Package org.apache.cassandra.db.filter
Class RowFilter.UserExpression
- java.lang.Object
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- org.apache.cassandra.db.filter.RowFilter.Expression
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- org.apache.cassandra.db.filter.RowFilter.UserExpression
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- Enclosing class:
- RowFilter
public abstract static class RowFilter.UserExpression extends RowFilter.Expression
A user defined filtering expression. These may be added to RowFilter programmatically by a QueryHandler implementation. No concrete implementations are provided and adding custom impls to the classpath is a task for operators (needless to say, this is something of a power user feature). Care must also be taken to register implementations, via the static register method during system startup. An implementation and its corresponding Deserializer must be registered before sending or receiving any messages containing expressions of that type. Use of custom filtering expressions in a mixed version cluster should be handled with caution as the order in which types are registered is significant: if continuity of use during upgrades is important, new types should registered last and obsoleted types should still be registered ( or dummy implementations registered in their place) to preserve consistent identifiers across the cluster). During serialization, the identifier for the Deserializer implementation is prepended to the implementation specific payload. To deserialize, the identifier is read first to obtain the Deserializer, which then provides the concrete expression instance.
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Nested Class Summary
Nested Classes Modifier and Type Class Description protected static class
RowFilter.UserExpression.Deserializer
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Nested classes/interfaces inherited from class org.apache.cassandra.db.filter.RowFilter.Expression
RowFilter.Expression.Kind
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Field Summary
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Fields inherited from class org.apache.cassandra.db.filter.RowFilter.Expression
column, operator, value
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Constructor Summary
Constructors Modifier Constructor Description protected
UserExpression(ColumnMetadata column, Operator operator, java.nio.ByteBuffer value)
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Method Summary
All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description protected RowFilter.Expression.Kind
kind()
static void
register(java.lang.Class<? extends RowFilter.UserExpression> expressionClass, RowFilter.UserExpression.Deserializer deserializer)
protected abstract void
serialize(DataOutputPlus out, int version)
protected abstract long
serializedSize(int version)
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Methods inherited from class org.apache.cassandra.db.filter.RowFilter.Expression
column, equals, getIndexValue, getValue, hashCode, isContains, isContainsKey, isCustom, isSatisfiedBy, isUserDefined, operator, validate, validateForIndexing
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Constructor Detail
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UserExpression
protected UserExpression(ColumnMetadata column, Operator operator, java.nio.ByteBuffer value)
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Method Detail
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register
public static void register(java.lang.Class<? extends RowFilter.UserExpression> expressionClass, RowFilter.UserExpression.Deserializer deserializer)
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kind
protected RowFilter.Expression.Kind kind()
- Specified by:
kind
in classRowFilter.Expression
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serialize
protected abstract void serialize(DataOutputPlus out, int version) throws java.io.IOException
- Throws:
java.io.IOException
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serializedSize
protected abstract long serializedSize(int version)
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