LZ4Factory (lz4 / xxhash - Java API 1.8-SNAPSHOT)

java.lang.Object
- net.jpountz.lz4.LZ4Factory

```
public final class LZ4Factory
extends java.lang.Object
```
Entry point for the LZ4 API.
This class has 3 instances
- a native instance which is a JNI binding to the original LZ4 C implementation.
- a safe Java instance which is a pure Java port of the original C library,
- an unsafe Java instance which is a Java port using the unofficial Unsafe API.
Only the safe instance is guaranteed to work on your JVM, as a consequence it is advised to use the fastestInstance() or fastestJavaInstance() to pull a LZ4Factory instance.
All methods from this class are very costly, so you should get an instance once, and then reuse it whenever possible. This is typically done by storing a LZ4Factory instance in a static field.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`LZ4Decompressor`	`decompressor()` Deprecated. use `fastDecompressor()`
`LZ4Compressor`	`fastCompressor()` Returns a blazing fast `LZ4Compressor`.
`LZ4FastDecompressor`	`fastDecompressor()` Returns a `LZ4FastDecompressor` instance.
`static LZ4Factory`	`fastestInstance()` Returns the fastest available `LZ4Factory` instance.
`static LZ4Factory`	`fastestJavaInstance()` Returns the fastest available `LZ4Factory` instance which does not rely on JNI bindings.
`LZ4Compressor`	`highCompressor()` Returns a `LZ4Compressor` which requires more memory than `fastCompressor()` and is slower but compresses more efficiently.
`LZ4Compressor`	`highCompressor(int compressionLevel)` Returns a `LZ4Compressor` which requires more memory than `fastCompressor()` and is slower but compresses more efficiently.
`static void`	`main(java.lang.String[] args)` Prints the fastest instance.
`static LZ4Factory`	`nativeInstance()` Returns a `LZ4Factory` instance that returns compressors and decompressors that are native bindings to the original C library.
`LZ4SafeDecompressor`	`safeDecompressor()` Returns a `LZ4SafeDecompressor` instance.
`static LZ4Factory`	`safeInstance()` Returns a `LZ4Factory` instance that returns compressors and decompressors that are written with Java's official API.
`java.lang.String`	`toString()`
`LZ4UnknownSizeDecompressor`	`unknownSizeDecompressor()` Deprecated. use `safeDecompressor()`
`static LZ4Factory`	`unsafeInstance()` Returns a `LZ4Factory` instance that returns compressors and decompressors that may use `Unsafe` to speed up compression and decompression.

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

- Method Detail
  - nativeInstance
```
public static LZ4Factory nativeInstance()
```
    Returns a LZ4Factory instance that returns compressors and decompressors that are native bindings to the original C library.
    Please note that this instance has some traps you should be aware of:
    1. Upon loading this instance, files will be written to the temporary directory of the system. Although these files are supposed to be deleted when the JVM exits, they might remain on systems that don't support removal of files being used such as Windows.
    2. The instance can only be loaded once per JVM. This can be a problem if your application uses multiple class loaders (such as most servlet containers): this instance will only be available to the children of the class loader which has loaded it. As a consequence, it is advised to either not use this instance in webapps or to put this library in the lib directory of your servlet container so that it is loaded by the system class loader.
    3. From lz4-java version 1.6.0, a LZ4FastDecompressor instance returned by fastDecompressor() of this instance is SLOWER than a LZ4SafeDecompressor instance returned by safeDecompressor(), due to a change in the original LZ4 C implementation. The corresponding C API function is deprecated. Hence use of fastDecompressor() is deprecated for this instance.
    Returns:
    
    a LZ4Factory instance that returns compressors and decompressors that are native bindings to the original C library
  - safeInstance
```
public static LZ4Factory safeInstance()
```
    Returns a LZ4Factory instance that returns compressors and decompressors that are written with Java's official API.
    
    Returns:
    
    a LZ4Factory instance that returns compressors and decompressors that are written with Java's official API.
  - unsafeInstance
```
public static LZ4Factory unsafeInstance()
```
    Returns a LZ4Factory instance that returns compressors and decompressors that may use Unsafe to speed up compression and decompression.
    
    Returns:
    
    a LZ4Factory instance that returns compressors and decompressors that may use Unsafe to speed up compression and decompression.
  - fastestJavaInstance
```
public static LZ4Factory fastestJavaInstance()
```
    Returns the fastest available LZ4Factory instance which does not rely on JNI bindings. It first tries to load the unsafe instance, and then the safe Java instance if the JVM doesn't have a working Unsafe.
    
    Returns:
    
    the fastest available LZ4Factory instance which does not rely on JNI bindings.
  - fastestInstance
```
public static LZ4Factory fastestInstance()
```
    Returns the fastest available LZ4Factory instance. If the class loader is the system class loader and if the native instance loads successfully, then the native instance is returned, otherwise the fastest Java instance is returned.
    Please read javadocs of nativeInstance() before using this method.
    
    Returns:
    
    the fastest available LZ4Factory instance
  - fastCompressor
```
public LZ4Compressor fastCompressor()
```
    Returns a blazing fast LZ4Compressor.
    
    Returns:
    
    a blazing fast LZ4Compressor
  - highCompressor
```
public LZ4Compressor highCompressor()
```
    Returns a LZ4Compressor which requires more memory than fastCompressor() and is slower but compresses more efficiently.
    
    Returns:
    
    a LZ4Compressor which requires more memory than fastCompressor() and is slower but compresses more efficiently.
  - highCompressor
```
public LZ4Compressor highCompressor(int compressionLevel)
```
    Returns a LZ4Compressor which requires more memory than fastCompressor() and is slower but compresses more efficiently. The compression level can be customized.
    For current implementations, the following is true about compression level:
    1. It should be in range [1, 17]
    2. A compression level higher than 17 would be treated as 17.
    3. A compression level lower than 1 would be treated as 9.
    Note that compression levels from different implementations (native, unsafe Java, and safe Java) cannot be compared with one another. Specifically, the native implementation of a high compression level is not necessarily faster than the safe/unsafe Java implementation of the same compression level.
    Parameters:
    
    compressionLevel - the compression level between [1, 17]; the higher the level, the higher the compression ratio
    
    Returns:
    
    a LZ4Compressor which requires more memory than fastCompressor() and is slower but compresses more efficiently.
  - fastDecompressor
```
public LZ4FastDecompressor fastDecompressor()
```
    Returns a LZ4FastDecompressor instance. Use of this method is deprecated for the native instance.
    
    Returns:
    
    a LZ4FastDecompressor instance
    
    See Also:
    
    nativeInstance()
  - safeDecompressor
```
public LZ4SafeDecompressor safeDecompressor()
```
    Returns a LZ4SafeDecompressor instance.
    
    Returns:
    
    a LZ4SafeDecompressor instance
  - unknownSizeDecompressor
```
public LZ4UnknownSizeDecompressor unknownSizeDecompressor()
```
    Deprecated. use safeDecompressor()
    
    Returns a LZ4UnknownSizeDecompressor instance.
    
    Returns:
    
    a LZ4UnknownSizeDecompressor instance
  - decompressor
```
public LZ4Decompressor decompressor()
```
    Deprecated. use fastDecompressor()
    
    Returns a LZ4Decompressor instance.
    
    Returns:
    
    a LZ4Decompressor instance
  - main
```
public static void main(java.lang.String[] args)
```
    Prints the fastest instance.
    
    Parameters:
    
    args - no argument required
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object

Class LZ4Factory

Method Summary

Methods inherited from class java.lang.Object

Method Detail

nativeInstance

safeInstance

unsafeInstance

fastestJavaInstance

fastestInstance

fastCompressor

highCompressor

highCompressor

fastDecompressor

safeDecompressor

unknownSizeDecompressor

decompressor

main

toString