예제 #1
0
        public void GetBlock(DeflateInput input, OutputBuffer output, bool isFinal)
        {
            int num = 0;

            if (input != null)
            {
                num = Math.Min(input.Count, output.FreeBytes - 5 - output.BitsInBuffer);
                if (num > 65531)
                {
                    num = 65531;
                }
            }
            if (isFinal)
            {
                output.WriteBits(3, 1u);
            }
            else
            {
                output.WriteBits(3, 0u);
            }
            output.FlushBits();
            this.WriteLenNLen((ushort)num, output);
            if (input != null && num > 0)
            {
                output.WriteBytes(input.Buffer, input.StartIndex, num);
                input.ConsumeBytes(num);
            }
        }
예제 #2
0
        private void GetCompressedOutput(DeflateInput input, OutputBuffer output, int maxBytesToCopy)
        {
            int bytesWritten = output.BytesWritten;
            int num          = 0;
            int num2         = this.BytesInHistory + input.Count;

            do
            {
                int num3 = (input.Count < this.inputWindow.FreeWindowSpace) ? input.Count : this.inputWindow.FreeWindowSpace;
                if (maxBytesToCopy >= 1)
                {
                    num3 = Math.Min(num3, maxBytesToCopy - num);
                }
                if (num3 > 0)
                {
                    this.inputWindow.CopyBytes(input.Buffer, input.StartIndex, num3);
                    input.ConsumeBytes(num3);
                    num += num3;
                }
                this.GetCompressedOutput(output);
            }while (this.SafeToWriteTo(output) && this.InputAvailable(input) && (maxBytesToCopy < 1 || num < maxBytesToCopy));
            int num4 = output.BytesWritten - bytesWritten;
            int num5 = this.BytesInHistory + input.Count;
            int num6 = num2 - num5;

            if (num4 != 0)
            {
                this.lastCompressionRatio = (double)num4 / (double)num6;
            }
        }
예제 #3
0
        // maxBytesToCopy limits the number of bytes we can copy from input. Set to any value < 1 if no limit
        private void GetCompressedOutput(DeflateInput input, OutputBuffer output, int maxBytesToCopy) {
            // snapshot for compression ratio stats
            int bytesWrittenPre = output.BytesWritten;
            int bytesConsumedFromInput = 0;
            int inputBytesPre = BytesInHistory + input.Count;

            do {
                // read more input data into the window if there is space available
                int bytesToCopy = (input.Count < inputWindow.FreeWindowSpace) ?
                                         input.Count : inputWindow.FreeWindowSpace;
                if (maxBytesToCopy >= 1) {
                    bytesToCopy = Math.Min(bytesToCopy, maxBytesToCopy - bytesConsumedFromInput);
                }
                if (bytesToCopy > 0) {
                    // copy data into history window
                    inputWindow.CopyBytes(input.Buffer, input.StartIndex, bytesToCopy);
                    input.ConsumeBytes(bytesToCopy);
                    bytesConsumedFromInput += bytesToCopy;
                }

                GetCompressedOutput(output);

            } while (SafeToWriteTo(output) && InputAvailable(input) && (maxBytesToCopy < 1 || bytesConsumedFromInput < maxBytesToCopy));

            // determine compression ratio, save
            int bytesWrittenPost = output.BytesWritten;
            int bytesWritten = bytesWrittenPost - bytesWrittenPre;
            int inputBytesPost = BytesInHistory + input.Count;
            int totalBytesConsumed = inputBytesPre - inputBytesPost;
            if (bytesWritten != 0) {
                lastCompressionRatio = (double)bytesWritten / (double)totalBytesConsumed;
            }

        }
예제 #4
0
        // null input means write an empty payload with formatting info. This is needed for the final block.
        public void GetBlock(DeflateInput input, OutputBuffer output, bool isFinal)
        {
            Debug.Assert(output != null);
            Debug.Assert(output.FreeBytes >= PaddingSize);

            // determine number of bytes to write
            int count = 0;

            if (input != null)
            {
                // allow space for padding and bits not yet flushed to buffer
                count = Math.Min(input.Count, output.FreeBytes - PaddingSize - output.BitsInBuffer);

                // we don't expect the output buffer to ever be this big (currently 4K), but we'll check this
                // just in case that changes.
                if (count > MaxUncompressedBlockSize - PaddingSize)
                {
                    count = MaxUncompressedBlockSize - PaddingSize;
                }
            }

            // write header and flush bits
            if (isFinal)
            {
                output.WriteBits(FastEncoderStatics.BFinalNoCompressionHeaderBitCount,
                                 FastEncoderStatics.BFinalNoCompressionHeader);
            }
            else
            {
                output.WriteBits(FastEncoderStatics.NoCompressionHeaderBitCount,
                                 FastEncoderStatics.NoCompressionHeader);
            }

            // now we're aligned
            output.FlushBits();

            // write len, nlen
            WriteLenNLen((ushort)count, output);

            // write uncompressed bytes
            if (input != null && count > 0)
            {
                output.WriteBytes(input.Buffer, input.StartIndex, count);
                input.ConsumeBytes(count);
            }
        }
예제 #5
0
        // null input means write an empty payload with formatting info. This is needed for the final block.
        public void GetBlock(DeflateInput input, OutputBuffer output, bool isFinal) {
            Debug.Assert(output != null);
            Debug.Assert(output.FreeBytes >= PaddingSize);

            // determine number of bytes to write
            int count = 0;
            if (input != null) {

                // allow space for padding and bits not yet flushed to buffer
                count = Math.Min(input.Count, output.FreeBytes - PaddingSize - output.BitsInBuffer); 

                // we don't expect the output buffer to ever be this big (currently 4K), but we'll check this
                // just in case that changes.
                if (count > MaxUncompressedBlockSize - PaddingSize) {
                    count = MaxUncompressedBlockSize - PaddingSize;
                }
            }

            // write header and flush bits
            if (isFinal) {
                output.WriteBits(FastEncoderStatics.BFinalNoCompressionHeaderBitCount,
                                        FastEncoderStatics.BFinalNoCompressionHeader);
            }
            else {
                output.WriteBits(FastEncoderStatics.NoCompressionHeaderBitCount,
                                        FastEncoderStatics.NoCompressionHeader);
            }

            // now we're aligned
            output.FlushBits(); 
            
            // write len, nlen
            WriteLenNLen((ushort)count, output);

            // write uncompressed bytes
            if (input != null && count > 0) {
                output.WriteBytes(input.Buffer, input.StartIndex, count);
                input.ConsumeBytes(count);
            }

        }
예제 #6
0
파일: FastEncoder.cs 프로젝트: supermax/TMS
        // maxBytesToCopy limits the number of bytes we can copy from input. Set to any value < 1 if no limit
        private void GetCompressedOutput(DeflateInput input, OutputBuffer output, int maxBytesToCopy)
        {
            // snapshot for compression ratio stats
            var bytesWrittenPre        = output.BytesWritten;
            var bytesConsumedFromInput = 0;
            var inputBytesPre          = BytesInHistory + input.Count;

            do
            {
                // read more input data into the window if there is space available
                var bytesToCopy = input.Count < inputWindow.FreeWindowSpace
                                        ? input.Count
                                        : inputWindow.FreeWindowSpace;
                if (maxBytesToCopy >= 1)
                {
                    bytesToCopy = Math.Min(bytesToCopy, maxBytesToCopy - bytesConsumedFromInput);
                }
                if (bytesToCopy > 0)
                {
                    // copy data into history window
                    inputWindow.CopyBytes(input.Buffer, input.StartIndex, bytesToCopy);
                    input.ConsumeBytes(bytesToCopy);
                    bytesConsumedFromInput += bytesToCopy;
                }

                GetCompressedOutput(output);
            } while (SafeToWriteTo(output) && InputAvailable(input) &&
                     (maxBytesToCopy < 1 || bytesConsumedFromInput < maxBytesToCopy));

            // determine compression ratio, save
            var bytesWrittenPost   = output.BytesWritten;
            var bytesWritten       = bytesWrittenPost - bytesWrittenPre;
            var inputBytesPost     = BytesInHistory + input.Count;
            var totalBytesConsumed = inputBytesPre - inputBytesPost;

            if (bytesWritten != 0)
            {
                LastCompressionRatio = bytesWritten / (double)totalBytesConsumed;
            }
        }