/// <summary>
/// Calculates the length in bytes of a TrailingChecksumWrapperStream initialized
/// with the given trailing headers and optional checksum
/// </summary>
/// <param name="trailingHeaders">Dictionary of trailing headers</param>
/// <param name="checksumAlgorithm">Trailing checksum</param>
/// <param name="baseStreamLength">Length of the base stream in bytes</param>
/// <returns>Length of a TrailingChecksumWrapperStream with given parameters, in bytes</returns>
public static long CalculateLength(IDictionary <string, string> trailingHeaders, CoreChecksumAlgorithm checksumAlgorithm, long baseStreamLength)
{
var prefixLength = baseStreamLength.ToString("X", CultureInfo.InvariantCulture).Length;
var trailingHeaderLength = 0;
if (trailingHeaders != null)
{
foreach (var key in trailingHeaders.Keys)
{
if (checksumAlgorithm != CoreChecksumAlgorithm.NONE && ChecksumUtils.GetChecksumHeaderKey(checksumAlgorithm) == key)
{
trailingHeaderLength += key.Length +
CryptoUtilFactory.GetChecksumBase64Length(checksumAlgorithm) + HEADER_ROW_PADDING_LENGTH;
}
else
{
trailingHeaderLength += key.Length + trailingHeaders[key].Length + HEADER_ROW_PADDING_LENGTH;
}
}
}
return(prefixLength +
NEWLINE_LENGTH +
baseStreamLength +
NEWLINE_LENGTH +
EMPTY_CHUNK_LENGTH +
trailingHeaderLength +
NEWLINE_LENGTH);
}
/// <summary>
/// Computes the total size of the data payload, including the chunk metadata
/// and optional trailing headers. Called externally so as to be able to set
/// the correct Content-Length header value.
/// </summary>
/// <param name="originalLength">Length of the wrapped stream</param>
/// <param name="signatureLength">Length of the signature for each chunk, in bytes</param>
/// <param name="trailingHeaders">Optional trailing headers</param>
/// <param name="trailingChecksum">Optional checksum algorithm for a trailing header</param>
/// <returns>Total size of the wrapped payload, in bytes</returns>
public static long ComputeChunkedContentLength(long originalLength, int signatureLength, IDictionary <string, string> trailingHeaders, CoreChecksumAlgorithm trailingChecksum)
{
if (originalLength < 0)
{
throw new ArgumentOutOfRangeException("originalLength", "Expected 0 or greater value for originalLength.");
}
int trailingHeaderLength = 0;
long chunkedContentLength;
// Calculate the size of the chunked content, before trailing headers/checksum
if (originalLength == 0)
{
chunkedContentLength = CalculateChunkHeaderLength(0, signatureLength);
}
else
{
var maxSizeChunks = originalLength / DefaultChunkSize;
var remainingBytes = originalLength % DefaultChunkSize;
chunkedContentLength = maxSizeChunks * CalculateChunkHeaderLength(DefaultChunkSize, signatureLength)
+ (remainingBytes > 0 ? CalculateChunkHeaderLength(remainingBytes, signatureLength) : 0)
+ CalculateChunkHeaderLength(0, signatureLength);
}
if (trailingHeaders?.Count > 0)
{
foreach (var key in trailingHeaders.Keys)
{
// If the trailing checksum key is already in dictionary, use the
// expected length since the checksum value may not be set yet.
if (trailingChecksum != CoreChecksumAlgorithm.NONE && ChecksumUtils.GetChecksumHeaderKey(trailingChecksum) == key)
{
trailingHeaderLength += key.Length +
CryptoUtilFactory.GetChecksumBase64Length(trailingChecksum) + HEADER_ROW_PADDING_LENGTH;
}
else
{
trailingHeaderLength += key.Length + trailingHeaders[key].Length + HEADER_ROW_PADDING_LENGTH;
}
}
trailingHeaderLength += TRAILING_HEADER_SIGNATURE_KEY.Length + signatureLength + HEADER_ROW_PADDING_LENGTH;
}
return(chunkedContentLength + trailingHeaderLength);
}