/// <summary>Calculates the Adler32 check-sum on specified portion of a buffer.</summary>
/// <param name="data">Data buffer to perform check-sum on.</param>
/// <param name="startIndex">Starts index in data buffer to begin check-sum.</param>
/// <param name="length">Total number of bytes from <paramref name="startIndex">startIndex</paramref> to
/// perform check-sum over.</param>
/// <remarks>
/// <para>
/// Computes Adler32 checksum for a stream of data. An Adler32 checksum is not as reliable as a CRC32
/// checksum, but a lot faster to compute.
/// </para>
/// <para>
/// The specification for Adler32 may be found in RFC 1950. ZLIB Compressed Data Format Specification
/// version 3.3.
/// </para>
/// </remarks>
/// <returns>Computed Adler32 checksum over the specified portion of the buffer.</returns>
public static uint Adler32Checksum(this byte[] data, int startIndex, int length)
{
Adler32 checksum = new Adler32();
checksum.Update(data, startIndex, length);
return checksum.Value;
}
/// <summary>
/// Creates a new inflater.
/// </summary>
/// <param name="noHeader">
/// True if no RFC1950/Zlib header and footer fields are expected in the input data
///
/// This is used for GZIPed/Zipped input.
///
/// For compatibility with
/// Sun JDK you should provide one byte of input more than needed in
/// this case.
/// </param>
public Inflater(bool noHeader)
{
this.noHeader = noHeader;
this.adler = new Adler32();
input = new StreamManipulator();
outputWindow = new OutputWindow();
mode = noHeader ? DECODE_BLOCKS : DECODE_HEADER;
}
/// <summary>
/// Construct instance with pending buffer
/// </summary>
/// <param name="pending">
/// Pending buffer to use
/// </param>>
public DeflaterEngine(DeflaterPending pending)
{
this.pending = pending;
huffman = new DeflaterHuffman(pending);
adler = new Adler32();
window = new byte[2 * WSIZE];
head = new short[HASH_SIZE];
prev = new short[WSIZE];
// We start at index 1, to avoid an implementation deficiency, that
// we cannot build a repeat pattern at index 0.
blockStart = strstart = 1;
}