[Rd] reducing redundant work in methods package

[Peter Haverty]

Doing it like this:

genericForPrimitive <- function(f, where = topenv(parent.frame()), mustFind
= TRUE) {

    ans = .BasicFunsList[[f]]

    ## this element may not exist (yet, during loading), dom't test null

    if(mustFind && identical(ans, FALSE))

        stop(gettextf("methods may not be defined for primitive function %s
in this version of R",

                      sQuote(f)),

             domain = NA)

    ans

}

or this:

genericForPrimitive <- function(f, where = topenv(parent.frame()), mustFind
= TRUE) {

    env = asNamespace("methods")

    funs <- env[[".BasicFunsList"]]

    ans = funs[[f]]

    ## this element may not exist (yet, during loading), dom't test null

    if(mustFind && identical(ans, FALSE))

        stop(gettextf("methods may not be defined for primitive function %s
in this version of R",

                      sQuote(f)),

             domain = NA)

    ans

}

Seems to work just fine.

Yes, "el" and "elNamed" can probably go now.

Pete

____________________
Peter M. Haverty, Ph.D.
Genentech, Inc.
phaverty at gene.com

On Wed, Jan 21, 2015 at 2:26 PM, Michael Lawrence <lawrence.michael at gene.com
> wrote:

> Note that setMethod() resolves .BasicFunsList in the methods namespace
> directly when setting a method on a primitive. Somehow there should be
> consistency between genericForPrimitive() and the check in setMethod().
>
> Also, we can probably step away from the use of elNamed(), given that [[
> now uses exact matching.
>
> Have you tried patching methods to use .BasicFunsList directly as in
> setMethod?
>
>
> On Wed, Jan 21, 2015 at 10:41 AM, Peter Haverty <haverty.peter at gene.com>
> wrote:
>
>> Hi all,
>>
>> The function call series genericForPrimitive -> .findBasicFuns -> .findAll
>> happens 4400 times while the GenomicRanges package is loading.  Each time
>> .findAll follows a chain of environments to determine that the methods
>> namespace is the only one that holds a variable called .BasicFunsList.
>> This
>> accounts for ~10% of package loading time. I'm sure there is some history
>> to that design, but would it be possible shortcut this operation? Could
>> .BasicFunsList be initialized in the methods namespace at startup and
>> might
>> genericForPrimitive just go straight there?
>>
>> Does anyone on the list know why it works this way?
>>
>> There are some other cases of seemingly redundant work, but this seems
>> like
>> an easy one to address.
>>
>> I have included some code below that was used to investigate some of the
>> above.
>>
>> # Try this to count calls to a function
>>
>> .count <-  0; trace(methods:::.findBasicFuns,tracer=function() { .count
>> <<-
>> .count + 1 }); library(GenomicRanges); print(.count)
>>
>> # Try this to capture the input and output of a set of functions you wish
>> to refactor
>>
>> .init_test_data_collection <- function(ns = asNamespace("methods")) {
>>
>>     funs = c("isClassUnion", "getClass", "genericForPrimitive",
>> "possibleExtends", ".dataSlot", ".requirePackage", ".classEnv",
>> "getClassDef", "outerLabels", ".getClassFromCache", "getFunction")
>>
>>     message(paste0("\nCollecting data for unit tests on ", paste(funs,
>> collapse=", "), " ...\n"))
>>
>>     # Make env with list to hold test input/output
>>
>>     TEST_ENV <- new.env()
>>
>>     for (fname in funs) {
>>
>>         # Make placeholder for input/output for future runs of this
>> function
>>
>>         TEST_ENV[[fname]] = list()  # Actually probably not necessary,
>> will
>> just be c(NULL, list(first result)) the first time
>>
>>         # Construct test version of function
>>
>>         unlockBinding(fname, ns)
>>
>>         fun = get(fname, envir=ns, mode="function")
>>
>>         funbody = deparse(body(fun))
>>
>>         newfun <- fun
>>
>>         newfun.body = c(
>>
>>             sprintf("fname = '%s'", fname),
>>
>>             "TEST_INFO = list()",
>>
>>             "TEST_INFO$input = mget(names(formals(fname)))",
>>
>>             c("realfun <- function()", funbody),
>>
>>             "TEST_INFO$output = realfun()",
>>
>>             "TEST_ENV[[fname]] = c(TEST_ENV[[fname]], list(TEST_INFO))",
>>
>>             "return(TEST_INFO$output)")
>>
>>         body(newfun) = as.call(c(as.name("{"),
>> as.list(parse(text=newfun.body))))
>>
>>         assign(fname, newfun, envir=ns)
>>
>>     }
>>
>>     return(TEST_ENV)
>>
>> }
>> # run code, print items in TEST_ENV
>>
>> The relevant code is in methods/R/BasicFunsList.R and
>> methods/R/ClassExtensions.R
>> Pete
>>
>> ____________________
>> Peter M. Haverty, Ph.D.
>> Genentech, Inc.
>> phaverty at gene.com
>>
>>         [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-devel at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>
>

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