Refactored is_a_{link,dir,node}() code.

This commit is contained in:
Adam Spiers 2011-11-17 18:24:53 +00:00
parent 7167eeb903
commit aefaad37a4

212
stow.in
View file

@ -1108,6 +1108,81 @@ sub process_tasks {
return; return;
} }
#===== SUBROUTINE ===========================================================
# Name : link_task_action()
# Purpose : finds the link task action for the given path, if there is one
# Parameters: $path
# Returns : 'remove', 'create', or '' if there is no action
# Throws : a fatal exception if an invalid action is found
# Comments : none
#============================================================================
sub link_task_action {
my ($path) = @_;
if (! exists $Link_Task_For{$path}) {
debug(4, " link_task_action($path): no task");
return '';
}
my $action = $Link_Task_For{$path}->{'action'};
internal_error("bad task action: $action")
unless $action eq 'remove' or $action eq 'create';
debug(4, " link_task_action($path): link task exists with action $action");
return $action;
}
#===== SUBROUTINE ===========================================================
# Name : dir_task_action()
# Purpose : finds the dir task action for the given path, if there is one
# Parameters: $path
# Returns : 'remove', 'create', or '' if there is no action
# Throws : a fatal exception if an invalid action is found
# Comments : none
#============================================================================
sub dir_task_action {
my ($path) = @_;
if (! exists $Dir_Task_For{$path}) {
debug(4, " dir_task_action($path): no task");
return '';
}
my $action = $Dir_Task_For{$path}->{'action'};
internal_error("bad task action: $action")
unless $action eq 'remove' or $action eq 'create';
debug(4, " dir_task_action($path): dir task exists with action $action");
return $action;
}
#===== SUBROUTINE ===========================================================
# Name : parent_link_scheduled_for_removal()
# Purpose : determines whether the given path or any parent thereof
# : is a link scheduled for removal
# Parameters: $path
# Returns : Boolean
# Throws : none
# Comments : none
#============================================================================
sub parent_link_scheduled_for_removal {
my ($path) = @_;
my $prefix = '';
for my $part (split m{/+}, $path) {
$prefix = join_paths($prefix, $part);
debug(4, " parent_link_scheduled_for_removal($path): prefix $prefix");
if (exists $Link_Task_For{$prefix} and
$Link_Task_For{$prefix}->{'action'} eq 'remove') {
debug(4, " parent_link_scheduled_for_removal($path): link scheduled for removal");
return 1;
}
}
debug(4, " parent_link_scheduled_for_removal($path): returning false");
return 0;
}
#===== SUBROUTINE =========================================================== #===== SUBROUTINE ===========================================================
# Name : is_a_link() # Name : is_a_link()
# Purpose : is the given path a current or planned link # Purpose : is the given path a current or planned link
@ -1121,40 +1196,26 @@ sub is_a_link {
my ($path) = @_; my ($path) = @_;
debug(4, " is_a_link($path)"); debug(4, " is_a_link($path)");
if (exists $Link_Task_For{$path}) { if (my $action = link_task_action($path)) {
my $action = $Link_Task_For{$path}->{'action'};
debug(4, "is_a_link($path): task exists with action $action");
if ($action eq 'remove') { if ($action eq 'remove') {
return 0; return 0;
} }
elsif ($action eq 'create') { elsif ($action eq 'create') {
return 1; return 1;
} }
else {
internal_error("bad task action: $action");
}
} }
elsif (-l $path) {
if (-l $path) {
# check if any of its parent are links scheduled for removal # check if any of its parent are links scheduled for removal
# (need this for edge case during unfolding) # (need this for edge case during unfolding)
debug(4, "is_a_link($path): is a real link"); debug(4, " is_a_link($path): is a real link");
my $parent = ''; return parent_link_scheduled_for_removal($path) ? 0 : 1;
for my $part (split m{/+}, $path) {
$parent = join_paths($parent, $part);
if (exists $Link_Task_For{$parent}) {
if ($Link_Task_For{$parent}->{'action'} eq 'remove') {
return 0;
}
}
}
return 1;
} }
debug(4, "is_a_link($path): returning false");
debug(4, " is_a_link($path): returning false");
return 0; return 0;
} }
#===== SUBROUTINE =========================================================== #===== SUBROUTINE ===========================================================
# Name : is_a_dir() # Name : is_a_dir()
# Purpose : is the given path a current or planned directory # Purpose : is the given path a current or planned directory
@ -1169,35 +1230,23 @@ sub is_a_dir {
my ($path) = @_; my ($path) = @_;
debug(4, " is_a_dir($path)"); debug(4, " is_a_dir($path)");
if (exists $Dir_Task_For{$path}) { if (my $action = dir_task_action($path)) {
my $action = $Dir_Task_For{$path}->{'action'};
debug(4, "is_a_dir($path): task exists with action $action");
if ($action eq 'remove') { if ($action eq 'remove') {
return 0; return 0;
} }
elsif ($action eq 'create') { elsif ($action eq 'create') {
return 1; return 1;
} }
else {
internal_error("bad task action: $action");
}
} }
# are we really following a link that is scheduled for removal return 0 if parent_link_scheduled_for_removal($path);
my $prefix = '';
for my $part (split m{/+}, $path) {
$prefix = join_paths($prefix, $part);
if (exists $Link_Task_For{$prefix} and
$Link_Task_For{$prefix}->{'action'} eq 'remove') {
return 0;
}
}
if (-d $path) { if (-d $path) {
debug(4, "is_a_dir($path): real dir"); debug(4, " is_a_dir($path): real dir");
return 1; return 1;
} }
debug(4, "is_a_dir($path): returning false");
debug(4, " is_a_dir($path): returning false");
return 0; return 0;
} }
@ -1215,51 +1264,60 @@ sub is_a_node {
my ($path) = @_; my ($path) = @_;
debug(4, " is_a_node($path)"); debug(4, " is_a_node($path)");
if (exists $Link_Task_For{$path}) { my $laction = link_task_action($path);
my $action = $Link_Task_For{$path}->{'action'}; my $daction = dir_task_action($path);
debug(4, "is_a_node($path): link task exists with action $action");
if ($action eq 'remove') { if ($laction eq 'remove') {
if ($daction eq 'remove') {
internal_error("removing link and dir: $path");
return 0; return 0;
} }
elsif ($action eq 'create') { elsif ($daction eq 'create') {
# Assume that we're unfolding $path, and that the link
# removal action is earlier than the dir creation action
# in the task queue. FIXME: is this a safe assumption?
return 1; return 1;
} }
else { else { # no dir action
internal_error("bad task action: $action"); return 0;
}
}
elsif ($laction eq 'create') {
if ($daction eq 'remove') {
# Assume that we're folding $path, and that the dir
# removal action is earlier than the link creation action
# in the task queue. FIXME: is this a safe assumption?
return 1;
}
elsif ($daction eq 'create') {
internal_error("creating link and dir: $path");
return 1;
}
else { # no dir action
return 1;
}
}
else {
# No link action
if ($daction eq 'remove') {
return 0;
}
elsif ($daction eq 'create') {
return 1;
}
else { # no dir action
# fall through to below
} }
} }
if (exists $Dir_Task_For{$path}) { return 0 if parent_link_scheduled_for_removal($path);
my $action = $Dir_Task_For{$path}->{'action'};
debug(4, "is_a_node($path): dir task exists with action $action");
if ($action eq 'remove') {
return 0;
}
elsif ($action eq 'create') {
return 1;
}
else {
internal_error("bad task action: $action");
}
}
# are we really following a link that is scheduled for removal
my $prefix = '';
for my $part (split m{/+}, $path) {
$prefix = join_paths($prefix, $part);
debug(4, "is_a_node($path): prefix $prefix");
if (exists $Link_Task_For{$prefix} and
$Link_Task_For{$prefix}->{'action'} eq 'remove') {
debug(4, "is_a_node($path): link scheduled for removal");
return 0;
}
}
if (-e $path) { if (-e $path) {
debug(4, "is_a_node($path): really exists"); debug(4, " is_a_node($path): really exists");
return 1; return 1;
} }
debug(4, "is_a_node($path): returning false");
debug(4, " is_a_node($path): returning false");
return 0; return 0;
} }
@ -1275,9 +1333,8 @@ sub is_a_node {
sub read_a_link { sub read_a_link {
my ($path) = @_; my ($path) = @_;
if (exists $Link_Task_For{$path}) { if (my $action = link_task_action($path)) {
my $action = $Link_Task_For{$path}->{'action'}; debug(4, " read_a_link($path): task exists with action $action");
debug(4, "read_a_link($path): task exists with action $action");
if ($action eq 'create') { if ($action eq 'create') {
return $Link_Task_For{$path}->{'source'}; return $Link_Task_For{$path}->{'source'};
@ -1287,12 +1344,9 @@ sub read_a_link {
"read_a_link() passed a path that is scheduled for removal: $path" "read_a_link() passed a path that is scheduled for removal: $path"
); );
} }
else {
internal_error("bad task action: $action");
}
} }
elsif (-l $path) { elsif (-l $path) {
debug(4, "read_a_link($path): real link"); debug(4, " read_a_link($path): real link");
return readlink $path return readlink $path
or error("Could not read link: $path"); or error("Could not read link: $path");
} }