com.healthmarketscience.jackcess.impl
Class IndexImpl

java.lang.Object
  com.healthmarketscience.jackcess.impl.IndexImpl

All Implemented Interfaces:

Index, Comparable<IndexImpl>

public class IndexImpl
extends Object
implements Index, Comparable<IndexImpl>

Access table (logical) index. Logical indexes are backed for IndexData, where one or more logical indexes could be backed by the same data.

Author:

Tim McCune

Nested Class Summary

static class

IndexImpl.ForeignKeyReference Information about a foreign key reference defined in an index (when referential integrity should be enforced).

Nested classes/interfaces inherited from interface com.healthmarketscience.jackcess.Index

Index.Column

Field Summary

static byte	FOREIGN_KEY_INDEX_TYPE index type for foreign key indexes
protected static org.apache.commons.logging.Log	LOG
static byte	PRIMARY_KEY_INDEX_TYPE index type for primary key indexes

Constructor Summary

protected

IndexImpl(ByteBuffer tableBuffer, List<IndexData> indexDatas, JetFormat format)

Method Summary

int	compareTo(IndexImpl other)
Object[]	constructIndexRow(Map<String,?> row) Constructs an array of values appropriate for this index from the given column values.
Object[]	constructIndexRow(String colName, Object value) Constructs an array of values appropriate for this index from the given column value.
Object[]	constructIndexRowFromEntry(Object... values) Constructs an array of values appropriate for this index from the given column values, expected to match the columns for this index.
Object[]	constructPartialIndexRow(Object filler, Map<String,?> row) Constructs an array of values appropriate for this index from the given column values, possibly only using a subset of the given values.
Object[]	constructPartialIndexRow(Object filler, String colName, Object value) Constructs an array of values appropriate for this index from the given column value, which must be the first column of the index.
Object[]	constructPartialIndexRowFromEntry(Object filler, Object... values) Constructs an array of values appropriate for this index from the given column values, possibly only providing a prefix subset of the index columns (at least one value must be provided).
IndexData.EntryCursor	cursor() Gets a new cursor for this index.
IndexData.EntryCursor	cursor(Object[] startRow, boolean startInclusive, Object[] endRow, boolean endInclusive) Gets a new cursor for this index, narrowed to the range defined by the given startRow and endRow.
int	getColumnCount()
List<IndexData.ColumnDescriptor>	getColumns()
JetFormat	getFormat()
IndexData	getIndexData()
byte	getIndexFlags()
int	getIndexNumber()
String	getName()
PageChannel	getPageChannel()
IndexImpl.ForeignKeyReference	getReference()
IndexImpl	getReferencedIndex()
TableImpl	getTable()
int	getUniqueEntryCount()
int	getUniqueEntryCountOffset()
void	initialize() Forces initialization of this index (actual parsing of index pages).
boolean	isForeignKey()
boolean	isInitialized() Whether or not the complete index state has been read.
boolean	isPrimaryKey()
boolean	isRequired() Whether or not values are required for index columns.
boolean	isUnique() Whether or not index entries must be unique.
CursorBuilder	newCursor() Convenience method for constructing a new CursorBuilder for this Index.
boolean	shouldIgnoreNulls() Whether or not null values are actually recorded in the index.
String	toString()
protected static void	writeDefinition(TableMutator mutator, IndexBuilder idx, ByteBuffer buffer)
protected static void	writeDefinitions(TableCreator creator, ByteBuffer buffer) Writes the logical index definitions into a table definition buffer.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

LOG

protected static final org.apache.commons.logging.Log LOG

PRIMARY_KEY_INDEX_TYPE

public static final byte PRIMARY_KEY_INDEX_TYPE

index type for primary key indexes

See Also:

Constant Field Values

FOREIGN_KEY_INDEX_TYPE

public static final byte FOREIGN_KEY_INDEX_TYPE

index type for foreign key indexes

See Also:

Constant Field Values

Constructor Detail

IndexImpl

protected IndexImpl(ByteBuffer tableBuffer,
                    List<IndexData> indexDatas,
                    JetFormat format)
             throws IOException

Throws:

IOException

Method Detail

getIndexData

public IndexData getIndexData()

getTable

public TableImpl getTable()

Specified by:

getTable in interface Index

getFormat

public JetFormat getFormat()

getPageChannel

public PageChannel getPageChannel()

getIndexNumber

public int getIndexNumber()

getIndexFlags

public byte getIndexFlags()

getUniqueEntryCount

public int getUniqueEntryCount()

getUniqueEntryCountOffset

public int getUniqueEntryCountOffset()

getName

public String getName()

Specified by:

getName in interface Index

isPrimaryKey

public boolean isPrimaryKey()

Specified by:

isPrimaryKey in interface Index

isForeignKey

public boolean isForeignKey()

Specified by:

isForeignKey in interface Index

getReference

public IndexImpl.ForeignKeyReference getReference()

getReferencedIndex

public IndexImpl getReferencedIndex()
                             throws IOException

Specified by:

getReferencedIndex in interface Index

Returns:

the Index referenced by this Index's ForeignKeyReference (if it has one), otherwise null.

Throws:

IOException

shouldIgnoreNulls

public boolean shouldIgnoreNulls()

Description copied from interface: Index

Whether or not null values are actually recorded in the index.

Specified by:

shouldIgnoreNulls in interface Index

isUnique

public boolean isUnique()

Description copied from interface: Index

Whether or not index entries must be unique.

Some notes about uniqueness:

• Access does not seem to consider multiple null entries invalid for a unique index
• text indexes collapse case, and Access seems to compare only the index entry bytes, therefore two strings which differ only in case will violate the unique constraint

Specified by:

isUnique in interface Index

isRequired

public boolean isRequired()

Description copied from interface: Index

Whether or not values are required for index columns.

Specified by:

isRequired in interface Index

getColumns

public List<IndexData.ColumnDescriptor> getColumns()

Specified by:

getColumns in interface Index

Returns:

the Columns for this index (unmodifiable)

getColumnCount

public int getColumnCount()

Specified by:

getColumnCount in interface Index

newCursor

public CursorBuilder newCursor()

Description copied from interface: Index

Convenience method for constructing a new CursorBuilder for this Index.

Specified by:

newCursor in interface Index

isInitialized

public boolean isInitialized()

Whether or not the complete index state has been read.

initialize

public void initialize()
                throws IOException

Forces initialization of this index (actual parsing of index pages). normally, the index will not be initialized until the entries are actually needed.

Throws:

IOException

cursor

public IndexData.EntryCursor cursor()
                             throws IOException

Gets a new cursor for this index.

Forces index initialization.

Throws:

IOException

cursor

public IndexData.EntryCursor cursor(Object[] startRow,
                                    boolean startInclusive,
                                    Object[] endRow,
                                    boolean endInclusive)
                             throws IOException

Gets a new cursor for this index, narrowed to the range defined by the given startRow and endRow.

Forces index initialization.

Parameters:

startRow - the first row of data for the cursor, or null for the first entry

startInclusive - whether or not startRow is inclusive or exclusive

endRow - the last row of data for the cursor, or null for the last entry

endInclusive - whether or not endRow is inclusive or exclusive

Throws:

IOException

constructIndexRowFromEntry

public Object[] constructIndexRowFromEntry(Object... values)

Constructs an array of values appropriate for this index from the given column values, expected to match the columns for this index.

Returns:

the appropriate sparse array of data

Throws:

IllegalArgumentException - if the wrong number of values are provided

constructPartialIndexRowFromEntry

public Object[] constructPartialIndexRowFromEntry(Object filler,
                                                  Object... values)

Constructs an array of values appropriate for this index from the given column values, possibly only providing a prefix subset of the index columns (at least one value must be provided). If a prefix entry is provided, any missing, trailing index entry values will use the given filler value.

Returns:

the appropriate sparse array of data

Throws:

IllegalArgumentException - if at least one value is not provided

constructIndexRow

public Object[] constructIndexRow(String colName,
                                  Object value)

Constructs an array of values appropriate for this index from the given column value.

Returns:

the appropriate sparse array of data or null if not all columns for this index were provided

constructPartialIndexRow

public Object[] constructPartialIndexRow(Object filler,
                                         String colName,
                                         Object value)

Constructs an array of values appropriate for this index from the given column value, which must be the first column of the index. Any missing, trailing index entry values will use the given filler value.

Returns:

the appropriate sparse array of data or null if no prefix list of columns for this index were provided

constructIndexRow

public Object[] constructIndexRow(Map<String,?> row)

Constructs an array of values appropriate for this index from the given column values.

Returns:

the appropriate sparse array of data or null if not all columns for this index were provided

constructPartialIndexRow

public Object[] constructPartialIndexRow(Object filler,
                                         Map<String,?> row)

Constructs an array of values appropriate for this index from the given column values, possibly only using a subset of the given values. A partial row can be created if one or more prefix column values are provided. If a prefix can be found, any missing, trailing index entry values will use the given filler value.

Returns:

the appropriate sparse array of data or null if no prefix list of columns for this index were provided

toString

public String toString()

Overrides:

toString in class Object

compareTo

public int compareTo(IndexImpl other)

Specified by:

compareTo in interface Comparable<IndexImpl>

writeDefinitions

protected static void writeDefinitions(TableCreator creator,
                                       ByteBuffer buffer)
                                throws IOException

Writes the logical index definitions into a table definition buffer.

Parameters:

creator - description of the indexes to write

buffer - Buffer to write to

Throws:

IOException

writeDefinition

protected static void writeDefinition(TableMutator mutator,
                                      IndexBuilder idx,
                                      ByteBuffer buffer)
                               throws IOException

Throws:

IOException