java.lang.Object
- org.lwjgl.util.zstd.Zdict

```
public class Zdict
extends java.lang.Object
```
Native bindings to the dictionary builder API of Zstandard (zstd).

Field Summary

Fields
Modifier and Type Field Description

static int ZDICT_CONTENTSIZE_MIN ZDICT_DICTSIZE_MIN

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static long`	`nZDICT_finalizeDictionary(long dictBuffer, long dictBufferCapacity, long dictContent, long dictContentSize, long samplesBuffer, long samplesSizes, int nbSamples, long parameters)`	Unsafe version of: `finalizeDictionary`
`static int`	`nZDICT_getDictID(long dictBuffer, long dictSize)`	Unsafe version of: `getDictID`
`static long`	`nZDICT_getErrorName(long errorCode)`
`static int`	`nZDICT_isError(long errorCode)`
`static long`	`nZDICT_optimizeTrainFromBuffer_cover(long dictBuffer, long dictBufferCapacity, long samplesBuffer, long samplesSizes, int nbSamples, long parameters)`	Unsafe version of: `optimizeTrainFromBuffer_cover`
`static long`	`nZDICT_trainFromBuffer(long dictBuffer, long dictBufferCapacity, long samplesBuffer, long samplesSizes, int nbSamples)`	Unsafe version of: `trainFromBuffer`
`static long`	`nZDICT_trainFromBuffer_cover(long dictBuffer, long dictBufferCapacity, long samplesBuffer, long samplesSizes, int nbSamples, long parameters)`	Unsafe version of: `trainFromBuffer_cover`
`static long`	`ZDICT_finalizeDictionary(java.nio.ByteBuffer dictBuffer, java.nio.ByteBuffer dictContent, java.nio.ByteBuffer samplesBuffer, org.lwjgl.PointerBuffer samplesSizes, ZDICTParams parameters)`	Given a custom content as a basis for dictionary, and a set of samples, finalize dictionary by adding headers and statistics.
`static int`	`ZDICT_getDictID(java.nio.ByteBuffer dictBuffer)`	Extracts `dictID`.
`static java.lang.String`	`ZDICT_getErrorName(long errorCode)`
`static boolean`	`ZDICT_isError(long errorCode)`
`static long`	`ZDICT_optimizeTrainFromBuffer_cover(java.nio.ByteBuffer dictBuffer, java.nio.ByteBuffer samplesBuffer, org.lwjgl.PointerBuffer samplesSizes, ZDICTCoverParams parameters)`	The same requirements as `trainFromBuffer_cover` hold for all the parameters except `parameters`.
`static long`	`ZDICT_trainFromBuffer(java.nio.ByteBuffer dictBuffer, java.nio.ByteBuffer samplesBuffer, org.lwjgl.PointerBuffer samplesSizes)`	Train a dictionary from an array of samples.
`static long`	`ZDICT_trainFromBuffer_cover(java.nio.ByteBuffer dictBuffer, java.nio.ByteBuffer samplesBuffer, org.lwjgl.PointerBuffer samplesSizes, ZDICTCoverParams parameters)`	Train a dictionary from an array of samples using the COVER algorithm.

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

- Field Detail
  - ZDICT_CONTENTSIZE_MIN
```
public static final int ZDICT_CONTENTSIZE_MIN
```
    See Also:
    
    Constant Field Values
  - ZDICT_DICTSIZE_MIN
```
public static final int ZDICT_DICTSIZE_MIN
```
    See Also:
    
    Constant Field Values
- Method Detail
  - nZDICT_trainFromBuffer
```
public static long nZDICT_trainFromBuffer(long dictBuffer,
                                          long dictBufferCapacity,
                                          long samplesBuffer,
                                          long samplesSizes,
                                          int nbSamples)
```
    Unsafe version of: trainFromBuffer
  - ZDICT_trainFromBuffer
```
public static long ZDICT_trainFromBuffer(java.nio.ByteBuffer dictBuffer,
                                         java.nio.ByteBuffer samplesBuffer,
                                         org.lwjgl.PointerBuffer samplesSizes)
```
    Train a dictionary from an array of samples.
    Redirect towards optimizeTrainFromBuffer_cover single-threaded, with d=8 and steps=4.
    
    Samples must be stored concatenated in a single flat buffer samplesBuffer, supplied with an array of sizes samplesSizes, providing the size of each sample, in order.
    
    The resulting dictionary will be saved into dictBuffer.
    
    Note: ZDICT_trainFromBuffer() requires about 9 bytes of memory for each input byte.
    
    Tips:
    
    In general, a reasonable dictionary has a size of ~ 100 KB.
    
    It's possible to select smaller or larger size, just by specifying dictBufferCapacity.
    
    In general, it's recommended to provide a few thousands samples, though this can vary a lot.
    
    It's recommended that total size of all samples be about ~x100 times the target size of dictionary.
    Returns:
    
    size of dictionary stored into dictBuffer (≤ dictBufferCapacity) or an error code, which can be tested with isError.
  - nZDICT_getDictID
```
public static int nZDICT_getDictID(long dictBuffer,
                                   long dictSize)
```
    Unsafe version of: getDictID
  - ZDICT_getDictID
```
public static int ZDICT_getDictID(java.nio.ByteBuffer dictBuffer)
```
    Extracts dictID.
    
    Returns:
    
    zero if error (not a valid dictionary)
  - nZDICT_isError
```
public static int nZDICT_isError(long errorCode)
```
  - ZDICT_isError
```
public static boolean ZDICT_isError(long errorCode)
```
  - nZDICT_getErrorName
```
public static long nZDICT_getErrorName(long errorCode)
```
  - ZDICT_getErrorName
```
@Nullable
public static java.lang.String ZDICT_getErrorName(long errorCode)
```
  - nZDICT_trainFromBuffer_cover
```
public static long nZDICT_trainFromBuffer_cover(long dictBuffer,
                                                long dictBufferCapacity,
                                                long samplesBuffer,
                                                long samplesSizes,
                                                int nbSamples,
                                                long parameters)
```
    Unsafe version of: trainFromBuffer_cover
  - ZDICT_trainFromBuffer_cover
```
public static long ZDICT_trainFromBuffer_cover(java.nio.ByteBuffer dictBuffer,
                                               java.nio.ByteBuffer samplesBuffer,
                                               org.lwjgl.PointerBuffer samplesSizes,
                                               ZDICTCoverParams parameters)
```
    Train a dictionary from an array of samples using the COVER algorithm.
    Samples must be stored concatenated in a single flat buffer samplesBuffer, supplied with an array of sizes samplesSizes, providing the size of each sample, in order.
    
    The resulting dictionary will be saved into dictBuffer.
    
    Note: ZDICT_trainFromBuffer_cover() requires about 9 bytes of memory for each input byte.
    
    Tips:
    
    In general, a reasonable dictionary has a size of ~ 100 KB.
    
    It's possible to select smaller or larger szie, just by specifying dictBufferCapacity.
    
    In general, it's recommended to provide a few thousands samples, though this can vary a lot.
    
    It's recommended that total size of all samples be about ~x100 times the target size of dictionary.
    Returns:
    
    size of dictionary stored into dictBuffer (≤ dictBufferCapacity) or an error code, which can be tested with isError.
  - nZDICT_optimizeTrainFromBuffer_cover
```
public static long nZDICT_optimizeTrainFromBuffer_cover(long dictBuffer,
                                                        long dictBufferCapacity,
                                                        long samplesBuffer,
                                                        long samplesSizes,
                                                        int nbSamples,
                                                        long parameters)
```
    Unsafe version of: optimizeTrainFromBuffer_cover
  - ZDICT_optimizeTrainFromBuffer_cover
```
public static long ZDICT_optimizeTrainFromBuffer_cover(java.nio.ByteBuffer dictBuffer,
                                                       java.nio.ByteBuffer samplesBuffer,
                                                       org.lwjgl.PointerBuffer samplesSizes,
                                                       ZDICTCoverParams parameters)
```
    The same requirements as trainFromBuffer_cover hold for all the parameters except parameters.
    This function tries many parameter combinations and picks the best parameters. *parameters is filled with the best parameters found, dictionary constructed with those parameters is stored in dictBuffer.
    
    All of the parameters d, k, steps are optional.
    
    If d is non-zero then we don't check multiple values of d, otherwise we check d = {6, 8, 10, 12, 14, 16}.
    
    If steps is zero it defaults to its default value.
    
    If k is non-zero then we don't check multiple values of k, otherwise we check steps values in [16, 2048].
    
    Note: ZDICT_optimizeTrainFromBuffer_cover() requires about 8 bytes of memory for each input byte and additionally another 5 bytes of memory for each byte of memory for each thread.
    Returns:
    
    size of dictionary stored into dictBuffer (≤ dictBufferCapacity) or an error code, which can be tested with isError. On success *parameters contains the parameters selected.
  - nZDICT_finalizeDictionary
```
public static long nZDICT_finalizeDictionary(long dictBuffer,
                                             long dictBufferCapacity,
                                             long dictContent,
                                             long dictContentSize,
                                             long samplesBuffer,
                                             long samplesSizes,
                                             int nbSamples,
                                             long parameters)
```
    Unsafe version of: finalizeDictionary
  - ZDICT_finalizeDictionary
```
public static long ZDICT_finalizeDictionary(java.nio.ByteBuffer dictBuffer,
                                            java.nio.ByteBuffer dictContent,
                                            java.nio.ByteBuffer samplesBuffer,
                                            org.lwjgl.PointerBuffer samplesSizes,
                                            ZDICTParams parameters)
```
    Given a custom content as a basis for dictionary, and a set of samples, finalize dictionary by adding headers and statistics.
    Samples must be stored concatenated in a flat buffer samplesBuffer, supplied with an array of sizes samplesSizes, providing the size of each sample in order.
    
    Notes:
    
    dictContentSize must be ≥ CONTENTSIZE_MIN bytes.
    
    maxDictSize must be ≥ dictContentSize, and must be ≥ DICTSIZE_MIN bytes.
    
    ZDICT_finalizeDictionary() will push notifications into stderr if instructed to, using notificationLevel>0.
    
    dictBuffer and dictContent can overlap.
    Returns:
    
    size of dictionary stored into dictBuffer (≤ dictBufferCapacity) or an error code, which can be tested with isError.

Class Zdict

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ZDICT_CONTENTSIZE_MIN

ZDICT_DICTSIZE_MIN

Method Detail

nZDICT_trainFromBuffer

ZDICT_trainFromBuffer

nZDICT_getDictID

ZDICT_getDictID

nZDICT_isError

ZDICT_isError

nZDICT_getErrorName

ZDICT_getErrorName

nZDICT_trainFromBuffer_cover

ZDICT_trainFromBuffer_cover

nZDICT_optimizeTrainFromBuffer_cover

ZDICT_optimizeTrainFromBuffer_cover

nZDICT_finalizeDictionary

ZDICT_finalizeDictionary