Cell (Apache HBase 2.5.0 API)

All Superinterfaces:

HeapSize

All Known Subinterfaces:

ExtendedCell, RawCell

All Known Implementing Classes:

BufferedDataBlockEncoder.OffheapDecodedExtendedCell, BufferedDataBlockEncoder.OnheapDecodedCell, ByteBufferChunkKeyValue, ByteBufferExtendedCell, ByteBufferKeyOnlyKeyValue, ByteBufferKeyValue, IndividualBytesFieldCell, KeyOnlyFilter.KeyOnlyByteBufferExtendedCell, KeyOnlyFilter.KeyOnlyCell, KeyValue, KeyValue.KeyOnlyKeyValue, MapReduceExtendedCell, Mutation.CellWrapper, NoTagByteBufferChunkKeyValue, NoTagsByteBufferKeyValue, NoTagsKeyValue, PrivateCellUtil.EmptyByteBufferExtendedCell, PrivateCellUtil.EmptyCell, PrivateCellUtil.FirstOnRowByteBufferExtendedCell, PrivateCellUtil.FirstOnRowCell, PrivateCellUtil.FirstOnRowColByteBufferExtendedCell, PrivateCellUtil.FirstOnRowColCell, PrivateCellUtil.FirstOnRowColTSByteBufferExtendedCell, PrivateCellUtil.FirstOnRowColTSCell, PrivateCellUtil.FirstOnRowDeleteFamilyCell, PrivateCellUtil.LastOnRowByteBufferExtendedCell, PrivateCellUtil.LastOnRowCell, PrivateCellUtil.LastOnRowColByteBufferExtendedCell, PrivateCellUtil.LastOnRowColCell, PrivateCellUtil.TagRewriteByteBufferExtendedCell, PrivateCellUtil.TagRewriteCell, PrivateCellUtil.ValueAndTagRewriteByteBufferExtendedCell, PrivateCellUtil.ValueAndTagRewriteCell, SizeCachedByteBufferKeyValue, SizeCachedKeyValue, SizeCachedNoTagsByteBufferKeyValue, SizeCachedNoTagsKeyValue
```
@InterfaceAudience.Public
public interface Cell
extends HeapSize
```
The unit of storage in HBase consisting of the following fields:
```
 1) row
 2) column family
 3) column qualifier
 4) timestamp
 5) type
 6) MVCC version
 7) value
 
```
Uniqueness is determined by the combination of row, column family, column qualifier, timestamp, and type.

The natural comparator will perform a bitwise comparison on row, column family, and column qualifier. Less intuitively, it will then treat the greater timestamp as the lesser value with the goal of sorting newer cells first.

Cell implements Comparable<Cell> which is only meaningful when comparing to other keys in the same table. It uses CellComparator which does not work on the -ROOT- and hbase:meta tables.

In the future, we may consider adding a boolean isOnHeap() method and a getValueBuffer() method that can be used to pass a value directly from an off-heap ByteBuffer to the network without copying into an on-heap byte[].

Historic note: the original Cell implementation (KeyValue) requires that all fields be encoded as consecutive bytes in the same byte[], whereas this interface allows fields to reside in separate byte[]'s.

Nested Class Summary

Nested Classes
Modifier and Type Interface and Description

static class Cell.Type
The valid types for user to build the cell.

Nested Classes
Modifier and Type	Interface and Description
`static class`	`Cell.Type` The valid types for user to build the cell.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods Deprecated Methods
Modifier and Type	Method and Description
`byte[]`	`getFamilyArray()` Contiguous bytes composed of legal HDFS filename characters which may start at any index in the containing array.
`byte`	`getFamilyLength()` Returns Number of family bytes.
`int`	`getFamilyOffset()` Returns Array index of first family byte
`byte[]`	`getQualifierArray()` Contiguous raw bytes that may start at any index in the containing array.
`int`	`getQualifierLength()` Returns Number of qualifier bytes.
`int`	`getQualifierOffset()` Returns Array index of first qualifier byte
`byte[]`	`getRowArray()` Contiguous raw bytes that may start at any index in the containing array.
`short`	`getRowLength()` Returns Number of row bytes.
`int`	`getRowOffset()` Returns Array index of first row byte
`long`	`getSequenceId()` Deprecated. As of HBase-2.0. Will be removed in HBase-3.0.
`int`	`getSerializedSize()` Returns Serialized size (defaults to include tag length if has some tags).
`byte[]`	`getTagsArray()` Deprecated. As of HBase-2.0. Will be removed in HBase-3.0. Tags are are now internal.
`int`	`getTagsLength()` Deprecated. As of HBase-2.0. Will be removed in HBase-3.0. Tags are are now internal.
`int`	`getTagsOffset()` Deprecated. As of HBase-2.0. Will be removed in HBase-3.0. Tags are are now internal.
`long`	`getTimestamp()` Return a long value representing time at which this cell was "Put" into the row.
`default Cell.Type`	`getType()` Returns the type of cell in a human readable format using `Cell.Type`.
`byte`	`getTypeByte()` Deprecated. As of HBase-2.0. Will be removed in HBase-3.0. Use `getType()`.
`byte[]`	`getValueArray()` Contiguous raw bytes that may start at any index in the containing array.
`int`	`getValueLength()` Returns Number of value bytes.
`int`	`getValueOffset()` Returns Array index of first value byte

Methods inherited from interface org.apache.hadoop.hbase.io.HeapSize
heapSize

- Method Detail
  - getRowArray
```
byte[] getRowArray()
```
    Contiguous raw bytes that may start at any index in the containing array. Max length is Short.MAX_VALUE which is 32,767 bytes.
    
    Returns:
    
    The array containing the row bytes.
  - getRowOffset
```
int getRowOffset()
```
    Returns Array index of first row byte
  - getRowLength
```
short getRowLength()
```
    Returns Number of row bytes. Must be < rowArray.length - offset.
  - getFamilyArray
```
byte[] getFamilyArray()
```
    Contiguous bytes composed of legal HDFS filename characters which may start at any index in the containing array. Max length is Byte.MAX_VALUE, which is 127 bytes.
    
    Returns:
    
    the array containing the family bytes.
  - getFamilyOffset
```
int getFamilyOffset()
```
    Returns Array index of first family byte
  - getFamilyLength
```
byte getFamilyLength()
```
    Returns Number of family bytes. Must be < familyArray.length - offset.
  - getQualifierArray
```
byte[] getQualifierArray()
```
    Contiguous raw bytes that may start at any index in the containing array.
    
    Returns:
    
    The array containing the qualifier bytes.
  - getQualifierOffset
```
int getQualifierOffset()
```
    Returns Array index of first qualifier byte
  - getQualifierLength
```
int getQualifierLength()
```
    Returns Number of qualifier bytes. Must be < qualifierArray.length - offset.
  - getTimestamp
```
long getTimestamp()
```
    Return a long value representing time at which this cell was "Put" into the row. Typically represents the time of insertion, but can be any value from 0 to Long.MAX_VALUE.
  - getTypeByte
```
@Deprecated
byte getTypeByte()
```
    Deprecated. As of HBase-2.0. Will be removed in HBase-3.0. Use getType().
    
    Return the byte representation of the KeyValue.TYPE of this cell: one of Put, Delete, etc
  - getSequenceId
```
@Deprecated
long getSequenceId()
```
    Deprecated. As of HBase-2.0. Will be removed in HBase-3.0.
    
    A region-specific unique monotonically increasing sequence ID given to each Cell. It always exists for cells in the memstore but is not retained forever. It will be kept for HConstants.KEEP_SEQID_PERIOD days, but generally becomes irrelevant after the cell's row is no longer involved in any operations that require strict consistency.
    
    Returns:
    
    seqId (always > 0 if exists), or 0 if it no longer exists
  - getValueArray
```
byte[] getValueArray()
```
    Contiguous raw bytes that may start at any index in the containing array. Max length is Integer.MAX_VALUE which is 2,147,483,647 bytes.
    
    Returns:
    
    The array containing the value bytes.
  - getValueOffset
```
int getValueOffset()
```
    Returns Array index of first value byte
  - getValueLength
```
int getValueLength()
```
    Returns Number of value bytes. Must be < valueArray.length - offset.
  - getSerializedSize
```
int getSerializedSize()
```
    Returns Serialized size (defaults to include tag length if has some tags).
  - getTagsArray
```
@Deprecated
byte[] getTagsArray()
```
    Deprecated. As of HBase-2.0. Will be removed in HBase-3.0. Tags are are now internal.
    
    Contiguous raw bytes representing tags that may start at any index in the containing array.
    
    Returns:
    
    the tags byte array
  - getTagsOffset
```
@Deprecated
int getTagsOffset()
```
    Deprecated. As of HBase-2.0. Will be removed in HBase-3.0. Tags are are now internal.
    
    Return the first offset where the tags start in the Cell
  - getTagsLength
```
@Deprecated
int getTagsLength()
```
    Deprecated. As of HBase-2.0. Will be removed in HBase-3.0. Tags are are now internal.
    
    HBase internally uses 2 bytes to store tags length in Cell. As the tags length is always a non-negative number, to make good use of the sign bit, the max of tags length is defined 2 * Short.MAX_VALUE + 1 = 65535. As a result, the return type is int, because a short is not capable of handling that. Please note that even if the return type is int, the max tags length is far less than Integer.MAX_VALUE.
    
    Returns:
    
    the total length of the tags in the Cell.
  - getType
```
default Cell.Type getType()
```
    Returns the type of cell in a human readable format using Cell.Type. Note : This does not expose the internal types of Cells like KeyValue.Type.Maximum and KeyValue.Type.Minimum
    
    Returns:
    
    The data type this cell: one of Put, Delete, etc

Interface Cell

Nested Class Summary

Method Summary

Methods inherited from interface org.apache.hadoop.hbase.io.HeapSize

Method Detail

getRowArray

getRowOffset

getRowLength

getFamilyArray

getFamilyOffset

getFamilyLength

getQualifierArray

getQualifierOffset

getQualifierLength

getTimestamp

getTypeByte

getSequenceId

getValueArray

getValueOffset

getValueLength

getSerializedSize

getTagsArray

getTagsOffset

getTagsLength

getType