From 5844b346080b0c691d6fea27456dc79398f95304 Mon Sep 17 00:00:00 2001 From: adam Date: Sun, 1 Jan 2006 23:55:41 +0000 Subject: [PATCH] comments on $pure, $othercollection --- Stow.pm | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/Stow.pm b/Stow.pm index 1039589..8fbd31c 100755 --- a/Stow.pm +++ b/Stow.pm @@ -143,9 +143,11 @@ sub Unstow { # we have to move up out of that hierarchy and back into the stow # directory. - # Does this directory only contain symlinks to the packages we are - # removing? We assume so and scan the directory until we find out - # otherwise. + # Does this directory only contain symlinks to a *single* package + # collection *other* than one we are removing? We assume so and + # scan the directory until we find out otherwise. We have to track + # this because if a subtree is found to be pure, we can fold it into + # a single symlink. my $pure = 1; # FIXME what is this? @@ -193,16 +195,26 @@ sub Unstow { # Yep, so get rid of it. &DoUnlink($contentPath); } else { - # No, it points to another package collection. + # No, it points to another package collection. Is there + # still a chance this directory is pure and can be folded? if ($pure) { + # Yes, so keep track of whether symlinks in the directory + # point to more than one collection. if ($othercollection) { + # More than one collection means impure => no folding possible. $pure = 0 if $collection ne $othercollection; } else { + # This is the first reference to another collection + # we've seen, so remember it for future comparison with + # other symlink targets. $othercollection = $collection; } } } } else { + # Link points outside the stow directory, therefore is not + # managed by stow and cannot be touched. So tree folding will + # not be possible. $pure = 0; } } @@ -226,10 +238,13 @@ sub Unstow { $othercollection = $subother; } } else { + # Subtree is impure therefore this directory is impure. $pure = 0; } } } else { + # Current directory contains something other than a symlink or a + # directory, therefore folding is not going to be possible. $pure = 0; } } @@ -242,6 +257,7 @@ sub Unstow { return ($pure, $othercollection); } +# This is the tree folding which the stow manual refers to. sub CoalesceTrees { my($parent, $stow, @trees) = @_;