Class LikeFilter

IFilter which compares the result of a member invocation with a value for pattern match.

Inheritance

object

ExtractorFilter

ComparisonFilter

LikeFilter

Implements

IPortableObject

IIndexAwareFilter

IEntryFilter

IFilter

Inherited Members

ComparisonFilter.Value

ComparisonFilter.Equals(object)

ComparisonFilter.GetHashCode()

ComparisonFilter.ToString()

ComparisonFilter.CalculateMatchEffectiveness(IDictionary, ICollection)

ComparisonFilter.CalculateRangeEffectiveness(IDictionary, ICollection)

ComparisonFilter.CalculateIteratorEffectiveness(int)

ComparisonFilter.m_value

ExtractorFilter.ValueExtractor

ExtractorFilter.Evaluate(object)

ExtractorFilter.EvaluateEntry(ICacheEntry)

ExtractorFilter.Extract(object)

ExtractorFilter.EVAL_COST

ExtractorFilter.m_extractor

object.Equals(object, object)

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

Namespace: Tangosol.Util.Filter

Assembly: Coherence.dll

Syntax

public class LikeFilter : ComparisonFilter, IPortableObject, IIndexAwareFilter, IEntryFilter, IFilter

Remarks

A pattern can include regular characters and wildcard characters '_' and '%'.

During pattern matching, regular characters must exactly match the characters in an evaluated string. Wildcard character '_' (underscore) can be matched with any single character, and wildcard character '%' can be matched with any string fragment of zero or more characters.

Constructors

LikeFilter()

Default constructor.

Declaration

public LikeFilter()

LikeFilter(string, string)

Construct a LikeFilter for pattern match.

Declaration

public LikeFilter(string member, string pattern)

Parameters

Type	Name	Description
string	member	The name of the member to invoke via reflection.
string	pattern	The string pattern to compare the result with.

LikeFilter(string, string, bool)

Construct a LikeFilter for pattern match.

Declaration

public LikeFilter(string member, string pattern, bool ignoreCase)

Parameters

Type	Name	Description
string	member	The name of the member to invoke via reflection.
string	pattern	The string pattern to compare the result with.
bool	ignoreCase	true to be case-insensitive.

LikeFilter(string, string, char, bool)

Construct a LikeFilter for pattern match.

Declaration

public LikeFilter(string member, string pattern, char escape, bool ignoreCase)

Parameters

Type	Name	Description
string	member	The name of the member to invoke via reflection.
string	pattern	The string pattern to compare the result with.
char	escape	The escape character for escaping '%' and '_'.
bool	ignoreCase	true to be case-insensitive.

LikeFilter(IValueExtractor, string, char, bool)

Construct a LikeFilter for pattern match.

Declaration

public LikeFilter(IValueExtractor extractor, string pattern, char escape, bool ignoreCase)

Parameters

Type	Name	Description
IValueExtractor	extractor	The IValueExtractor to use by this filter.
string	pattern	The string pattern to compare the result with.
char	escape	The escape character for escaping '%' and '_'.
bool	ignoreCase	true to be case-insensitive.

Properties

EscapeChar

Obtain the escape character that is used for escaping '%' and '_' in the pattern or zero if there is no escape.

Declaration

public virtual char EscapeChar { get; }

Property Value

Type	Description
char	The escape character.

IgnoreCase

Check whether or not the filter is case incensitive.

Declaration

public virtual bool IgnoreCase { get; }

Property Value

Type	Description
bool	true if case insensitivity is specifically enabled.

IsIgnoreCase

Check whether or not the filter is case incensitive.

Declaration

[Obsolete("As of Coherence 3.4 this property is replaced with IgnoreCase")]
public virtual bool IsIgnoreCase { get; }

Property Value

Type	Description
bool	true if case insensitivity is specifically enabled.

Pattern

Obtain the filter's pattern string.

Declaration

public virtual string Pattern { get; }

Property Value

Type	Description
string	The pattern string.

Methods

ApplyIndex(IDictionary, ICollection)

Filter remaining keys using an IDictionary of available indexes.

Declaration

public IFilter ApplyIndex(IDictionary indexes, ICollection keys)

Parameters

Type	Name	Description
IDictionary	indexes	The available ICacheIndex objects keyed by the related IValueExtractor; read-only.
ICollection	keys	The mutable set of keys that remain to be filtered.

Returns

Type	Description
IFilter	An IFilter object that can be used to process the remaining keys, or null if no additional filter processing is necessary.

Remarks

The filter is responsible for removing all keys from the passed set of keys that the applicable indexes can prove should be filtered. If the filter does not fully evaluate the remaining keys using just the index information, it must return a filter (which may be an IEntryFilter) that can complete the task using an iterating implementation. If, on the other hand, the filter does fully evaluate the remaining keys using just the index information, then it should return null to indicate that no further filtering is necessary.

BuildPlan()

Build a plan for processing the LIKE functionality.

Declaration

protected virtual void BuildPlan()

CalculateEffectiveness(IDictionary, ICollection)

Given an IDictionary of available indexes, determine if this IIndexAwareFilter can use any of the indexes to assist in its processing, and if so, determine how effective the use of that index would be.

Declaration

public int CalculateEffectiveness(IDictionary indexes, ICollection keys)

Parameters

Type	Name	Description
IDictionary	indexes	The available ICacheIndex objects keyed by the related IValueExtractor; read-only.
ICollection	keys	The set of keys that will be filtered; read-only.

Returns

Type	Description
int	An effectiveness estimate of how well this filter can use the specified indexes to filter the specified keys.

Remarks

The returned value is an effectiveness estimate of how well this filter can use the specified indexes to filter the specified keys. An operation that requires no more than a single access to the index content (i.e. Equals, NotEquals) has an effectiveness of one. Evaluation of a single entry is assumed to have an effectiveness that depends on the index implementation and is usually measured as a constant number of the single operations. This number is referred to as evaluation cost.

If the effectiveness of a filter evaluates to a number larger than the keys.size() then a user could avoid using the index and iterate through the keys calling Evaluate rather than ApplyIndex.

EvaluateExtracted(object)

Evaluate the specified extracted value.

Declaration

protected override bool EvaluateExtracted(object extracted)

Parameters

Type	Name	Description
object	extracted	An extracted value to evaluate.

Returns

Type	Description
bool	true if the test passes, false otherwise.

Overrides

ExtractorFilter.EvaluateExtracted(object)

IsMatch(string)

Check the passed string value to see if it matches the pattern that this filter was constructed with.

Declaration

protected virtual bool IsMatch(string value)

Parameters

Type	Name	Description
string	value	The string value to match against this filter's pattern.

Returns

Type	Description
bool	true if the passed string value is LIKE this filter's pattern.

ReadExternal(IPofReader)

Restore the contents of a user type instance by reading its state using the specified IPofReader object.

Declaration

public override void ReadExternal(IPofReader reader)

Parameters

Type	Name	Description
IPofReader	reader	The IPofReader from which to read the object's state.

Overrides

ComparisonFilter.ReadExternal(IPofReader)

Exceptions

Type	Condition
IOException	If an I/O error occurs.

WriteExternal(IPofWriter)

Save the contents of a POF user type instance by writing its state using the specified IPofWriter object.

Declaration

public override void WriteExternal(IPofWriter writer)

Parameters

Type	Name	Description
IPofWriter	writer	The IPofWriter to which to write the object's state.

Overrides

ComparisonFilter.WriteExternal(IPofWriter)

Exceptions

Type	Condition
IOException	If an I/O error occurs.

Implements

IPortableObject

IIndexAwareFilter

IEntryFilter

IFilter