Class SimpleCacheIndex

SimpleCacheIndex is an ICacheIndex implementation used to correlate property values extracted from resource cache entries with corresponding keys using what is commonly known as an Inverted Index algorithm..

Inheritance

object

SimpleCacheIndex

ConditionalIndex

Implements

ICacheIndex

Inherited Members

object.Equals(object, object)

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

Namespace: Tangosol.Net.Cache

Assembly: Coherence.dll

Syntax

public class SimpleCacheIndex : ICacheIndex

Constructors

SimpleCacheIndex(IValueExtractor, bool, IComparer)

Construct an index.

Declaration

public SimpleCacheIndex(IValueExtractor extractor, bool ordered, IComparer comparer)

Parameters

Type	Name	Description
IValueExtractor	extractor	The IValueExtractor that is used to extract an indexed value from a resource cache entry.
bool	ordered	true iff the contents of the indexed information should be ordered; false otherwise.
IComparer	comparer	The IComparator object which imposes an ordering on entries in the index map; or null if the entries' values natural ordering should be used.

SimpleCacheIndex(IValueExtractor, bool, IComparer, bool)

Construct an index.

Declaration

public SimpleCacheIndex(IValueExtractor extractor, bool ordered, IComparer comparer, bool init)

Parameters

Type	Name	Description
IValueExtractor	extractor	The IValueExtractor that is used to extract an indexed value from a resource cache entry.
bool	ordered	true iff the contents of the indexed information should be ordered; false otherwise.
IComparer	comparer	The IComparator object which imposes an ordering on entries in the index map; or null if the entries' values natural ordering should be used.
bool	init	Initialize the index if true.

Fields

NO_VALUE

Marker object used to represent extractor failure.

Declaration

protected static readonly object NO_VALUE

Field Value

Type	Description
object

m_cLogMissingIdx

The number of "missing inverse index" messages that have been logged.

Declaration

protected int m_cLogMissingIdx

Field Value

Type	Description
int

m_fImmutableValues

Specifies whether or not the index is based on the immutable values (e.g. keys).

Declaration

protected bool m_fImmutableValues

Field Value

Type	Description
bool

m_keysExcluded

A set of keys for the entries, which could not be included in the index.

Declaration

protected SafeHashSet m_keysExcluded

Field Value

Type	Description
SafeHashSet

m_ldtLogMissingIdx

The time at which the most recent logging of "missing inverse index" messages started.

Declaration

protected long m_ldtLogMissingIdx

Field Value

Type	Description
long

m_splitCollection

If a value extracted by the IValueExtractor is an ICollection, this property specifies whether or not it should be treated as a collection of contained attributes or indexed as a single composite attribute.

Declaration

protected bool m_splitCollection

Field Value

Type	Description
bool

Properties

Comparer

IComparer used to sort the index. Used iff Ordered is true. Could be null, which implicates a natural order.

Declaration

public virtual IComparer Comparer { get; protected set; }

Property Value

Type	Description
IComparer

IndexContents

The IDictionary that contains the index contents.

Declaration

public IDictionary IndexContents { get; protected set; }

Property Value

Type	Description
IDictionary

Remarks

The keys of the IDictionary are the return values from the IValueExtractor operating against the indexed ICache's values, and for each key, the corresponding value stored in the IDictionary is an ICollection of keys to the indexed value.

If the ICacheIndex is known to be ordered, then the returned IDictionary object will be an instance of SortedList (or wrapper thereof). The SortedList may or may not have an IComparer object associated with it.

A client should assume that the returned IDictionary object is read-only and must not attempt to modify it.

IndexForward

IDictionary that contains the index values (forward index). The keys of the IDictionary are the keys to the indexed cache and the values are the extracted values. This map is used by IIndexAwareFilter implementations to avoid conversion and value extraction steps.

Declaration

protected IDictionary IndexForward { get; set; }

Property Value

Type	Description
IDictionary

IsOrdered

Specifies whether or not this ICacheIndex orders the contents of the indexed information.

Declaration

public virtual bool IsOrdered { get; protected set; }

Property Value

Type	Description
bool

IsPartial

Determine if indexed information for any entry in the indexed ICache has been excluded from this index. This information is used by IIndexAwareFilter implementations to determine the most optimal way to apply the index.

Declaration

public virtual bool IsPartial { get; }

Property Value

Type	Description
bool	true if any entry of the indexed ICache has been excluded from the index, false otherwise

ValueExtractor

IValueExtractor object that this ICacheIndex uses to extract an indexable Object from a [converted] value stored in the Storage. This property is never null.

Declaration

public virtual IValueExtractor ValueExtractor { get; protected set; }

Property Value

Type	Description
IValueExtractor

Methods

AddInverseCollectionMapping(IDictionary, ICollection, object)

Add new mappings from the elements of the given value to the given key in the supplied index.

Declaration

protected virtual void AddInverseCollectionMapping(IDictionary index, ICollection value, object key)

Parameters

Type	Name	Description
IDictionary	index	the index to which to add the mapping
ICollection	value	the indexed ICollection value (each element serves as a key in the inverse index)
object	key	the key to insert into the inverse index

AddInverseMapping(IDictionary, object, object)

Add a new mapping from the given indexed value to the given key in the supplied index.

Declaration

protected virtual void AddInverseMapping(IDictionary index, object value, object key)

Parameters

Type	Name	Description
IDictionary	index	the index to which to add the mapping
object	value	the indexed value
object	key	the key to insert into the inverse index

AddInverseMapping(object, object)

Add a new mapping from the given indexed value to the given key in the inverse index.

Declaration

protected virtual void AddInverseMapping(object value, object key)

Parameters

Type	Name	Description
object	value	The index value (serves as a key in the inverse index).
object	key	the key to insert into the inverse index

CollectRemoved(object, object)

Given that the old value is known to be a Collection or an array, collect all the enclosed elements that are not part of the new value.

Declaration

protected HashSet CollectRemoved(object valueOld, object valueNew)

Parameters

Type	Name	Description
object	valueOld	The old value, must be a collection or an array.
object	valueNew	The new value.

Returns

Type	Description
HashSet	The set of values that are contained in the old collection or array, but not part of the new value.

Delete(ICacheEntry)

Update this index in response to a remove operation on a cache.

Declaration

public virtual void Delete(ICacheEntry entry)

Parameters

Type	Name	Description
ICacheEntry	entry	The entry representing the object being removed.

DeleteInternal(ICacheEntry)

Update this index in response to a remove operation on a cache.

Declaration

protected virtual void DeleteInternal(ICacheEntry entry)

Parameters

Type	Name	Description
ICacheEntry	entry	The entry representing the object being removed.

EnsureCollection(object)

Return a Collection representation of the specified value, which could be a Collection, Object[], scalar, or NO_VALUE.

Declaration

protected static ICollection EnsureCollection(object value)

Parameters

Type	Name	Description
object	value	The value.

Returns

Type	Description
ICollection	A Collection representation of the specified value, or an empty Collection if NO_VALUE.

Equals(object)

Determines whether the specified object is equal to this object.

Declaration

public override bool Equals(object obj)

Parameters

Type	Name	Description
object	obj	The object to compare with this object.

Returns

Type	Description
bool	true if the specified object is equal to this object; otherwise, false.

Overrides

object.Equals(object)

Equals(SimpleCacheIndex)

Compares this index with another index for equality.

Declaration

public virtual bool Equals(SimpleCacheIndex index)

Parameters

Type	Name	Description
SimpleCacheIndex	index	index to compare this index with.

Returns

Type	Description
bool	true if the two indexes are equal; false otherwise.

Remarks

This method returns true if this index and the specified index have exactly the same contents.

ExtractNewValue(ICacheEntry)

Extract the "new" value from the specified entry.

Declaration

protected object ExtractNewValue(ICacheEntry entry)

Parameters

Type	Name	Description
ICacheEntry	entry	The entry to extract the "new" value from.

Returns

Type	Description
object	The extracted "new" value, or NO_VALUE if the extraction failed

ExtractOldValue(CacheEntry)

Extract the "old" value from the specified entry.

Declaration

protected object ExtractOldValue(CacheEntry entry)

Parameters

Type	Name	Description
CacheEntry	entry	The entry to extract the "old" value from.

Returns

Type	Description
object	The extracted "old" value, or NO_VALUE if the extraction failed.

Get(object)

Using the index information if possible, get the value associated with the specified key. This is expected to be more efficient than using the IValueExtractor against an object containing the value, because the index should already have the necessary information at hand.

Declaration

public virtual object Get(object key)

Parameters

Type	Name	Description
object	key	The key that specifies the object to extract the value from.

Returns

Type	Description
object	The value that would be extracted by this ICacheIndex's IValueExtractor from the object specified by the passed key; NO_VALUE if the index does not have the necessary information.

GetForwardValue(object)

Get the forward index value associated with the specified key.

Declaration

protected virtual object GetForwardValue(object key)

Parameters

Type	Name	Description
object	key	The key.

Returns

Type	Description
object	The value associated with the key.

GetHashCode()

Returns a hash code for this object.

Declaration

public override int GetHashCode()

Returns

Type	Description
int	A hash code for this object.

Overrides

object.GetHashCode()

Initialize(bool)

Initialize the index's data structures.

Declaration

protected virtual void Initialize(bool forwardIndex)

Parameters

Type	Name	Description
bool	forwardIndex	true If forward index is supported; false otherwise.

Insert(ICacheEntry)

Update this index in response to a insert operation on a cache.

Declaration

public virtual void Insert(ICacheEntry entry)

Parameters

Type	Name	Description
ICacheEntry	entry	The entry representing the object being inserted.

InsertInternal(ICacheEntry)

Update this index in response to a insert operation on a cache.

Declaration

protected virtual void InsertInternal(ICacheEntry entry)

Parameters

Type	Name	Description
ICacheEntry	entry	The entry representing the object being inserted.

InstantiateForwardIndex()

Instantiate the forward index.

Declaration

protected virtual IDictionary InstantiateForwardIndex()

Returns

Type	Description
IDictionary	The forward index.

InstatiateInverseIndex(bool, IComparer)

Instantiate the inverse index.

Declaration

protected virtual IDictionary InstatiateInverseIndex(bool ordered, IComparer comparer)

Parameters

Type	Name	Description
bool	ordered	true iff the contents of the indexed information should be ordered; false otherwise.
IComparer	comparer	The IComparator object which imposes an ordering on entries in the index; or null if the entries' values natural ordering should be used.

Returns

Type	Description
IDictionary	The inverse index.

IsKeyExcluded(object)

Check if the entry with the given key is excluded from the index.

Declaration

protected bool IsKeyExcluded(object key)

Parameters

Type	Name	Description
object	key	The key to test

Returns

Type	Description
bool	True if the key is in the list of keys currently excluded from the index, false if the entry with the key is in the index.

LogMissingIdx(object, object)

Log messages for missing inverse index.

Declaration

protected void LogMissingIdx(object value, object key)

Parameters

Type	Name	Description
object	value	the indexed value
object	key	the key

RemoveForwardEntry(object)

Remove the forward index entry for the specified key.

Declaration

protected virtual void RemoveForwardEntry(object key)

Parameters

Type	Name	Description
object	key	The key to remove the forward index entry for.

RemoveInverseMapping(IDictionary, object, object)

Remove the mapping from the given indexed value to the given key from the supplied index.

Declaration

protected virtual void RemoveInverseMapping(IDictionary index, object value, object key)

Parameters

Type	Name	Description
IDictionary	index	the index from which to remove the mapping
object	value	the indexed value
object	key	the key

RemoveInverseMapping(object, object)

Remove the mapping from the given indexed value to the given key from the inverse index.

Declaration

protected virtual void RemoveInverseMapping(object value, object key)

Parameters

Type	Name	Description
object	value	The indexed value, or NO_VALUE if unknown.
object	key	The key

RemoveInverseMapping(object, object, ICollection)

Remove the mapping from the given indexed value to the given key from the inverse index.

Declaration

protected virtual void RemoveInverseMapping(object value, object key, ICollection colIgnore)

Parameters

Type	Name	Description
object	value	The indexed value.
object	key	The key.
ICollection	colIgnore	The Collection of values to ignore (exclude from removal), or null.

ToString()

Returns string representation of this instance.

Declaration

public override string ToString()

Returns

Type	Description
string	String representation of this instance.

Overrides

object.ToString()

Update(ICacheEntry)

Update this index in response to a update operation on a cache.

Declaration

public virtual void Update(ICacheEntry entry)

Parameters

Type	Name	Description
ICacheEntry	entry	The entry representing the object being updated.

UpdateExcludedKeys(ICacheEntry, bool)

Check the entry against the set of entries not included in the index and update the set if necessary.

Declaration

protected void UpdateExcludedKeys(ICacheEntry entry, bool excluded)

Parameters

Type	Name	Description
ICacheEntry	entry	The entry to be checked.
bool	excluded	True if the insert or update of the entry into the index caused an exception.

UpdateInternal(ICacheEntry)

Update this index in response to a update operation on a cache.

Declaration

protected virtual void UpdateInternal(ICacheEntry entry)

Parameters

Type	Name	Description
ICacheEntry	entry	The entry representing the object being updated.

Implements

ICacheIndex