X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/f827a2af9dfc2519d85ae328b3dca3c752e1bd80..5b2945cc921b222b07415ebea0c0d699f2a9dace:/doc/todo/tracking_bugs_with_dependencies.mdwn diff --git a/doc/todo/tracking_bugs_with_dependencies.mdwn b/doc/todo/tracking_bugs_with_dependencies.mdwn index 8b36f1e59..707790a75 100644 --- a/doc/todo/tracking_bugs_with_dependencies.mdwn +++ b/doc/todo/tracking_bugs_with_dependencies.mdwn @@ -196,21 +196,100 @@ account all comments above (which doesn't mean it is above reproach :) ). --[[W > Very belated code review of last version of the patch: > > * `is_globlist` is no longer needed + +>> Good :) + > * I don't understand why the pagespec match regexp is changed > from having flags `igx` to `ixgs`. Don't see why you > want `.` to match '\n` in it, and don't see any `.` in the regexp > anyway? + +>> Because you have to define all the named pagespecs in the pagespec, you sometimes end up with very long pagespecs. I found it useful to split them over multiple lines. That didn't work at one point and I added the 's' to make it work. I may have further altered the regex since then to make the 's' redundant. Remove it and see if multi-line pagespecs still work. :) + +>>> Well, I can tell you that multi-line pagespecs are supported w/o +>>> your patch .. I use them all the time. The reason I find your +>>> use of `/s` unlikely is because without it `\s` already matches +>>> a newline. Only if you want to treat a newline as non-whitespace +>>> is `/s` typically necessary. --[[Joey]] + > * Some changes of `@_` to `%params` in `pagespec_makeperl` do not > make sense to me. I don't see where \%params is defined and populated, > except with `\$params{specFunc}`. + +>> I'm not a perl hacker. This was a mighty battle for me to get going. +>> There is probably some battlefield carnage from my early struggles +>> learning perl left here. Part of this is that @_ / @params already +>> existed as a way of passing in extra parameters. I didn't want to +>> pollute that top level namespace - just at my own parameter (a hash) +>> which contained the data I needed. + +>>> I think I understand how the various `%params` +>>> (there's not just one) work in your code now, but it's really a mess. +>>> Explaining it in words would take pages.. It could be fixed by, +>>> in `pagespec_makeperl` something like: +>>> +>>> my %specFuncs; +>>> push @_, specFuncs => \%specFuncs; +>>> +>>> With that you have the hash locally available for populating +>>> inside `pagespec_makeperl`, and when the `match_*` functions +>>> are called the same hash data will be available inside their +>>> `@_` or `%params`. No need to change how the functions are called +>>> or do any of the other hacks. +>>> +>>> Currently, specFuncs is populated by building up code +>>> that recursively calls `pagespec_makeperl`, and is then +>>> evaluated when the pagespec gets evaluated. My suggested +>>> change to `%params` will break that, but that had to change +>>> anyway. +>>> +>>> It probably has a security hole, and is certianly inviting +>>> one, since the pagespec definition is matched by a loose regexp (`.*`) +>>> and then subject to string interpolation before being evaluated +>>> inside perl code. I recently changed ikiwiki to never interpolate +>>> user-supplied strings when translating pagespecs, and that +>>> needs to happen here too. The obvious way, it seems to me, +>>> is to not generate perl code, but just directly run perl code that +>>> populates specFuncs. + +>>>> I don't think this is as bad as you make out, but your addition of the +>>>> data array will break with the recursion my patch adds in pagespec_makeperl. +>>>> To fix that I'll need to pass a reference to that array into pagespec_makeperl. +>>>> I think I can then do the same thing to $params{specFuncs}. -- [[Will]] + > * Seems that the only reason `match_glob` has to check for `~` is > because when a named spec appears in a pagespec, it is translated > to `match_glob("~foo")`. If, instead, `pagespec_makeperl` checked > for named specs, it could convert them into `check_named_spec("foo")` > and avoid that ugliness. + +>> Yeah - I wanted to make named specs syntactically different on my first pass. You are right in that this could be made a fallback - named specs always override pagenames. + > * The changes to `match_link` seem either unecessary, or incomplete. > Shouldn't it check for named specs and call > `check_named_spec_existential`? + +>> An earlier version did. Then I realised it wasn't actually needed in that case - match_link() already included a loop that was like a type of existential matching. Each time through the loop it would +>> call match_glob(). match_glob() in turn will handle the named spec. I tested this version briefly and it seemed to work. I remember looking at this again later and wondering if I had mis-understood +>> some of the logic in match_link(), which might mean there are cases where you would need an explicit call to check_named_spec_existential() - I never checked it properly after having that thought. + +>>> In the common case, `match_link` does not call `match_glob`, +>>> because the link target it is being asked to check for is a single +>>> page name, not a glob. + +>>>> A named pagespec should fall into the glob case. These two pagespecs should be the same: + + link(a*) + +>>>> and + + define(aStar, a*) and link(aStar) + +>>>> In the first case, we want the pagespec to match any page that links to a page matching the glob. +>>>> In the second case, we want the pagespec to match any page that links to a page matching the named spec. +>>>> match_link() was already doing existential part. The patches to this code were simply to remove the `lc()` +>>>> call from the named pagespec name. Can that `lc` be removed entirely? -- [[Will]] + > * Generally, the need to modify `match_*` functions so that they > check for and handle named pagespecs seems suboptimal, if > only because there might be others people may want to use named @@ -221,120 +300,214 @@ account all comments above (which doesn't mean it is above reproach :) ). --[[W > that is not a page name at all, and it could be weird > if such a parameter were accidentially interpreted as a named > pagespec. (But, that seems unlikely to happen.) + +>> Possibly. I'm not sure which I prefer between the current solution and that one. Each have advantages and disadvantages. +>> It really isn't much code for the match functions to add a call to check_named_spec_existential(). + +>>> But if a plugin adds its own match function, it has +>>> to explicitly call that code to support named pagespecs. + +>>>> Yes, and it can do that in just three lines of code. But if we automatically check for named pagespecs all the time we +>>>> potentially break any matching function that doesn't accept pages, or wants to use multiple arguments. + > * I need to check if your trick to avoid infinite recursion > works if there are two named specs that recursively > call one-another. I suspect it does, but will test this > myself.. -> + +>> It worked for me. :) + +> * I also need to verify if memoizing the named pagespecs has +> really guarded against very expensive pagespecs DOSing the wiki.. + > --[[Joey]] +>> There is one issue that I've been thinking about that I haven't raised anywhere (or checked myself), and that is how this all interacts with page dependencies. +>> Firstly, I'm not sure anymore that the `pagespec_merge` function will continue to work in all cases. + +>>> The problem I can see there is that if two pagespecs +>>> get merged and both use `~foo` but define it differently, +>>> then the second definition might be used at a point when +>>> it shouldn't (but I haven't verified that really happens). +>>> That could certianly be a show-stopper. --[[Joey]] + +>>>> Even if that works, this is a good argument for having a syntactic difference between named pagespecs and normal pages. +>>>> If you're joining two pagespecs with 'or', you don't want a named pagespec in the first part overriding a page name in the +>>>> second part. Oh, and I assume 'or' has the right operator precedence that "a and b or c" is "(a and b) or c", and not "a and (b or c)" -- [[Will]] + +>>>>> Looks like its bracketed in the code anyway... -- [[Will]] + +>> Secondly, it seems that there are two types of dependency, and ikiwiki +>> currently only handles one of them. The first type is "Rebuild this +>> page when any of these other pages changes" - ikiwiki handles this. +>> The second type is "rebuild this page when set of pages referred to by +>> this pagespec changes" - ikiwiki doesn't seem to handle this. I +>> suspect that named pagespecs would make that second type of dependency +>> more important. I'll try to come up with a good example. -- [[Will]] + +>>> Hrm, I was going to build an example of this with backlinks, but it +>>> looks like that is handled as a special case at the moment (line 458 of +>>> render.pm). I'll see if I can breapk +>>> things another way. Fixing this properly would allow removal of that special case. -- [[Will]] + +>>>> I can't quite understand the distinction you're trying to draw +>>>> between the two types of dependencies. Backlinks are a very special +>>>> case though and I'll be suprised if they fit well into pagespecs. +>>>> --[[Joey]] + +>>>>> The issue is that the existential pagespec matching allows you to build things that have similar +>>>>> problems to backlinks. +>>>>> e.g. the following inline: + + \[[!inline pages="define(~done, link(done)) and link(~done)" archive=yes]] + +>>>>> includes any page that links to a page that links to done. Now imagine I add a new link to 'done' on +>>>>> some random page somewhere - a page which some other page links to which didn't previously get included - the set of pages accepted by the pagespec, and hence the set of +>>>>> pages inlined, will change. But, there is no dependency anywhere on the page that I altered, so +>>>>> ikiwiki will not rebuild the page with the inline in it. What is happening is that the page that I altered affects +>>>>> the set of pages matched by the pagespec without itself being matched by the pagespec, and hence included in the dependency list. + +>>>>> To make this work well, I think you need to recognise two types of dependencies for each page (and no +>>>>> special cases for particular types of links, eg backlinks). The first type of dependency says, "The content of +>>>>> this page depends upon the content of these other pages". The `add_depends()` in the shortcuts +>>>>> plugin is of this form: any time the shortcuts page is edited, any page with a shortcut on it +>>>>> is rebuilt. The inline plugin also needs to add dependencies of this form to detect when the inlined +>>>>> content changes. By contrast, the map plugin does not need a dependency of this form, because it +>>>>> doesn't actually care about the content of any pages, just which pages it needs to include (which we'll handle next). + +>>>>> The second type of dependency says, "The content of this page depends upon the exact set of pages matched +>>>>> by this pagespec". The first type of dependency was about the content of some pages, the second type is about +>>>>> which pages get matched by a pagespec. This is the type of dependency tracking that the map plugin needs. +>>>>> If the set of pages matched by map pagespec changes, then the page with the map on it needs to be rebuilt to show a different list of pages. +>>>>> Inline needs this type of dependency as well as the previous type - This type handles a change in which pages +>>>>> are inlined, the previous type handles a change in the content of any of those pages. Shortcut does not need this type of +>>>>> dependency. Most of the places that use `add_depends()` seem to need this type of dependency rather than the first type. + +>>>>> Implementation Details: The first type of dependency can be handled very similarly to the current +>>>>> dependency system. You just need to keep a list of pages that the content depends upon. You could +>>>>> keep that list as a pagespec, but if you do this you might want to check that the pagespec doesn't change, +>>>>> possibly by adding a dependency of the second type along with the dependency of the first type. + +>>>>> The second type of dependency is a little more tricky. For each page, we'd need a list of pagespecs that +>>>>> the page depended on, and for each pagespec you'd want to store the list of pages that currently match it. +>>>>> On refresh, you'd need to check each pagespec to see if the set of pages that match it has changed, and if +>>>>> that set has changed, then rebuild the dependent page(s). Oh, and for this second type of dependency, I +>>>>> don't think you can merge pagespecs. If I wanted to know if either "\*" or "link(done)" changes, then just checking +>>>>> to see if the set of pages matched by "\* or link(done)" changes doesn't work. + +>>>>> The current system works because even though you usually want dependencies of the second type, the set of pages +>>>>> referred to by a pagespec can only change if one of those pages itself changes. i.e. A dependency check of the +>>>>> first type will catch a dependency change of the second type with current pagespecs. +>>>>> This doesn't work with backlinks, and it doesn't work with existential matching. Backlinks are currently special-cased. I don't know +>>>>> how to special-case existential matching - I suspect you're better off just getting the dependency tracking right. + +>>>>> I also tried to come up with other possible solutions: e.g. can we find the dependencies for a pagespec? That +>>>>> would be the set of pages where a change on one of those pages could lead to a change in the set of pages matched by the pagespec. +>>>>> For old-style pagespecs without backlinks, the dependency set for a pagespec is the same as the set of pages the pagespec matches. +>>>>> Unfortunately, with existential matching, the set of pages that each +>>>>> pagespec depends upon can quickly become "*", which is not very useful. -- [[Will]] + +Patch updated to use closures rather than inline generated code for named pagespecs. Also includes some new use of ErrorReason where appropriate. -- [[Will]] + ---- diff --git a/IkiWiki.pm b/IkiWiki.pm - index 4e4da11..8b3cdfe 100644 + index 061a1c6..1e78a63 100644 --- a/IkiWiki.pm +++ b/IkiWiki.pm - @@ -1550,7 +1550,16 @@ sub globlist_to_pagespec ($) { - - sub is_globlist ($) { - my $s=shift; - - return ( $s =~ /[^\s]+\s+([^\s]+)/ && $1 ne "and" && $1 ne "or" ); - + return ! ($s =~ / - + (^\s* - + [^\s(]+ # single item - + (\( # possibly with parens after it - + ([^)]* # with stuff inside those parens - + (\([^)]*\))*)* # maybe even nested parens - + \))?\s*$ - + ) | - + (\s and \s) | (\s or \s) # or we find 'and' or 'or' somewhere - + /xs); - } - - sub safequote ($) { - @@ -1631,7 +1640,7 @@ sub pagespec_merge ($$) { + @@ -1774,8 +1774,12 @@ sub pagespec_merge ($$) { return "($a) or ($b)"; } -sub pagespec_translate ($) { - +sub pagespec_makeperl ($) { + +# is perl really so dumb it requires a forward declaration for recursive calls? + +sub pagespec_translate ($$); + + + +sub pagespec_translate ($$) { my $spec=shift; + + my $specFuncsRef=shift; - # Support for old-style GlobLists. - @@ -1650,12 +1659,14 @@ sub pagespec_translate ($) { + # Convert spec to perl code. + my $code=""; + @@ -1789,7 +1793,9 @@ sub pagespec_translate ($) { | \) # ) | - \w+\([^\)]*\) # command(params) - + define\(\s*~\w+\s*,((\([^()]*\)) | ([^()]+))+\) # define(~specName, spec) - spec can contain parens 1 deep + + define\(\s*~\w+\s*,((\([^()]*\)) | ([^()]+))+\) # define(~specName, spec) - spec can contain parens 1 deep + | + \w+\([^()]*\) # command(params) - params cannot contain parens | [^\s()]+ # any other text ) - \s* # ignore whitespace - - }igx) { - + }igxs) { - my $word=$1; - if (lc $word eq 'and') { - $code.=' &&'; - @@ -1666,16 +1677,23 @@ sub pagespec_translate ($) { + @@ -1805,10 +1811,19 @@ sub pagespec_translate ($) { elsif ($word eq "(" || $word eq ")" || $word eq "!") { $code.=' '.$word; } - elsif ($word =~ /^(\w+)\((.*)\)$/) { - + elsif ($word =~ /^define\(\s*~(\w+)\s*,(.*)\)$/s) { - + $code .= " (\$params{specFuncs}->{$1}="; # (exists \$params{specFuncs}) && - + $code .= "memoize("; - + $code .= &pagespec_makeperl($2); - + $code .= ")"; - + $code .= ") "; + + elsif ($word =~ /^define\(\s*(~\w+)\s*,(.*)\)$/s) { + + my $name = $1; + + my $subSpec = $2; + + my $newSpecFunc = pagespec_translate($subSpec, $specFuncsRef); + + return if $@ || ! defined $newSpecFunc; + + $specFuncsRef->{$name} = $newSpecFunc; + + push @data, qq{Created named pagespec "$name"}; + + $code.="IkiWiki::SuccessReason->new(\$data[$#data])"; + } + elsif ($word =~ /^(\w+)\((.*)\)$/s) { if (exists $IkiWiki::PageSpec::{"match_$1"}) { - - $code.="IkiWiki::PageSpec::match_$1(\$page, ".safequote($2).", \@_)"; - + $code.="IkiWiki::PageSpec::match_$1(\$page, ".safequote($2).", \%params)"; + push @data, $2; + - $code.="IkiWiki::PageSpec::match_$1(\$page, \$data[$#data], \@_)"; + + $code.="IkiWiki::PageSpec::match_$1(\$page, \$data[$#data], \@_, specFuncs => \$specFuncsRef)"; } else { - $code.=' 0'; - } + push @data, qq{unknown function in pagespec "$word"}; + @@ -1817,7 +1832,7 @@ sub pagespec_translate ($) { } else { - - $code.=" IkiWiki::PageSpec::match_glob(\$page, ".safequote($word).", \@_)"; - + $code.=" IkiWiki::PageSpec::match_glob(\$page, ".safequote($word).", \%params)"; + push @data, $word; + - $code.=" IkiWiki::PageSpec::match_glob(\$page, \$data[$#data], \@_)"; + + $code.=" IkiWiki::PageSpec::match_glob(\$page, \$data[$#data], \@_, specFuncs => \$specFuncsRef)"; } } - @@ -1683,8 +1701,18 @@ sub pagespec_translate ($) { - $code=0; + @@ -1826,7 +1841,7 @@ sub pagespec_translate ($) { } - + return 'sub { my $page=shift; my %params = @_; '.$code.' }'; - +} - + - +sub pagespec_translate ($) { - + my $spec=shift; - + - + my $code = pagespec_makeperl($spec); - + - + # print STDERR "Spec '$spec' generated code '$code'\n"; - + no warnings; - return eval 'sub { my $page=shift; '.$code.' }'; - + return eval $code; + + return eval 'memoize (sub { my $page=shift; '.$code.' })'; } sub pagespec_match ($$;@) { - @@ -1699,7 +1727,7 @@ sub pagespec_match ($$;@) { + @@ -1839,7 +1854,7 @@ sub pagespec_match ($$;@) { + unshift @params, 'location'; + } - my $sub=pagespec_translate($spec); - return IkiWiki::FailReason->new("syntax error in pagespec \"$spec\"") if $@; - - return $sub->($page, @params); - + return $sub->($page, @params, specFuncs => {}); - } + - my $sub=pagespec_translate($spec); + + my $sub=pagespec_translate($spec, +{}); + return IkiWiki::ErrorReason->new("syntax error in pagespec \"$spec\"") + if $@ || ! defined $sub; + return $sub->($page, @params); + @@ -1850,7 +1865,7 @@ sub pagespec_match_list ($$;@) { + my $spec=shift; + my @params=@_; + - my $sub=pagespec_translate($spec); + + my $sub=pagespec_translate($spec, +{}); + error "syntax error in pagespec \"$spec\"" + if $@ || ! defined $sub; + + @@ -1872,7 +1887,7 @@ sub pagespec_match_list ($$;@) { sub pagespec_valid ($) { - @@ -1748,11 +1776,78 @@ sub new { + my $spec=shift; + + - my $sub=pagespec_translate($spec); + + my $sub=pagespec_translate($spec, +{}); + return ! $@; + } + + @@ -1919,6 +1934,68 @@ sub new { package IkiWiki::PageSpec; @@ -342,15 +515,14 @@ account all comments above (which doesn't mean it is above reproach :) ). --[[W + my $page=shift; + my $specName=shift; + my %params=@_; - + - + error("Unable to find specFuncs in params to check_named_spec()!") unless exists $params{specFuncs}; + + + + return IkiWiki::ErrorReason->new("Unable to find specFuncs in params to check_named_spec()!") + + unless exists $params{specFuncs}; + + my $specFuncsRef=$params{specFuncs}; - + - + return IkiWiki::FailReason->new("Named page spec '$specName' is not valid") + + + + return IkiWiki::ErrorReason->new("Named page spec '$specName' is not valid") + unless (substr($specName, 0, 1) eq '~'); - + - + $specName = substr($specName, 1); + + if (exists $specFuncsRef->{$specName}) { + # remove the named spec from the spec refs @@ -361,7 +533,7 @@ account all comments above (which doesn't mean it is above reproach :) ). --[[W + $specFuncsRef->{$specName} = $sub; + return $result; + } else { - + return IkiWiki::FailReason->new("Page spec '$specName' does not exist"); + + return IkiWiki::ErrorReason->new("Page spec '$specName' does not exist"); + } +} + @@ -370,14 +542,14 @@ account all comments above (which doesn't mean it is above reproach :) ). --[[W + my $specName=shift; + my $funcref=shift; + my %params=@_; - + - + error("Unable to find specFuncs in params to check_named_spec_existential()!") unless exists $params{specFuncs}; + + + + return IkiWiki::ErrorReason->new("Unable to find specFuncs in params to check_named_spec_existential()!") + + unless exists $params{specFuncs}; + my $specFuncsRef=$params{specFuncs}; + - + return IkiWiki::FailReason->new("Named page spec '$specName' is not valid") + + return IkiWiki::ErrorReason->new("Named page spec '$specName' is not valid") + unless (substr($specName, 0, 1) eq '~'); - + $specName = substr($specName, 1); - + + + + if (exists $specFuncsRef->{$specName}) { + # remove the named spec from the spec refs + # when we recurse to avoid infinite recursion @@ -389,7 +561,7 @@ account all comments above (which doesn't mean it is above reproach :) ). --[[W + my $tempResult = $funcref->($page, $nextpage, %params); + if ($tempResult) { + $specFuncsRef->{$specName} = $sub; - + return $tempResult; + + return IkiWiki::SuccessReason->new("Existential check of '$specName' matches because $tempResult"); + } + } + } @@ -397,12 +569,14 @@ account all comments above (which doesn't mean it is above reproach :) ). --[[W + $specFuncsRef->{$specName} = $sub; + return IkiWiki::FailReason->new("No page in spec '$specName' was successfully matched"); + } else { - + return IkiWiki::FailReason->new("Named page spec '$specName' does not exist"); + + return IkiWiki::ErrorReason->new("Named page spec '$specName' does not exist"); + } +} + - sub match_glob ($$;@) { - my $page=shift; + sub derel ($$) { + my $path=shift; + my $from=shift; + @@ -1937,6 +2014,10 @@ sub match_glob ($$;@) { my $glob=shift; my %params=@_; @@ -410,30 +584,31 @@ account all comments above (which doesn't mean it is above reproach :) ). --[[W + return check_named_spec($page, $glob, %params); + } + - my $from=exists $params{location} ? $params{location} : ''; - - # relative matching - @@ -1782,11 +1877,12 @@ sub match_internal ($$;@) { + $glob=derel($glob, $params{location}); + + my $regexp=IkiWiki::glob2re($glob); + @@ -1959,8 +2040,9 @@ sub match_internal ($$;@) { sub match_link ($$;@) { my $page=shift; - my $link=lc(shift); - + my $fulllink=shift; + + my $fullLink=shift; my %params=@_; - + my $link=lc($fulllink); + + my $link=lc($fullLink); + $link=derel($link, $params{location}); my $from=exists $params{location} ? $params{location} : ''; - - - + - # relative matching - if ($link =~ m!^\.! && defined $from) { - $from=~s#/?[^/]+$##; - @@ -1804,19 +1900,32 @@ sub match_link ($$;@) { + @@ -1975,25 +2057,37 @@ sub match_link ($$;@) { } else { return IkiWiki::SuccessReason->new("$page links to page $p matching $link") - if match_glob($p, $link, %params); - + if match_glob($p, $fulllink, %params); + + if match_glob($p, $fullLink, %params); + $p=~s/^\///; + $link=~s/^\///; + return IkiWiki::SuccessReason->new("$page links to page $p matching $link") + - if match_glob($p, $link, %params); + + if match_glob($p, $fullLink, %params); } } return IkiWiki::FailReason->new("$page does not link to $link"); @@ -455,23 +630,24 @@ account all comments above (which doesn't mean it is above reproach :) ). --[[W sub match_created_before ($$;@) { my $page=shift; my $testpage=shift; - + my @params=@_; + my %params=@_; + - + + if (substr($testpage, 0, 1) eq '~') { - + return check_named_spec_existential($page, $testpage, \&match_created_before, @params); + + return check_named_spec_existential($page, $testpage, \&match_created_before, %params); + } + + + $testpage=derel($testpage, $params{location}); if (exists $IkiWiki::pagectime{$testpage}) { - if ($IkiWiki::pagectime{$page} < $IkiWiki::pagectime{$testpage}) { - @@ -1834,6 +1943,11 @@ sub match_created_before ($$;@) { - sub match_created_after ($$;@) { - my $page=shift; + @@ -2014,6 +2108,10 @@ sub match_created_after ($$;@) { my $testpage=shift; - + my @params=@_; - + + my %params=@_; + + if (substr($testpage, 0, 1) eq '~') { - + return check_named_spec_existential($page, $testpage, \&match_created_after, @params); + + return check_named_spec_existential($page, $testpage, \&match_created_after, %params); + } + + + $testpage=derel($testpage, $params{location}); if (exists $IkiWiki::pagectime{$testpage}) { - if ($IkiWiki::pagectime{$page} > $IkiWiki::pagectime{$testpage}) {