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| -rw-r--r-- | doc/todo/tracking_bugs_with_dependencies.mdwn | 83 |
1 files changed, 75 insertions, 8 deletions
diff --git a/doc/todo/tracking_bugs_with_dependencies.mdwn b/doc/todo/tracking_bugs_with_dependencies.mdwn index 464f68363..417d5910e 100644 --- a/doc/todo/tracking_bugs_with_dependencies.mdwn +++ b/doc/todo/tracking_bugs_with_dependencies.mdwn @@ -206,12 +206,51 @@ account all comments above (which doesn't mean it is above reproach :) ). --[[W >> 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'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. > * Seems that the only reason `match_glob` has to check for `~` is > because when a named spec appears in a pagespec, it is translated @@ -229,6 +268,10 @@ account all comments above (which doesn't mean it is above reproach :) ). --[[W >> 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. + > * 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 @@ -243,6 +286,9 @@ account all comments above (which doesn't mean it is above reproach :) ). --[[W >> 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. + > * 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 @@ -250,17 +296,38 @@ account all comments above (which doesn't mean it is above reproach :) ). --[[W >> 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. 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 break +>> 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]] + +>> 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]] + ---- diff --git a/IkiWiki.pm b/IkiWiki.pm |