suneido.database.immudb.ForeignKeyTargets.java Source code

Introduction

Here is the source code for suneido.database.immudb.ForeignKeyTargets.java

Source

/* Copyright 2011 (c) Suneido Software Corp. All rights reserved.
 * Licensed under GPLv2.
 */

package suneido.database.immudb;

import java.util.Map;
import java.util.Set;

import suneido.util.Immutable;

import com.google.common.base.Predicates;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;
import com.google.common.collect.Maps;

import suneido.util.PersistentMap;

/** Map<ForeignKey, ImmutableSet<ForeignKeyTarget>> */
@Immutable
class ForeignKeyTargets {
    private final PersistentMap<ForeignKey, ImmutableSet<ForeignKeyTarget>> targets;

    private ForeignKeyTargets(PersistentMap<ForeignKey, ImmutableSet<ForeignKeyTarget>> targets) {
        this.targets = targets;
    }

    static ForeignKeyTargets empty() {
        PersistentMap<ForeignKey, ImmutableSet<ForeignKeyTarget>> targets = PersistentMap.empty();
        return new ForeignKeyTargets(targets);
    }

    ForeignKeyTargets with(ForeignKey source, ForeignKeyTarget target) {
        ImmutableSet.Builder<ForeignKeyTarget> fks = ImmutableSet.builder();
        Set<ForeignKeyTarget> cur = targets.get(source);
        if (cur != null)
            fks.addAll(cur);
        fks.add(target);
        return new ForeignKeyTargets(targets.with(source, fks.build()));
    }

    ForeignKeyTargets without(ForeignKey source, ForeignKeyTarget target) {
        Set<ForeignKeyTarget> cur = targets.get(source);
        ImmutableSet<ForeignKeyTarget> wo = ImmutableSet
                .copyOf(Iterables.filter(cur, Predicates.not(Predicates.equalTo(target))));
        return new ForeignKeyTargets(targets.with(source, wo));
    }

    Set<ForeignKeyTarget> get(String tablename, String columns) {
        return targets.get(new ForeignKey(tablename, columns));
    }

    static Builder builder() {
        return new Builder();
    }

    /** Used by {@link Tables} */
    static class Builder {
        private final Map<ForeignKey, ImmutableSet.Builder<ForeignKeyTarget>> targets = Maps.newHashMap();

        void add(ForeignKey source, ForeignKeyTarget target) {
            assert source != null;
            assert target != null;
            ImmutableSet.Builder<ForeignKeyTarget> fkeys = targets.get(source);
            if (fkeys == null)
                fkeys = ImmutableSet.builder();
            fkeys.add(target);
            targets.put(source, fkeys);
        }

        ForeignKeyTargets build() {
            PersistentMap.Builder<ForeignKey, ImmutableSet<ForeignKeyTarget>> b = PersistentMap.builder();
            for (Map.Entry<ForeignKey, ImmutableSet.Builder<ForeignKeyTarget>> e : targets.entrySet())
                b.put(e.getKey(), e.getValue().build());
            return new ForeignKeyTargets(b.build());
        }

    }

}