public Deflate(
ZLibStream zStream,
ZlibOptions options,
int method,
int windowBits,
int memLevel)
{
int noheader = 0;
zStream.Message = null;
CompressionLevel level = options.CompressionLevel.GetValueOrDefault();
CompressionStrategy strategy = options.CompressionStrategy;
if (level == CompressionLevel.DefaultCompression)
{
level = CompressionLevel.Level6;
}
if (level == CompressionLevel.NoCompression)
{
memLevel = DEFNOCOMPRESSIONMEMLEVEL;
}
if (windowBits < 0)
{
// undocumented feature: suppress zlib header
noheader = 1;
windowBits = -windowBits;
}
if (memLevel < 1 || memLevel > MAXMEMLEVEL)
{
ThrowHelper.ThrowArgumentRangeException(nameof(memLevel));
}
if (method != ZDEFLATED)
{
ThrowHelper.ThrowArgumentRangeException(nameof(method));
}
if (windowBits < 9 || windowBits > 15)
{
ThrowHelper.ThrowArgumentRangeException(nameof(windowBits));
}
if (level < CompressionLevel.NoCompression || level > CompressionLevel.BestCompression)
{
ThrowHelper.ThrowArgumentRangeException(nameof(level));
}
if (strategy < CompressionStrategy.DefaultStrategy || strategy > CompressionStrategy.Fixed)
{
ThrowHelper.ThrowArgumentRangeException(nameof(strategy));
}
#if USE_QUICK
if (level == ZlibCompressionLevel.ZBESTSPEED)
{
windowBits = 13;
}
#endif
this.NoHeader = noheader;
this.wBits = windowBits;
this.wSize = 1 << this.wBits;
this.wMask = this.wSize - 1;
this.hashBits = memLevel + 7;
this.hashSize = 1 << this.hashBits;
this.hashMask = (uint)this.hashSize - 1;
this.litBufsize = 1 << (memLevel + 6); // 16K elements by default
this.dBuf = this.litBufsize;
this.lBuf = (1 + 2) * this.litBufsize;
this.level = level;
this.Strategy = strategy;
this.method = (byte)method;
this.FixedBuffers = new FixedLengthBuffers();
this.DynamicBuffers = new DynamicLengthBuffers(this.wSize, this.hashSize, this.litBufsize * 4);
this.DeflateReset(zStream);
}