/*
 * PartEntryFactory.java February 2007
 *
 * Copyright (C) 2007, Niall Gallagher <niallg@users.sf.net>
 *
 * Licensed 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.simpleframework.http.message;

import org.simpleframework.util.buffer.Allocator;

/**
 * This <code>PartEntryFactory</code> object provides a factory for creating
 * part entry consumers. The part entry consumers created read individual
 * entries from a list of parts within a stream. This is basically a convenience
 * factory for the list consumer.
 * 
 * @author Niall Gallagher
 * 
 * @see org.simpleframework.http.message.PartSeriesConsumer
 */
class PartEntryFactory {

    /**
     * This is used to accumulate all the parts of the upload.
     */
    private final PartSeries series;

    /**
     * This is used to allocate the buffers used by the entry.
     */
    private final Allocator allocator;

    /**
     * This is the terminal token used to delimiter the upload.
     */
    private final byte[] terminal;

    /**
     * Constructor for the <code>PartEntryFactory</code> object. This is used to
     * create a factory for entry consumers that can be used to read an entry
     * from a part list.
     * 
     * @param allocator
     *            this is the allocator used for buffers
     * @param series
     *            this is the list of parts that are extracted
     * @param terminal
     *            this is the terminal buffer to be used
     */
    public PartEntryFactory(Allocator allocator, PartSeries series,
            byte[] terminal) {
        this.allocator = allocator;
        this.terminal = terminal;
        this.series = series;
    }

    /**
     * This creates a new part entry consumer that can be used to read the next
     * part from the list. The consumer instantiated by this factory acquires
     * the allocator, list and boundary from the enclosing part list consumer
     * instance.
     * 
     * @return a part entry consumer for this part list consumer
     */
    public PartEntryConsumer getInstance() {
        return new PartEntryConsumer(this.allocator, this.series, this.terminal);
    }
}