Esempio n. 1
0
        public override int Read(byte[] buffer, int offset, int count)
        {
            if (_position >= _length)
            {
                return(0);
            }

            int totalRead = 0;

            while (totalRead < count && _position < _length)
            {
                // If current region is outside the area of interest, clean it up
                if (_currentExtent != null && (_position < _currentExtent.Start || _position >= _currentExtent.Start + _currentExtent.Length))
                {
                    _currentExtent.DisposeReadState();
                    _currentExtent = null;
                }

                // If we need to find a new region, look for it
                if (_currentExtent == null)
                {
                    int idx = _extents.BinarySearch(new SearchExtent(_position), new ExtentRangeComparer());
                    if (idx >= 0)
                    {
                        BuilderExtent extent = _extents[idx];
                        extent.PrepareForRead();
                        _currentExtent = extent;
                    }
                }

                int numRead = 0;

                // If the block is outside any known extent, defer to base stream.
                if (_currentExtent == null)
                {
                    _baseStream.Position = _position;
                    BuilderExtent nextExtent = FindNext(_position);
                    if (nextExtent != null)
                    {
                        numRead = _baseStream.Read(buffer, offset + totalRead, (int)Math.Min(count - totalRead, nextExtent.Start - _position));
                    }
                    else
                    {
                        numRead = _baseStream.Read(buffer, offset + totalRead, count - totalRead);
                    }
                }
                else
                {
                    numRead = _currentExtent.Read(_position, buffer, offset + totalRead, count - totalRead);
                }

                _position += numRead;
                totalRead += numRead;
            }

            return(totalRead);
        }
Esempio n. 2
0
        protected override void Dispose(bool disposing)
        {
            try
            {
                if (disposing)
                {
                    if (_currentExtent != null)
                    {
                        _currentExtent.DisposeReadState();
                        _currentExtent = null;
                    }

                    if (_baseStream != null)
                    {
                        _baseStream.Dispose();
                        _baseStream = null;
                    }
                }
            }
            finally
            {
                base.Dispose(disposing);
            }
        }