[jira] [Comment Edited] (SHIRO-317) Read session from cache once per request

[Benjamin Marwell (Jira)]

    [ 
https://issues.apache.org/jira/browse/SHIRO-317?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13596478#comment-13596478
 ] 

Benjamin Marwell edited comment on SHIRO-317 at 2/1/21, 10:32 AM:
------------------------------------------------------------------

In the meantime, I wrote up a DelegatingThreadLocalCache. Now this code might 
not be perfect, as there were the size, keys and values methods that I don't 
think ThreadLocal could do, so it just delegates to the actual Cache that is 
being wrapped. But here is the code, in case you want to use it.


{code}
package com.whatever.you.need.here;

import org.apache.shiro.cache.Cache;
import org.apache.shiro.cache.CacheException;

import java.io.Serializable;
import java.util.Collection;
import java.util.Set;

/**
 * A simple wrapper Cache that wraps around any cache, where the get will first 
look if there is an object (typically Session) in thread local and
 * return it, if not it calls the wrapped cache.
 */
public class ThreadLocalDelegatingCache implements Cache<Serializable, 
Serializable> {

  ThreadLocal<Serializable> sessionThreadLocal = new 
ThreadLocal<Serializable>();

  Cache<Serializable, Serializable> wrappedCache;

  public void setWrappedCache(Cache wrappedCache) {
    this.wrappedCache = wrappedCache;
  }

  @Override
  public void clear() throws CacheException {
    Serializable session = sessionThreadLocal.get();
    if (session != null) {
      sessionThreadLocal.remove();
    }
    wrappedCache.clear();
  }

  @Override
  public Serializable get(Serializable o) throws CacheException {
    Serializable session = sessionThreadLocal.get();
    if (session != null) {
      return session;
    } else {
      return wrappedCache.get(o);
    }
  }

  @Override
  public Serializable put(Serializable o, Serializable o2) throws 
CacheException {
    Serializable returnValue = wrappedCache.put(o, o2);
    sessionThreadLocal.set(o2);
    return returnValue;
  }

  @Override
  public Serializable remove(Serializable o) throws CacheException {
    Serializable returnValue = wrappedCache.remove(o);
    sessionThreadLocal.remove();
    return returnValue;
  }

  @Override
  public int size() {
    return wrappedCache.size();
  }

  @Override
  public Set keys() {
    return wrappedCache.keys();
  }

  @Override
  public Collection values() {
    return wrappedCache.values();
  }
}
{code}


was (Author: bytor99999):
In the meantime, I wrote up a DelegatingThreadLocalCache. Now this code might 
not be perfect, as there were the size, keys and values methods that I don't 
think ThreadLocal could do, so it just delegates to the actual Cache that is 
being wrapped. But here is the code, in case you want to use it.



package com.whatever.you.need.here;

import org.apache.shiro.cache.Cache;
import org.apache.shiro.cache.CacheException;

import java.io.Serializable;
import java.util.Collection;
import java.util.Set;

/**
 * A simple wrapper Cache that wraps around any cache, where the get will first 
look if there is an object (typically Session) in thread local and
 * return it, if not it calls the wrapped cache.
 */
public class ThreadLocalDelegatingCache implements Cache<Serializable, 
Serializable> {

  ThreadLocal<Serializable> sessionThreadLocal = new 
ThreadLocal<Serializable>();

  Cache<Serializable, Serializable> wrappedCache;

  public void setWrappedCache(Cache wrappedCache) {
    this.wrappedCache = wrappedCache;
  }

  @Override
  public void clear() throws CacheException {
    Serializable session = sessionThreadLocal.get();
    if (session != null) {
      sessionThreadLocal.remove();
    }
    wrappedCache.clear();
  }

  @Override
  public Serializable get(Serializable o) throws CacheException {
    Serializable session = sessionThreadLocal.get();
    if (session != null) {
      return session;
    } else {
      return wrappedCache.get(o);
    }
  }

  @Override
  public Serializable put(Serializable o, Serializable o2) throws 
CacheException {
    Serializable returnValue = wrappedCache.put(o, o2);
    sessionThreadLocal.set(o2);
    return returnValue;
  }

  @Override
  public Serializable remove(Serializable o) throws CacheException {
    Serializable returnValue = wrappedCache.remove(o);
    sessionThreadLocal.remove();
    return returnValue;
  }

  @Override
  public int size() {
    return wrappedCache.size();
  }

  @Override
  public Set keys() {
    return wrappedCache.keys();
  }

  @Override
  public Collection values() {
    return wrappedCache.values();
  }
}


> Read session from cache once per request
> ----------------------------------------
>
>                 Key: SHIRO-317
>                 URL: https://issues.apache.org/jira/browse/SHIRO-317
>             Project: Shiro
>          Issue Type: New Feature
>    Affects Versions: 1.1.0, 1.2.0, 1.2.1
>            Reporter: Luke Biddell
>            Assignee: Les Hazlewood
>            Priority: Minor
>
> As per our discussion on the mailing thread, I've wired up my sessions to be 
> stored in memcached (membase in the longer term). On a per request basis I'm 
> seeing approximately 5 hits on my cache to retrieve the session. I would 
> expect to see only one hit per threaded request, with the session stored as a 
> thread local.
> For distributed caches this saves on network calls and for local caches it 
> will save on potential lock contention.



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