"function readInt($file)\n"
"{\n"
" $b1 = ord(fgetc($file)); $b2 = ord(fgetc($file));\n"
" $b3 = ord(fgetc($file)); $b4 = ord(fgetc($file));\n"
" return ($b1<<24)|($b2<<16)|($b3<<8)|$b4;\n"
"}\n"
"\n"
"function readString($file)\n"
"{\n"
" $result=\"\";\n"
" while (ord($c=fgetc($file))) $result.=$c;\n"
" return $result;\n"
"}\n"
"\n"
"function readHeader($file)\n"
"{\n"
" $header =fgetc($file); $header.=fgetc($file);\n"
" $header.=fgetc($file); $header.=fgetc($file);\n"
" return $header;\n"
"}\n"
"\n"
"function computeIndex($word)\n"
"{\n"
" // Simple hashing that allows for substring search\n"
" if (strlen($word)<2) return -1;\n"
" // high char of the index\n"
" $hi = ord($word{0});\n"
" if ($hi==0) return -1;\n"
" // low char of the index\n"
" $lo = ord($word{1});\n"
" if ($lo==0) return -1;\n"
" // return index\n"
" return $hi*256+$lo;\n"
"}\n"
"\n"
"function search($file,$word,&$statsList)\n"
"{\n"
" $index = computeIndex($word);\n"
" if ($index!=-1) // found a valid index\n"
" {\n"
" fseek($file,$index*4+4); // 4 bytes per entry, skip header\n"
" $index = readInt($file);\n"
" if ($index) // found words matching the hash key\n"
" {\n"
" $start=sizeof($statsList);\n"
" $count=$start;\n"
" fseek($file,$index);\n"
" $w = readString($file);\n"
" while ($w)\n"
" {\n"
" $statIdx = readInt($file);\n"
" if ($word==substr($w,0,strlen($word)))\n"
" { // found word that matches (as substring)\n"
" $statsList[$count++]=array(\n"
" \"word\"=>$word,\n"
" \"match\"=>$w,\n"
" \"index\"=>$statIdx,\n"
" \"full\"=>strlen($w)==strlen($word),\n"
" \"docs\"=>array()\n"
" );\n"
" }\n"
" $w = readString($file);\n"
" }\n"
" $totalHi=0;\n"
" $totalFreqHi=0;\n"
" $totalFreqLo=0;\n"
" for ($count=$start;$count<sizeof($statsList);$count++)\n"
" {\n"
" $statInfo = &$statsList[$count];\n"
" $multiplier = 1;\n"
" // whole word matches have a double weight\n"
" if ($statInfo[\"full\"]) $multiplier=2;\n"
" fseek($file,$statInfo[\"index\"]); \n"
" $numDocs = readInt($file);\n"
" $docInfo = array();\n"
" // read docs info + occurrence frequency of the word\n"
" for ($i=0;$i<$numDocs;$i++)\n"
" {\n"
" $idx=readInt($file); \n"
" $freq=readInt($file); \n"
" $docInfo[$i]=array(\"idx\" => $idx,\n"
" \"freq\" => $freq>>1,\n"
" \"rank\" => 0.0,\n"
" \"hi\" => $freq&1\n"
" );\n"
" if ($freq&1) // word occurs in high priority doc\n"
" {\n"
" $totalHi++;\n"
" $totalFreqHi+=$freq*$multiplier;\n"
" }\n"
" else // word occurs in low priority doc\n"
" {\n"
" $totalFreqLo+=$freq*$multiplier;\n"
" }\n"
" }\n"
" // read name and url info for the doc\n"
" for ($i=0;$i<$numDocs;$i++)\n"
" {\n"
" fseek($file,$docInfo[$i][\"idx\"]);\n"
" $docInfo[$i][\"name\"]=readString($file);\n"
" $docInfo[$i][\"url\"]=readString($file);\n"
" }\n"
" $statInfo[\"docs\"]=$docInfo;\n"
" }\n"
" $totalFreq=($totalHi+1)*$totalFreqLo + $totalFreqHi;\n"
" for ($count=$start;$count<sizeof($statsList);$count++)\n"
" {\n"
" $statInfo = &$statsList[$count];\n"
" $multiplier = 1;\n"
" // whole word matches have a double weight\n"
" if ($statInfo[\"full\"]) $multiplier=2;\n"
" for ($i=0;$i<sizeof($statInfo[\"docs\"]);$i++)\n"
" {\n"
" $docInfo = &$statInfo[\"docs\"];\n"
" // compute frequency rank of the word in each doc\n"
" $freq=$docInfo[$i][\"freq\"];\n"
" if ($docInfo[$i][\"hi\"])\n"
" {\n"
" $statInfo[\"docs\"][$i][\"rank\"]=\n"
" (float)($freq*$multiplier+$totalFreqLo)/$totalFreq;\n"
" }\n"
" else\n"
" {\n"
" $statInfo[\"docs\"][$i][\"rank\"]=\n"
" (float)($freq*$multiplier)/$totalFreq;\n"
" }\n"
" }\n"
" }\n"
" }\n"
" }\n"
" return $statsList;\n"
"}\n"
"\n"
"function combine_results($results,&$docs)\n"
"{\n"
" foreach ($results as $wordInfo)\n"
" {\n"
" $docsList = &$wordInfo[\"docs\"];\n"
" foreach ($docsList as $di)\n"
" {\n"
" $key=$di[\"url\"];\n"
" $rank=$di[\"rank\"];\n"
" if (in_array($key, array_keys($docs)))\n"
" {\n"
" $docs[$key][\"rank\"]+=$rank;\n"
" }\n"
" else\n"
" {\n"
" $docs[$key] = array(\"url\"=>$key,\n"
" \"name\"=>$di[\"name\"],\n"
" \"rank\"=>$rank\n"
" );\n"
" }\n"
" $docs[$key][\"words\"][] = array(\n"
" \"word\"=>$wordInfo[\"word\"],\n"
" \"match\"=>$wordInfo[\"match\"],\n"
" \"freq\"=>$di[\"freq\"]\n"
" );\n"
" }\n"
" }\n"
" return $docs;\n"
"}\n"
"\n"
"function filter_results($docs,&$requiredWords,&$forbiddenWords)\n"
"{\n"
" $filteredDocs=array();\n"
" while (list ($key, $val) = each ($docs)) \n"
" {\n"
" $words = &$docs[$key][\"words\"];\n"
" $copy=1; // copy entry by default\n"
" if (sizeof($requiredWords)>0)\n"
" {\n"
" foreach ($requiredWords as $reqWord)\n"
" {\n"
" $found=0;\n"
" foreach ($words as $wordInfo)\n"
" { \n"
" $found = $wordInfo[\"word\"]==$reqWord;\n"
" if ($found) break;\n"
" }\n"
" if (!$found) \n"
" {\n"
" $copy=0; // document contains none of the required words\n"
" break;\n"
" }\n"
" }\n"
" }\n"
" if (sizeof($forbiddenWords)>0)\n"
" {\n"
" foreach ($words as $wordInfo)\n"
" {\n"
" if (in_array($wordInfo[\"word\"],$forbiddenWords))\n"
" {\n"
" $copy=0; // document contains a forbidden word\n"
" break;\n"
" }\n"
" }\n"
" }\n"
" if ($copy) $filteredDocs[$key]=$docs[$key];\n"
" }\n"
" return $filteredDocs;\n"
"}\n"
"\n"
"function compare_rank($a,$b)\n"
"{\n"
" if ($a[\"rank\"] == $b[\"rank\"]) \n"
" {\n"
" return 0;\n"
" }\n"
" return ($a[\"rank\"]>$b[\"rank\"]) ? -1 : 1; \n"
"}\n"
"\n"
"function sort_results($docs,&$sorted)\n"
"{\n"
" $sorted = $docs;\n"
" usort($sorted,\"compare_rank\");\n"
" return $sorted;\n"
"}\n"
"\n"
"function report_results(&$docs)\n"
"{\n"
" echo \"<table cellspacing=\\\"2\\\">\\n\";\n"
" echo \" <tr>\\n\";\n"
" echo \" <td colspan=\\\"2\\\"><h2>\".search_results().\"</h2></td>\\n\";\n"
" echo \" </tr>\\n\";\n"
" $numDocs = sizeof($docs);\n"
" if ($numDocs==0)\n"
" {\n"
" echo \" <tr>\\n\";\n"
" echo \" <td colspan=\\\"2\\\">\".matches_text(0).\"</td>\\n\";\n"
" echo \" </tr>\\n\";\n"
" }\n"
" else\n"
" {\n"
" echo \" <tr>\\n\";\n"
" echo \" <td colspan=\\\"2\\\">\".matches_text($numDocs);\n"
" echo \"\\n\";\n"
" echo \" </td>\\n\";\n"
" echo \" </tr>\\n\";\n"
" $num=1;\n"
" foreach ($docs as $doc)\n"
" {\n"
" echo \" <tr>\\n\";\n"
" echo \" <td align=\\\"right\\\">$num.</td>\";\n"
" echo \"<td><a class=\\\"el\\\" href=\\\"\".$doc[\"url\"].\"\\\">\".$doc[\"name\"].\"</a></td>\\n\";\n"
" echo \" <tr>\\n\";\n"
" echo \" <td></td><td class=\\\"tiny\\\">\".report_matches().\" \";\n"
" foreach ($doc[\"words\"] as $wordInfo)\n"
" {\n"
" $word = $wordInfo[\"word\"];\n"
" $matchRight = substr($wordInfo[\"match\"],strlen($word));\n"
" echo \"<b>$word</b>$matchRight(\".$wordInfo[\"freq\"].\") \";\n"
" }\n"
" echo \" </td>\\n\";\n"
" echo \" </tr>\\n\";\n"
" $num++;\n"
" }\n"
" }\n"
" echo \"</table>\\n\";\n"
"}\n"
"\n"
"function main()\n"
"{\n"
" if(strcmp('4.1.0', phpversion()) > 0) \n"
" {\n"
" die(\"Error: PHP version 4.1.0 or above required!\");\n"
" }\n"
" if (!($file=fopen(\"search/search.idx\",\"rb\"))) \n"
" {\n"
" die(\"Error: Search index file could NOT be opened!\");\n"
" }\n"
" if (readHeader($file)!=\"DOXS\")\n"
" {\n"
" die(\"Error: Header of index file is invalid!\");\n"
" }\n"
" $query=\"\";\n"
" if (array_key_exists(\"query\", $_GET))\n"
" {\n"
" $query=$_GET[\"query\"];\n"
" }\n"
" end_form(preg_replace(\"/[^a-zA-Z0-9\\-\\_\\.]/i\", \" \", $query ));\n"
" echo \" \\n<div class=\\\"searchresults\\\">\\n\";\n"
" $results = array();\n"
" $requiredWords = array();\n"
" $forbiddenWords = array();\n"
" $foundWords = array();\n"
" $word=strtok($query,\" \");\n"
" while ($word) // for each word in the search query\n"
" {\n"
" if (($word{0}=='+')) { $word=substr($word,1); $requiredWords[]=$word; }\n"
" if (($word{0}=='-')) { $word=substr($word,1); $forbiddenWords[]=$word; }\n"
" if (!in_array($word,$foundWords))\n"
" {\n"
" $foundWords[]=$word;\n"
" search($file,strtolower($word),$results);\n"
" }\n"
" $word=strtok(\" \");\n"
" }\n"
" $docs = array();\n"
" combine_results($results,$docs);\n"
" // filter out documents with forbidden word or that do not contain\n"
" // required words\n"
" $filteredDocs = filter_results($docs,$requiredWords,$forbiddenWords);\n"
" // sort the results based on rank\n"
" $sorted = array();\n"
" sort_results($filteredDocs,$sorted);\n"
" // report results to the user\n"
" report_results($sorted);\n"
" echo \"</div>\\n\";\n"
" fclose($file);\n"
"}\n"
"\n"
"main();\n"
"\n"