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Permazen core API classes which provide objects, fields, indexes, queries, and schema management on top of a key/value store.

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/*
 * Copyright (C) 2015 Archie L. Cobbs. All rights reserved.
 */

package io.permazen.core;

import com.google.common.base.Preconditions;

import io.permazen.encoding.Encoding;
import io.permazen.schema.SchemaCompositeIndex;

/**
 * A composite index on two or more fields in an {@link ObjType}.
 */
public class CompositeIndex extends Index {

// Constructor

    CompositeIndex(Schema schema, SchemaCompositeIndex index, ObjType objType, Iterable> fields) {
        super(schema, index, index.getName(), objType, fields);
        assert this.fields.size() >= 2;
        assert this.fields.stream().noneMatch(field -> field.parent != null);
    }

// IndexSwitch

    @Override
    public  R visit(IndexSwitch target) {
        Preconditions.checkArgument(target != null, "null target");
        return target.caseCompositeIndex(this);
    }

// Object

    @Override
    public String toString() {
        return "composite " + super.toString();
    }

// Package Methods

    @Override
    public AbstractCoreIndex getIndex(Transaction tx) {
        switch (this.encodings.size()) {
        case 2:
            return this.buildIndex(tx, this.encodings.get(0), this.encodings.get(1));
        case 3:
            return this.buildIndex(tx, this.encodings.get(0), this.encodings.get(1), this.encodings.get(2));
        case 4:
            return this.buildIndex(tx, this.encodings.get(0), this.encodings.get(1), this.encodings.get(2), this.encodings.get(3));
        // COMPOSITE-INDEX
        default:
            throw new RuntimeException("internal error");
        }
    }

    // This method exists solely to bind the generic type parameters
    private  CoreIndex2 buildIndex(Transaction tx,
      Encoding value1Encoding,
      Encoding value2Encoding) {
        return new CoreIndex2<>(tx.kvt, new Index2View<>(this.storageId,
          value1Encoding,
          value2Encoding,
          Encodings.OBJ_ID));
    }

    // This method exists solely to bind the generic type parameters
    private  CoreIndex3 buildIndex(Transaction tx,
      Encoding value1Encoding,
      Encoding value2Encoding,
      Encoding value3Encoding) {
        return new CoreIndex3<>(tx.kvt, new Index3View<>(this.storageId,
          value1Encoding,
          value2Encoding,
          value3Encoding,
          Encodings.OBJ_ID));
    }

    // This method exists solely to bind the generic type parameters
    private  CoreIndex4 buildIndex(Transaction tx,
      Encoding value1Encoding,
      Encoding value2Encoding,
      Encoding value3Encoding,
      Encoding value4Encoding) {
        return new CoreIndex4<>(tx.kvt, new Index4View<>(this.storageId,
          value1Encoding,
          value2Encoding,
          value3Encoding,
          value4Encoding,
          Encodings.OBJ_ID));
    }
}