  - HEADER_LENGTH_OFFSET
```
public static final int HEADER_LENGTH_OFFSET
```
    Byte offset from beginning of header to the header length.
    
    See Also:
    
    Constant Field Values
  - RECORD_COUNT_OFFSET
```
public static final int RECORD_COUNT_OFFSET
```
    Byte offset from beginning of header to the record count.
    
    See Also:
    
    Constant Field Values
  - INDEX_ARRAY_OFFSET
```
public static final int INDEX_ARRAY_OFFSET
```
    Byte offset from beginning of header to the index array length.
    
    See Also:
    
    Constant Field Values
  - BIT_INFO_OFFSET
```
public static final int BIT_INFO_OFFSET
```
    Byte offset from beginning of header to bit info word.
    
    See Also:
    
    Constant Field Values
  - USER_LENGTH_OFFSET
```
public static final int USER_LENGTH_OFFSET
```
    Byte offset from beginning of header to the user header length.
    
    See Also:
    
    Constant Field Values
  - MAGIC_OFFSET
```
public static final int MAGIC_OFFSET
```
    Byte offset from beginning of header to the record length.
    
    See Also:
    
    Constant Field Values
  - REGISTER1_OFFSET
```
public static final int REGISTER1_OFFSET
```
    Byte offset from beginning of header to the user register #1.
    
    See Also:
    
    Constant Field Values
  - TRAILER_POSITION_OFFSET
```
public static final int TRAILER_POSITION_OFFSET
```
    Byte offset from beginning of header to write trailer position.
    
    See Also:
    
    Constant Field Values
  - INT1_OFFSET
```
public static final int INT1_OFFSET
```
    Byte offset from beginning of header to the user integer #1.
    
    See Also:
    
    Constant Field Values
  - INT2_OFFSET
```
public static final int INT2_OFFSET
```
    Byte offset from beginning of header to the user integer #2.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - FileHeader
```
public FileHeader()
```
    Default, no-arg constructor.
  - FileHeader
```
public FileHeader(boolean isEvio)
```
    Constructor which sets the type of header this is and file id.
    
    Parameters:
    
    isEvio - if true, file has EVIO file id and header type, else is HIPO.
- Method Detail
  - clone
```
public java.lang.Object clone()
```
    Overrides:
    
    clone in class java.lang.Object
  - copy
```
public void copy(FileHeader head)
```
    Copy the contents of the arg into this object.
    
    Parameters:
    
    head - object to copy
  - reset
```
public void reset()
```
    Reset most internal variables (not file id and header type).
  - getByteOrder
```
public java.nio.ByteOrder getByteOrder()
```
    Get the byte order of the file this header was read from. Defaults to little endian.
    
    Returns:
    
    byte order of the file this header was read from.
  - getFileNumber
```
public int getFileNumber()
```
    Get the file number or split number.
    
    Returns:
    
    file number.
  - getFileId
```
public int getFileId()
```
    Get the file id.
    
    Returns:
    
    file id.
  - getUserRegister
```
public long getUserRegister()
```
    Get the user register value.
    
    Returns:
    
    user register value.
  - getTrailerPosition
```
public long getTrailerPosition()
```
    Get the trailer's (trailing header's) file position in bytes.
    
    Returns:
    
    trailer's (trailing header's) file position in bytes.
  - getUserIntFirst
```
public int getUserIntFirst()
```
    Get the first user integer value.
    
    Returns:
    
    first user integer value.
  - getUserIntSecond
```
public int getUserIntSecond()
```
    Get the second user integer value.
    
    Returns:
    
    second user integer value.
  - getPosition
```
public long getPosition()
```
    Get the position of this record in a file.
    
    Returns:
    
    position of this record in a file.
  - getEntries
```
public int getEntries()
```
    Get the number of events or entries in index.
    
    Returns:
    
    number of events or entries in index.
  - getUserHeaderLength
```
public int getUserHeaderLength()
```
    Get the length of the user-defined header in bytes.
    
    Returns:
    
    length of the user-defined header in bytes.
  - getUserHeaderLengthWords
```
public int getUserHeaderLengthWords()
```
    Get the length of the user-defined header in words.
    
    Returns:
    
    length of the user-defined header in words.
  - getVersion
```
public int getVersion()
```
    Get the Evio format version number.
    
    Returns:
    
    Evio format version number.
  - getIndexLength
```
public int getIndexLength()
```
    Get the length of the index array in bytes.
    
    Returns:
    
    length of the index array in bytes.
  - getHeaderLength
```
public int getHeaderLength()
```
    Get the length of this header data in bytes.
    
    Returns:
    
    length of this header data in bytes.
  - getHeaderType
```
public HeaderType getHeaderType()
```
    Get the type of header this is.
    
    Returns:
    
    type of header this is.
  - getLength
```
public int getLength()
```
    Get the total length of header + index + user header (including padding) in bytes. Never compressed.
    
    Returns:
    
    total length of header + index + user header (including padding) in bytes.
  - getUserHeaderLengthPadding
```
public int getUserHeaderLengthPadding()
```
    Get the user header's padding - the number of bytes required to bring uncompressed user header to 4-byte boundary.
    
    Returns:
    
    user header's padding
  - getBitInfoWord
```
public int getBitInfoWord()
```
    Get the bit info word.
    
    Returns:
    
    bit info word.
  - setBitInfo
```
public int setBitInfo(boolean haveFirst,
                      boolean haveDictionary,
                      boolean haveTrailerWithIndex)
```
    Set the bit info word for a file header. Retains current header type, user header length padding, and version.
    
    Parameters:
    
    haveFirst - true if file has first event.
    
    haveDictionary - true if file has dictionary in user header.
    
    haveTrailerWithIndex - true if file has trailer with record length index.
    
    Returns:
    
    new bit info word.
  - getFileType
```
public HeaderType getFileType()
```
    Get the file's type.
    
    Returns:
    
    the file's HeaderType.
  - getFileType
```
public static HeaderType getFileType(int word)
```
    Get the file's type from the bit info word.
    
    Parameters:
    
    word - bit-info word.
    
    Returns:
    
    the file's HeaderType.
  - hasFirstEvent
```
public int hasFirstEvent(boolean hasFirst)
```
    Set the bit which says file has a first event.
    
    Parameters:
    
    hasFirst - true if file has a first event.
    
    Returns:
    
    new bitInfo word.
  - hasFirstEvent
```
public boolean hasFirstEvent()
```
    Does this header have a first event in the file header?
    
    Returns:
    
    true if header has a first event in the file header, else false.
  - hasFirstEvent
```
public static boolean hasFirstEvent(int bitInfo)
```
    Does this bitInfo arg indicate the existence of a first event in the file header?
    
    Parameters:
    
    bitInfo - bitInfo word.
    
    Returns:
    
    true if header has a first event in the file header, else false.
  - hasDictionary
```
public int hasDictionary(boolean hasDictionary)
```
    Set the bit in the file header which says there is a dictionary.
    
    Parameters:
    
    hasDictionary - true if file has a dictionary.
    
    Returns:
    
    new bitInfo word.
  - hasDictionary
```
public boolean hasDictionary()
```
    Does this header have a dictionary in the file header?
    
    Returns:
    
    true if header has a dictionary in the file header, else false.
  - hasDictionary
```
public static boolean hasDictionary(int bitInfo)
```
    Does this bitInfo arg indicate the existence of a dictionary in the file header?
    
    Parameters:
    
    bitInfo - bitInfo word.
    
    Returns:
    
    true if header has a dictionary in the file header, else false.
  - hasTrailerWithIndex
```
public int hasTrailerWithIndex(boolean hasTrailerWithIndex)
```
    Set the bit in the file header which says there is a trailer with a record length index.
    
    Parameters:
    
    hasTrailerWithIndex - true if file has a trailer with a record length index.
    
    Returns:
    
    new bitInfo word.
  - hasTrailerWithIndex
```
public boolean hasTrailerWithIndex()
```
    Does this file have a trailer with a record length index?
    
    Returns:
    
    true if file has a trailer with a record length index, else false.
  - hasTrailerWithIndex
```
public static boolean hasTrailerWithIndex(int bitInfo)
```
    Does this bitInfo arg indicate the existence of a trailer with a record length index?
    
    Parameters:
    
    bitInfo - bitInfo word.
    
    Returns:
    
    true if file has a trailer with a record length index, else false.
  - hasUserHeader
```
public boolean hasUserHeader()
```
    Is this header followed by a user header?
    
    Returns:
    
    true if header followed by a user header, else false.
  - hasIndex
```
public boolean hasIndex()
```
    Does this file have a valid index of record lengths immediately following header? There should be at least one integer for valid index. Must have integral number of entries.
    
    Returns:
    
    true if file has a valid index, else false.
  - setFileNumber
```
public FileHeader setFileNumber(int num)
```
    Set the file number which is the split number starting at 1.
    
    Parameters:
    
    num - file number starting at 1.
    
    Returns:
    
    this object.
  - setUserRegister
```
public FileHeader setUserRegister(long val)
```
    Set the first user register.
    
    Parameters:
    
    val - first user register.
    
    Returns:
    
    this object.
  - setUserIntFirst
```
public FileHeader setUserIntFirst(int val)
```
    Set the first user integer.
    
    Parameters:
    
    val - first user integer.
    
    Returns:
    
    this object.
  - setUserIntSecond
```
public FileHeader setUserIntSecond(int val)
```
    Set the second user integer.
    
    Parameters:
    
    val - second user integer.
    
    Returns:
    
    this object.
  - setPosition
```
public FileHeader setPosition(long pos)
```
    Set the position of this record in a file.
    
    Parameters:
    
    pos - position of this record in a file.
    
    Returns:
    
    this object.
  - setIndexLength
```
public FileHeader setIndexLength(int length)
```
    Set the length of the index array in bytes. Length is forced to be a multiple of 4! Sets the total length too.
    
    Parameters:
    
    length - length of index array in bytes.
    
    Returns:
    
    this object.
  - setEntries
```
public FileHeader setEntries(int n)
```
    Set the number of record entries. No compression for other values.
    
    Parameters:
    
    n - number of record entries.
    
    Returns:
    
    this object.
  - setUserHeaderLength
```
public FileHeader setUserHeaderLength(int length)
```
    Set the user-defined header's length in bytes and words and the padding. Sets the total length too.
    
    Parameters:
    
    length - user-defined header's length in bytes.
    
    Returns:
    
    this object.
  - setHeaderLength
```
public FileHeader setHeaderLength(int length)
```
    Set the this header's length in bytes and words. Minimum length of 56 (14 words) is enforced. If length is not a multiple of 4, you're on your own! Sets the total length too.
    
    Parameters:
    
    length - this header's length in bytes.
    
    Returns:
    
    this object.
  - setLength
```
public FileHeader setLength(int length)
```
    Set the total length in bytes, header + index + user header. This includes padding and is on a 4-byte boundary. Never compressed.
    
    Parameters:
    
    length - total length in bytes, header + index + user header.
    
    Returns:
    
    this object.
  - writeHeader
```
public void writeHeader(java.nio.ByteBuffer buf,
                        int off)
                 throws HipoException
```
    Writes the file (not record!) header into the given byte buffer.
    
    Parameters:
    
    buf - byte buffer to write file header into.
    
    off - position in buffer to begin writing.
    
    Throws:
    
    HipoException - if buffer is null or contains too little room.
  - writeHeader
```
public void writeHeader(java.nio.ByteBuffer buffer)
                 throws HipoException
```
    Writes the file (not record!) header into the given byte buffer starting at beginning.
    
    Parameters:
    
    buffer - byte buffer to write file header into.
    
    Throws:
    
    HipoException - if buffer is null or contains too little room.
  - readHeader
```
public void readHeader(java.nio.ByteBuffer buffer,
                       int offset)
                throws HipoException
```
    Reads the file header information from a byte buffer and validates it by checking the magic word (8th word). This magic word also determines the byte order. The given buffer's position does NOT change.
    
    Parameters:
    
    buffer - buffer to read from.
    
    offset - position of first word to be read.
    
    Throws:
    
    HipoException - if buffer is null, remaining buffer space (limit - off) is too small, data is not in proper format, or version earlier than 6.
  - readHeader
```
public void readHeader(java.nio.ByteBuffer buffer)
                throws HipoException
```
    Reads the file header information from a byte buffer and validates it by checking the magic word (8th word). This magic word also determines the byte order. The given buffer's position does NOT change.
    
    Parameters:
    
    buffer - buffer to read from starting at the beginning.
    
    Throws:
    
    HipoException - if buffer is not in the proper format or earlier than version 6
  - toString
```
public java.lang.String toString()
```
    Returns a string representation of the record.
    
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    a string representation of the record.
  - byteBufferBinaryString
```
public static void byteBufferBinaryString(java.nio.ByteBuffer buffer)
```
    Print out each word of the given buffer as binary, hex, and decimal.
    
    Parameters:
    
    buffer - buffer to print out.
  - main
```
public static void main(java.lang.String[] args)
```
    Run this class as an executable which tests the writing and reading of a record.
    
    Parameters:
    
    args - args

Class FileHeader

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

HIPO_FILE_UNIQUE_WORD

EVIO_FILE_UNIQUE_WORD

HEADER_SIZE_WORDS

HEADER_SIZE_BYTES

HEADER_MAGIC

FILE_ID_OFFSET

FILE_NUMBER_OFFSET

HEADER_LENGTH_OFFSET

RECORD_COUNT_OFFSET

INDEX_ARRAY_OFFSET

BIT_INFO_OFFSET

USER_LENGTH_OFFSET

MAGIC_OFFSET

REGISTER1_OFFSET

TRAILER_POSITION_OFFSET

INT1_OFFSET

INT2_OFFSET

Constructor Detail

FileHeader

FileHeader

Method Detail

clone

copy

reset

getByteOrder

getFileNumber

getFileId

getUserRegister

getTrailerPosition

getUserIntFirst

getUserIntSecond

getPosition

getEntries

getUserHeaderLength

getUserHeaderLengthWords

getVersion

getIndexLength

getHeaderLength

getHeaderType

getLength

getUserHeaderLengthPadding

getBitInfoWord

setBitInfo

getFileType

getFileType

hasFirstEvent

hasFirstEvent

hasFirstEvent

hasDictionary

hasDictionary

hasDictionary

hasTrailerWithIndex

hasTrailerWithIndex

hasTrailerWithIndex

hasUserHeader

hasIndex

setFileNumber

setUserRegister

setUserIntFirst

setUserIntSecond

setPosition

setIndexLength

setEntries

setUserHeaderLength

setHeaderLength

setLength

writeHeader

writeHeader

readHeader

readHeader

toString

byteBufferBinaryString

main