/// <inheritdoc />
public async ValueTask InvokeAsync(TiffImageDecoderContext context, ITiffImageDecoderPipelineNode next)
{
if (context is null)
{
throw new ArgumentNullException(nameof(context));
}
if (next is null)
{
throw new ArgumentNullException(nameof(next));
}
if (context.ContentReader is null)
{
throw new ArgumentException("ContentReader is not provided in the TiffImageDecoderContext instance.");
}
if (context.OperationContext is null)
{
throw new ArgumentException("OperationContext is not provided in the TiffImageDecoderContext instance.");
}
bool isParallel = !(context.GetService(typeof(TiffParallelDecodingState)) is null);
// Initialize the cache
TiffFieldReader? reader = null;
TiffStrileOffsetCache cache;
if (_lazyLoad)
{
reader = new TiffFieldReader(context.ContentReader, context.OperationContext, leaveOpen: true);
cache = new TiffStrileOffsetCache(reader, _stripOffsetsEntry, _stripsByteCountEntry, CacheSize);
}
else
{
cache = new TiffStrileOffsetCache(_stripOffsets, _stripsByteCount);
}
try
{
int rowsPerStrip = _rowsPerStrip;
CancellationToken cancellationToken = context.CancellationToken;
// Special case for mailformed file.
if (rowsPerStrip <= 0 && _stripCount == 1)
{
rowsPerStrip = context.SourceImageSize.Height;
}
// Make sure the region to read is in the image boundary.
if (context.SourceReadOffset.X >= context.SourceImageSize.Width || context.SourceReadOffset.Y >= context.SourceImageSize.Height)
{
return;
}
context.ReadSize = new TiffSize(Math.Min(context.ReadSize.Width, context.SourceImageSize.Width - context.SourceReadOffset.X), Math.Min(context.ReadSize.Height, context.SourceImageSize.Height - context.SourceReadOffset.Y));
if (context.ReadSize.IsAreaEmpty)
{
return;
}
// Create a wrapped context
int planeCount = _planeCount;
TiffImageEnumeratorDecoderContext? wrapperContext = null;
TiffMutableValueCollection <TiffStreamRegion> planarRegions = default;
if (!isParallel)
{
wrapperContext = new TiffImageEnumeratorDecoderContext(context);
planarRegions = new TiffMutableValueCollection <TiffStreamRegion>(planeCount);
}
// loop through all the strips overlapping with the region to read
int stripStart = context.SourceReadOffset.Y / rowsPerStrip;
int stripEnd = (context.SourceReadOffset.Y + context.ReadSize.Height + rowsPerStrip - 1) / rowsPerStrip;
int actualStripCount = _stripCount / _planeCount;
for (int stripIndex = stripStart; stripIndex < stripEnd; stripIndex++)
{
if (isParallel)
{
wrapperContext = new TiffImageEnumeratorDecoderContext(context);
planarRegions = new TiffMutableValueCollection <TiffStreamRegion>(planeCount);
}
// Calculate size info of this strip
int currentYOffset = stripIndex * rowsPerStrip;
int stripImageHeight = Math.Min(rowsPerStrip, context.SourceImageSize.Height - currentYOffset);
int skippedScanlines = Math.Max(0, context.SourceReadOffset.Y - currentYOffset);
int requestedScanlines = Math.Min(stripImageHeight - skippedScanlines, context.SourceReadOffset.Y + context.ReadSize.Height - currentYOffset - skippedScanlines);
wrapperContext !.SourceImageSize = new TiffSize(context.SourceImageSize.Width, stripImageHeight);
wrapperContext.SourceReadOffset = new TiffPoint(context.SourceReadOffset.X, skippedScanlines);
wrapperContext.ReadSize = new TiffSize(context.ReadSize.Width, requestedScanlines);
// Update size info of the destination buffer
wrapperContext.SetCropSize(new TiffPoint(0, Math.Max(0, currentYOffset - context.SourceReadOffset.Y)), context.ReadSize);
// Check to see if there is any region area to be read
if (wrapperContext.ReadSize.IsAreaEmpty)
{
continue;
}
// Prepare stream regions of this strip
for (int planarIndex = 0; planarIndex < planeCount; planarIndex++)
{
int accessIndex = planarIndex * actualStripCount + stripIndex;
planarRegions[planarIndex] = await cache.GetOffsetAndCountAsync(accessIndex, cancellationToken).ConfigureAwait(false);
}
wrapperContext.PlanarRegions = planarRegions.GetReadOnlyView();
cancellationToken.ThrowIfCancellationRequested();
// Pass down the data
await next.RunAsync(wrapperContext).ConfigureAwait(false);
}
}
finally
{
((IDisposable)cache).Dispose();
reader?.Dispose();
}
}
/// <inheritdoc />
public async ValueTask InvokeAsync(TiffImageDecoderContext context, ITiffImageDecoderPipelineNode next)
{
if (context is null)
{
throw new ArgumentNullException(nameof(context));
}
if (next is null)
{
throw new ArgumentNullException(nameof(next));
}
if (context.ContentReader is null)
{
throw new ArgumentException("ContentReader is not provided in the TiffImageDecoderContext instance.");
}
if (context.OperationContext is null)
{
throw new ArgumentException("OperationContext is not provided in the TiffImageDecoderContext instance.");
}
bool isParallel = !(context.GetService(typeof(TiffParallelDecodingState)) is null);
// Initialize the cache
TiffFieldReader? reader = null;
TiffStrileOffsetCache cache;
if (_lazyLoad)
{
reader = new TiffFieldReader(context.ContentReader, context.OperationContext, leaveOpen: true);
cache = new TiffStrileOffsetCache(reader, _tileOffsetsEntry, _tileByteCountsEntry, CacheSize);
}
else
{
cache = new TiffStrileOffsetCache(_tileOffsets, _tileByteCounts);
}
int tileWidth = _tileWidth;
int tileHeight = _tileHeight;
try
{
int tileAcross = (context.SourceImageSize.Width + tileWidth - 1) / tileWidth;
int tileDown = (context.SourceImageSize.Height + tileHeight - 1) / tileHeight;
int tileCount = tileAcross * tileDown;
CancellationToken cancellationToken = context.CancellationToken;
// Make sure the region to read is in the image boundary.
if (context.SourceReadOffset.X >= context.SourceImageSize.Width || context.SourceReadOffset.Y >= context.SourceImageSize.Height)
{
return;
}
context.ReadSize = new TiffSize(Math.Min(context.ReadSize.Width, context.SourceImageSize.Width - context.SourceReadOffset.X), Math.Min(context.ReadSize.Height, context.SourceImageSize.Height - context.SourceReadOffset.Y));
if (context.ReadSize.IsAreaEmpty)
{
return;
}
int planeCount = _planaCount;
TiffImageEnumeratorDecoderContext? wrapperContext = null;
TiffMutableValueCollection <TiffStreamRegion> planarRegions = default;
if (!isParallel)
{
wrapperContext = new TiffImageEnumeratorDecoderContext(context);
planarRegions = new TiffMutableValueCollection <TiffStreamRegion>(planeCount);
}
// loop through all the tiles overlapping with the region to read.
int colStart = context.SourceReadOffset.X / tileWidth;
int colEnd = (context.SourceReadOffset.X + context.ReadSize.Width + tileWidth - 1) / tileWidth;
int rowStart = context.SourceReadOffset.Y / tileHeight;
int rowEnd = (context.SourceReadOffset.Y + context.ReadSize.Height + tileHeight - 1) / tileHeight;
for (int row = rowStart; row < rowEnd; row++)
{
// Calculate coordinates on the y direction for the tiles on this row.
int currentYOffset = row * tileHeight;
int skippedScanlines = Math.Max(0, context.SourceReadOffset.Y - currentYOffset);
int requestedScanlines = Math.Min(tileHeight - skippedScanlines, context.SourceReadOffset.Y + context.ReadSize.Height - currentYOffset - skippedScanlines);
for (int col = colStart; col < colEnd; col++)
{
if (isParallel)
{
wrapperContext = new TiffImageEnumeratorDecoderContext(context);
planarRegions = new TiffMutableValueCollection <TiffStreamRegion>(planeCount);
}
wrapperContext !.SourceImageSize = new TiffSize(tileWidth, tileHeight);
// Calculate coordinates on the y direction for this tile.
int currentXOffset = col * tileWidth;
int skippedXOffset = Math.Max(0, context.SourceReadOffset.X - currentXOffset);
int requestedWidth = Math.Min(tileWidth - skippedXOffset, context.SourceReadOffset.X + context.ReadSize.Width - currentXOffset - skippedXOffset);
// Update size info of this tile
wrapperContext.SourceReadOffset = new TiffPoint(skippedXOffset, skippedScanlines);
wrapperContext.ReadSize = new TiffSize(requestedWidth, requestedScanlines);
// Update size info of the destination buffer
wrapperContext.SetCropSize(new TiffPoint(Math.Max(0, currentXOffset - context.SourceReadOffset.X), Math.Max(0, currentYOffset - context.SourceReadOffset.Y)), context.ReadSize);
// Check to see if there is any region area to be read
if (wrapperContext.ReadSize.IsAreaEmpty)
{
continue;
}
// Prepare stream regions of this tile
for (int planarIndex = 0; planarIndex < planeCount; planarIndex++)
{
int tileIndex = planarIndex * tileCount + row * tileAcross + col;
planarRegions[planarIndex] = await cache.GetOffsetAndCountAsync(tileIndex, cancellationToken).ConfigureAwait(false);
}
wrapperContext.PlanarRegions = planarRegions.GetReadOnlyView();
cancellationToken.ThrowIfCancellationRequested();
// Pass down the data
await next.RunAsync(wrapperContext).ConfigureAwait(false);
}
}
}
finally
{
((IDisposable)cache).Dispose();
reader?.Dispose();
}
}
