DeviceEmotion/ApiService/lib/compression/brotli/BrotliInputStream.cs

namespace System.Net.ApiService.Compression.Brotli {
	/// <summary>
	/// <see cref="System.IO.Stream"/>
	/// decorator that decompresses brotli data.
	/// <p> Not thread-safe.
	/// </summary>
	public class BrotliInputStream : System.IO.Stream {
		public const int DefaultInternalBufferSize = 16384;

		/// <summary>Internal buffer used for efficient byte-by-byte reading.</summary>
		private byte[] buffer;

		/// <summary>Number of decoded but still unused bytes in internal buffer.</summary>
		private int remainingBufferBytes;

		/// <summary>Next unused byte offset.</summary>
		private int bufferOffset;

		/// <summary>Decoder state.</summary>
		private readonly System.Net.ApiService.Compression.Brotli.State state = new System.Net.ApiService.Compression.Brotli.State();

		/// <summary>
		/// Creates a
		/// <see cref="System.IO.Stream"/>
		/// wrapper that decompresses brotli data.
		/// <p> For byte-by-byte reading (
		/// <see cref="ReadByte()"/>
		/// ) internal buffer with
		/// <see cref="DefaultInternalBufferSize"/>
		/// size is allocated and used.
		/// <p> Will block the thread until first kilobyte of data of source is available.
		/// </summary>
		/// <param name="source">underlying data source</param>
		/// <exception cref="System.IO.IOException">in case of corrupted data or source stream problems</exception>
		public BrotliInputStream(System.IO.Stream source)
			: this(source, DefaultInternalBufferSize, null) {
		}

		/// <summary>
		/// Creates a
		/// <see cref="System.IO.Stream"/>
		/// wrapper that decompresses brotli data.
		/// <p> For byte-by-byte reading (
		/// <see cref="ReadByte()"/>
		/// ) internal buffer of specified size is
		/// allocated and used.
		/// <p> Will block the thread until first kilobyte of data of source is available.
		/// </summary>
		/// <param name="source">compressed data source</param>
		/// <param name="byteReadBufferSize">
		/// size of internal buffer used in case of
		/// byte-by-byte reading
		/// </param>
		/// <exception cref="System.IO.IOException">in case of corrupted data or source stream problems</exception>
		public BrotliInputStream(System.IO.Stream source, int byteReadBufferSize)
			: this(source, byteReadBufferSize, null) {
		}

		/// <summary>
		/// Creates a
		/// <see cref="System.IO.Stream"/>
		/// wrapper that decompresses brotli data.
		/// <p> For byte-by-byte reading (
		/// <see cref="ReadByte()"/>
		/// ) internal buffer of specified size is
		/// allocated and used.
		/// <p> Will block the thread until first kilobyte of data of source is available.
		/// </summary>
		/// <param name="source">compressed data source</param>
		/// <param name="byteReadBufferSize">
		/// size of internal buffer used in case of
		/// byte-by-byte reading
		/// </param>
		/// <param name="customDictionary">
		/// custom dictionary data;
		/// <see langword="null"/>
		/// if not used
		/// </param>
		/// <exception cref="System.IO.IOException">in case of corrupted data or source stream problems</exception>
		public BrotliInputStream(System.IO.Stream source, int byteReadBufferSize, byte[] customDictionary) {
			if (byteReadBufferSize <= 0) {
				throw new System.ArgumentException("Bad buffer size:" + byteReadBufferSize);
			} else if (source == null) {
				throw new System.ArgumentException("source is null");
			}
			this.buffer = new byte[byteReadBufferSize];
			this.remainingBufferBytes = 0;
			this.bufferOffset = 0;
			try {
				System.Net.ApiService.Compression.Brotli.State.SetInput(state, source);
			} catch (System.Net.ApiService.Compression.Brotli.BrotliRuntimeException ex) {
				throw new System.IO.IOException("Brotli decoder initialization failed", ex);
			}
			if (customDictionary != null) {
				System.Net.ApiService.Compression.Brotli.Decode.SetCustomDictionary(state, customDictionary);
			}
		}

		/// <summary><inheritDoc/></summary>
		/// <exception cref="System.IO.IOException"/>
		public override void Close() {
			System.Net.ApiService.Compression.Brotli.State.Close(state);
		}

		/// <summary><inheritDoc/></summary>
		/// <exception cref="System.IO.IOException"/>
		public override int ReadByte() {
			if (bufferOffset >= remainingBufferBytes) {
				remainingBufferBytes = Read(buffer, 0, buffer.Length);
				bufferOffset = 0;
				if (remainingBufferBytes == -1) {
					return -1;
				}
			}
			return buffer[bufferOffset++] & unchecked((int)(0xFF));
		}

		/// <summary><inheritDoc/></summary>
		/// <exception cref="System.IO.IOException"/>
		public override int Read(byte[] destBuffer, int destOffset, int destLen) {
			if (destOffset < 0) {
				throw new System.ArgumentException("Bad offset: " + destOffset);
			} else if (destLen < 0) {
				throw new System.ArgumentException("Bad length: " + destLen);
			} else if (destOffset + destLen > destBuffer.Length) {
				throw new System.ArgumentException("Buffer overflow: " + (destOffset + destLen) + " > " + destBuffer.Length);
			} else if (destLen == 0) {
				return 0;
			}
			int copyLen = System.Math.Max(remainingBufferBytes - bufferOffset, 0);
			if (copyLen != 0) {
				copyLen = System.Math.Min(copyLen, destLen);
				System.Array.Copy(buffer, bufferOffset, destBuffer, destOffset, copyLen);
				bufferOffset += copyLen;
				destOffset += copyLen;
				destLen -= copyLen;
				if (destLen == 0) {
					return copyLen;
				}
			}
			try {
				state.output = destBuffer;
				state.outputOffset = destOffset;
				state.outputLength = destLen;
				state.outputUsed = 0;
				System.Net.ApiService.Compression.Brotli.Decode.Decompress(state);
				if (state.outputUsed == 0) {
					return -1;
				}
				return state.outputUsed + copyLen;
			} catch (System.Net.ApiService.Compression.Brotli.BrotliRuntimeException ex) {
				throw new System.IO.IOException("Brotli stream decoding failed", ex);
			}
		}
		// <{[INJECTED CODE]}>
		public override bool CanRead {
			get {
				return true;
			}
		}

		public override bool CanSeek {
			get {
				return false;
			}
		}
		public override long Length {
			get {
				throw new System.NotSupportedException();
			}
		}
		public override long Position {
			get {
				throw new System.NotSupportedException();
			}
			set {
				throw new System.NotSupportedException();
			}
		}
		public override long Seek(long offset, System.IO.SeekOrigin origin) {
			throw new System.NotSupportedException();
		}
		public override void SetLength(long value) {
			throw new System.NotSupportedException();
		}

		public override bool CanWrite {
			get {
				return false;
			}
		}
		public override System.IAsyncResult BeginWrite(byte[] buffer, int offset,
				int count, System.AsyncCallback callback, object state) {
			throw new System.NotSupportedException();
		}
		public override void Write(byte[] buffer, int offset, int count) {
			throw new System.NotSupportedException();
		}

		public override void Flush() {
		}
	}
}