This should fix some tests on PHP 7.1. The work is far from done, we
still have a lot of variables without proper accessibility defined.

In an older version of PHP a file_exists() call would issue a warning
when the file did not exist. This was fixed in later PHP releases. Since
we require PHP 5.3 now, there's no need to supress any error here
anymore. This might even give a minor performance boost.

1. cachetime setting should only be applied to the cache_renderer
   class.  Previously it was applied to cache_parser (and by
   extension cache_handler).
2. two special cachetime values, -1 & 0, weren't handled, per
   FS#2183

To handle the cachetime setting, -1, disable caching, a new
property _nocache is added.  When that property is true, any cache
file must not be used and storecache() should not store any values

Caching had been completely broken (disabled) for caches with events
because the default event handler (cache::_useCache()) was protected and
thus couldn't be executed by the event handler. This was broken in
c59b3e00

This changes fundamentally when metadata is rendered. This commit
introduces a new cache file for every page that just contains a
timestamp and is updated whenever the metadata of that page is rendered.

Metadata is rendered when p_get_metadata is called and the last
rendering has been before a page, metadata, configuration or renderer
update or purge is set like in the xhtml renderer cache.

Metadata is no longer automatically rendered when the xhtml renderer
cache isn't used but will still be rendered when needed as
p_get_metadata is called in the cache.

Metadata is also no longer rendered in the indexer script when missing
as that is already done by pageinfo() before anything else is done so
the indexer script won't be called when there is no metadata file.

Classes are loaded throug PHP5's class autoloader, all other
includes are just loaded by default. This skips a lot of
require_once calls.

Parser and Plugin stuff isn't handled by the class loader yet.

Ignore-this: fa3ae95ced3fbec584a8ceb5162b654d

darcs-hash:20091130112027-9b77a-07dbd7e47c8ea1a14b8d93fd92a9a874db85f645.gz

darcs-hash:20091113123458-e4919-d4841ea9c627059a4afa8e0032dd889b3cc579cb.gz

  Changes of behaviour are:
  * Allow the user name, title & description \e2\80\9c0\e2\80\9d
  * Default to Port 443 if using HTTPS
  * Set $INFO['isadmin'] and $INFO['ismanager'] to \e2\80\9cfalse\e2\80\9d even if no user is
    logged in
  * Do not pass empty fragment field in the event data for event
    ACTION_SHOW_REDIRECT
  * Handle chunked encoding in HTTPClient

darcs-hash:20091104100115-e4919-5cf6397d4a457e3f98a8ca49fbdab03f2147721d.gz

Ignore-this: 27ea52110bce929b2c61ed8faba67cfc

darcs-hash:20091016205526-c0bf4-35eba4e65d37980a667ba982f7f1ea5b7b07f01c.gz

- add mediameta and license config files into the cascade
- update the cache validity code in cache.php, css.php & js.php to use config_cascade
- redo inclusion of main config files to avoid suppression of errors in config files
- add getConfigFiles($type) function
- minor updates elsewhere to use config_cascade rather than hardcoded config file names

darcs-hash:20090122114457-f07c6-98ad5627fd5df93edf8dd03289b9cf6d81962afe.gz

darcs-hash:20081213090400-7ad00-4e21cd75978bb07513f32f5d750658e8d777c59e.gz

FS#1090 ensured DW would never rebuild instructions in the same run by forcing subsequent
instruction requests to use the version cached on the first request.  That introduced problems
when the caching of the instructions failed (FS#1334).  This patch allows subsequent rebuilds
when cache storage failed.

darcs-hash:20080223025539-d26fc-26202a049a6969816553d950a2bb8f71a02ae76e.gz

bool page_exists($id, $rev

darcs-hash:20070930021040-d26fc-e3847bfdd20a36154685262eca94211cfd461e83.gz

The use of realpath() to clean up relative file names caused some
trouble in certain setups relying on symlinks or having restricitve
file structure setups.

This patch replaces all realpath() calls with a PHP only replacement
which should solve those problems.

darcs-hash:20070930184250-7ad00-512ff04c95f57fc9eaf104f80372237a3c94286f.gz

rss syntax extended to include a refresh parameter
 <digits><period>  period can be d,h,m for days, hours, minutes respectively
                   if not specified will default to 4 hours
                   dokuwiki imposes a minimum of 10 minutes

metadata now used "date valid age" (seconds) rather than "date valid end"

darcs-hash:20060925201222-9b6ab-c8e6d8e40bb178295bab874fce5147ccff35fbbb.gz

Cache
- add dependency for metadata renderer file
- check metadata for end of page life, "date valid end".

Metadata Renderer
- RSS syntax mode now sets rendered page expiry, "date valid end"
  and includes the feed URL in "relation haspart".

Purgefile
For all wiki installations the purgefile records the earliest
time before which no cache purge (based on data consistency)
is required. Cache files older than this time MAY need to be
purged.
- remove purgeonadd configuration setting

darcs-hash:20060924202157-9b6ab-4531e91411c41914eeab2b6a8160c3d46b001cee.gz

darcs-hash:20060923203609-9b6ab-ecca679faa254a29772868508050fcf3206b0814.gz

Reduce overhead by only storing cache hit stats while
the allowdebug option is enabled.

darcs-hash:20060917230403-05dcb-92afea926b5a3fc302327f964e482787aec2d982.gz

- add code to ensure page metadata is refreshed along with cache
- bug fix for missing global $conf

darcs-hash:20060917193934-9b6ab-c53c8b6e4764d4c63014ecbaadf0797eb959224f.gz

this update changes the processing sequence slightly
to make the cache item's dependencies ($this->depends)
available before _useCache is called.

ie. the dependencies will be available to and modifiable
    by handlers of the PARSER_USE_CACHE event.

darcs-hash:20060915144735-9b6ab-b0db479f9ef305aed21ca291ea909002baae4e21.gz

This patch primarily updates p_cached_xhtml() and p_cached_instructions() to
allow their caching logic to be surrounded by an event trigger.

p_cached_xhtml() has been rewritten as the more general p_cached_output() to
support other render output formats besides 'xhtml'. All calls to
p_cached_xhtml() have been changed to refer to the new function.

New event:

name:        PARSER_CACHE_USE
data:        cache object (see below)
action:      determine if cache file can be used
preventable: yes
result:      bool, true to use cache file, false otherwise

Cache operations have been generalised in a new class, cache, extended to
cache_parser, cache_renderer & cache_instructions. Details can be found in
inc/cache.php

For handling of above event, key properties are:
- page, if present the wiki page id,
        may not always be present, e.g. when called for locale xhtml files
- file, source file
- mode, renderer mode (e.g. 'xhtml') or 'i' for instructions

Other changes:
- cache class counts cache hits against attempts, results are stored in
  {cache_dir}/cache_stats.txt
- adds metadata dependency to renderer page cache
- replaces purgefile dependency for renderer cache with metadata
  'relation references' (internal link) dependency for wiki pages only

darcs-hash:20060911021418-9b6ab-19601ed194b8c8e45236ab72c3e23d78bf777e6c.gz