WikiDB is a container for WikiDB_Pages
* which in turn contain WikiDB_PageRevisions.
*
* Conceptually a WikiDB contains all possible WikiDB_Pages,
* whether they have been initialized or not. Since all possible pages are already
* contained in a WikiDB, a call to WikiDB::getPage() will never fail
* (barring bugs and e.g. filesystem or SQL database problems.)
*
* Also each WikiDB_Page always contains at least one WikiDB_PageRevision:
* the default content (e.g. "Describe [PageName] here."). This default content
* has a version number of zero.
*
* WikiDB_PageRevisions have read-only semantics. One can only create new
* revisions or delete old ones --- one can not modify an existing revision.
*/
class WikiDB {
/**
* Open a WikiDB database.
*
* This is a static member function. This function inspects its
* arguments to determine the proper subclass of WikiDB to instantiate,
* and then it instantiates it.
*
* @access public
*
* @param $dbparams hash Database configuration parameters.
* Some pertinent paramters are:
*
* - dbtype
*
- The back-end type. Current supported types are:
*
* - SQL
*
- Generic SQL backend based on the PEAR/DB database abstraction
* library.
*
- dba
*
- Dba based backend.
*
*
* - dsn
*
- (Used by the SQL backend.)
* The DSN specifying which database to connect to.
*
*
- prefix
*
- Prefix to be prepended to database table (and file names).
*
*
- directory
*
- (Used by the dba backend.)
* Which directory db files reside in.
*
*
- timeout
*
- (Used by the dba backend.)
* Timeout in seconds for opening (and obtaining lock) on the db files.
*
*
- dba_handler
*
- (Used by the dba backend.)
* Which dba handler to use. Good choices are probably either 'gdbm'
* or 'db2'.
*
*
* @return object A WikiDB object.
**/
function open ($dbparams) {
$dbtype = $dbparams{'dbtype'};
include_once("lib/WikiDB/$dbtype.php");
$class = 'WikiDB_' . $dbtype;
return new $class ($dbparams);
}
/**
* Constructor
* @access protected
*/
function WikiDB ($backend, $dbparams) {
$this->_backend = &$backend;
$this->_cache = new WikiDB_cache($backend);
//FIXME: devel checking.
//$this->_backend->check();
}
/**
* Get any user-level warnings about this WikiDB.
*
* Some back-ends, e.g. by default create there data files
* in the global /tmp directory. We would like to warn the user
* when this happens (since /tmp files tend to get wiped
* periodically.) Warnings such as these may be communicated
* from specific back-ends through this method.
*
* @access public
*
* @return string A warning message (or false if there is none.)
*/
function genericWarnings() {
return false;
}
/**
* Close database connection.
*
* The database may no longer be used after it is closed.
*
* Closing a WikiDB invalidates all WikiDB_Pages,
* WikiDB_PageRevisions and WikiDB_PageIterators which
* have been obtained from it.
*
* @access public
*/
function close () {
$this->_backend->close();
$this->_cache->close();
}
/**
* Get a WikiDB_Page from a WikiDB.
*
* A WikiDB consists of the (infinite) set of all possible pages,
* therefore this method never fails.
*
* @access public
* @param $pagename string Which page to get.
* @return object The requested WikiDB_Page.
*/
function getPage($pagename) {
assert(is_string($pagename) && $pagename);
return new WikiDB_Page($this, $pagename);
}
// Do we need this?
//function nPages() {
//}
/**
* Determine whether page exists (in non-default form).
*
*
* $is_page = $dbi->isWikiPage($pagename);
*
* is equivalent to
*
* $page = $dbi->getPage($pagename);
* $current = $page->getCurrentRevision();
* $is_page = ! $current->hasDefaultContents();
*
* however isWikiPage may be implemented in a more efficient
* manner in certain back-ends.
*
* @access public
*
* @param $pagename string Which page to check.
*
* @return boolean True if the page actually exists with non-default contents
* in the WikiDataBase.
*/
function isWikiPage ($pagename) {
$page = $this->getPage($pagename);
$current = $page->getCurrentRevision();
return ! $current->hasDefaultContents();
}
/**
* Delete page from the WikiDB.
*
* Deletes all revisions of the page from the WikiDB.
* Also resets all page meta-data to the default values.
*
* @access public
*
* @param $pagename string Name of page to delete.
*/
function deletePage($pagename) {
$this->_cache->delete_page($pagename);
$this->_backend->set_links($pagename, false);
}
/**
* Retrieve all pages.
*
* Gets the set of all pages with non-default contents.
*
* FIXME: do we need this? I think so. The simple searches
* need this stuff.
*
* @access public
*
* @param $include_defaulted boolean Normally pages whose most recent
* revision has empty content are considered to be non-existant.
* Unless $include_defaulted is set to true, those pages will
* not be returned.
*
* @return object A WikiDB_PageIterator which contains all pages
* in the WikiDB which have non-default contents.
*/
function getAllPages($include_defaulted = false) {
$result = $this->_backend->get_all_pages($include_defaulted);
return new WikiDB_PageIterator($this, $result);
}
/**
* Title search.
*
* Search for pages containing (or not containing) certain words in their
* names.
*
* Pages are returned in alphabetical order whenever it is practical
* to do so.
*
* FIXME: should titleSearch and fullSearch be combined? I think so.
*
* @access public
* @param $search object A TextSearchQuery
* @return object A WikiDB_PageIterator containing the matching pages.
* @see TextSearchQuery
*/
function titleSearch($search) {
$result = $this->_backend->text_search($search);
return new WikiDB_PageIterator($this, $result);
}
/**
* Full text search.
*
* Search for pages containing (or not containing) certain words in their
* entire text (this includes the page content and the page name).
*
* Pages are returned in alphabetical order whenever it is practical
* to do so.
*
* @access public
*
* @param $search object A TextSearchQuery object.
* @return object A WikiDB_PageIterator containing the matching pages.
* @see TextSearchQuery
*/
function fullSearch($search) {
$result = $this->_backend->text_search($search, 'full_text');
return new WikiDB_PageIterator($this, $result);
}
/**
* Find the pages with the greatest hit counts.
*
* Pages are returned in reverse order by hit count.
*
* @access public
*
* @param $limit unsigned The maximum number of pages to return.
* Set $limit to zero to return all pages.
*
* @return object A WikiDB_PageIterator containing the matching pages.
*/
function mostPopular($limit = 20) {
$result = $this->_backend->most_popular($limit);
return new WikiDB_PageIterator($this, $result);
}
/**
* Find recent page revisions.
*
* Revisions are returned in reverse order by creation time.
*
* @access public
*
* @param $params hash This hash is used to specify various optional
* parameters:
*
* - limit
*
- (integer) At most this many revisions will be returned.
*
- since
*
- (integer) Only revisions since this time (unix-timestamp) will be returned.
*
- include_minor_revisions
*
- (boolean) Also include minor revisions. (Default is not to.)
*
- exclude_major_revisions
*
- (boolean) Don't include non-minor revisions.
* (Exclude_major_revisions implies include_minor_revisions.)
*
- include_all_revisions
*
- (boolean) Return all matching revisions for each page.
* Normally only the most recent matching revision is returned
* for each page.
*
*
* @return object A WikiDB_PageRevisionIterator containing the matching revisions.
*/
function mostRecent($params = false) {
$result = $this->_backend->most_recent($params);
return new WikiDB_PageRevisionIterator($this, $result);
}
};
/**
* An abstract base class which representing a wiki-page within a WikiDB.
*
* A WikiDB_Page contains a number (at least one) of WikiDB_PageRevisions.
*/
class WikiDB_Page
{
function WikiDB_Page(&$wikidb, $pagename) {
$this->_wikidb = &$wikidb;
$this->_pagename = $pagename;
assert(!empty($this->_pagename));
}
/**
* Get the name of the wiki page.
*
* @access public
*
* @return string The page name.
*/
function getName() {
return $this->_pagename;
}
/**
* Delete an old revision of a WikiDB_Page.
*
* Deletes the specified revision of the page.
* It is a fatal error to attempt to delete the current revision.
*
* @access public
*
* @param $version integer Which revision to delete. (You can also
* use a WikiDB_PageRevision object here.)
*/
function deleteRevision($version) {
$backend = &$this->_wikidb->_backend;
$cache = &$this->_wikidb->_cache;
$pagename = &$this->_pagename;
$version = $this->_coerce_to_version($version);
if ($version == 0)
return;
$backend->lock();
$latestversion = $backend->get_latest_version($pagename);
if ($latestversion && $version == $latestversion) {
$backend->unlock();
trigger_error("Attempt to delete most recent revision of '$pagename'",
E_USER_ERROR);
return;
}
$cache->delete_versiondata($pagename, $version);
$backend->unlock();
}
/*
* Delete a revision, or possibly merge it with a previous
* revision.
*
* The idea is this:
* Suppose an author make a (major) edit to a page. Shortly
* after that the same author makes a minor edit (e.g. to fix
* spelling mistakes he just made.)
*
* Now some time later, where cleaning out old saved revisions,
* and would like to delete his minor revision (since there's really
* no point in keeping minor revisions around for a long time.)
*
* Note that the text after the minor revision probably represents
* what the author intended to write better than the text after the
* preceding major edit.
*
* So what we really want to do is merge the minor edit with the
* preceding edit.
*
* We will only do this when:
*
* - The revision being deleted is a minor one, and
*
- It has the same author as the immediately preceding revision.
*
*/
function mergeRevision($version) {
$backend = &$this->_wikidb->_backend;
$cache = &$this->_wikidb->_cache;
$pagename = &$this->_pagename;
$version = $this->_coerce_to_version($version);
if ($version == 0)
return;
$backend->lock();
$latestversion = $backend->get_latest_version($pagename);
if ($latestversion && $version == $latestversion) {
$backend->unlock();
trigger_error("Attempt to merge most recent revision of '$pagename'",
E_USER_ERROR);
return;
}
$versiondata = $cache->get_versiondata($pagename, $version, true);
if (!$versiondata) {
// Not there? ... we're done!
$backend->unlock();
return;
}
if ($versiondata['is_minor_edit']) {
$previous = $backend->get_previous_version($pagename, $version);
if ($previous) {
$prevdata = $cache->get_versiondata($pagename, $previous);
if ($prevdata['author_id'] == $versiondata['author_id']) {
// This is a minor revision, previous version is by the
// same author. We will merge the revisions.
$cache->update_versiondata($pagename, $previous,
array('%content' => $versiondata['%content'],
'_supplanted' => $versiondata['_supplanted']));
}
}
}
$cache->delete_versiondata($pagename, $version);
$backend->unlock();
}
/**
* Create a new revision of a WikiDB_Page.
*
* @access public
*
* @param $content string Contents of new revision.
*
* @param $metadata hash Metadata for new revision.
* All values in the hash should be scalars (strings or integers).
*
*
* @param $version int Version number for new revision.
* To ensure proper serialization of edits, $version must be
* exactly one higher than the current latest version.
* (You can defeat this check by setting $version to
* WIKIDB_FORCE_CREATE --- not usually recommended.)
*
* @param $links array List of pagenames which this page links to.
*
* @return object Returns the new WikiDB_PageRevision object. If $version was incorrect,
* returns false
*/
function createRevision($version, &$content, $metadata, $links) {
$backend = &$this->_wikidb->_backend;
$cache = &$this->_wikidb->_cache;
$pagename = &$this->_pagename;
$backend->lock();
$latestversion = $backend->get_latest_version($pagename);
$newversion = $latestversion + 1;
assert($newversion >= 1);
if ($version != WIKIDB_FORCE_CREATE && $version != $newversion) {
$backend->unlock();
return false;
}
$data = $metadata;
foreach ($data as $key => $val) {
if (empty($val) || $key[0] == '_' || $key[0] == '%')
unset($data[$key]);
}
assert(!empty($data['author_id']));
if (empty($data['author_id']))
@$data['author_id'] = $data['author'];
if (empty($data['mtime']))
$data['mtime'] = time();
if ($latestversion) {
// Ensure mtimes are monotonic.
$pdata = $cache->get_versiondata($pagename, $latestversion);
if ($data['mtime'] < $pdata['mtime']) {
trigger_error("$pagename: Date of new revision non-monotonic",
E_USER_NOTICE);
$data['orig_mtime'] = $data['mtime'];
$data['mtime'] = $pdata['mtime'];
}
// FIXME: use (possibly user specified) 'mtime' time or time()?
$cache->update_versiondata($pagename, $latestversion,
array('_supplanted' => $data['mtime']));
}
$data['%content'] = &$content;
$cache->set_versiondata($pagename, $newversion, $data);
//$cache->update_pagedata($pagename, array(':latestversion' => $newversion,
//':deleted' => empty($content)));
$backend->set_links($pagename, $links);
$backend->unlock();
// FIXME: probably should have some global state information in the backend
// to control when to optimize.
if (time() % 50 == 0) {
trigger_error('"Optimizing" backend', E_USER_NOTICE);
$backend->optimize();
}
return new WikiDB_PageRevision($this->_wikidb, $pagename, $newversion, $data);
}
/**
* Get the most recent revision of a page.
*
* @access public
*
* @return object The current WikiDB_PageRevision object.
*/
function getCurrentRevision() {
$backend = &$this->_wikidb->_backend;
$cache = &$this->_wikidb->_cache;
$pagename = &$this->_pagename;
$backend->lock();
$version = $backend->get_latest_version($pagename);
$revision = $this->getRevision($version);
$backend->unlock();
assert($revision);
return $revision;
}
/**
* Get a specific revision of a WikiDB_Page.
*
* @access public
*
* @param $version integer Which revision to get.
*
* @return object The requested WikiDB_PageRevision object, or false if the
* requested revision does not exist in the WikiDB. Note that
* version zero of any page always exists.
*/
function getRevision($version) {
$cache = &$this->_wikidb->_cache;
$pagename = &$this->_pagename;
if ($version == 0)
return new WikiDB_PageRevision($this->_wikidb, $pagename, 0);
assert($version > 0);
$vdata = $cache->get_versiondata($pagename, $version);
if (!$vdata)
return false;
return new WikiDB_PageRevision($this->_wikidb, $pagename, $version, $vdata);
}
/**
* Get previous page revision.
*
* This method find the most recent revision before a specified version.
*
* @access public
*
* @param $version integer Find most recent revision before this version.
* You can also use a WikiDB_PageRevision object to specify the $version.
*
* @return object The requested WikiDB_PageRevision object, or false if the
* requested revision does not exist in the WikiDB. Note that
* unless $version is greater than zero, a revision (perhaps version zero,
* the default revision) will always be found.
*/
function getRevisionBefore($version) {
$backend = &$this->_wikidb->_backend;
$pagename = &$this->_pagename;
$version = $this->_coerce_to_version($version);
if ($version == 0)
return false;
$backend->lock();
$previous = $backend->get_previous_version($pagename, $version);
$revision = $this->getRevision($previous);
$backend->unlock();
assert($revision);
return $revision;
}
/**
* Get all revisions of the WikiDB_Page.
*
* This does not include the version zero (default) revision in the
* returned revision set.
*
* @return object a WikiDB_PageRevisionIterator containing all revisions of
* this WikiDB_Page in reverse order by version number.
*/
function getAllRevisions() {
$backend = &$this->_wikidb->_backend;
$revs = $backend->get_all_revisions($this->_pagename);
return new WikiDB_PageRevisionIterator($this->_wikidb, $revs);
}
/**
* Find pages which link to or are linked from a page.
*
* @access public
*
* @param $reversed enum Which links to find: true for backlinks (default).
*
* @return object A WikiDB_PageIterator containing all matching pages.
*/
function getLinks($reversed = true) {
$backend = &$this->_wikidb->_backend;
$result = $backend->get_links($this->_pagename, $reversed);
return new WikiDB_PageIterator($this->_wikidb, $result);
}
/**
* Access WikiDB_Page meta-data.
*
* @access public
*
* @param $key string Which meta data to get.
* Some reserved meta-data keys are:
*
* - 'locked'
- Is page locked?
*
- 'hits'
- Page hit counter.
*
- 'score
- Page score (not yet implement, do we need?)
*
*
* @return scalar The requested value, or false if the requested data
* is not set.
*/
function get($key) {
$cache = &$this->_wikidb->_cache;
if (!$key || $key[0] == '%')
return false;
$data = $cache->get_pagedata($this->_pagename);
return isset($data[$key]) ? $data[$key] : false;
}
/**
* Get all the page meta-data as a hash.
*
* @return hash The page meta-data.
*/
function getMetaData() {
$cache = &$this->_wikidb->_cache;
$data = $cache->get_pagedata($this->_pagename);
$meta = array();
foreach ($data as $key => $val) {
if (!empty($val) && $key[0] != '%')
$meta[$key] = $val;
}
return $meta;
}
/**
* Set page meta-data.
*
* @see get
* @access public
*
* @param $key string Meta-data key to set.
* @param $newval string New value.
*/
function set($key, $newval) {
$cache = &$this->_wikidb->_cache;
$pagename = &$this->_pagename;
assert($key && $key[0] != '%');
$data = $cache->get_pagedata($pagename);
if (!empty($newval)) {
if (!empty($data[$key]) && $data[$key] == $newval)
return; // values identical, skip update.
}
else {
if (empty($data[$key]))
return; // values identical, skip update.
}
$cache->update_pagedata($pagename, array($key => $newval));
}
/**
* Increase page hit count.
*
* FIXME: IS this needed? Probably not.
*
* This is a convenience function.
* $page->increaseHitCount();
* is functionally identical to
* $page->set('hits',$page->get('hits')+1);
*
* Note that this method may be implemented in more efficient ways
* in certain backends.
*
* @access public
*/
function increaseHitCount() {
@$newhits = $this->get('hits') + 1;
$this->set('hits', $newhits);
}
/**
* Return a string representation of the WikiDB_Page
*
* This is really only for debugging.
*
* @access public
*
* @return string Printable representation of the WikiDB_Page.
*/
function asString () {
ob_start();
printf("[%s:%s\n", get_class($this), $this->getName());
print_r($this->getMetaData());
echo "]\n";
$strval = ob_get_contents();
ob_end_clean();
return $strval;
}
/**
* @access private
* @param $version_or_pagerevision int or object
* Takes either the version number (and int) or a WikiDB_PageRevision
* object.
* @return int The version number.
*/
function _coerce_to_version($version_or_pagerevision) {
if (method_exists($version_or_pagerevision, "getContent"))
$version = $version_or_pagerevision->getVersion();
else
$version = (int) $version_or_pagerevision;
assert($version >= 0);
return $version;
}
};
/**
* This class represents a specific revision of a WikiDB_Page within
* a WikiDB.
*
* A WikiDB_PageRevision has read-only semantics. You may only
* create new revisions (and delete old ones) --- you cannot
* modify existing revisions.
*/
class WikiDB_PageRevision
{
function WikiDB_PageRevision(&$wikidb, $pagename, $version, $versiondata = false) {
$this->_wikidb = &$wikidb;
$this->_pagename = $pagename;
$this->_version = $version;
$this->_data = $versiondata ? $versiondata : array();
}
/**
* Get the WikiDB_Page which this revision belongs to.
*
* @access public
*
* @return object The WikiDB_Page which this revision belongs to.
*/
function getPage() {
return new WikiDB_Page($this->_wikidb, $this->_pagename);
}
/**
* Get the version number of this revision.
*
* @access public
*
* @return int The version number of this revision.
*/
function getVersion() {
return $this->_version;
}
/**
* Determine whether this revision has defaulted content.
*
* The default revision (version 0) of each page, as well as
* any pages which are created with empty content
* have their content defaulted to something like:
*
* Describe [ThisPage] here.
*
*
* @access public
*
* @return boolean Returns true if the page has default content.
*/
function hasDefaultContents() {
$data = &$this->_data;
return empty($data['%content']);
}
/**
* Get the content as an array of lines.
*
* @access public
*
* @return array An array of lines.
* The lines should contain no trailing white space.
*/
function getContent() {
return explode("\n", $this->getPackedContent());
}
/**
* Get the content as a string.
*
* @access public
*
* @return string The page content.
* Lines are separated by new-lines.
*/
function getPackedContent() {
$data = &$this->_data;
if (empty($data['%content'])) {
// Replace empty content with default value.
return sprintf(gettext("Describe [%s] here."),
$this->_pagename);
}
// There is (non-default) content.
assert($this->_version > 0);
if (!is_string($data['%content'])) {
// Content was not provided to us at init time.
// (This is allowed because for some backends, fetching
// the content may be expensive, and often is not wanted
// by the user.)
//
// In any case, now we need to get it.
$data['%content'] = $this->_get_content();
assert(is_string($data['%content']));
}
return $data['%content'];
}
function _get_content() {
$cache = &$this->_wikidb->_cache;
$pagename = $this->_pagename;
$version = $this->_version;
assert($version > 0);
$newdata = $cache->get_versiondata($pagename, $version, true);
if ($newdata) {
assert(is_string($newdata['%content']));
return $newdata['%content'];
}
else {
// else revision has been deleted... What to do?
return "Acck! Revision $version of $pagename seems to have been deleted!";
}
}
/**
* Get meta-data for this revision.
*
*
* @access public
*
* @param $key string Which meta-data to access.
*
* Some reserved revision meta-data keys are:
*
* - 'mtime'
- Time this revision was created (seconds since midnight Jan 1, 1970.)
* The 'mtime' meta-value is normally set automatically by the database
* backend, but it may be specified explicitly when creating a new revision.
*
- orig_mtime
*
- To ensure consistency of RecentChanges, the mtimes of the versions
* of a page must be monotonically increasing. If an attempt is
* made to create a new revision with an mtime less than that of
* the preceeding revision, the new revisions timestamp is force
* to be equal to that of the preceeding revision. In that case,
* the originally requested mtime is preserved in 'orig_mtime'.
*
- '_supplanted'
- Time this revision ceased to be the most recent.
* This meta-value is always automatically maintained by the database
* backend. (It is set from the 'mtime' meta-value of the superceding
* revision.) '_supplanted' has a value of 'false' for the current revision.
*
* FIXME: this could be refactored:
*
- author
*
- Author of the page (as he should be reported in, e.g. RecentChanges.)
*
- author_id
*
- Authenticated author of a page. This is used to identify
* the distinctness of authors when cleaning old revisions from
* the database.
*
- 'is_minor_edit'
- Set if change was marked as a minor revision by the author.
*
- 'summary'
- Short change summary entered by page author.
*
*
* Meta-data keys must be valid C identifers (they have to start with a letter
* or underscore, and can contain only alphanumerics and underscores.)
*
* @return string The requested value, or false if the requested value
* is not defined.
*/
function get($key) {
if (!$key || $key[0] == '%')
return false;
$data = &$this->_data;
return isset($data[$key]) ? $data[$key] : false;
}
/**
* Get all the revision page meta-data as a hash.
*
* @return hash The revision meta-data.
*/
function getMetaData() {
$meta = array();
foreach ($this->_data as $key => $val) {
if (!empty($val) && $key[0] != '%')
$meta[$key] = $val;
}
return $meta;
}
/**
* Return a string representation of the revision.
*
* This is really only for debugging.
*
* @access public
*
* @return string Printable representation of the WikiDB_Page.
*/
function asString () {
ob_start();
printf("[%s:%d\n", get_class($this), $this->get('version'));
print_r($this->_data);
echo $this->getPackedContent() . "\n]\n";
$strval = ob_get_contents();
ob_end_clean();
return $strval;
}
};
/**
* A class which represents a sequence of WikiDB_Pages.
*/
class WikiDB_PageIterator
{
function WikiDB_PageIterator(&$wikidb, &$pages) {
$this->_pages = $pages;
$this->_wikidb = &$wikidb;
}
/**
* Get next WikiDB_Page in sequence.
*
* @access public
*
* @return object The next WikiDB_Page in the sequence.
*/
function next () {
if ( ! ($next = $this->_pages->next()) )
return false;
$pagename = &$next['pagename'];
if (isset($next['pagedata']))
$this->_wikidb->_cache->cache_data($next);
return new WikiDB_Page($this->_wikidb, $pagename);
}
/**
* Release resources held by this iterator.
*
* The iterator may not be used after free() is called.
*
* There is no need to call free(), if next() has returned false.
* (I.e. if you iterate through all the pages in the sequence,
* you do not need to call free() --- you only need to call it
* if you stop before the end of the iterator is reached.)
*
* @access public
*/
function free() {
$this->_pages->free();
}
};
/**
* A class which represents a sequence of WikiDB_PageRevisions.
*/
class WikiDB_PageRevisionIterator
{
function WikiDB_PageRevisionIterator(&$wikidb, &$revisions) {
$this->_revisions = $revisions;
$this->_wikidb = &$wikidb;
}
/**
* Get next WikiDB_PageRevision in sequence.
*
* @access public
*
* @return object The next WikiDB_PageRevision in the sequence.
*/
function next () {
if ( ! ($next = $this->_revisions->next()) )
return false;
$this->_wikidb->_cache->cache_data($next);
$pagename = $next['pagename'];
$version = $next['version'];
$versiondata = $next['versiondata'];
assert(!empty($pagename));
assert(is_array($versiondata));
assert($version > 0);
return new WikiDB_PageRevision($this->_wikidb, $pagename, $version, $versiondata);
}
/**
* Release resources held by this iterator.
*
* The iterator may not be used after free() is called.
*
* There is no need to call free(), if next() has returned false.
* (I.e. if you iterate through all the revisions in the sequence,
* you do not need to call free() --- you only need to call it
* if you stop before the end of the iterator is reached.)
*
* @access public
*/
function free() {
$this->_revisions->free();
}
};
/**
* Data cache used by WikiDB.
*
* FIXME: Maybe rename this to caching_backend (or some such).
*
* @access protected
*/
class WikiDB_cache
{
// FIXME: cache (limited) version data, too.
function WikiDB_cache (&$backend) {
$this->_backend = &$backend;
$this->_pagedata_cache = array();
}
function close() {
$this->_pagedata_cache = false;
}
function get_pagedata($pagename) {
assert(is_string($pagename) && $pagename);
$cache = &$this->_pagedata_cache;
if (!isset($cache[$pagename]) || !is_array($cache[$pagename])) {
$cache[$pagename] = $this->_backend->get_pagedata($pagename);
if (empty($cache[$pagename]))
$cache[$pagename] = array();
}
return $cache[$pagename];
}
function update_pagedata($pagename, $newdata) {
assert(is_string($pagename) && $pagename);
$this->_backend->update_pagedata($pagename, $newdata);
if (is_array($this->_pagedata_cache[$pagename])) {
$cachedata = &$this->_pagedata_cache[$pagename];
foreach($newdata as $key => $val)
$cachedata[$key] = $val;
}
}
function invalidate_cache($pagename) {
$this->_pagedata_cache[$pagename] = false;
}
function delete_page($pagename) {
$this->_backend->delete_page($pagename);
$this->_pagedata_cache[$pagename] = false;
}
// FIXME: ugly
function cache_data($data) {
if (isset($data['pagedata']))
$this->_pagedata_cache[$data['pagename']] = $data['pagedata'];
}
function get_versiondata($pagename, $version, $need_content = false) {
$vdata = $this->_backend->get_versiondata($pagename, $version, $need_content);
// FIXME: ugly
if ($vdata && !empty($vdata['%pagedata']))
$this->_pagedata_cache[$pagename] = $vdata['%pagedata'];
return $vdata;
}
function set_versiondata($pagename, $version, $data) {
$new = $this->_backend->
set_versiondata($pagename, $version, $data);
}
function update_versiondata($pagename, $version, $data) {
$new = $this->_backend->
update_versiondata($pagename, $version, $data);
}
function delete_versiondata($pagename, $version) {
$new = $this->_backend->
delete_versiondata($pagename, $version);
}
};
// Local Variables:
// mode: php
// tab-width: 8
// c-basic-offset: 4
// c-hanging-comment-ender-p: nil
// indent-tabs-mode: nil
// End:
?>