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#' Unload packages
#'
#' It will unload `packages` and their loaded reverse dependencies
#' (imports, really).
#'
#' It will not unload
#' * base packages
#' * pak
#' * packages that are not loaded, obviously.
#'
#' This function is similar to `pkgload::unload()`, but it is specialized
#' to pak, in that
#' * it does not deal with packages loaded by pkgload.
#' * it will not unload base packages and pak itself.
#' * it will also unload the loaded reverse dependencies of the unloaded
#' packages, in the right order.
#' * It never forces an unload. (It does not need to, since reverse
#' dependencies are unloaded first.)
#'
#' @param packages [character] The packages to unload.
#' @return The unloaded packages, unvisibly.
#'
#' @noRd
unload <- function(packages, msg = " Unloading %s...") {
badbase <- intersect(base_packages(), packages)
if (length(badbase) > 0) {
packages <- setdiff(packages, badbase)
warning("Will not unload base packages: ", paste(badbase, collapse = ", "))
}
if ("pak" %in% packages) {
packages <- setdiff(packages, "pak")
warning("Will not unload pak")
}
badloaded <- setdiff(packages, loadedNamespaces())
if (length(badloaded) > 0) {
packages <- setdiff(packages, badloaded)
warning(
"Will not unload packages that are load not loaded: ",
paste(badloaded, collapse = ", ")
)
}
# This will also include reverse dependencies
packages <- unload_order_topo(packages)
# Always run garbage collector to force any deleted external pointers to
# finalise
gc()
for (pkg in packages) {
message(sprintf(msg, pkg))
unloadNamespace(pkg)
unload_dll(pkg)
}
# TODO: summary of packages unloaded
bad <- intersect(packages, loadedNamespaces())
if (length(bad) > 0) {
stop(
"Could not unload ",
if (length(bad) == 1) "one package: " else "some packages: ",
paste(bad, collapse = ", ")
)
}
message()
invisible(packages)
}
#' Query additional packages that need to be unloaded
#'
#' @param packages [character] Packages that we want to unload.
#' @return [character] All packages that need to be unloaded, because
#' they (recursively) depend on `packages`.
#'
#' @noRd
needs_unload <- function(packages) {
packages <- setdiff(packages, c(base_packages(), "pak"))
packages <- intersect(packages, loadedNamespaces())
unload_order_topo(packages)
}
package_imports <- function(package, base = FALSE) {
imp <- unique(names(getNamespaceInfo(package, "imports")))
if (!base) imp <- imp[! imp %in% base_packages()]
# pkgload has some unnamed components somehow?
imp[imp != ""]
}
unload_order_topo <- function(packages) {
all <- setdiff(loadedNamespaces(), base_packages())
imp <- lapply_with_names(all, package_imports)
imp_by <- lapply_with_names(all, function(p) {
all[vlapply(imp, `%in%`, x = p)]
})
revs <- packages
while (length(more <- setdiff(unlist(imp_by[revs]), revs)) > 0) {
revs <- c(revs, more)
}
imp_by <- lapply(imp_by, intersect, revs)[revs]
topo <- character()
while (length(topo) < length(revs)) {
new <- names(imp_by)[viapply(imp_by, length) == 0]
if (length(new) == 0) stop("Loop in package imports???")
topo <- c(topo, new)
imp_by <- lapply(imp_by, setdiff, new)[setdiff(names(imp_by), new)]
}
topo
}
unload_dll <- function(package) {
pkglibs <- loaded_dlls(package)
for (lib in pkglibs) {
dyn.unload(lib[["path"]])
}
# Remove the unloaded dlls from .dynLibs()
libs <- .dynLibs()
.dynLibs(libs[!(libs %in% pkglibs)])
invisible()
}
loaded_dlls <- function(package) {
libs <- .dynLibs()
matchidx <- vapply(libs, "[[", character(1), "name") == package
libs[matchidx]
}
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