Package net.jpountz.lz4

Class LZ4SafeDecompressor

java.lang.Object
net.jpountz.lz4.LZ4SafeDecompressor
All Implemented Interfaces:
LZ4UnknownSizeDecompressor
public abstract class LZ4SafeDecompressor extends Object implements LZ4UnknownSizeDecompressor
LZ4 decompressor that requires the size of the compressed data to be known.

Implementations of this class are usually a little slower than those of LZ4FastDecompressor but do not require the size of the original data to be known.

  • Constructor Details

    • LZ4SafeDecompressor

      public LZ4SafeDecompressor()

  • Method Details

    • decompress

      public abstract int decompress(byte[] src, int srcOff, int srcLen, byte[] dest, int destOff, int maxDestLen)
      Decompresses src[srcOff:srcOff+srcLen] into dest[destOff:destOff+maxDestLen] and returns the number of decompressed bytes written into dest.
      Specified by:
      decompress in interface LZ4UnknownSizeDecompressor
      Parameters:
      src - the compressed data
      srcOff - the start offset in src
      srcLen - the exact size of the compressed data
      dest - the destination buffer to store the decompressed data
      destOff - the start offset in dest
      maxDestLen - the maximum number of bytes to write in dest
      Returns:
      the original input size
      Throws:
      LZ4Exception - if maxDestLen is too small

    • decompress

      public abstract int decompress(ByteBuffer src, int srcOff, int srcLen, ByteBuffer dest, int destOff, int maxDestLen)
      Decompresses src[srcOff:srcOff+srcLen] into dest[destOff:destOff+maxDestLen] and returns the number of decompressed bytes written into dest. The positions and limits of the ByteBuffers remain unchanged.
      Parameters:
      src - the compressed data
      srcOff - the start offset in src
      srcLen - the exact size of the compressed data
      dest - the destination buffer to store the decompressed data
      destOff - the start offset in dest
      maxDestLen - the maximum number of bytes to write in dest
      Returns:
      the original input size
      Throws:
      LZ4Exception - if maxDestLen is too small

    • decompress

      public final int decompress(byte[] src, int srcOff, int srcLen, byte[] dest, int destOff)
      Convenience method, equivalent to calling decompress(src, srcOff, srcLen, dest, destOff, dest.length - destOff).
      Specified by:
      decompress in interface LZ4UnknownSizeDecompressor
      Parameters:
      src - the compressed data
      srcOff - the start offset in src
      srcLen - the exact size of the compressed data
      dest - the destination buffer to store the decompressed data
      destOff - the start offset in dest
      Returns:
      the original input size
      Throws:
      LZ4Exception - if dest is too small

    • decompress

      public final int decompress(byte[] src, byte[] dest)
      Convenience method, equivalent to calling decompress(src, 0, src.length, dest, 0)
      Parameters:
      src - the compressed data
      dest - the destination buffer to store the decompressed data
      Returns:
      the original input size
      Throws:
      LZ4Exception - if dest is too small

    • decompress

      public final byte[] decompress(byte[] src, int srcOff, int srcLen, int maxDestLen)
      Convenience method which returns src[srcOff:srcOff+srcLen] decompressed.

      Warning: this method has an important overhead due to the fact that it needs to allocate a buffer to decompress into, and then needs to resize this buffer to the actual decompressed length.

      Here is how this method is implemented:

       byte[] decompressed = new byte[maxDestLen];
 final int decompressedLength = decompress(src, srcOff, srcLen, decompressed, 0, maxDestLen);
 if (decompressedLength != decompressed.length) {
   decompressed = Arrays.copyOf(decompressed, decompressedLength);
 }
 return decompressed;
      Parameters:
      src - the compressed data
      srcOff - the start offset in src
      srcLen - the exact size of the compressed data
      maxDestLen - the maximum number of bytes to write in dest
      Returns:
      the decompressed data
      Throws:
      LZ4Exception - if maxDestLen is too small

    • decompress

      public final byte[] decompress(byte[] src, int maxDestLen)
      Convenience method, equivalent to calling decompress(src, 0, src.length, maxDestLen).
      Parameters:
      src - the compressed data
      maxDestLen - the maximum number of bytes to write in dest
      Returns:
      the decompressed data
      Throws:
      LZ4Exception - if maxDestLen is too small

    • decompress

      public final void decompress(ByteBuffer src, ByteBuffer dest)
      Decompresses src into dest. src's Buffer.remaining() must be exactly the size of the compressed data. This method moves the positions of the buffers.
      Parameters:
      src - the compressed data
      dest - the destination buffer to store the decompressed data
      Throws:
      LZ4Exception - if dest is too small

    • toString

      public String toString()
      Overrides:
      toString in class Object