Column (apache-cassandra API)

java.lang.Object
- org.apache.cassandra.db.Column

All Implemented Interfaces:

IColumn, OnDiskAtom

Direct Known Subclasses:

CounterColumn, CounterUpdateColumn, DeletedColumn, ExpiringColumn
```
public class Column
extends java.lang.Object
implements IColumn
```
Column is immutable, which prevents all kinds of confusion in a multithreaded environment. (TODO: look at making SuperColumn immutable too. This is trickier but is probably doable with something like PCollections -- http://code.google.com

Nested Class Summary
- Nested classes/interfaces inherited from interface org.apache.cassandra.db.OnDiskAtom
  OnDiskAtom.Serializer

Field Summary

Fields
Modifier and Type Field and Description

protected java.nio.ByteBuffer name

protected long timestamp

protected java.nio.ByteBuffer value
- Fields inherited from interface org.apache.cassandra.db.IColumn
  MAX_NAME_LENGTH

Fields
Modifier and Type	Field and Description
`protected java.nio.ByteBuffer`	`name`
`protected long`	`timestamp`
`protected java.nio.ByteBuffer`	`value`

Constructor Summary

Constructors
Constructor and Description
`Column(java.nio.ByteBuffer name, java.nio.ByteBuffer value)`
`Column(java.nio.ByteBuffer name, java.nio.ByteBuffer value, long timestamp)`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addColumn(IColumn column)`
`void`	`addColumn(IColumn column, Allocator allocator)`
`static Column`	`create(boolean value, long timestamp, java.lang.String... names)`
`static Column`	`create(java.nio.ByteBuffer value, long timestamp, java.lang.String... names)`
`static Column`	`create(double value, long timestamp, java.lang.String... names)`
`static Column`	`create(java.net.InetAddress value, long timestamp, java.lang.String... names)`
`static Column`	`create(int value, long timestamp, java.lang.String... names)`
`static Column`	`create(java.lang.String value, long timestamp, java.lang.String... names)`
`int`	`dataSize()` the size of user-provided data, not including internal overhead
`IColumn`	`diff(IColumn column)`
`boolean`	`equals(java.lang.Object o)`
`int`	`getLocalDeletionTime()`
`long`	`getMarkedForDeleteAt()`
`java.lang.String`	`getString(AbstractType<?> comparator)`
`Column`	`getSubColumn(java.nio.ByteBuffer columnName)`
`java.util.Collection<IColumn>`	`getSubColumns()`
`int`	`hashCode()`
`boolean`	`hasIrrelevantData(int gcBefore)`
`boolean`	`isLive()` For a simple column, live == !isMarkedForDelete.
`boolean`	`isMarkedForDelete()`
`IColumn`	`localCopy(ColumnFamilyStore cfs)` clones the column for the row cache, interning column names and making copies of other underlying byte buffers
`IColumn`	`localCopy(ColumnFamilyStore cfs, Allocator allocator)` clones the column for the memtable, interning column names and making copies of other underlying byte buffers.
`long`	`maxTimestamp()` For a standard column, this is the same as timestamp().
`long`	`minTimestamp()` For a standard column, this is the same as timestamp().
`long`	`mostRecentLiveChangeAt()`
`long`	`mostRecentNonGCableChangeAt(int gcbefore)`
`java.nio.ByteBuffer`	`name()`
`static OnDiskAtom.Serializer`	`onDiskSerializer()`
`IColumn`	`reconcile(IColumn column)`
`IColumn`	`reconcile(IColumn column, Allocator allocator)`
`int`	`serializationFlags()`
`int`	`serializedSize(TypeSizes typeSizes)`
`long`	`serializedSizeForSSTable()`
`static ColumnSerializer`	`serializer()`
`long`	`timestamp()`
`void`	`updateDigest(java.security.MessageDigest digest)`
`void`	`validateFields(CFMetaData metadata)`
`protected void`	`validateName(CFMetaData metadata)`
`java.nio.ByteBuffer`	`value()`

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - name
```
protected final java.nio.ByteBuffer name
```
  - value
```
protected final java.nio.ByteBuffer value
```
  - timestamp
```
protected final long timestamp
```
- Constructor Detail
  - Column
```
public Column(java.nio.ByteBuffer name,
      java.nio.ByteBuffer value)
```
  - Column
```
public Column(java.nio.ByteBuffer name,
      java.nio.ByteBuffer value,
      long timestamp)
```
- Method Detail
  - serializer
```
public static ColumnSerializer serializer()
```
  - onDiskSerializer
```
public static OnDiskAtom.Serializer onDiskSerializer()
```
  - name
```
public java.nio.ByteBuffer name()
```
    Specified by:
    
    name in interface OnDiskAtom
  - getSubColumn
```
public Column getSubColumn(java.nio.ByteBuffer columnName)
```
    Specified by:
    
    getSubColumn in interface IColumn
  - value
```
public java.nio.ByteBuffer value()
```
    Specified by:
    
    value in interface IColumn
  - getSubColumns
```
public java.util.Collection<IColumn> getSubColumns()
```
    Specified by:
    
    getSubColumns in interface IColumn
  - timestamp
```
public long timestamp()
```
    Specified by:
    
    timestamp in interface IColumn
  - minTimestamp
```
public long minTimestamp()
```
    Description copied from interface: OnDiskAtom
    
    For a standard column, this is the same as timestamp(). For a super column, this is the min/max column timestamp of the sub columns.
    
    Specified by:
    
    minTimestamp in interface OnDiskAtom
  - maxTimestamp
```
public long maxTimestamp()
```
    Description copied from interface: IColumn
    
    For a standard column, this is the same as timestamp(). For a super column, this is the max column timestamp of the sub columns.
    
    Specified by:
    
    maxTimestamp in interface IColumn
    
    Specified by:
    
    maxTimestamp in interface OnDiskAtom
  - isMarkedForDelete
```
public boolean isMarkedForDelete()
```
    Specified by:
    
    isMarkedForDelete in interface IColumn
    
    Returns:
    true if the column has been deleted (is a tombstone). This depends on comparing the server clock with getLocalDeletionTime, so it can change during a single request if you're not careful.
  - getMarkedForDeleteAt
```
public long getMarkedForDeleteAt()
```
    Specified by:
    
    getMarkedForDeleteAt in interface IColumn
  - mostRecentLiveChangeAt
```
public long mostRecentLiveChangeAt()
```
    Specified by:
    
    mostRecentLiveChangeAt in interface IColumn
  - mostRecentNonGCableChangeAt
```
public long mostRecentNonGCableChangeAt(int gcbefore)
```
    Specified by:
    
    mostRecentNonGCableChangeAt in interface IColumn
  - dataSize
```
public int dataSize()
```
    Description copied from interface: IColumn
    
    the size of user-provided data, not including internal overhead
    
    Specified by:
    
    dataSize in interface IColumn
  - serializedSize
```
public int serializedSize(TypeSizes typeSizes)
```
    Specified by:
    
    serializedSize in interface OnDiskAtom
  - serializedSizeForSSTable
```
public long serializedSizeForSSTable()
```
    Specified by:
    
    serializedSizeForSSTable in interface OnDiskAtom
  - serializationFlags
```
public int serializationFlags()
```
    Specified by:
    
    serializationFlags in interface IColumn
  - addColumn
```
public void addColumn(IColumn column)
```
    Specified by:
    
    addColumn in interface IColumn
  - addColumn
```
public void addColumn(IColumn column,
             Allocator allocator)
```
    Specified by:
    
    addColumn in interface IColumn
  - diff
```
public IColumn diff(IColumn column)
```
    Specified by:
    
    diff in interface IColumn
  - updateDigest
```
public void updateDigest(java.security.MessageDigest digest)
```
    Specified by:
    
    updateDigest in interface OnDiskAtom
  - getLocalDeletionTime
```
public int getLocalDeletionTime()
```
    Specified by:
    
    getLocalDeletionTime in interface OnDiskAtom
  - reconcile
```
public IColumn reconcile(IColumn column)
```
    Specified by:
    
    reconcile in interface IColumn
  - reconcile
```
public IColumn reconcile(IColumn column,
                Allocator allocator)
```
    Specified by:
    
    reconcile in interface IColumn
  - equals
```
public boolean equals(java.lang.Object o)
```
    Overrides:
    
    equals in class java.lang.Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object
  - localCopy
```
public IColumn localCopy(ColumnFamilyStore cfs)
```
    Description copied from interface: IColumn
    
    clones the column for the row cache, interning column names and making copies of other underlying byte buffers
    
    Specified by:
    
    localCopy in interface IColumn
  - localCopy
```
public IColumn localCopy(ColumnFamilyStore cfs,
                Allocator allocator)
```
    Description copied from interface: IColumn
    
    clones the column for the memtable, interning column names and making copies of other underlying byte buffers. Unlike the other localCopy, this uses Allocator to allocate values in contiguous memory regions, which helps avoid heap fragmentation.
    
    Specified by:
    
    localCopy in interface IColumn
  - getString
```
public java.lang.String getString(AbstractType<?> comparator)
```
    Specified by:
    
    getString in interface IColumn
  - isLive
```
public boolean isLive()
```
    Description copied from interface: IColumn
    
    For a simple column, live == !isMarkedForDelete. For a supercolumn, live means it has at least one subcolumn whose timestamp is greater than the supercolumn deleted-at time.
    
    Specified by:
    
    isLive in interface IColumn
  - validateName
```
protected void validateName(CFMetaData metadata)
                     throws MarshalException
```
    Throws:
    
    MarshalException
  - validateFields
```
public void validateFields(CFMetaData metadata)
                    throws MarshalException
```
    Specified by:
    
    validateFields in interface IColumn
    
    Specified by:
    
    validateFields in interface OnDiskAtom
    
    Throws:
    
    MarshalException
  - hasIrrelevantData
```
public boolean hasIrrelevantData(int gcBefore)
```
    Specified by:
    
    hasIrrelevantData in interface IColumn
    
    Returns:
    true if the column or any its subcolumns is no longer relevant after @param gcBefore
  - create
```
public static Column create(java.lang.String value,
            long timestamp,
            java.lang.String... names)
```
  - create
```
public static Column create(int value,
            long timestamp,
            java.lang.String... names)
```
  - create
```
public static Column create(boolean value,
            long timestamp,
            java.lang.String... names)
```
  - create
```
public static Column create(double value,
            long timestamp,
            java.lang.String... names)
```
  - create
```
public static Column create(java.nio.ByteBuffer value,
            long timestamp,
            java.lang.String... names)
```
  - create
```
public static Column create(java.net.InetAddress value,
            long timestamp,
            java.lang.String... names)
```

Class Column

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.cassandra.db.OnDiskAtom

Field Summary

Fields inherited from interface org.apache.cassandra.db.IColumn

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

name

value

timestamp

Constructor Detail

Column

Column

Method Detail

serializer

onDiskSerializer

name

getSubColumn

value

getSubColumns

timestamp

minTimestamp

maxTimestamp

isMarkedForDelete

getMarkedForDeleteAt

mostRecentLiveChangeAt

mostRecentNonGCableChangeAt

dataSize

serializedSize

serializedSizeForSSTable

serializationFlags

addColumn

addColumn

diff

updateDigest

getLocalDeletionTime

reconcile

reconcile

equals

hashCode

localCopy

localCopy

getString

isLive

validateName

validateFields

hasIrrelevantData

create

create

create

create

create

create