HandDriverUPM/TouchSocket/Core/IO/FileIO/FileStorageStream.cs

//------------------------------------------------------------------------------
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//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
using System.IO;

namespace TouchSocket.Core
{
    /// <summary>
    /// FileStorageStream。非线程安全。
    /// </summary>
    //IntelligentCoder.AsyncMethodPoster(Flags = IntelligentCoder.MemberFlags.Public)]
    public partial class FileStorageStream : Stream
    {
        private long m_position;

        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="fileStorage"></param>
        public FileStorageStream(FileStorage fileStorage)
        {
            this.FileStorage = fileStorage ?? throw new System.ArgumentNullException(nameof(fileStorage));
        }

        /// <summary>
        /// 析构函数
        /// </summary>
        ~FileStorageStream()
        {
            // 不要更改此代码。请将清理代码放入“Dispose(bool disposing)”方法中
            this.Dispose(disposing: false);
        }

        /// <summary>
        /// <inheritdoc/>
        /// </summary>
        public override bool CanRead => this.FileStorage.FileStream.CanRead;

        /// <summary>
        /// <inheritdoc/>
        /// </summary>
        public override bool CanSeek => this.FileStorage.FileStream.CanSeek;

        /// <summary>
        /// <inheritdoc/>
        /// </summary>
        public override bool CanWrite => this.FileStorage.FileStream.CanWrite;

        /// <summary>
        /// 文件存储器
        /// </summary>
        public FileStorage FileStorage { get; private set; }

        /// <summary>
        /// <inheritdoc/>
        /// </summary>
        public override long Length => this.FileStorage.FileStream.Length;

        /// <summary>
        /// <inheritdoc/>
        /// </summary>
        public override long Position { get => this.m_position; set => this.m_position = value; }

        /// <summary>
        /// <inheritdoc/>
        /// </summary>
        //[IntelligentCoder.AsyncMethodIgnore]
        public override void Flush()
        {
            this.FileStorage.Flush();
        }

        /// <summary>
        /// <inheritdoc/>
        /// </summary>
        /// <param name="buffer"></param>
        /// <param name="offset"></param>
        /// <param name="count"></param>
        /// <returns></returns>
        public override int Read(byte[] buffer, int offset, int count)
        {
            int r = this.FileStorage.Read(this.m_position, buffer, offset, count);
            this.m_position += r;
            return r;
        }

        /// <summary>
        /// <inheritdoc/>
        /// </summary>
        /// <param name="offset"></param>
        /// <param name="origin"></param>
        /// <returns></returns>
        public override long Seek(long offset, SeekOrigin origin)
        {
            switch (origin)
            {
                case SeekOrigin.Begin:
                    this.m_position = offset;
                    break;

                case SeekOrigin.Current:
                    this.m_position += offset;
                    break;

                case SeekOrigin.End:
                    this.m_position = this.Length + offset;
                    break;
            }
            return this.m_position;
        }

        /// <summary>
        /// <inheritdoc/>
        /// </summary>
        /// <param name="value"></param>
        public override void SetLength(long value)
        {
            this.FileStorage.FileStream.SetLength(value);
        }

        /// <summary>
        /// <inheritdoc/>
        /// </summary>
        /// <param name="buffer"></param>
        /// <param name="offset"></param>
        /// <param name="count"></param>
        public override void Write(byte[] buffer, int offset, int count)
        {
            this.FileStorage.Write(this.m_position, buffer, offset, count);
            this.m_position += count;
        }

        /// <summary>
        /// <inheritdoc/>
        /// </summary>
        /// <param name="disposing"></param>
        protected override void Dispose(bool disposing)
        {
            FilePool.TryReleaseFile(this.FileStorage.Path);
            base.Dispose(disposing);
        }
    }
}