//
// Copyright (c) 2008-2011, Kenneth Bell
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//

namespace DiscUtils
{
    using System;

    /// <summary>
    /// Base class represented a stored extent of a virtual disk.
    /// </summary>
    /// <remarks>
    /// Some file formats can divide a logical disk layer into multiple extents, stored in
    /// different files.  This class represents those extents.  Normally, all virtual disks
    /// have at least one extent.
    /// </remarks>
    public abstract class VirtualDiskExtent : IDisposable
    {
        /// <summary>
        /// Gets a value indicating whether the extent only stores meaningful sectors.
        /// </summary>
        public abstract bool IsSparse
        {
            get;
        }

        /// <summary>
        /// Gets the capacity of the extent (in bytes).
        /// </summary>
        public abstract long Capacity
        {
            get;
        }

        /// <summary>
        /// Gets the size of the extent (in bytes) on underlying storage.
        /// </summary>
        public abstract long StoredSize
        {
            get;
        }

        /// <summary>
        /// Gets the content of this extent.
        /// </summary>
        /// <param name="parent">The parent stream (if any).</param>
        /// <param name="ownsParent">Controls ownership of the parent stream.</param>
        /// <returns>The content as a stream.</returns>
        public abstract MappedStream OpenContent(SparseStream parent, Ownership ownsParent);

        /// <summary>
        /// Disposes of this instance, freeing underlying resources.
        /// </summary>
        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        /// <summary>
        /// Disposes of underlying resources.
        /// </summary>
        /// <param name="disposing"><c>true</c> if running inside Dispose(), indicating
        /// graceful cleanup of all managed objects should be performed, or <c>false</c>
        /// if running inside destructor.</param>
        protected virtual void Dispose(bool disposing)
        {
        }
    }
}
