\name{ObjectStore}
\alias{ObjectStore}
\title{An Object store}
\description{Store/retrieve object by \code{key}, is \code{dir} is not
  \code{NULL} objects are also saved in a file called \code{key} under
  the directory \code{dir}.

  ObjectStore(dir) allow to create a static Object store
  getObj(key)      allow to retrieve an object indexed by \code{key}. If
  \code{dir} was not \code{NULL} and if the object is not found, then
  ObjectStore look for a file \code{key} in directory \code{dir}, if it
  exists the object is loaded from the file and returned

  storeObj(key,obj) allow to store an object indexed by \code{key}. If
  \code{dir} was not \code{NULL} then is also stored in a file
  \code{key} in directory \code{dir}.
  
}
\usage{
# Build object 
static ObjectStore(dir)
static getObj(key,disk=TRUE)
static storeObj(key,obj,disk=TRUE)
}

\arguments{
  \item{dir}{A directory, if not null object will be stored/retriveved
    in this directory}
  \item{disk}{If \code{FALSE} do not try to retrive/store from/on disk}
}
\value{

} 
\seealso{
 }
\examples{
ObjectStore(dir='.')
setConstructorS3("O",function(x=NULL)extend(Object(),'O',x=x))
o1=O(1:1000000)
ObjectStore$storeObj('o1',o1)
ObjectStore$getObj('o1')
## Restart R
ObjectStore(dir='.')
o1=ObjectStore$getObj('o1')
}