public Class LZ4HC

Compression level.

Compression level.

Compression level.

Compression level.

This is an experimental API that allows for the efficient use of a static dictionary many times.

Rather than re-loading the dictionary buffer into a working context before each compression, or copying a pre-loaded dictionary's LZ4_streamHC_t into a working LZ4_streamHC_t, this function introduces a no-copy setup mechanism, in which the working stream references the dictionary stream in-place.

Several assumptions are made about the state of the dictionary stream. Currently, only streams which have been prepared by loadDictHC should be expected to work.

Alternatively, the provided dictionary stream pointer may be NULL, in which case any existing dictionary stream is unset.

A dictionary should only be attached to a stream without any history (i.e., a stream that has just been reset).

The dictionary will remain attached to the working stream only for the current stream session. Calls to resetStreamHC_fast will remove the dictionary context association from the working stream. The dictionary stream (and source buffer) must remain in-place / accessible / unchanged through the lifetime of the stream session.

Compress data from src into dst, using the powerful but slower "HC" algorithm.

Compression is guaranteed to succeed if dstCapacity ≥ compressBound(srcSize)`

Parameters

dst:ByteBuffer

must be already allocated

compressionLevel:int

any value between 1 and CLEVEL_MAX will work. Values > CLEVEL_MAX behave the same as CLEVEL_MAX.

Returns:int

the number of bytes written into dst or 0 if compression fails

Similar to compress_HC_continue, but will read as much data as possible from src to fit into targetDstSize budget.

Parameters

srcSizePtr:IntBuffer

on success, *srcSizePtr will be updated to indicate how much bytes were read from src. Note that this function may not consume the entire input.

Returns:int

the number of bytes written into dst (necessarily ≤ targetDstSize) or 0 if compression fails

Since

1.9.0

Will compress as much data as possible from src to fit into targetDstSize budget.

Parameters

srcSizePtr:IntBuffer

on success, *srcSizePtr is updated to indicate how much bytes were read from src

Returns:int

the number of bytes written into dst (necessarily ≤ targetDstSize) or 0 if compression fails

Since

1.9.0

Same as compress_HC, but using an externally allocated memory segment for state.

state size is provided by sizeofStateHC. Memory segment must be aligned on 8-bytes boundaries (which a normal malloc() should do properly).

A variant of compress_HC_extStateHC.

Using this variant avoids an expensive initialization step. It is only safe to call if the state buffer is known to be correctly initialized already (see comment on resetStreamHC_fast for a definition of "correctly initialized"). From a high level, the difference is that this function initializes the provided state with a call to resetStreamHC_fast while compress_HC_extStateHC starts with a call to initStreamHC.

Creates memory for LZ4 HC streaming state.

Newly created states are automatically initialized. A same state can be used multiple times consecutively, starting with resetStreamHC_fast to start a new stream of blocks.

Annotations

@NativeType:LZ4_streamHC_t *

Parser will favor decompression speed over compression ratio.

Only applicable to levels ≥ CLEVEL_OPT_MIN.

Since

version 1.8.2 (experimental)

Releases memory for LZ4 HC streaming state.

Required before first use of a statically allocated LZ4_streamHC_t.

Annotations

@NativeType:LZ4_streamHC_t *

Since

1.9.0

When an LZ4_streamHC_t is known to be in a internally coherent state, it can often be prepared for a new compression with almost no work, only sometimes falling back to the full, expensive reset that is always required when the stream is in an indeterminate state (i.e., the reset performed by initStreamHC).

LZ4_streamHCs are guaranteed to be in a valid state when:

• returned from createStreamHC
• reset by initStreamHC
• memset(stream, 0, sizeof(LZ4_streamHC_t))
• the stream was in a valid state and was reset by resetStreamHC_fast
• the stream was in a valid state and was then used in any compression call that returned success
• the stream was in an indeterminate state and was used in a compression call that fully reset the state (compress_HC_extStateHC) and that returned success

It's possible to change compression level between successive invocations of LZ4_compress_HC_continue*() for dynamic adaptation.

Unsafe version of: attach_HC_dictionary

Unsafe version of: compress_HC

Parameters

srcSize:int

max supported value is MAX_INPUT_SIZE

Unsafe version of: compress_HC_continue_destSize

Parameters

srcSizePtr:long

on success, *srcSizePtr will be updated to indicate how much bytes were read from src. Note that this function may not consume the entire input.

Unsafe version of: compress_HC_destSize

Parameters

srcSizePtr:long

on success, *srcSizePtr is updated to indicate how much bytes were read from src

Unsafe version of: compress_HC_extStateHC

Unsafe version of: compress_HC_extStateHC_fastReset

Unsafe version of: favorDecompressionSpeed

Unsafe version of: freeStreamHC

Unsafe version of: initStreamHC

Unsafe version of: resetStreamHC_fast

Unsafe version of: setCompressionLevel