R/readCache.R

In gmbecker/RCacheSuite: State and Dependency Aware Caching

readCachedData = function(dir, load_data = TRUE,
                          exclude_hashes = character(),
                          write_allowed = TRUE,
                          write_on_cache = FALSE)
    {
        if(!file.exists(dir))
            return(list())
        chash = gsub(".*_([[:alnum:]]*).*", "\\1",
                     normalizePath(file.path(dir, "..")))
        fils = list.files(dir, pattern="cache_.*\\.rda", full.names=TRUE)
        if(length(exclude_hashes))
        {
            excl = match(exclude_hashes, fils)
            fils = fils[ excl == 0 ]
        }
        fils = fils[!is.na(fils)]
        ihashes = gsub(".*_([[:alnum:]]*).*", "\\1", fils)
        
        if(!length(fils))
            return(list())
        mapply(function(file, ihash, chash)
               {
                   
                   cacheout = new("CachedData", code_hash = chash,
                                  inputs_hash = ihash,
                                  provstore = readProvTab(dirname(file), ihash = ihash),
                                  .data = new.env(),
                                  disk_location = dirname(file),
                                  file_stale = FALSE,
                                  write_allowed = write_allowed,
                                  write_on_cache = write_on_cache)
                   if(load_data)
                       load(file = file, envir = cacheout$.data)
                   cacheout
               }, file = fils, ihash = ihashes, chash = chash)
    }


readProvTab = function(dir, ihash = NULL) {
    colcl = sapply(provdf(), class)
    if(is.null(ihash) && file.exists(file.path(dir, "allprov.csv")))
        ProvStoreDF(df = read.csv(file.path(dir, "allprov.csv"),
                                  colClasses = colcl))
    else if(file.exists(file.path(dir, paste0(ihash, "_prov.csv"))))
        ProvStoreDF(df = read.csv(file.path(dir, paste0(ihash, "_prov.csv")),
                                  colClasses = colcl))
    else
        ProvStoreDF()
}

readCodeCache = function(dir, load_data = TRUE, write_allowed = TRUE,
                         write_on_cache = FALSE)
{
    if(!validCodeCache(dir))
        return(NULL)
    hash = gsub(".*_([[:alnum:]]*).*", "\\1", dir)
    code = unparse(parse(file.path(dir, "code.R"), keep.source=FALSE))
    cSetOut = new("CodeCacheSet", hash = hash, cache_dir = dir,
                  code = code, write_allowed = write_allowed,
                  write_on_cache = write_on_cache,
                  provstore = readProvTab(dir, NULL))
    cSetOut$populate(load_data = load_data)
    cSetOut
}