com.apple.foundationdb.record

Class IndexEntry

java.lang.Object

com.apple.foundationdb.record.IndexEntry

@API(value=MAINTAINED)
public class IndexEntry
extends Object

An IndexEntry carries around the key and value read from an index (as the name would imply). Further, if the key and value were produced by applying an index key expression to a record, this will carry around additional information about the nulls contained in the expression.

Constructor Summary

Constructors

Constructor and Description
IndexEntry(Index index, Key.Evaluated key)
IndexEntry(Index index, Key.Evaluated key, Key.Evaluated value)
IndexEntry(Index index, Tuple key, Tuple value)

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o)
Index	getIndex() Get the index associated with this entry.
Tuple	getKey() Get the key portion of the index entry.
Key.Evaluated.NullStandin	getKeyNullType(int idx) Get the type of null stored in a given key index location.
int	getKeySize()
Object	getKeyValue(int idx) Get a tuple element of the key tuple.
Tuple	getPrimaryKey() Get the primary key of the record associated with this entry.
Tuple	getValue() Get the value portion of the index entry.
int	hashCode()
boolean	keyContainsNonUniqueNull() Returns true if the key expression contains a NULL value that is not a Key.Evaluated.NullStandin.NULL_UNIQUE value.
IndexEntry	subKey(int startIdx, int endIdx) Produces a new IndexEntry whose key is a subset of this IndexEntry.
String	toString()
void	validateInIndex(Index index) Validate that this entry is associated with the given index.

Methods inherited from class java.lang.Object

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

Constructor Detail

IndexEntry

@API(value=INTERNAL)
public IndexEntry(@Nonnull
                                       Index index,
                                       @Nonnull
                                       Key.Evaluated key,
                                       @Nonnull
                                       Key.Evaluated value)

IndexEntry

@API(value=INTERNAL)
public IndexEntry(@Nonnull
                                       Index index,
                                       @Nonnull
                                       Key.Evaluated key)

IndexEntry

@API(value=INTERNAL)
public IndexEntry(@Nonnull
                                       Index index,
                                       @Nonnull
                                       Tuple key,
                                       @Nonnull
                                       Tuple value)

Method Detail

getIndex

@Nonnull
public Index getIndex()

Get the index associated with this entry. This entry was either created in order to store within this index or it was constructed from reading this index.

Returns:

the index associated with this entry

getKey

@Nonnull
public Tuple getKey()

Get the key portion of the index entry. This is stored in the key portion of the key-value pair in the database. Index entries are generally sorted by key, and this key must be unique for all entries in an index. As a result, it generally contains the primary key of its associated record as a sub-component.

Returns:

the key portion of the index entry

See Also:

getPrimaryKey()

getValue

@Nonnull
public Tuple getValue()

Get the value portion of the index entry. This is stored in the value portion of the key-value pair in the database. Index entries are not sorted by value, but the user might configure indexes to have additional fields in the index value in order to increase the number of queries that can be satisfied without needing to resolve the underlying record.

Returns:

the value portion of the index entry

getKeySize

public int getKeySize()

getPrimaryKey

@Nonnull
public Tuple getPrimaryKey()

Get the primary key of the record associated with this entry. Note that some indexes, such as the atomic mutation indexes, erase the primary key information from the indexes they store. In that case, this method might not return a reasonable result.

Returns:

the primary key of the record that produced this index entry

getKeyValue

@Nullable
public Object getKeyValue(int idx)

Get a tuple element of the key tuple.

Parameters:

idx - the index of the desired element

Returns:

the tuple element at index idx

validateInIndex

@API(value=INTERNAL)
public void validateInIndex(@Nonnull
                                                 Index index)

Validate that this entry is associated with the given index.

Parameters:

index - the index this entry should be a member of

keyContainsNonUniqueNull

public boolean keyContainsNonUniqueNull()

Returns true if the key expression contains a NULL value that is not a Key.Evaluated.NullStandin.NULL_UNIQUE value. Calling this method on a IndexEntry that was created directly from tuples will result in an exception.

Returns:

true if the key contains a non-unique null value

getKeyNullType

@Nonnull
public Key.Evaluated.NullStandin getKeyNullType(int idx)

Get the type of null stored in a given key index location. Calling this method on an IndexEntry that was created directly from tuples, or if the value at idx is not null, will result in an exception.

Parameters:

idx - the index of a null element

Returns:

the type of null stored at idx

subKey

@Nonnull
public IndexEntry subKey(int startIdx,
                                  int endIdx)

Produces a new IndexEntry whose key is a subset of this IndexEntry.

Parameters:

startIdx - the starting offset of the key to use for the new value

endIdx - the ending offset (exclusive) of the key to use for the new value

Returns:

a new index entry with the subset key between startIdx and endIdx

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object