java.lang.Object
- com.github.luben.zstd.AutoCloseBase
- - com.github.luben.zstd.ZstdCompressCtx

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable
```
public class ZstdCompressCtx
extends AutoCloseBase
```

Field Summary

Fields
Modifier and Type Field Description

private ZstdDictCompress compression_dict

private long nativePtr

Constructor Summary

Constructors
Constructor Description

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

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`byte[]`	`compress(byte[] src)`
`int`	`compress(byte[] dst, byte[] src)`
`java.nio.ByteBuffer`	`compress(java.nio.ByteBuffer srcBuf)`	Compresses the data in buffer 'srcBuf'
`int`	`compress(java.nio.ByteBuffer dstBuf, java.nio.ByteBuffer srcBuf)`	Compresses the data in buffer 'srcBuf'
`int`	`compressByteArray(byte[] dstBuff, int dstOffset, int dstSize, byte[] srcBuff, int srcOffset, int srcSize)`	Compresses byte array 'srcBuff' into byte array 'dstBuff' reusing this ZstdCompressCtx.
`private static long`	`compressByteArray0(long ptr, byte[] dst, int dstOffset, int dstSize, byte[] src, int srcOffset, int srcSize)`
`int`	`compressDirectByteBuffer(java.nio.ByteBuffer dstBuff, int dstOffset, int dstSize, java.nio.ByteBuffer srcBuff, int srcOffset, int srcSize)`	Compresses buffer 'srcBuff' into buffer 'dstBuff' reusing this ZstdCompressCtx.
`private static long`	`compressDirectByteBuffer0(long ptr, java.nio.ByteBuffer dst, int dstOffset, int dstSize, java.nio.ByteBuffer src, int srcOffset, int srcSize)`
`boolean`	`compressDirectByteBufferStream(java.nio.ByteBuffer dst, java.nio.ByteBuffer src, EndDirective endOp)`	Compress as much of the `src` `ByteBuffer` into the `dst` `ByteBuffer` as possible.
`private static long`	`compressDirectByteBufferStream0(long ptr, java.nio.ByteBuffer dst, int dstOffset, int dstSize, java.nio.ByteBuffer src, int srcSize, int srcOffset, int endOp)`	4 pieces of information are packed into the return value of this method, which must be treated as an unsigned long.
`(package private) void`	`doClose()`
`private void`	`ensureOpen()`
`private static void`	`free(long ptr)`
`ZstdFrameProgression`	`getFrameProgression()`	Tells how much data has been ingested (read from input), consumed (input actually compressed) and produced (output) for current frame.
`private static ZstdFrameProgression`	`getFrameProgression0(long ptr)`
`private static long`	`init()`
`private long`	`loadCDict0(long ptr, byte[] dict)`
`private long`	`loadCDictFast0(long ptr, ZstdDictCompress dict)`
`ZstdCompressCtx`	`loadDict(byte[] dict)`	Load compression dictionary to be used for subsequently compressed frames.
`ZstdCompressCtx`	`loadDict(ZstdDictCompress dict)`	Load compression dictionary to be used for subsequently compressed frames.
`void`	`reset()`	Clear all state and parameters from the compression context.
`private static long`	`reset0(long ptr)`
`ZstdCompressCtx`	`setChecksum(boolean checksumFlag)`	Enable or disable compression checksums
`private static void`	`setChecksum0(long ptr, boolean checksumFlag)`
`ZstdCompressCtx`	`setContentSize(boolean contentSizeFlag)`	Enable or disable content size
`private static void`	`setContentSize0(long ptr, boolean contentSizeFlag)`
`ZstdCompressCtx`	`setDictID(boolean dictIDFlag)`	Enable or disable dictID
`private static void`	`setDictID0(long ptr, boolean dictIDFlag)`
`ZstdCompressCtx`	`setLevel(int level)`	Set compression level
`private static void`	`setLevel0(long ptr, int level)`
`ZstdCompressCtx`	`setLong(int windowLog)`	Enable or disable LongDistanceMatching and set the window size
`ZstdCompressCtx`	`setMagicless(boolean magiclessFlag)`	Enable or disable magicless frames
`void`	`setPledgedSrcSize(long srcSize)`	Promise to compress a certain number of source bytes.
`private static long`	`setPledgedSrcSize0(long ptr, long srcSize)`
`ZstdCompressCtx`	`setWorkers(int workers)`

Methods inherited from class com.github.luben.zstd.AutoCloseBase
acquireSharedLock, close, releaseSharedLock, storeFence

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - nativePtr
```
private long nativePtr
```
  - compression_dict
```
private ZstdDictCompress compression_dict
```
- 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
  - init
```
private static long init()
```
  - free
```
private static void free(long ptr)
```
  - doClose
```
void doClose()
```
    Specified by:
    
    doClose in class AutoCloseBase
  - ensureOpen
```
private void ensureOpen()
```
  - setLevel
```
public ZstdCompressCtx setLevel(int level)
```
    Set compression level
    
    Parameters:
    
    level - compression level, default: Zstd.defaultCompressionLevel()
  - setLevel0
```
private static void setLevel0(long ptr,
                              int level)
```
  - setMagicless
```
public 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
```
public 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
  - setChecksum0
```
private static void setChecksum0(long ptr,
                                 boolean checksumFlag)
```
  - setWorkers
```
public ZstdCompressCtx setWorkers(int workers)
```
  - setContentSize
```
public ZstdCompressCtx setContentSize(boolean contentSizeFlag)
```
    Enable or disable content size
    
    Parameters:
    
    contentSizeFlag - Content size will be written into frame header _whenever known_, default: true
  - setContentSize0
```
private static void setContentSize0(long ptr,
                                    boolean contentSizeFlag)
```
  - setDictID
```
public ZstdCompressCtx setDictID(boolean dictIDFlag)
```
    Enable or disable dictID
    
    Parameters:
    
    dictIDFlag - When applicable, dictionary's ID is written into frame header, default: true
  - setDictID0
```
private static void setDictID0(long ptr,
                               boolean dictIDFlag)
```
  - setLong
```
public 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.
  - loadDict
```
public ZstdCompressCtx loadDict(ZstdDictCompress dict)
```
    Load compression dictionary to be used for subsequently compressed frames.
    
    Parameters:
    
    dict - the dictionary or `null` to remove loaded dictionary
  - loadCDictFast0
```
private long loadCDictFast0(long ptr,
                            ZstdDictCompress dict)
```
  - loadDict
```
public ZstdCompressCtx loadDict(byte[] dict)
```
    Load compression dictionary to be used for subsequently compressed frames.
    
    Parameters:
    
    dict - the dictionary or `null` to remove loaded dictionary
  - loadCDict0
```
private long loadCDict0(long ptr,
                        byte[] dict)
```
  - getFrameProgression
```
public ZstdFrameProgression getFrameProgression()
```
    Tells how much data has been ingested (read from input), consumed (input actually compressed) and produced (output) for current frame.
  - getFrameProgression0
```
private static ZstdFrameProgression getFrameProgression0(long ptr)
```
  - 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.
  - reset0
```
private static long reset0(long ptr)
```
  - 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.
  - setPledgedSrcSize0
```
private static long setPledgedSrcSize0(long ptr,
                                       long srcSize)
```
  - compressDirectByteBufferStream
```
public boolean compressDirectByteBufferStream(java.nio.ByteBuffer dst,
                                              java.nio.ByteBuffer src,
                                              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
  - compressDirectByteBufferStream0
```
private static long compressDirectByteBufferStream0(long ptr,
                                                    java.nio.ByteBuffer dst,
                                                    int dstOffset,
                                                    int dstSize,
                                                    java.nio.ByteBuffer src,
                                                    int srcSize,
                                                    int srcOffset,
                                                    int endOp)
```
    4 pieces of information are packed into the return value of this method, which must be treated as an unsigned long. The highest bit is set if all data has been flushed from internal buffers. The next 31 bits are the new position of the destination buffer. The next bit is set if an error occurred. If an error occurred, the lowest 31 bits encode a zstd error code. Otherwise, the lowest 31 bits are the new position of the source buffer.
  - compressDirectByteBuffer
```
public int compressDirectByteBuffer(java.nio.ByteBuffer dstBuff,
                                    int dstOffset,
                                    int dstSize,
                                    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'.
  - compressDirectByteBuffer0
```
private static long compressDirectByteBuffer0(long ptr,
                                              java.nio.ByteBuffer dst,
                                              int dstOffset,
                                              int dstSize,
                                              java.nio.ByteBuffer src,
                                              int srcOffset,
                                              int srcSize)
```
  - compressByteArray
```
public int compressByteArray(byte[] dstBuff,
                             int dstOffset,
                             int dstSize,
                             byte[] 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'.
  - compressByteArray0
```
private static long compressByteArray0(long ptr,
                                       byte[] dst,
                                       int dstOffset,
                                       int dstSize,
                                       byte[] src,
                                       int srcOffset,
                                       int srcSize)
```
  - compress
```
public int compress(java.nio.ByteBuffer dstBuf,
                    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
```
public java.nio.ByteBuffer compress(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[] dst,
                    byte[] src)
```
  - compress
```
public byte[] compress(byte[] src)
```

Modifier and Type	Field	Description
`private ZstdDictCompress`	`compression_dict`
`private long`	`nativePtr`

Class ZstdCompressCtx

Field Summary

Constructor Summary

Method Summary

Methods inherited from class com.github.luben.zstd.AutoCloseBase

Methods inherited from class java.lang.Object

Field Detail

nativePtr

compression_dict

Constructor Detail

ZstdCompressCtx

Method Detail

init

free

doClose

ensureOpen

setLevel

setLevel0

setMagicless

setChecksum

setChecksum0

setWorkers

setContentSize

setContentSize0

setDictID

setDictID0

setLong

loadDict

loadCDictFast0

loadDict

loadCDict0

getFrameProgression

getFrameProgression0

reset

reset0

setPledgedSrcSize

setPledgedSrcSize0

compressDirectByteBufferStream

compressDirectByteBufferStream0

compressDirectByteBuffer

compressDirectByteBuffer0

compressByteArray

compressByteArray0

compress

compress

compress

compress