PersistentCachePreloadingConfiguration (Jackrabbit Oak 1.88.0 API)

java.lang.Object
- org.apache.jackrabbit.oak.segment.spi.persistence.persistentcache.PersistentCachePreloadingConfiguration

```
public class PersistentCachePreloadingConfiguration
extends Object
```
Configuration for a segment preload mechanism that preloads segments into a PersistentCache. The preload mechanism is triggered whenever a segment in the cache is {@link PersistentCache#readSegment(long, long, Callable)|accessed}. When this happens, all segments referenced by the accessed segment are asynchronously preloaded.
Next to the concurrency level, i.e. how many threads are used for preloading, the maxPreloadDepth (default: 1, which controls how many recursive levels of referenced segments are preloaded, can be configured.
Prefetching is done asynchronously, but it may add some overhead. It is primarily recommended to parallelize slow I/O, e.g. when using a remote persistence.
Different scenarios may warrant different preloading strategies. A short-lived process traversing a repository (e.g. copy, offline-compaction) with an initially empty cache may benefit from a more threads and a higher preload-depth, while a long-running process, e.g. a web application, may perform better with fewer threads and a lower preload depth.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`getConcurrency()`
`int`	`getMaxPreloadDepth()`
`String`	`toString()`
`static PersistentCachePreloadingConfiguration`	`withConcurrency(int concurrency)`	Creates a new `PersistentCachePreloadingConfiguration` with the given concurrency level and a `preloadDepth` of `1`.
`PersistentCachePreloadingConfiguration`	`withMaxPreloadDepth(int maxPreloadDepth)`	Set how many recursive levels of referenced segments should be preloaded.

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

- Method Detail
  - withConcurrency
```
public static PersistentCachePreloadingConfiguration withConcurrency(int concurrency)
```
    Creates a new PersistentCachePreloadingConfiguration with the given concurrency level and a preloadDepth of 1.
    
    Parameters:
    
    concurrency - number of threads to use for preloading
    
    Returns:
    
    a new configuration
  - withMaxPreloadDepth
```
public PersistentCachePreloadingConfiguration withMaxPreloadDepth(int maxPreloadDepth)
```
    Set how many recursive levels of referenced segments should be preloaded.
    
    Parameters:
    
    maxPreloadDepth - depth of the preloading, i.e. how many levels of referenced segments should be preloaded (default: 1)
    
    Returns:
    
    this configuration
  - getConcurrency
```
public int getConcurrency()
```
  - getMaxPreloadDepth
```
public int getMaxPreloadDepth()
```
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object