/// <summary>Decompress data and resize output if needed.</summary>
/// <param name="input">Array segment to decompress.</param>
/// <param name="output">Output buffer to write to.</param>
/// <param name="offset">Output offset to write to.</param>
/// <returns>Total number of bytes written to the output.</returns>
public int Decompress(ArraySegment <byte> input, ref byte[] output, int offset)
{
// Validate
if (Disposed)
{
throw new ObjectDisposedException(GetType().FullName);
}
else if (output == null)
{
throw new ArgumentNullException(nameof(output), "Output buffer is null");
}
else if (offset < 0)
{
throw new ArgumentOutOfRangeException(nameof(offset), string.Format(
"Output offset {0} is negative", offset
));
}
// Decompress
using (Stream stream = new MemoryStream(input.Array, input.Offset, input.Count, false))
using (Stream zip = new DeflateStream(stream, CompressionMode.Decompress)) {
int total = 0, outputOffset = offset, count;
do
{
// Expand output if needed
if (output == null || outputOffset >= output.Length)
{
output = Allocator.ExpandMessage(output, outputOffset);
}
// Process next chunk
count = zip.Read(output, outputOffset, output.Length - outputOffset);
outputOffset += count;
total += count;
} while (count > 0);
return(total);
}
}
/// <summary>Decompress data and resize output if needed.</summary>
/// <param name="input">Array segment to decompress.</param>
/// <param name="output">Output buffer to write to.</param>
/// <param name="offset">Output offset to write to.</param>
/// <returns>Total number of bytes written to the output.</returns>
public int Decompress(ArraySegment <byte> input, ref byte[] output, int offset)
{
// Validate
if (Disposed)
{
throw new ObjectDisposedException(GetType().FullName);
}
else if (output == null)
{
throw new ArgumentNullException(nameof(output), "Output buffer is null");
}
else if (offset < 0)
{
throw new ArgumentOutOfRangeException(nameof(offset), string.Format(
"Output offset {0} is negative", offset
));
}
uint iidx = 0;
uint oidx = 0;
do
{
uint ctrl = input.Array[input.Offset + iidx++];
if (ctrl < (1 << 5))
{
ctrl++;
// Expand output if needed
if (output == null || output.Length < oidx + ctrl)
{
output = Allocator.ExpandMessage(output, (int)oidx, (int)ctrl);
}
do
{
output[oidx++] = input.Array[input.Offset + iidx++];
} while ((--ctrl) != 0);
}
else
{
uint len = ctrl >> 5;
int reference = (int)(oidx - ((ctrl & 0x1f) << 8) - 1);
if (len == 7)
{
len += input.Array[input.Offset + iidx++];
}
reference -= input.Array[input.Offset + iidx++];
if (reference < 0)
{
throw new InvalidOperationException("Bad compressed data");
}
// Expand output if needed
if (output == null || output.Length < oidx + len + 2)
{
output = Allocator.ExpandMessage(output, (int)oidx, (int)(len + 2));
}
output[oidx++] = output[reference++];
output[oidx++] = output[reference++];
do
{
output[oidx++] = output[reference++];
} while ((--len) != 0);
}
} while (iidx < input.Count);
return((int)oidx);
}
