org.apache.accumulo.core.data

Class Key

java.lang.Object

org.apache.accumulo.core.data.Key

All Implemented Interfaces:

Cloneable, Comparable<Key>, org.apache.hadoop.io.Writable, org.apache.hadoop.io.WritableComparable<Key>

public class Key
extends Object
implements org.apache.hadoop.io.WritableComparable<Key>, Cloneable

This is the Key used to store and access individual values in Accumulo. A Key is a tuple composed of a row, column family, column qualifier, column visibility, timestamp, and delete marker. Keys are comparable and therefore have a sorted order defined by compareTo(Key).

Field Summary

Fields

Modifier and Type	Field and Description
protected byte[]	colFamily
protected byte[]	colQualifier
protected byte[]	colVisibility
protected boolean	deleted
protected byte[]	row
protected long	timestamp

Constructor Summary

Constructors

Constructor and Description
Key() Creates a key with empty row, empty column family, empty column qualifier, empty column visibility, timestamp Long.MAX_VALUE, and delete marker false.
Key(byte[] row, byte[] colFamily, byte[] colQualifier, byte[] colVisibility, long timestamp) Creates a key.
Key(byte[] row, byte[] cf, byte[] cq, byte[] cv, long ts, boolean deleted) Creates a key.
Key(byte[] row, byte[] cf, byte[] cq, byte[] cv, long ts, boolean deleted, boolean copy) Creates a key.
Key(byte[] row, int rOff, int rLen, byte[] cf, int cfOff, int cfLen, byte[] cq, int cqOff, int cqLen, byte[] cv, int cvOff, int cvLen, long ts) Creates a key.
Key(CharSequence row) Converts CharSequence to Text and creates a Key using Key(Text).
Key(CharSequence row, CharSequence cf) Converts CharSequence to Text and creates a Key using Key(Text,Text).
Key(CharSequence row, CharSequence cf, CharSequence cq) Converts CharSequence to Text and creates a Key using Key(Text,Text,Text).
Key(CharSequence row, CharSequence cf, CharSequence cq, CharSequence cv) Converts CharSequence to Text and creates a Key using Key(Text,Text,Text,Text).
Key(CharSequence row, CharSequence cf, CharSequence cq, CharSequence cv, long ts) Converts CharSequence to Text and creates a Key using Key(Text,Text,Text,Text,long).
Key(CharSequence row, CharSequence cf, CharSequence cq, ColumnVisibility cv, long ts) Converts CharSequence to Text and creates a Key using Key(Text,Text,Text,ColumnVisibility,long).
Key(CharSequence row, CharSequence cf, CharSequence cq, long ts) Converts CharSequence to Text and creates a Key using Key(Text,Text,Text,long).
Key(Key other) Creates a key with the same row, column family, column qualifier, column visibility, timestamp, and delete marker as the given key.
Key(org.apache.hadoop.io.Text row) Creates a key with the specified row, empty column family, empty column qualifier, empty column visibility, timestamp Long.MAX_VALUE, and delete marker false.
Key(org.apache.hadoop.io.Text row, long ts) Creates a key with the specified row, empty column family, empty column qualifier, empty column visibility, the specified timestamp, and delete marker false.
Key(org.apache.hadoop.io.Text row, org.apache.hadoop.io.Text cf) Creates a key with the specified row, the specified column family, empty column qualifier, empty column visibility, timestamp Long.MAX_VALUE, and delete marker false.
Key(org.apache.hadoop.io.Text row, org.apache.hadoop.io.Text cf, org.apache.hadoop.io.Text cq) Creates a key with the specified row, the specified column family, the specified column qualifier, empty column visibility, timestamp Long.MAX_VALUE, and delete marker false.
Key(org.apache.hadoop.io.Text row, org.apache.hadoop.io.Text cf, org.apache.hadoop.io.Text cq, ColumnVisibility cv, long ts) Creates a key with the specified row, the specified column family, the specified column qualifier, the specified column visibility, the specified timestamp, and delete marker false.
Key(org.apache.hadoop.io.Text row, org.apache.hadoop.io.Text cf, org.apache.hadoop.io.Text cq, long ts) Creates a key with the specified row, the specified column family, the specified column qualifier, empty column visibility, the specified timestamp, and delete marker false.
Key(org.apache.hadoop.io.Text row, org.apache.hadoop.io.Text cf, org.apache.hadoop.io.Text cq, org.apache.hadoop.io.Text cv) Creates a key with the specified row, the specified column family, the specified column qualifier, the specified column visibility, timestamp Long.MAX_VALUE, and delete marker false.
Key(org.apache.hadoop.io.Text row, org.apache.hadoop.io.Text cf, org.apache.hadoop.io.Text cq, org.apache.hadoop.io.Text cv, long ts) Creates a key with the specified row, the specified column family, the specified column qualifier, the specified column visibility, the specified timestamp, and delete marker false.
Key(org.apache.accumulo.core.data.thrift.TKey tkey) Creates a key from Thrift.

Method Summary

Modifier and Type	Method and Description
static StringBuilder	appendPrintableString(byte[] ba, int offset, int len, int maxLen, StringBuilder sb) Appends ASCII printable characters to a string, based on the given byte array, treating the bytes as ASCII characters.
Object	clone()
int	compareColumnFamily(org.apache.hadoop.io.Text cf) Compares this key's column family with another.
int	compareColumnQualifier(org.apache.hadoop.io.Text cq) Compares this key's column qualifier with another.
int	compareRow(org.apache.hadoop.io.Text r) Compares this key's row ID with another.
int	compareTo(Key other)
int	compareTo(Key other, PartialKey part) Compares elements of a key given by a PartialKey.
static List<org.apache.accumulo.core.data.thrift.TKeyValue>	compress(List<? extends KeyValue> param) Compresses a list of key/value pairs before sending them via thrift.
static void	decompress(List<org.apache.accumulo.core.data.thrift.TKeyValue> param) Decompresses a list of key/value pairs received from thrift.
boolean	equals(Key other, PartialKey part) Compares part of a key.
boolean	equals(Object o)
Key	followingKey(PartialKey part) Returns a key that will sort immediately after this key.
org.apache.hadoop.io.Text	getColumnFamily() Gets the column family as a Text object.
org.apache.hadoop.io.Text	getColumnFamily(org.apache.hadoop.io.Text cf) Writes the column family into the given Text.
ByteSequence	getColumnFamilyData() Returns the column family as a byte sequence.
org.apache.hadoop.io.Text	getColumnQualifier() Gets the column qualifier as a Text object.
org.apache.hadoop.io.Text	getColumnQualifier(org.apache.hadoop.io.Text cq) Writes the column qualifier into the given Text.
ByteSequence	getColumnQualifierData() Returns the column qualifier as a byte sequence.
org.apache.hadoop.io.Text	getColumnVisibility() Gets the column visibility as a Text object.
org.apache.hadoop.io.Text	getColumnVisibility(org.apache.hadoop.io.Text cv) Writes the column visibvility into the given Text.
ByteSequence	getColumnVisibilityData() Returns the column visibility as a byte sequence.
ColumnVisibility	getColumnVisibilityParsed() Gets the column visibility.
int	getLength() Returns the sums of the lengths of the row, column family, column qualifier, and column visibility.
org.apache.hadoop.io.Text	getRow() Gets the row ID as a Text object.
org.apache.hadoop.io.Text	getRow(org.apache.hadoop.io.Text r) Writes the row ID into the given Text.
ByteSequence	getRowData() Returns the row ID as a byte sequence.
int	getSize() Same as getLength().
long	getTimestamp() Gets the timestamp.
int	hashCode()
boolean	isDeleted() Determines if this key is deleted (i.e., has a delete marker = true).
void	readFields(DataInput in)
void	set(Key k) Sets this key's row, column family, column qualifier, column visibility, timestamp, and delete marker to be the same as another key's.
void	setDeleted(boolean deleted) Sets the delete marker on this key.
void	setTimestamp(long ts) Sets the timestamp.
static String	toPrintableString(byte[] ba, int offset, int len, int maxLen) Returns an ASCII printable string form of the given byte array, treating the bytes as ASCII characters.
String	toString()
String	toStringNoTime() Converts this key to a string, not including timestamp or delete marker.
String	toStringNoTruncate() Stringify this Key, avoiding truncation of each component, only limiting each component to a length of Integer.MAX_VALUE
org.apache.accumulo.core.data.thrift.TKey	toThrift() Converts this key to Thrift.
void	write(DataOutput out)

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

row

protected byte[] row

colFamily

protected byte[] colFamily

colQualifier

protected byte[] colQualifier

colVisibility

protected byte[] colVisibility

timestamp

protected long timestamp

deleted

protected boolean deleted

Constructor Detail

Key

public Key()

Creates a key with empty row, empty column family, empty column qualifier, empty column visibility, timestamp Long.MAX_VALUE, and delete marker false.

Key

public Key(org.apache.hadoop.io.Text row)

Creates a key with the specified row, empty column family, empty column qualifier, empty column visibility, timestamp Long.MAX_VALUE, and delete marker false.

Parameters:

row - row ID

Key

public Key(org.apache.hadoop.io.Text row,
           long ts)

Creates a key with the specified row, empty column family, empty column qualifier, empty column visibility, the specified timestamp, and delete marker false.

Parameters:

row - row ID

ts - timestamp

Key

public Key(byte[] row,
           int rOff,
           int rLen,
           byte[] cf,
           int cfOff,
           int cfLen,
           byte[] cq,
           int cqOff,
           int cqLen,
           byte[] cv,
           int cvOff,
           int cvLen,
           long ts)

Creates a key. The delete marker defaults to false.

Parameters:

row - bytes containing row ID

rOff - offset into row where key's row ID begins (inclusive)

rLen - length of row ID in row

cf - bytes containing column family

cfOff - offset into cf where key's column family begins (inclusive)

cfLen - length of column family in cf

cq - bytes containing column qualifier

cqOff - offset into cq where key's column qualifier begins (inclusive)

cqLen - length of column qualifier in cq

cv - bytes containing column visibility

cvOff - offset into cv where key's column visibility begins (inclusive)

cvLen - length of column visibility in cv

ts - timestamp

Key

public Key(byte[] row,
           byte[] colFamily,
           byte[] colQualifier,
           byte[] colVisibility,
           long timestamp)

Creates a key. The delete marker defaults to false.

Parameters:

row - row ID

colFamily - column family

colQualifier - column qualifier

colVisibility - column visibility

timestamp - timestamp

Key

public Key(byte[] row,
           byte[] cf,
           byte[] cq,
           byte[] cv,
           long ts,
           boolean deleted)

Creates a key.

Parameters:

row - row ID

cf - column family

cq - column qualifier

cv - column visibility

ts - timestamp

deleted - delete marker

Key

public Key(byte[] row,
           byte[] cf,
           byte[] cq,
           byte[] cv,
           long ts,
           boolean deleted,
           boolean copy)

Creates a key.

Parameters:

row - row ID

cf - column family

cq - column qualifier

cv - column visibility

ts - timestamp

deleted - delete marker

copy - if true, forces copy of byte array values into key

Key

public Key(org.apache.hadoop.io.Text row,
           org.apache.hadoop.io.Text cf)

Creates a key with the specified row, the specified column family, empty column qualifier, empty column visibility, timestamp Long.MAX_VALUE, and delete marker false.

Key

public Key(org.apache.hadoop.io.Text row,
           org.apache.hadoop.io.Text cf,
           org.apache.hadoop.io.Text cq)

Creates a key with the specified row, the specified column family, the specified column qualifier, empty column visibility, timestamp Long.MAX_VALUE, and delete marker false.

Key

public Key(org.apache.hadoop.io.Text row,
           org.apache.hadoop.io.Text cf,
           org.apache.hadoop.io.Text cq,
           org.apache.hadoop.io.Text cv)

Creates a key with the specified row, the specified column family, the specified column qualifier, the specified column visibility, timestamp Long.MAX_VALUE, and delete marker false.

Key

public Key(org.apache.hadoop.io.Text row,
           org.apache.hadoop.io.Text cf,
           org.apache.hadoop.io.Text cq,
           long ts)

Creates a key with the specified row, the specified column family, the specified column qualifier, empty column visibility, the specified timestamp, and delete marker false.

Key

public Key(org.apache.hadoop.io.Text row,
           org.apache.hadoop.io.Text cf,
           org.apache.hadoop.io.Text cq,
           org.apache.hadoop.io.Text cv,
           long ts)

Creates a key with the specified row, the specified column family, the specified column qualifier, the specified column visibility, the specified timestamp, and delete marker false.

Key

public Key(org.apache.hadoop.io.Text row,
           org.apache.hadoop.io.Text cf,
           org.apache.hadoop.io.Text cq,
           ColumnVisibility cv,
           long ts)

Creates a key with the specified row, the specified column family, the specified column qualifier, the specified column visibility, the specified timestamp, and delete marker false.

Key

public Key(CharSequence row)

Converts CharSequence to Text and creates a Key using Key(Text).

Key

public Key(CharSequence row,
           CharSequence cf)

Converts CharSequence to Text and creates a Key using Key(Text,Text).

Key

public Key(CharSequence row,
           CharSequence cf,
           CharSequence cq)

Converts CharSequence to Text and creates a Key using Key(Text,Text,Text).

Key

public Key(CharSequence row,
           CharSequence cf,
           CharSequence cq,
           CharSequence cv)

Converts CharSequence to Text and creates a Key using Key(Text,Text,Text,Text).

Key

public Key(CharSequence row,
           CharSequence cf,
           CharSequence cq,
           long ts)

Converts CharSequence to Text and creates a Key using Key(Text,Text,Text,long).

Key

public Key(CharSequence row,
           CharSequence cf,
           CharSequence cq,
           CharSequence cv,
           long ts)

Converts CharSequence to Text and creates a Key using Key(Text,Text,Text,Text,long).

Key

public Key(CharSequence row,
           CharSequence cf,
           CharSequence cq,
           ColumnVisibility cv,
           long ts)

Converts CharSequence to Text and creates a Key using Key(Text,Text,Text,ColumnVisibility,long).

Key

public Key(Key other)

Creates a key with the same row, column family, column qualifier, column visibility, timestamp, and delete marker as the given key.

Key

public Key(org.apache.accumulo.core.data.thrift.TKey tkey)

Creates a key from Thrift.

Parameters:

tkey - Thrift key

Method Detail

equals

public boolean equals(Object o)

Overrides:

equals in class Object

followingKey

public Key followingKey(PartialKey part)

Returns a key that will sort immediately after this key.

Parameters:

part - PartialKey except PartialKey.ROW_COLFAM_COLQUAL_COLVIS_TIME_DEL

getRow

public org.apache.hadoop.io.Text getRow(org.apache.hadoop.io.Text r)

Writes the row ID into the given Text. This method gives users control over allocation of Text objects by copying into the passed in text.

Parameters:

r - Text object to copy into

Returns:

the Text that was passed in

getRowData

public ByteSequence getRowData()

Returns the row ID as a byte sequence. This method returns a pointer to the key's internal data and does not copy it.

Returns:

ByteSequence that points to the internal key row ID data

getRow

public org.apache.hadoop.io.Text getRow()

Gets the row ID as a Text object.

Returns:

Text containing the row ID

compareRow

public int compareRow(org.apache.hadoop.io.Text r)

Compares this key's row ID with another.

Parameters:

r - row ID to compare

Returns:

same as getRow().compareTo(r)

getColumnFamilyData

public ByteSequence getColumnFamilyData()

Returns the column family as a byte sequence. This method returns a pointer to the key's internal data and does not copy it.

Returns:

ByteSequence that points to the internal key column family data

getColumnFamily

public org.apache.hadoop.io.Text getColumnFamily(org.apache.hadoop.io.Text cf)

Writes the column family into the given Text. This method gives users control over allocation of Text objects by copying into the passed in text.

Parameters:

cf - Text object to copy into

Returns:

the Text that was passed in

getColumnFamily

public org.apache.hadoop.io.Text getColumnFamily()

Gets the column family as a Text object.

Returns:

Text containing the column family

compareColumnFamily

public int compareColumnFamily(org.apache.hadoop.io.Text cf)

Compares this key's column family with another.

Parameters:

cf - column family to compare

Returns:

same as getColumnFamily().compareTo(cf)

getColumnQualifierData

public ByteSequence getColumnQualifierData()

Returns the column qualifier as a byte sequence. This method returns a pointer to the key's internal data and does not copy it.

Returns:

ByteSequence that points to the internal key column qualifier data

getColumnQualifier

public org.apache.hadoop.io.Text getColumnQualifier(org.apache.hadoop.io.Text cq)

Writes the column qualifier into the given Text. This method gives users control over allocation of Text objects by copying into the passed in text.

Parameters:

cq - Text object to copy into

Returns:

the Text that was passed in

getColumnQualifier

public org.apache.hadoop.io.Text getColumnQualifier()

Gets the column qualifier as a Text object.

Returns:

Text containing the column qualifier

compareColumnQualifier

public int compareColumnQualifier(org.apache.hadoop.io.Text cq)

Compares this key's column qualifier with another.

Parameters:

cq - column qualifier to compare

Returns:

same as getColumnQualifier().compareTo(cq)

setTimestamp

public void setTimestamp(long ts)

Sets the timestamp.

Parameters:

ts - timestamp

getTimestamp

public long getTimestamp()

Gets the timestamp.

Returns:

timestamp

isDeleted

public boolean isDeleted()

Determines if this key is deleted (i.e., has a delete marker = true).

Returns:

true if key is deleted, false if not

setDeleted

public void setDeleted(boolean deleted)

Sets the delete marker on this key.

Parameters:

deleted - delete marker (true to delete)

getColumnVisibilityData

public ByteSequence getColumnVisibilityData()

Returns the column visibility as a byte sequence. This method returns a pointer to the key's internal data and does not copy it.

Returns:

ByteSequence that points to the internal key column visibility data

getColumnVisibility

public final org.apache.hadoop.io.Text getColumnVisibility()

Gets the column visibility as a Text object.

Returns:

Text containing the column visibility

getColumnVisibility

public final org.apache.hadoop.io.Text getColumnVisibility(org.apache.hadoop.io.Text cv)

Writes the column visibvility into the given Text. This method gives users control over allocation of Text objects by copying into the passed in text.

Parameters:

cv - Text object to copy into

Returns:

the Text that was passed in

getColumnVisibilityParsed

public final ColumnVisibility getColumnVisibilityParsed()

Gets the column visibility. WARNING: using this method may inhibit performance since a new ColumnVisibility object is created on every call.

Returns:

ColumnVisibility representing the column visibility

Since:

1.5.0

set

public void set(Key k)

Sets this key's row, column family, column qualifier, column visibility, timestamp, and delete marker to be the same as another key's. This method does not copy data from the other key, but only references to it.

Parameters:

k - key to set from

readFields

public void readFields(DataInput in)
                throws IOException

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Throws:

IOException

write

public void write(DataOutput out)
           throws IOException

Specified by:

write in interface org.apache.hadoop.io.Writable

Throws:

IOException

equals

public boolean equals(Key other,
                      PartialKey part)

Compares part of a key. For example, compares just the row and column family, and if those are equal then return true.

Parameters:

other - key to compare to

part - part of key to compare

Returns:

true if specified parts of keys match, false otherwise

compareTo

public int compareTo(Key other,
                     PartialKey part)

Compares elements of a key given by a PartialKey. The corresponding elements (row, column family, column qualifier, column visibility, timestamp, and delete marker) are compared in order until unequal elements are found. The row, column family, column qualifier, and column visibility are compared lexographically and sorted ascending. The timestamps are compared numerically and sorted descending so that the most recent data comes first. Lastly, a delete marker of true sorts before a delete marker of false. The result of the first unequal comparison is returned. For example, for PartialKey.ROW_COLFAM, this method compares just the row and column family. If the row IDs are not equal, return the result of the row comparison; otherwise, returns the result of the column family comparison.

Parameters:

other - key to compare to

part - part of key to compare

Returns:

comparison result

See Also:

compareTo(Key)

compareTo

public int compareTo(Key other)

Specified by:

compareTo in interface Comparable<Key>

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toPrintableString

public static String toPrintableString(byte[] ba,
                                       int offset,
                                       int len,
                                       int maxLen)

Returns an ASCII printable string form of the given byte array, treating the bytes as ASCII characters. See appendPrintableString(byte[], int, int, int, StringBuilder) for caveats.

Parameters:

ba - byte array

offset - offset to start with in byte array (inclusive)

len - number of bytes to print

maxLen - maximum number of bytes to convert to printable form

Returns:

printable string

See Also:

appendPrintableString(byte[], int, int, int, StringBuilder)

appendPrintableString

public static StringBuilder appendPrintableString(byte[] ba,
                                                  int offset,
                                                  int len,
                                                  int maxLen,
                                                  StringBuilder sb)

Appends ASCII printable characters to a string, based on the given byte array, treating the bytes as ASCII characters. If a byte can be converted to a ASCII printable character it is appended as is; otherwise, it is appended as a character code, e.g., %05; for byte value 5. If len > maxlen, the string includes a "TRUNCATED" note at the end.

Parameters:

ba - byte array

offset - offset to start with in byte array (inclusive)

len - number of bytes to print

maxLen - maximum number of bytes to convert to printable form

sb - StringBuilder to append to

Returns:

given StringBuilder

toString

public String toString()

Overrides:

toString in class Object

toStringNoTruncate

public String toStringNoTruncate()

Stringify this Key, avoiding truncation of each component, only limiting each component to a length of Integer.MAX_VALUE

Since:

1.7.0

toStringNoTime

public String toStringNoTime()

Converts this key to a string, not including timestamp or delete marker.

Returns:

string form of key

getLength

public int getLength()

Returns the sums of the lengths of the row, column family, column qualifier, and column visibility.

Returns:

sum of key field lengths

getSize

public int getSize()

Same as getLength().

Returns:

sum of key field lengths

compress

public static List<org.apache.accumulo.core.data.thrift.TKeyValue> compress(List<? extends KeyValue> param)

Compresses a list of key/value pairs before sending them via thrift.

Parameters:

param - list of key/value pairs

Returns:

list of Thrift key/value pairs

decompress

public static void decompress(List<org.apache.accumulo.core.data.thrift.TKeyValue> param)

Decompresses a list of key/value pairs received from thrift. Decompression occurs in place, in the list.

Parameters:

param - list of Thrift key/value pairs

toThrift

public org.apache.accumulo.core.data.thrift.TKey toThrift()

Converts this key to Thrift.

Returns:

Thrift key

clone

public Object clone()
             throws CloneNotSupportedException

Overrides:

clone in class Object

Throws:

CloneNotSupportedException