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root / src / R / cachecache.R @ 5e1de699

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get_content = structure( function(## Get content from cached
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### Access to the cached content of a file via the global variable CACHE_CACHE. Load content in CACHE_CACHE if needed.
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filename, ##<< The path to the file that contain dataset
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class=NULL, ##<< The class of dataset
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FORCE_RELOAD=FALSE, ##<< Force cachecache to reload the value
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... ##<< Parameters that will be passed to my_read
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) {
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  if (inherits(try(CACHE_CACHE,TRUE), "try-error") || is.null(CACHE_CACHE)) {
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    CACHE_CACHE <<- list()
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  }
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  obj = list(filename=filename)
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  class(obj) = class
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  if (is.null(CACHE_CACHE[[obj$filename]]) | FORCE_RELOAD) {
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    print(paste("Loading file ",obj$filename, sep=""))
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		tmp_content = my_read(obj, ...)
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    print("affect it...")
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    CACHE_CACHE[[obj$filename]] <<- tmp_content
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    print("done.")
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  }
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  return(CACHE_CACHE[[obj$filename]])
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### Returns the cached content of the current object.
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}, ex=function(){
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	# Create a dataframe
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	df = data.frame(list(key1 = "value1", key2 = "value2"), stringsAsFactors=FALSE)
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	df = rbind(df, list(key1 = "value1'", key2 = "value3'"))
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	# Dump it into tmp file
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	write.table(df, file="/tmp/tmp.dump.table.tmp")
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	# Load it into cache using feature.
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	# First time it will be load into cache
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	print(get_content("/tmp/tmp.dump.table.tmp", "table", stringsAsFactors=FALSE))
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	# Second time not
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	print(get_content("/tmp/tmp.dump.table.tmp", "table", stringsAsFactors=FALSE))
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})
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my_read = function(
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### Abstract my_read function.
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	obj, ...) {
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  UseMethod("my_read", obj)
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}
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my_read.default = function(
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### Default my_read function.
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	obj, ...){
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  stop(paste("ERROR, my_read is not defined for any Objects (file ", obj$filename," )", sep=""))
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}
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my_read.table = function(


    		
  

  

  

    
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### my_read function for table files.	


    		
  

  

  

    
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	obj, ...){


    		
  

  

  

    
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	if (rev(unlist(strsplit(obj$filename, ".", fixed=TRUE)))[1] == "gz") {


    		
  

  

  

    
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	  return(read.table(file=gzfile(obj$filename), ...))			


    		
  

  

  

    
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	} else { 


    		
  

  

  

    
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	  return(read.table(file=obj$filename, ...))


    		
  

  

  

    
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	}


    		
  

  

  

    
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}	


    		
  

  

  

    
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my_read.cvs = function(


    		
  

  

  

    
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### my_read function for cvs files.	


    		
  

  

  

    
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	obj, ...){


    		
  

  

  

    
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  return(read.csv(file=obj$filename, ...))


    		
  

  

  

    
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}