DataRewinder.java

package com.bumptech.glide.load.data;

import java.io.IOException;

/**
 * Responsible for rewinding a stream like data types.
 *
 * @param <T> The stream like data type that can be rewound.
 */
public interface DataRewinder<T> {

  /**
   * A factory interface for producing individual
   * {@link com.bumptech.glide.load.data.DataRewinder}s.
   *
   * @param <T> The type of data that the {@link com.bumptech.glide.load.data.DataRewinder} will
   *            wrap.
   */
  interface Factory<T> {
    /**
     * Returns a new {@link com.bumptech.glide.load.data.DataRewinder} wrapping the given data.
     */
    DataRewinder<T> build(T data);

    /**
     * Returns the class of data this factory can produce
     * {@link com.bumptech.glide.load.data.DataRewinder}s for.
     */
    Class<T> getDataClass();
  }

  /**
   * Rewinds the wrapped data back to the position it was at when this object was instantiated and
   * returns the re-wound data (or a wrapper for the re-wound data).
   *
   * @return An object pointing to the wrapped data.
   * @throws IOException
   */
  T rewindAndGet() throws IOException;

  /**
   * Called when this rewinder is no longer needed and can be cleaned up.
   *
   * <p> The underlying data may still be in use and should not be closed or invalidated. </p>
   */
  void cleanup();
}