<?php
rcs_id('$Id$');
/*
Database functions:
OpenDataBase($dbname)
CloseDataBase($dbi)
PadSerializedData($data)
UnPadSerializedData($data)
RetrievePage($dbi, $pagename, $pagestore)
InsertPage($dbi, $pagename, $pagehash)
SaveCopyToArchive($dbi, $pagename, $pagehash)
IsWikiPage($dbi, $pagename)
IsInArchive($dbi, $pagename)
InitTitleSearch($dbi, $search)
TitleSearchNextMatch($dbi, &$pos)
InitFullSearch($dbi, $search)
FullSearchNextMatch($dbi, &$pos)
MakeBackLinkSearchRegexp($pagename)
InitBackLinkSearch($dbi, $pagename)
BackLinkSearchNextMatch($dbi, &$pos)
IncreaseHitCount($dbi, $pagename)
GetHitCount($dbi, $pagename)
InitMostPopular($dbi, $limit)
MostPopularNextMatch($dbi, &$res)
GetAllWikiPagenames($dbi)
*/
// open a database and return the handle
// loop until we get a handle; php has its own
// locking mechanism, thank god.
// Suppress ugly error message with @.
function OpenDataBase($dbname) {
global $WikiDB; // hash of all the DBM file names
reset($WikiDB);
while (list($key, $file) = each($WikiDB)) {
while (($dbi[$key] = @dba_open($file, "c", DBM_FILE_TYPE)) < 1) {
$numattempts++;
if ($numattempts > MAX_DBM_ATTEMPTS) {
ExitWiki("Cannot open database '$key' : '$file', giving up.");
}
sleep(1);
}
}
return $dbi;
}
function CloseDataBase($dbi) {
reset($dbi);
while (list($dbmfile, $dbihandle) = each($dbi)) {
dba_close($dbihandle);
}
return;
}
// take a serialized hash, return same padded out to
// the next largest number bytes divisible by 500. This
// is to save disk space in the long run, since DBM files
// leak memory.
function PadSerializedData($data) {
// calculate the next largest number divisible by 500
$nextincr = 500 * ceil(strlen($data) / 500);
// pad with spaces
$data = sprintf("%-${nextincr}s", $data);
return $data;
}
// strip trailing whitespace from the serialized data
// structure.
function UnPadSerializedData($data) {
return chop($data);
}
// Return hash of page + attributes or default
function RetrievePage($dbi, $pagename, $pagestore) {
if ($data = dba_fetch($pagename, $dbi[$pagestore])) {
// unserialize $data into a hash
$pagehash = unserialize(UnPadSerializedData($data));
$pagehash['pagename'] = $pagename;
return $pagehash;
} else {
return -1;
}
}
// Either insert or replace a key/value (a page)
function InsertPage($dbi, $pagename, $pagehash) {
$pagedata = PadSerializedData(serialize($pagehash));
if (!dba_insert($pagename, $pagedata, $dbi['wiki'])) {
if (!dba_replace($pagename, $pagedata, $dbi['wiki'])) {
ExitWiki("Error inserting page '$pagename'");
}
}
}
// for archiving pages to a seperate dbm
function SaveCopyToArchive($dbi, $pagename, $pagehash) {
global $ArchivePageStore;
$pagedata = PadSerializedData(serialize($pagehash));
if (!dba_insert($pagename, $pagedata, $dbi[$ArchivePageStore])) {
if (!dba_replace($pagename, $pagedata, $dbi['archive'])) {
ExitWiki("Error storing '$pagename' into archive");
}
}
}
function IsWikiPage($dbi, $pagename) {
return dba_exists($pagename, $dbi['wiki']);
}
function IsInArchive($dbi, $pagename) {
return dba_exists($pagename, $dbi['archive']);
}
// setup for title-search
function InitTitleSearch($dbi, $search) {
$pos['search'] = '=' . preg_quote($search) . '=i';
$pos['key'] = dba_firstkey($dbi['wiki']);
return $pos;
}
// iterating through database
function TitleSearchNextMatch($dbi, &$pos) {
while ($pos['key']) {
$page = $pos['key'];
$pos['key'] = dba_nextkey($dbi['wiki']);
if (preg_match($pos['search'], $page)) {
return $page;
}
}
return 0;
}
// setup for full-text search
function InitFullSearch($dbi, $search) {
return InitTitleSearch($dbi, $search);
}
//iterating through database
function FullSearchNextMatch($dbi, &$pos) {
while ($pos['key']) {
$key = $pos['key'];
$pos['key'] = dba_nextkey($dbi['wiki']);
$pagedata = dba_fetch($key, $dbi['wiki']);
// test the serialized data
if (preg_match($pos['search'], $pagedata)) {
$page['pagename'] = $key;
$pagedata = unserialize(UnPadSerializedData($pagedata));
$page['content'] = $pagedata['content'];
return $page;
}
}
return 0;
}
////////////////////////
// new database features
// Compute PCRE suitable for searching for links to the given page.
function MakeBackLinkSearchRegexp($pagename) {
global $WikiNameRegexp;
$quoted_pagename = preg_quote($pagename, '/');
if (preg_match("/^$WikiNameRegexp\$/", $pagename)) {
// FIXME: This may need modification for non-standard (non-english) $WikiNameRegexp.
return "/(?<![A-Za-z0-9!])$quoted_pagename(?![A-Za-z0-9])/";
}
else {
// Note from author: Sorry. :-/
return ( '/'
. '(?<!\[)\[(?!\[)' // Single, isolated '['
. '([^]|]*\|)?' // Optional stuff followed by '|'
. '\s*' // Optional space
. $quoted_pagename // Pagename
. '\s*\]/' ); // Optional space, followed by ']'
// FIXME: the above regexp is still not quite right.
// Consider the text: " [ [ test page ]". This is a link to a page
// named '[ test page'. The above regexp will recognize this
// as a link either to '[ test page' (good) or to 'test page' (wrong).
}
}
// setup for back-link search
function InitBackLinkSearch($dbi, $pagename) {
$pos['search'] = MakeBackLinkSearchRegexp($pagename);
$pos['key'] = dba_firstkey($dbi['wiki']);
return $pos;
}
// iterating through back-links
function BackLinkSearchNextMatch($dbi, &$pos) {
while ($pos['key']) {
$page = $pos['key'];
$pos['key'] = dba_nextkey($dbi['wiki']);
$rawdata = dba_fetch($page, $dbi['wiki']);
if ( ! preg_match($pos['search'], $rawdata))
continue;
$pagedata = unserialize(UnPadSerializedData($rawdata));
while (list($i, $line) = each($pagedata['content'])) {
if (preg_match($pos['search'], $line))
return $page;
}
}
return 0;
}
function IncreaseHitCount($dbi, $pagename) {
if (dba_exists($pagename, $dbi['hitcount'])) {
// increase the hit count
// echo "$pagename there, incrementing...<br>\n";
$count = dba_fetch($pagename, $dbi['hitcount']);
$count++;
dba_replace($pagename, $count, $dbi['hitcount']);
} else {
// add it, set the hit count to one
// echo "adding $pagename to hitcount...<br>\n";
$count = 1;
dba_insert($pagename, $count, $dbi['hitcount']);
}
}
function GetHitCount($dbi, $pagename) {
if (dba_exists($pagename, $dbi['hitcount'])) {
// increase the hit count
$count = dba_fetch($pagename, $dbi['hitcount']);
return $count;
} else {
return 0;
}
}
function InitMostPopular($dbi, $limit) {
// iterate through the whole dbm file for hit counts
// sort the results highest to lowest, and return
// n..$limit results
$pagename = dba_firstkey($dbi['hitcount']);
$res[$pagename] = dba_fetch($pagename, $dbi['hitcount']);
while ($pagename = dba_nextkey($dbi['hitcount'])) {
$res[$pagename] = dba_fetch($pagename, $dbi['hitcount']);
//echo "got $pagename with value " . $res[$pagename] . "<br>\n";
}
arsort($res);
return($res);
}
function MostPopularNextMatch($dbi, &$res) {
// the return result is a two element array with 'hits'
// and 'pagename' as the keys
if (count($res) == 0)
return 0;
if (list($pagename, $hits) = each($res)) {
//echo "most popular next match called<br>\n";
//echo "got $pagename, $hits back<br>\n";
$nextpage = array(
"hits" => $hits,
"pagename" => $pagename
);
// $dbm_mostpopular_cntr++;
return $nextpage;
} else {
return 0;
}
}
function GetAllWikiPagenames($dbi) {
$namelist = array();
$ctr = 0;
$namelist[$ctr] = $key = dba_firstkey($dbi);
while ($key = dba_nextkey($dbi)) {
$ctr++;
$namelist[$ctr] = $key;
}
return $namelist;
}
?>
