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The Apache Cassandra Project develops a highly scalable second-generation distributed database, bringing together Dynamo's fully distributed design and Bigtable's ColumnFamily-based data model.
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.cassandra.schema;
import java.nio.ByteBuffer;
import java.util.*;
import java.util.function.Predicate;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import com.google.common.collect.*;
import org.apache.cassandra.cql3.functions.*;
import org.apache.cassandra.db.marshal.AbstractType;
import org.apache.cassandra.db.marshal.UserType;
import static java.util.stream.Collectors.toList;
import static com.google.common.collect.Iterables.any;
/**
* An immutable container for a keyspace's UDAs and UDFs (and, in case of {@link org.apache.cassandra.db.SystemKeyspace},
* native functions and aggregates).
*/
public final class Functions implements Iterable
{
public enum Filter implements Predicate
{
ALL, UDF, UDA;
public boolean test(Function function)
{
switch (this)
{
case UDF: return function instanceof UDFunction;
case UDA: return function instanceof UDAggregate;
default: return true;
}
}
}
private final ImmutableMultimap functions;
private Functions(Builder builder)
{
functions = builder.functions.build();
}
public static Builder builder()
{
return new Builder();
}
public static Functions none()
{
return builder().build();
}
public static Functions of(Function... funs)
{
return builder().add(funs).build();
}
public Iterator iterator()
{
return functions.values().iterator();
}
public Stream stream()
{
return functions.values().stream();
}
public int size()
{
return functions.size();
}
/**
* @return a stream of keyspace's UDFs
*/
public Stream udfs()
{
return stream().filter(Filter.UDF).map(f -> (UDFunction) f);
}
/**
* @return a stream of keyspace's UDAs
*/
public Stream udas()
{
return stream().filter(Filter.UDA).map(f -> (UDAggregate) f);
}
public Iterable referencingUserType(ByteBuffer name)
{
return Iterables.filter(this, f -> f.referencesUserType(name));
}
public Functions withUpdatedUserType(UserType udt)
{
if (!any(this, f -> f.referencesUserType(udt.name)))
return this;
Collection udfs = udfs().map(f -> f.withUpdatedUserType(udt)).collect(toList());
Collection udas = udas().map(f -> f.withUpdatedUserType(udfs, udt)).collect(toList());
return builder().add(udfs).add(udas).build();
}
/**
* @return a stream of aggregates that use the provided function as either a state or a final function
* @param function the referree function
*/
public Stream aggregatesUsingFunction(Function function)
{
return udas().filter(uda -> uda.hasReferenceTo(function));
}
/**
* Get all function overloads with the specified name
*
* @param name fully qualified function name
* @return an empty list if the function name is not found; a non-empty collection of {@link Function} otherwise
*/
public Collection get(FunctionName name)
{
return functions.get(name);
}
/**
* Get all UDFs overloads with the specified name
*
* @param name fully qualified function name
* @return an empty list if the function name is not found; a non-empty collection of {@link UDFunction} otherwise
*/
public Collection getUdfs(FunctionName name)
{
return functions.get(name)
.stream()
.filter(Filter.UDF)
.map(f -> (UDFunction) f)
.collect(Collectors.toList());
}
/**
* Get all UDAs overloads with the specified name
*
* @param name fully qualified function name
* @return an empty list if the function name is not found; a non-empty collection of {@link UDAggregate} otherwise
*/
public Collection getUdas(FunctionName name)
{
return functions.get(name)
.stream()
.filter(Filter.UDA)
.map(f -> (UDAggregate) f)
.collect(Collectors.toList());
}
public Optional find(FunctionName name, List> argTypes)
{
return find(name, argTypes, Filter.ALL);
}
/**
* Find the function with the specified name
*
* @param name fully qualified function name
* @param argTypes function argument types
* @return an empty {@link Optional} if the function name is not found; a non-empty optional of {@link Function} otherwise
*/
public Optional find(FunctionName name, List> argTypes, Filter filter)
{
return get(name).stream()
.filter(filter.and(fun -> typesMatch(fun.argTypes(), argTypes)))
.findAny();
}
public boolean isEmpty()
{
return functions.isEmpty();
}
/*
* We need to compare the CQL3 representation of the type because comparing
* the AbstractType will fail for example if a UDT has been changed.
* Reason is that UserType.equals() takes the field names and types into account.
* Example CQL sequence that would fail when comparing AbstractType:
* CREATE TYPE foo ...
* CREATE FUNCTION bar ( par foo ) RETURNS foo ...
* ALTER TYPE foo ADD ...
* or
* ALTER TYPE foo ALTER ...
* or
* ALTER TYPE foo RENAME ...
*/
private static boolean typesMatch(AbstractType t1, AbstractType t2)
{
return t1.freeze().asCQL3Type().toString().equals(t2.freeze().asCQL3Type().toString());
}
public static boolean typesMatch(List> t1, List> t2)
{
if (t1.size() != t2.size())
return false;
for (int i = 0; i < t1.size(); i++)
if (!typesMatch(t1.get(i), t2.get(i)))
return false;
return true;
}
public static int typeHashCode(AbstractType t)
{
return t.asCQL3Type().toString().hashCode();
}
public static int typeHashCode(List> types)
{
int h = 0;
for (AbstractType type : types)
h = h * 31 + typeHashCode(type);
return h;
}
public Functions filter(Predicate predicate)
{
Builder builder = builder();
stream().filter(predicate).forEach(builder::add);
return builder.build();
}
/**
* Create a Functions instance with the provided function added
*/
public Functions with(Function fun)
{
if (find(fun.name(), fun.argTypes()).isPresent())
throw new IllegalStateException(String.format("Function %s already exists", fun.name()));
return builder().add(this).add(fun).build();
}
/**
* Creates a Functions instance with the function with the provided name and argument types removed
*/
public Functions without(FunctionName name, List> argTypes)
{
Function fun =
find(name, argTypes).orElseThrow(() -> new IllegalStateException(String.format("Function %s doesn't exists", name)));
return without(fun);
}
public Functions without(Function function)
{
return builder().add(Iterables.filter(this, f -> f != function)).build();
}
public Functions withAddedOrUpdated(Function function)
{
return builder().add(Iterables.filter(this, f -> !(f.name().equals(function.name()) && Functions.typesMatch(f.argTypes(), function.argTypes()))))
.add(function)
.build();
}
@Override
public boolean equals(Object o)
{
return this == o || (o instanceof Functions && functions.equals(((Functions) o).functions));
}
@Override
public int hashCode()
{
return functions.hashCode();
}
@Override
public String toString()
{
return functions.values().toString();
}
public static final class Builder
{
final ImmutableMultimap.Builder functions = new ImmutableMultimap.Builder<>();
private Builder()
{
// we need deterministic iteration order; otherwise Functions.equals() breaks down
functions.orderValuesBy(Comparator.comparingInt(Object::hashCode));
}
public Functions build()
{
return new Functions(this);
}
public Builder add(Function fun)
{
functions.put(fun.name(), fun);
return this;
}
public Builder add(Function... funs)
{
for (Function fun : funs)
add(fun);
return this;
}
public Builder add(Iterable funs)
{
funs.forEach(this::add);
return this;
}
}
@SuppressWarnings("unchecked")
static FunctionsDiff udfsDiff(Functions before, Functions after)
{
return (FunctionsDiff) FunctionsDiff.diff(before, after, Filter.UDF);
}
@SuppressWarnings("unchecked")
static FunctionsDiff udasDiff(Functions before, Functions after)
{
return (FunctionsDiff) FunctionsDiff.diff(before, after, Filter.UDA);
}
public static final class FunctionsDiff extends Diff
{
static final FunctionsDiff NONE = new FunctionsDiff<>(Functions.none(), Functions.none(), ImmutableList.of());
private FunctionsDiff(Functions created, Functions dropped, ImmutableCollection> altered)
{
super(created, dropped, altered);
}
private static FunctionsDiff diff(Functions before, Functions after, Filter filter)
{
if (before == after)
return NONE;
Functions created = after.filter(filter.and(k -> !before.find(k.name(), k.argTypes(), filter).isPresent()));
Functions dropped = before.filter(filter.and(k -> !after.find(k.name(), k.argTypes(), filter).isPresent()));
ImmutableList.Builder> altered = ImmutableList.builder();
before.stream().filter(filter).forEach(functionBefore ->
{
after.find(functionBefore.name(), functionBefore.argTypes(), filter).ifPresent(functionAfter ->
{
functionBefore.compare(functionAfter).ifPresent(kind -> altered.add(new Altered<>(functionBefore, functionAfter, kind)));
});
});
return new FunctionsDiff<>(created, dropped, altered.build());
}
}
}