Hello,
The first time in a session I call .packages( all.available = T ), it
takes a long time (I have many packages installed from CRAN):
> system.time( packs <- .packages( all = T ) )
user system elapsed
0.738 0.276 43.787
When I call it again, the time is now much reduced, so there must be
some caching somewhere. I would like to try to reduce the time it takes
the first time, but I have not been able to identify where the caching
takes place, and so how I can remove it to try to improve the running
time without the caching. Without this, I have to restart my computer
each time to vanish the caching to test a new version of the function
(this is not going to happen)
Here is the .packages function, I am suspicious about this part : "ans
<- c(ans, nam)" which grows the ans vector each time a suitable package
is found, this does not sound right.
> .packages
function (all.available = FALSE, lib.loc = NULL)
{
if (is.null(lib.loc))
lib.loc <- .libPaths()
if (all.available) {
ans <- character(0L)
lib.loc <- lib.loc[file.exists(lib.loc)]
valid_package_version_regexp <-
.standard_regexps()$valid_package_version
for (lib in lib.loc)
{
a <- list.files(lib, all.files = FALSE, full.names =
FALSE)
for (nam in a)
{
pfile <- file.path(lib, nam, "Meta",
"package.rds")
if
(file.exists(pfile))
info <-
.readRDS(pfile)$DESCRIPTION[c("Package",
"Version")]
else
next
if ((length(info) != 2L) || any(is.na(info)))
next
if (!grepl(valid_package_version_regexp, info["Version"]))
next
ans <- c(ans, nam) ########## suspicious about this
}
}
return(unique(ans))
}
s <- search()
return(invisible(substring(s[substr(s, 1L, 8L) == "package:"],
9)))
}
> version
_
platform i686-pc-linux-gnu
arch i686
os linux-gnu
system i686, linux-gnu
status Under development (unstable)
major 2
minor 9.0
year 2009
month 02
day 08
svn rev 47879
language R
version.string R version 2.9.0 Under development (unstable) (2009-02-08
r47879)
--
Romain Francois
Independent R Consultant
+33(0) 6 28 91 30 30
http://romainfrancois.blog.free.fr
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