public PNGAnalyzer(byte[] data)
{
pngData = data;
index = 0;
foundIEND = false;
memoryStream = new MemoryStream();
// zlib initialization
zBuf = new byte[8192];
zStream = new zlib.ZStream();
zStream.inflateInit();
zStream.next_out = zBuf;
zStream.avail_out = zBuf.Length;
}
protected ZStream(RubyClass/*!*/ cls, zlib.ZStream/*!*/ stream)
: base(cls)
{
Debug.Assert(stream != null);
_stream = stream;
}
private static zlib.ZStream CreateInflateStream(int windowBits)
{
var zst = new zlib.ZStream();
int result = zst.inflateInit(windowBits);
if (result != Z_OK) {
throw MakeError(result, zst.msg);
}
return zst;
}
private static zlib.ZStream CreateDeflateStream(int level, int windowBits, int memLevel, int strategy)
{
var stream = new zlib.ZStream();
int result = stream.deflateInit(level, windowBits, memLevel, (zlib.CompressionStrategy)strategy);
if (result != Z_OK) {
throw MakeError(result, null);
}
return stream;
}
public static byte[] ZLibBufferToString(this byte[] buf, int len)
{
//using (var ms = new MemoryStream(buf, 0, len))
//using (var ds = new GZipStream(ms, CompressionMode.Decompress))
//{
// byte[] decompressed = new byte[32 * 1024 + 10];
// int readlen = 0;
// int readSum = 0;
// do
// {
// readlen = ds.Read(decompressed, readlen, decompressed.Length - readSum);
// readSum += readlen;
// } while (readlen != 0);
// return decompressed.Take(readSum).ToArray();
//}
var strm = new zlib.ZStream();
strm.next_in = buf;
strm.avail_in = len;
if (strm.inflateInit() != zlib.zlibConst.Z_OK)
{
return(null);
}
bool done = false;
byte[] decompressed = new byte[32 * 1024];
int status = 0;
while (!done)
{
// Make sure we have enough room and reset the lengths.
strm.next_out = decompressed;
strm.avail_out = decompressed.Length;
// Inflate another chunk.
status = strm.inflate(zlib.zlibConst.Z_SYNC_FLUSH);
if (status == zlib.zlibConst.Z_STREAM_END)
{
done = true;
}
else if (status != zlib.zlibConst.Z_OK)
{
break;
}
}
if (strm.inflateEnd() != zlib.zlibConst.Z_OK)
{
return(null);
}
// Set real length.
if (done)
{
//using (var ms = new MemoryStream(decompressed, 0, (int)strm.total_out))
//{
// using (StreamReader reader = new StreamReader(ms, Encoding.Unicode))
// {
// var res = reader.ReadToEnd();
// return res;
// }
//}
if (decompressed.Length == (int)strm.total_out)
{
return(decompressed);
}
return(decompressed.Take((int)strm.total_out).ToArray());
}
else
{
return(null);
}
}
public static byte[] ReadZPacket(this RawData data, int compressedLength, int uncompressedLength)
{
byte[] uncompressedData = new byte[uncompressedLength];
var zs = new zlib.ZStream
{
next_in_index = data.CurrentPosition,
next_in = data.Data,
avail_in = 0,
next_out = uncompressedData,
avail_out = uncompressedLength
};
var res = zs.inflateInit(-15);
if (res != zlib.zlibConst.Z_OK)
throw new Exception("Inflate init failed: " + res);
zs.avail_in = compressedLength;
res = zs.inflate(zlib.zlibConst.Z_FINISH);
if (res != zlib.zlibConst.Z_STREAM_END)
throw new Exception("Inflate failed: " + res);
res = zs.inflateEnd();
if (res != zlib.zlibConst.Z_OK)
throw new Exception("Inflate end failed: " + res);
data.CurrentPosition += compressedLength;
return uncompressedData;
}
