Engine (Deep Java Library 0.15.0 API specification)

java.lang.Object
- ai.djl.engine.Engine

```
public abstract class Engine
extends java.lang.Object
```
The Engine interface is the base of the provided implementation for DJL.
Any engine-specific functionality should be provided through this class. In general, it should contain methods to detect information about the usable machine hardware and to create a new NDManager and Model.

See Also:

Engine Guide, EngineProvider, The guide on resource and engine caching

Constructor Summary

Constructors
Constructor and Description

Engine()

Constructors
Constructor and Description
`Engine()`

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`static void`	`debugEnvironment()` Prints debug information about the environment for debugging environment issues.
`Device`	`defaultDevice()` Returns the engine's default `Device`.
`static java.util.Set<java.lang.String>`	`getAllEngines()` Returns a set of engine names that are loaded.
`abstract Engine`	`getAlternativeEngine()` Returns the alternative `engine` if available.
`static java.lang.String`	`getDefaultEngineName()` Returns the default Engine name.
`Device[]`	`getDevices()` Returns an array of devices.
`Device[]`	`getDevices(int maxGpus)` Returns an array of devices given the maximum number of GPUs to use.
`static Engine`	`getEngine(java.lang.String engineName)` Returns the `Engine` with the given name.
`abstract java.lang.String`	`getEngineName()` Returns the name of the Engine.
`int`	`getGpuCount()` Returns the number of GPUs available in the system.
`static Engine`	`getInstance()` Returns the default Engine.
`abstract int`	`getRank()` Return the rank of the `Engine`.
`java.lang.Integer`	`getSeed()` Returns the random seed in DJL Engine.
`abstract java.lang.String`	`getVersion()` Returns the version of the deep learning engine.
`abstract boolean`	`hasCapability(java.lang.String capability)` Returns whether the engine has the specified capability.
`static boolean`	`hasEngine(java.lang.String engineName)` Returns if the specified engine is available.
`abstract NDManager`	`newBaseManager()` Creates a new top-level `NDManager`.
`abstract NDManager`	`newBaseManager(Device device)` Creates a new top-level `NDManager` with specified `Device`.
`abstract GradientCollector`	`newGradientCollector()` Returns a new instance of `GradientCollector`.
`abstract Model`	`newModel(java.lang.String name, Device device)` Constructs a new model.
`ParameterServer`	`newParameterServer(Optimizer optimizer)` Returns a new instance of `ParameterServer`.
`abstract SymbolBlock`	`newSymbolBlock(NDManager manager)` Construct an empty SymbolBlock for loading.
`static void`	`registerEngine(EngineProvider provider)` Registers a `EngineProvider` if not registered.
`void`	`setRandomSeed(int seed)` Seeds the random number generator in DJL Engine.

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

- Constructor Detail
  - Engine
```
public Engine()
```
- Method Detail
  - getAlternativeEngine
```
public abstract Engine getAlternativeEngine()
```
    Returns the alternative engine if available.
    
    Returns:
    
    the alternative engine
  - getEngineName
```
public abstract java.lang.String getEngineName()
```
    Returns the name of the Engine.
    
    Returns:
    
    the name of the engine
  - getRank
```
public abstract int getRank()
```
    Return the rank of the Engine.
    
    Returns:
    
    the rank of the engine
  - getDefaultEngineName
```
public static java.lang.String getDefaultEngineName()
```
    Returns the default Engine name.
    
    Returns:
    
    the default Engine name
  - getInstance
```
public static Engine getInstance()
```
    Returns the default Engine.
    
    Returns:
    
    the instance of Engine
    
    See Also:
    
    EngineProvider
  - hasEngine
```
public static boolean hasEngine(java.lang.String engineName)
```
    Returns if the specified engine is available.
    
    Parameters:
    
    engineName - the name of Engine to check
    
    Returns:
    
    true if the specified engine is available
    
    See Also:
    
    EngineProvider
  - registerEngine
```
public static void registerEngine(EngineProvider provider)
```
    Registers a EngineProvider if not registered.
    
    Parameters:
    
    provider - the EngineProvider to be registered
  - getAllEngines
```
public static java.util.Set<java.lang.String> getAllEngines()
```
    Returns a set of engine names that are loaded.
    
    Returns:
    
    a set of engine names that are loaded
  - getEngine
```
public static Engine getEngine(java.lang.String engineName)
```
    Returns the Engine with the given name.
    
    Parameters:
    
    engineName - the name of Engine to retrieve
    
    Returns:
    
    the instance of Engine
    
    See Also:
    
    EngineProvider
  - getVersion
```
public abstract java.lang.String getVersion()
```
    Returns the version of the deep learning engine.
    
    Returns:
    
    the version number of the deep learning engine
  - hasCapability
```
public abstract boolean hasCapability(java.lang.String capability)
```
    Returns whether the engine has the specified capability.
    
    Parameters:
    
    capability - the capability to retrieve
    
    Returns:
    
    true if the engine has the specified capability
  - defaultDevice
```
public Device defaultDevice()
```
    Returns the engine's default Device.
    
    Returns:
    
    the engine's default Device
  - getDevices
```
public Device[] getDevices()
```
    Returns an array of devices.
    If GPUs are available, it will return an array of Device of size \(min(numAvailable, maxGpus)\). Else, it will return an array with a single CPU device.
    
    Returns:
    
    an array of devices
  - getDevices
```
public Device[] getDevices(int maxGpus)
```
    Returns an array of devices given the maximum number of GPUs to use.
    If GPUs are available, it will return an array of Device of size \(min(numAvailable, maxGpus)\). Else, it will return an array with a single CPU device.
    
    Parameters:
    
    maxGpus - the max number of GPUs to use. Use 0 for no GPUs.
    
    Returns:
    
    an array of devices
  - getGpuCount
```
public int getGpuCount()
```
    Returns the number of GPUs available in the system.
    
    Returns:
    
    the number of GPUs available in the system
  - newSymbolBlock
```
public abstract SymbolBlock newSymbolBlock(NDManager manager)
```
    Construct an empty SymbolBlock for loading.
    
    Parameters:
    
    manager - the manager to manage parameters
    
    Returns:
    
    Empty SymbolBlock for static graph
  - newModel
```
public abstract Model newModel(java.lang.String name,
                               Device device)
```
    Constructs a new model.
    
    Parameters:
    
    name - the model name
    
    device - the device that the model will be loaded onto
    
    Returns:
    
    a new Model instance using the network defined in block
  - newBaseManager
```
public abstract NDManager newBaseManager()
```
    Creates a new top-level NDManager.
    NDManager will inherit default Device.
    
    Returns:
    
    a new top-level NDManager
  - newBaseManager
```
public abstract NDManager newBaseManager(Device device)
```
    Creates a new top-level NDManager with specified Device.
    
    Parameters:
    
    device - the default Device
    
    Returns:
    
    a new top-level NDManager
  - newGradientCollector
```
public abstract GradientCollector newGradientCollector()
```
    Returns a new instance of GradientCollector.
    
    Returns:
    
    a new instance of GradientCollector
  - newParameterServer
```
public ParameterServer newParameterServer(Optimizer optimizer)
```
    Returns a new instance of ParameterServer.
    
    Parameters:
    
    optimizer - the optimizer to update
    
    Returns:
    
    a new instance of ParameterServer
  - setRandomSeed
```
public void setRandomSeed(int seed)
```
    Seeds the random number generator in DJL Engine.
    This will affect all Devices and all operators using Engine's random number generator.
    
    Parameters:
    
    seed - the seed to be fixed in Engine
  - getSeed
```
public java.lang.Integer getSeed()
```
    Returns the random seed in DJL Engine.
    
    Returns:
    
    seed the seed to be fixed in Engine
  - debugEnvironment
```
public static void debugEnvironment()
```
    Prints debug information about the environment for debugging environment issues.

Class Engine

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Engine

Method Detail

getAlternativeEngine

getEngineName

getRank

getDefaultEngineName

getInstance

hasEngine

registerEngine

getAllEngines

getEngine

getVersion

hasCapability

defaultDevice

getDevices

getDevices

getGpuCount

newSymbolBlock

newModel

newBaseManager

newBaseManager

newGradientCollector

newParameterServer

setRandomSeed

getSeed

debugEnvironment