/// <summary>Creates new instance of <see cref="LZ4HighChainEncoder"/></summary>
/// <param name="level">Compression level.</param>
/// <param name="blockSize">Block size.</param>
/// <param name="extraBlocks">Number of extra blocks.</param>
public LZ4HighChainEncoder(LZ4Level level, int blockSize, int extraBlocks = 0) :
base(true, blockSize, extraBlocks)
{
if (level < LZ4Level.L03_HC)
{
level = LZ4Level.L03_HC;
}
if (level > LZ4Level.L12_MAX)
{
level = LZ4Level.L12_MAX;
}
_context = (LZ4Context *)Mem.AllocZero(sizeof(LZ4Context));
LZ4_64_HC.LZ4_resetStreamHC(_context, (int)level);
}
/// <summary>Compresses data from one buffer into another.</summary>
/// <param name="source">Input buffer.</param>
/// <param name="sourceLength">Length of input buffer.</param>
/// <param name="target">Output buffer.</param>
/// <param name="targetLength">Output buffer length.</param>
/// <param name="level">Compression level.</param>
/// <returns>Number of bytes written, or negative value if output buffer is too small.</returns>
public static unsafe int Encode(
byte *source, int sourceLength,
byte *target, int targetLength,
LZ4Level level = LZ4Level.L00_FAST)
{
if (sourceLength <= 0)
{
return(0);
}
var encoded =
level == LZ4Level.L00_FAST
? LZ4_64.LZ4_compress_default(source, target, sourceLength, targetLength)
: LZ4_64_HC.LZ4_compress_HC(
source, target, sourceLength, targetLength, (int)level);
return(encoded <= 0 ? -1 : encoded);
}
/// <inheritdoc /> protected override int CopyDict(byte *target, int length) => LZ4_64_HC.LZ4_saveDictHC(_context, target, length);
/// <inheritdoc />
protected override int EncodeBlock(
byte *source, int sourceLength, byte *target, int targetLength) =>
LZ4_64_HC.LZ4_compress_HC_continue(
_context, source, target, sourceLength, targetLength);
protected override int CopyDict(byte *buffer, int length) => LZ4_64_HC.LZ4_saveDictHC(_context, buffer, length);
