SDSCache (I2P Anonymous Network - Java Documentation

java.lang.Object
- net.i2p.data.SDSCache<V>

public class SDSCache<V extends SimpleDataStructure>
extends Object

A least recently used cache with a max size, for SimpleDataStructures. The index to the cache is the first 4 bytes of the data, so the data must be sufficiently random. This caches the SDS objects, and also uses SimpleByteCache to cache the unused byte arrays themselves Following is sample usage:


    private static final SDSCache<Foo> _cache = new SDSCache(Foo.class, LENGTH, 1024);

    public static Foo create(byte[] data) {
        return _cache.get(data);
    }

    public static Foo create(byte[] data, int off) {
        return _cache.get(data, off);
    }

    public static Foo create(InputStream in) throws IOException {
        return _cache.get(in);
    }

Since:: 0.8.3
Author:: zzz

Constructor Summary

Constructors
Constructor Description

SDSCache(Class<V> rvClass, int len, int max)

Constructors
Constructor	Description
`SDSCache(Class<V> rvClass, int len, int max)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`clear()`
`V`	`get(byte[] data)`	WARNING - If the SDS is found in the cache, the passed-in byte array will be returned to the SimpleByteCache for reuse.
`V`	`get(byte[] b, int off)`
`V`	`get(InputStream in)`

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

- Constructor Detail
  - SDSCache
```
public SDSCache(Class<V> rvClass,
                int len,
                int max)
```
    Parameters:
    
    rvClass - the class that we are storing, i.e. an extension of SimpleDataStructure
    
    len - the length of the byte array in the SimpleDataStructure
    
    max - maximum size of the cache assuming 128MB of mem. The actual max size will be scaled based on available memory.
- Method Detail
  - clear
```
public void clear()
```
    Since:
    
    0.9.17
  - get
```
public V get(byte[] data)
```
    WARNING - If the SDS is found in the cache, the passed-in byte array will be returned to the SimpleByteCache for reuse. Do NOT save a reference to the passed-in data, or use or modify it, after this call.
    
    Parameters:
    
    data - non-null, the byte array for the SimpleDataStructure
    
    Returns:
    
    the cached value if available, otherwise makes a new object and returns it
    
    Throws:
    
    IllegalArgumentException - if data is not the correct number of bytes
    
    NullPointerException
  - get
```
public V get(byte[] b,
             int off)
```
  - get
```
public V get(InputStream in)
      throws IOException
```
    Throws:
    
    IOException

Class SDSCache<V extends SimpleDataStructure>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

SDSCache

Method Detail

clear

get

get

get