private static int Process(zlib.ZStream/*!*/ zst, zlib.FlushStrategy flush, bool compress,
ref MutableString trailingUncompressedData)
{
if (zst.next_out == null) {
zst.next_out = new byte[DEFAULTALLOC];
zst.next_out_index = 0;
zst.avail_out = zst.next_out.Length;
}
int result = compress ? zst.deflate(flush) : zst.inflate(flush);
while (result == Z_OK && zst.avail_out == 0) {
byte[] output = zst.next_out;
int oldLength = output.Length;
Array.Resize(ref output, oldLength * 2);
zst.next_out = output;
zst.avail_out = oldLength;
result = compress ? zst.deflate(flush) : zst.inflate(flush);
}
if (!compress && (result == Z_STREAM_END || result == Z_STREAM_ERROR && !zst.IsInitialized)) {
// MRI hack: any data left in the stream are saved into a separate buffer and returned when "finish" is called
// This is weird behavior, one would expect the rest of the stream is either ignored or copied to the output buffer.
#if COPY_UNCOMPRESSED_DATA_TO_OUTPUT_BUFFER
Debug.Assert(zst.next_in_index + zst.avail_in <= zst.next_in.Length);
Debug.Assert(zst.next_out_index + zst.avail_out <= zst.next_out.Length);
if (zst.avail_in > zst.avail_out) {
byte[] output = zst.next_out;
int oldLength = output.Length;
Array.Resize(ref output, Math.Max(zst.next_out_index + zst.avail_in, oldLength * 2));
zst.next_out = output;
}
Buffer.BlockCopy(zst.next_in, zst.next_in_index, zst.next_out, zst.next_out_index, zst.avail_in);
// MRI subtracts till 0 is reached:
zst.avail_out = Math.Max(zst.avail_out - zst.avail_in, 0);
zst.next_out_index += zst.avail_in;
zst.avail_in = 0;
#else
if (trailingUncompressedData == null) {
trailingUncompressedData = MutableString.CreateBinary();
}
trailingUncompressedData.Append(zst.next_in, zst.next_in_index, zst.avail_in);
// MRI subtracts till 0 is reached:
zst.avail_out = Math.Max(zst.avail_out - zst.avail_in, 0);
zst.avail_in = 0;
#endif
result = Z_STREAM_END;
}
return result;
}
internal static int Process(zlib.ZStream/*!*/ zst, MutableString str, zlib.FlushStrategy flush, bool compress,
out MutableString/*!*/ result, ref MutableString trailingUncompressedData)
{
result = MutableString.CreateBinary();
// add previously compressed data to the output:
if (zst.next_out != null) {
result.Append(zst.next_out, 0, zst.next_out_index);
}
int err;
int bufferStart = zst.next_out_index;
err = Process(zst, str, flush, compress, ref trailingUncompressedData);
result.Append(zst.next_out, bufferStart, zst.next_out_index - bufferStart);
if (err == Z_STREAM_END && (flush == zlib.FlushStrategy.Z_FINISH || str == null)) {
err = compress ? zst.deflateEnd() : zst.inflateEnd();
}
zst.next_out = null;
zst.next_out_index = 0;
zst.avail_out = 0;
return err;
}
internal static int Process(zlib.ZStream/*!*/ zst, MutableString str, zlib.FlushStrategy flush, bool compress,
ref MutableString trailingUncompressedData)
{
if (str == null) {
str = MutableString.FrozenEmpty;
flush = zlib.FlushStrategy.Z_FINISH;
} else if (str.Length == 0 && flush == NO_FLUSH) {
return Z_OK;
}
// data still available from previous input:
if (zst.avail_in > 0) {
int err = Process(zst, flush, compress, ref trailingUncompressedData);
// double flush:
if (compress && flush != zlib.FlushStrategy.Z_FINISH && err == (int)zlib.ZLibResultCode.Z_DATA_ERROR) {
return Z_OK;
}
// append new input to the current input:
if (err != Z_OK && err != Z_STREAM_END) {
byte[] currentInput = zst.next_in;
byte[] newInput = str.ToByteArray();
int minLength = zst.next_in_index + zst.avail_in + newInput.Length;
if (currentInput.Length < minLength) {
Array.Resize(ref currentInput, Math.Max(currentInput.Length * 2, minLength));
}
Buffer.BlockCopy(newInput, 0, currentInput, zst.next_in_index + zst.avail_in, newInput.Length);
zst.next_in = currentInput;
zst.avail_in += newInput.Length;
return err;
}
}
if (str != null) {
byte[] input = str.ToByteArray();
zst.next_in = input;
zst.next_in_index = 0;
zst.avail_in = input.Length;
} else {
zst.avail_in = 0;
}
return Process(zst, flush, compress, ref trailingUncompressedData);
}
protected ZStream(RubyClass/*!*/ cls, zlib.ZStream/*!*/ stream)
: base(cls)
{
Debug.Assert(stream != null);
_stream = stream;
}
