proc _cachefile {url key {keyIsHash 1}} {
		if {$keyIsHash} {
			set key [_hash_sep $key]
		}

		set file [file join $::appfs::cachedir $key]

		file mkdir -- [file dirname $file]
		file mkdir [file dirname $file]

		if {![file exists $file]} {
			set tmpfile "${file}.new"

			set fd [open $tmpfile "w"]

			set token [::http::geturl $url -channel $fd]