Package com.github.luben.zstd

Class ZstdCompressCtx

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable
    public class ZstdCompressCtx
extends java.lang.Object

    • Constructor Detail

      • ZstdCompressCtx

        public ZstdCompressCtx()
        Create a context for faster compress operations One such context is required for each thread - put this in a ThreadLocal.

    • Method Detail

      • setMagicless

        @NotNull
public @NotNull ZstdCompressCtx setMagicless​(boolean magiclessFlag)
        Enable or disable magicless frames
        Parameters:
        magiclessFlag - A 32-bits magic number is written at start of frame, default: false

      • setChecksum

        @NotNull
public @NotNull ZstdCompressCtx setChecksum​(boolean checksumFlag)
        Enable or disable compression checksums
        Parameters:
        checksumFlag - A 32-bits checksum of content is written at end of frame, default: false

      • setWorkers

        @NotNull
public @NotNull ZstdCompressCtx setWorkers​(int workers)

      • setOverlapLog

        @NotNull
public @NotNull ZstdCompressCtx setOverlapLog​(int overlapLog)

      • setJobSize

        @NotNull
public @NotNull ZstdCompressCtx setJobSize​(int jobSize)

      • setTargetLength

        @NotNull
public @NotNull ZstdCompressCtx setTargetLength​(int targetLength)

      • setMinMatch

        @NotNull
public @NotNull ZstdCompressCtx setMinMatch​(int minMatch)

      • setSearchLog

        @NotNull
public @NotNull ZstdCompressCtx setSearchLog​(int searchLog)

      • setChainLog

        @NotNull
public @NotNull ZstdCompressCtx setChainLog​(int chainLog)

      • setHashLog

        @NotNull
public @NotNull ZstdCompressCtx setHashLog​(int hashLog)

      • setWindowLog

        @NotNull
public @NotNull ZstdCompressCtx setWindowLog​(int windowLog)

      • setStrategy

        @NotNull
public @NotNull ZstdCompressCtx setStrategy​(int strategy)

      • setContentSize

        @NotNull
public @NotNull ZstdCompressCtx setContentSize​(boolean contentSizeFlag)
        Enable or disable content size
        Parameters:
        contentSizeFlag - Content size will be written into frame header _whenever known_, default: true

      • setDictID

        @NotNull
public @NotNull ZstdCompressCtx setDictID​(boolean dictIDFlag)
        Enable or disable dictID
        Parameters:
        dictIDFlag - When applicable, dictionary's ID is written into frame header, default: true

      • setLong

        @NotNull
public @NotNull ZstdCompressCtx setLong​(int windowLog)
        Enable or disable LongDistanceMatching and set the window size
        Parameters:
        windowLog - Maximum allowed back-reference distance, expressed as power of 2. This will set a memory budget for streaming decompression, with larger values requiring more memory and typically compressing more. Must be clamped between 10 and 32/64 but values greater than 27 may not be decompressable in all context as they require more memory. 0 disables LDM.

      • registerSequenceProducer

        @NotNull
public @NotNull ZstdCompressCtx registerSequenceProducer​(@Nullable
                                                         @Nullable SequenceProducer producer)
        Register an external sequence producer
        Parameters:
        producer - the user-defined SequenceProducer to register.

      • setSequenceProducerFallback

        @NotNull
public @NotNull ZstdCompressCtx setSequenceProducerFallback​(boolean fallbackFlag)
        Enable or disable sequence producer fallback
        Parameters:
        fallbackFlag - fall back to the default internal sequence producer if an external sequence producer returns an error code, default: false

      • setSearchForExternalRepcodes

        @NotNull
public @NotNull ZstdCompressCtx setSearchForExternalRepcodes​(@NotNull
                                                             Zstd.ParamSwitch searchRepcodes)
        Set whether to search external sequences for repeated offsets that can be encoded as repcodes.
        Parameters:
        searchRepcodes - whether to search for repcodes

      • setValidateSequences

        @NotNull
public @NotNull ZstdCompressCtx setValidateSequences​(@NotNull
                                                     Zstd.ParamSwitch validateSequences)
        Enable or disable sequence validation. Useful for the sequence-level API and with external sequence producers.
        Parameters:
        validateSequences - whether to enable sequence validation

      • setEnableLongDistanceMatching

        @NotNull
public @NotNull ZstdCompressCtx setEnableLongDistanceMatching​(@NotNull
                                                              Zstd.ParamSwitch enableLDM)
        Enable or disable long-distance matching.
        Parameters:
        enableLDM - whether to enable long-distance matching.

      • loadDict

        @NotNull
public @NotNull ZstdCompressCtx loadDict​(@Nullable
                                         @Nullable ZstdDictCompress dict)
        Load compression dictionary to be used for subsequently compressed frames.
        Parameters:
        dict - the dictionary

      • loadDict

        @NotNull
public @NotNull ZstdCompressCtx loadDict​(byte @Nullable [] dict)
        Load compression dictionary to be used for subsequently compressed frames.
        Parameters:
        dict - the dictionary or `null` to remove loaded dictionary

      • getFrameProgression

        @NotNull
public @NotNull ZstdFrameProgression getFrameProgression()
        Tells how much data has been ingested (read from input), consumed (input actually compressed) and produced (output) for current frame.

      • reset

        public void reset()
        Clear all state and parameters from the compression context. This leaves the object in a state identical to a newly created compression context.

      • setPledgedSrcSize

        public void setPledgedSrcSize​(long srcSize)
        Promise to compress a certain number of source bytes. Knowing the number of bytes to compress up front helps to choose proper compression settings and size internal buffers. Additionally, the pledged size is stored in the header of the output stream, allowing decompressors to know how much uncompressed data to expect. Attempting to compress more or less than the pledged size will result in an error.

      • compressByteBufferStream

        public boolean compressByteBufferStream​(@NotNull
                                        @NotNull java.nio.ByteBuffer dst,
                                        @NotNull
                                        @NotNull java.nio.ByteBuffer src,
                                        @NotNull
                                        @NotNull EndDirective endOp)
        Compress as much of the src ByteBuffer into the dst ByteBuffer as possible. Both buffers may be direct or array-backed heap buffers. The destination buffer must be writable.
        Parameters:
        dst - destination of compressed data
        src - buffer to compress
        endOp - directive for handling the end of the stream
        Returns:
        true if all state has been flushed from internal buffers
        Throws:
        java.lang.IllegalArgumentException - if either buffer is unsupported or the destination is read-only

      • compressDirectByteBufferStream

        public boolean compressDirectByteBufferStream​(@NotNull
                                              @NotNull java.nio.ByteBuffer dst,
                                              @NotNull
                                              @NotNull java.nio.ByteBuffer src,
                                              @NotNull
                                              @NotNull EndDirective endOp)
        Compress as much of the src ByteBuffer into the dst ByteBuffer as possible.
        Parameters:
        dst - destination of compressed data
        src - buffer to compress
        endOp - directive for handling the end of the stream
        Returns:
        true if all state has been flushed from internal buffers

      • compressDirectByteBuffer

        public int compressDirectByteBuffer​(@NotNull
                                    @NotNull java.nio.ByteBuffer dstBuff,
                                    int dstOffset,
                                    int dstSize,
                                    @NotNull
                                    @NotNull java.nio.ByteBuffer srcBuff,
                                    int srcOffset,
                                    int srcSize)
        Compresses buffer 'srcBuff' into buffer 'dstBuff' reusing this ZstdCompressCtx. Destination buffer should be sized to handle worst cases situations (input data not compressible). Worst case size evaluation is provided by function ZSTD_compressBound(). This is a low-level function that does not take into account or affect the `limit` or `position` of source or destination buffers.
        Parameters:
        dstBuff - the destination buffer - must be direct
        dstOffset - the start offset of 'dstBuff'
        dstSize - the size of 'dstBuff' (after 'dstOffset')
        srcBuff - the source buffer - must be direct
        srcOffset - the start offset of 'srcBuff'
        srcSize - the length of 'srcBuff' (after 'srcOffset')
        Returns:
        the number of bytes written into buffer 'dstBuff'.

      • compressByteArray

        public int compressByteArray​(byte @NotNull [] dstBuff,
                             int dstOffset,
                             int dstSize,
                             byte @NotNull [] srcBuff,
                             int srcOffset,
                             int srcSize)
        Compresses byte array 'srcBuff' into byte array 'dstBuff' reusing this ZstdCompressCtx. Destination buffer should be sized to handle worst cases situations (input data not compressible). Worst case size evaluation is provided by function ZSTD_compressBound().
        Parameters:
        dstBuff - the destination buffer (byte array)
        dstOffset - the start offset of 'dstBuff'
        dstSize - the size of 'dstBuff' (after 'dstOffset')
        srcBuff - the source buffer (byte array)
        srcOffset - the start offset of 'srcBuff'
        srcSize - the length of 'srcBuff' (after 'srcOffset')
        Returns:
        the number of bytes written into buffer 'dstBuff'.

      • compress

        public int compress​(@NotNull
                    @NotNull java.nio.ByteBuffer dstBuf,
                    @NotNull
                    @NotNull java.nio.ByteBuffer srcBuf)
        Compresses the data in buffer 'srcBuf'
        Parameters:
        dstBuf - the destination buffer - must be direct. It is assumed that the `position()` of this buffer marks the offset at which the compressed data are to be written, and that the `limit()` of this buffer is the maximum compressed data size to allow.

        When this method returns successfully, its `position()` will be set to its current `position()` plus the compressed size of the data.

        srcBuf - the source buffer - must be direct. It is assumed that the `position()` of this buffer marks the beginning of the uncompressed data to be compressed, and that the `limit()` of this buffer marks its end.

        When this method returns successfully, its `position()` will be set to the initial `limit()`.

        Returns:
        the size of the compressed data

      • compress

        @NotNull
public @NotNull java.nio.ByteBuffer compress​(@NotNull
                                             @NotNull java.nio.ByteBuffer srcBuf)
                                      throws ZstdException
        Compresses the data in buffer 'srcBuf'
        Parameters:
        srcBuf - the source buffer - must be direct. It is assumed that the `position()` of the buffer marks the beginning of the uncompressed data to be compressed, and that the `limit()` of this buffer marks its end.

        When this method returns successfully, its `position()` will be set to its initial `limit()`.

        Returns:
        A newly allocated direct ByteBuffer containing the compressed data.
        Throws:
        ZstdException

      • compress

        public int compress​(byte @NotNull [] dst,
                    byte @NotNull [] src)

      • compress

        public byte @NotNull [] compress​(byte @NotNull [] src)

      • close

        public void close()
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable