<?php
/**
* SeekQuarry/Yioop --
* Open Source Pure PHP Search Engine, Crawler, and Indexer
*
* Copyright (C) 2009 - 2023 Chris Pollett chris@pollett.org
*
* LICENSE:
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*
* END LICENSE
*
* @author Chris Pollett chris@pollett.org
* @license https://www.gnu.org/licenses/ GPL3
* @link https://www.seekquarry.com/
* @copyright 2009 - 2023
* @filesource
*/
namespace seekquarry\yioop\models;
use seekquarry\yioop\configs as C;
use seekquarry\yioop\library as L;
use seekquarry\yioop\library\CrawlConstants;
use seekquarry\yioop\library\FetchUrl;
use seekquarry\yioop\library\UrlParser;
/** For crawlHash function and Yioop Project constants */
require_once __DIR__."/../library/Utility.php";
/**
*
* This is a base class for all models
* in the SeekQuarry search engine. It provides
* support functions for formatting search results
*
* @author Chris Pollett
*/
class Model implements CrawlConstants
{
const SNIPPET_TITLE_LENGTH = 20;
const MAX_SNIPPET_TITLE_LENGTH = 20;
const SNIPPET_LENGTH_LEFT = 20;
const SNIPPET_LENGTH_RIGHT = 40;
const MIN_SNIPPET_LENGTH = 100;
/**
* Default maximum character length of a search summary
*/
const DEFAULT_DESCRIPTION_LENGTH = 150;
/** Reference to a DatasourceManager
* @var object
*/
public $db;
/** Name of the search engine database
* @var string
*/
public $db_name;
/** Reference to a private DatasourceManager
* @var object
*/
public $private_db;
/** Name of the private search engine database
* @var string
*/
public $private_db_name;
/**
* Associative array of page summaries which might be used to
* override default page summaries if set.
* @var array
*/
public $edited_page_summaries = null;
/**
* These fields if present in $search_array (used by @see getRows() ),
* but with value "-1", will be skipped as part of the where clause
* but will be used for order by clause
* @var array
*/
public $any_fields = [];
/**
* Associations of the form
* name of field for web forms => database column names/abbreviations
* @var array
*/
public $search_table_column_map = [];
/** Reference to a WebSite object in use to serve pages (if any)
* @var object
*/
public $web_site;
/**
* Cache object to be used if we are doing caching
* @var object
*/
public static $cache;
/**
* Sets up the database manager that will be used and name of the search
* engine database
*
* @param string $db_name the name of the database for the search engine
* @param bool $connect whether to connect to the database by default
* after making the datasource class
* @param WebSite an optional object that might be used to serve webpages
* when Yioop run in CLI mode. This object has fileGetContents and
* filePutContents methods which allow RAM caching of files.
*/
public function __construct($db_name = C\DB_NAME, $connect = true,
$web_site = null)
{
$db_class = C\NS_DATASOURCES . ucfirst(C\DBMS). "Manager";
$private_db_class = C\NS_DATASOURCES . ucfirst(C\PRIVATE_DBMS).
"Manager";
$this->db = new $db_class();
$this->private_db = new $private_db_class();
if ($connect) {
$this->db->connect();
$this->private_db->connect(C\PRIVATE_DB_HOST, C\PRIVATE_DB_USER,
C\PRIVATE_DB_PASSWORD, C\PRIVATE_DB_NAME);
}
$this->db_name = $db_name;
$this->private_db_name = C\PRIVATE_DB_NAME;
$this->web_site = $web_site;
}
/**
* Either a wrapper for file_get_contents, or if a WebSite object is being
* used to serve pages, it reads it in using blocking I/O
* file_get_contents() and caches it before return its string contents.
* Note this function assumes that only the web server is performing I/O
* with this file. filemtime() can be used to see if a file on disk has been
* changed and then you can use $force_read = true below to force re-
* reading the file into the cache
*
* @param string $filename name of file to get contents of
* @param bool $force_read whether to force the file to be read from
* persistent storage rather than the cache
* @return string contents of the file given by $filename
*/
public function fileGetContents($filename, $force_read = false)
{
if (!empty($this->web_site)) {
return $this->web_site->fileGetContents($filename, $force_read);
}
return file_get_contents($filename);
}
/**
* Either a wrapper for file_put_contents, or if a WebSite object is being
* used to serve pages, writes $data to the persistent file with name
* $filename. Saves a copy in the RAM cache if there is a copy already
* there.
*
* @param string $filename name of file to write to persistent storages
* @param string $data string of data to store in file
*/
public function filePutContents($filename, $data)
{
if (!empty($this->web_site)) {
return $this->web_site->filePutContents($filename, $data);
}
return file_put_contents($filename, $data);
}
/**
* Creates a directory and sets it to world permission if it doesn't
* already exist
*
* @param string $directory name of directory to create
* @return int -1 on failure, 0 if already existed, 1 if created
*/
public function createIfNecessaryDirectory($directory)
{
if (file_exists($directory)) {
return 0;
} else {
set_error_handler(null);
@mkdir($directory);
@chmod($directory, 0777);
set_error_handler(C\NS_CONFIGS . "yioop_error_handler");
}
if (file_exists($directory)) {
return 1;
}
return -1;
}
/**
* Given a page summary, extracts snippets which
* are related to a set of search words. For each snippet, bold faces the
* search terms, and then creates a new summary array.
*
* @param array $page a single search result summary
* @param array $words keywords (typically what was searched on)
* @param int $description_length length of the description
* @return array $page which has been snippified and bold faced
*/
public function formatSinglePageResult($page, $words = null,
$description_length = self::DEFAULT_DESCRIPTION_LENGTH)
{
if (empty($page[self::TITLE])) {
$page[self::TITLE] = "";
}
$page[self::TITLE] = strip_tags($page[self::TITLE]);
$page[self::DESCRIPTION] = strip_tags(
preg_replace("/\<\s+([a-zA-Z])/", '<$1',
$page[self::DESCRIPTION]));
if (strlen($page[self::TITLE]) == 0) {
$offset = min(mb_strlen($page[self::DESCRIPTION]),
self::SNIPPET_TITLE_LENGTH);
$end_title = mb_strpos($page[self::DESCRIPTION], " ", $offset);
$ellipsis = "";
if ($end_title > self::SNIPPET_TITLE_LENGTH) {
$ellipsis = "...";
if ($end_title > self::MAX_SNIPPET_TITLE_LENGTH) {
$end_title = self::MAX_SNIPPET_TITLE_LENGTH;
}
}
$page[self::TITLE] = mb_substr($page[self::DESCRIPTION], 0,
$end_title) . $ellipsis;
//still no text revert to url
if (strlen($page[self::TITLE]) == 0 &&
isset($page[self::URL])) {
$page[self::TITLE] = $page[self::URL];
}
}
// do a little cleaning on text
if ($words != null) {
$page[self::TITLE] =
$this->boldKeywords($page[self::TITLE], $words);
if (!isset($page[self::IS_FEED])) {
$page[self::DESCRIPTION] =
$this->getSnippets($page[self::DESCRIPTION],
$words, $description_length);
}
$page[self::DESCRIPTION] =
$this->boldKeywords($page[self::DESCRIPTION], $words);
} else {
$page[self::DESCRIPTION] = mb_substr($page[self::DESCRIPTION],
0, $description_length);
$test_snippet = preg_replace('/[^\s]+$/u', "",
$page[self::DESCRIPTION]);
if(!empty($test_snippet)) {
$page[self::DESCRIPTION] = $test_snippet;
}
}
$page[self::TITLE] = trim($page[self::TITLE], " .");
$pre_description = preg_replace("/\p{C}+|^[^\p{L}]+/u", "",
$page[self::DESCRIPTION]);
$page[self::DESCRIPTION] = (substr($pre_description, 0, 2) == "b>") ?
"<" . $pre_description : $pre_description;
return $page;
}
/**
* Given a string, extracts a snippets of text related to a given set of
* key words. For a given word a snippet is a window of characters to its
* left and right that is less than a maximum total number of characters.
* There is also a rule that a snippet should avoid ending in the middle of
* a word
*
* @param string $text haystack to extract snippet from
* @param array $words keywords used to make look in haystack
* @param string $description_length length of the description desired
* @return string a concatenation of the extracted snippets of each word
*/
public function getSnippets($text, $words, $description_length)
{
static $search_words = [];
static $last_words = "";
static $word_regex = "";
if (mb_strlen($text) < $description_length) {
return $text;
}
if (empty($words)) {
$snippet_string = mb_substr($text, 0, $description_length);
$rpos = strrpos($snippet_string, " ");
if ($rpos) {
$snippet_string = mb_substr($snippet_string, 0, $rpos);
}
return $snippet_string;
}
$word_string = implode(" ", $words);
$words_change = false;
if ($word_string != $last_words) {
$words_change = true;
$last_words = $word_string;
}
$start_regex = "/";
$left = self::SNIPPET_LENGTH_LEFT;
$left3 = $left - 3;
$right = self::SNIPPET_LENGTH_RIGHT;
//note we don't want ' to count as the cause of a word boundary
$start_regex2 = "/\b(\w{3}.{0,$left3})?(?:(?:";
$end_regex = "/ui";
$end_regex2 = ").{0,$right}\b)+/ui";
$ellipsis = "";
if ($words_change || empty($search_words)) {
// original list of words might have had space separated phrases;
$search_words = array_filter(array_unique(
explode(" ", $word_string)));
$word_regex = "";
$delim = "";
foreach ($search_words as $word) {
//term must start on word boundary and end within 3 chars of one
$word_regex .= $delim . "\b" . preg_quote($word, '/') .
".{0,3}?\b";
$delim = "|";
}
}
$snippet_string = "";
$text_sources = array_filter(array_unique(explode(".. ", $text)));
foreach ($text_sources as $text_source) {
$len = mb_strlen($text_source);
$offset = 0;
if ($len < self::MIN_SNIPPET_LENGTH) {
if (preg_match($start_regex . $word_regex .
$end_regex, $text_source, $match)) {
if (stristr($snippet_string, $text_source) === false) {
$snippet_string .= $ellipsis . $text_source;
$ellipsis = " ... ";
}
}
} else {
preg_match_all($start_regex2 . $word_regex . $end_regex2,
$text_source, $matches);
if (isset($matches[0])) {
$seen_match = [];
foreach ($matches[0] as $match) {
$match = trim($match, ".");
if (stristr($snippet_string, $match) === false) {
$snippet_string .= $ellipsis. $match;
$ellipsis = " ... ";
if (mb_strlen($snippet_string) >=
$description_length) {
break;
}
}
}
}
}
if (mb_strlen($snippet_string) >= $description_length) {
$snippet_string = mb_substr($snippet_string, 0,
$description_length);
$test_snippet = preg_replace('/[^\s]+$/', "",
$snippet_string);
if(!empty($test_snippet)) {
$snippet_string = $test_snippet;
}
break;
}
}
return $snippet_string;
}
/**
* Given a string, wraps in bold html tags a set of key words it contains.
*
* @param string $text haystack string to look for the key words
* @param array $words an array of words to bold face
*
* @return string the resulting string after boldfacing has been applied
*/
public function boldKeywords($text, $words)
{
$words = array_unique($words);
foreach ($words as $word) {
if ($word != "" && !stristr($word, "/")) {
$pattern = '/(\b)(' . preg_quote($word, '/').'.{0,3}?)(\b)/i';
$new_text = preg_replace($pattern, '$1<b>$2</b>$3', $text);
$text = $new_text;
}
}
return $text;
}
/**
* Gets a list of all DBMS that work with the search engine
*
* @return array Names of available data sources
*/
public function getDbmsList()
{
$list = [];
$data_managers = glob(C\BASE_DIR.'/models/datasources/*Manager.php');
foreach ($data_managers as $data_manager) {
$dbms =
substr($data_manager,
strlen(C\BASE_DIR.'/models/datasources/'), -
strlen("Manager.php"));
if ($dbms != 'Datasource') {
$list[] = $dbms;
}
}
return $list;
}
/**
* Returns whether the provided dbms needs a login and password or not
* (sqlite or sqlite3)
*
* @param string $dbms the name of a database management system
* @return bool true if needs a login and password; false otherwise
*/
public function loginDbms($dbms)
{
return !in_array($dbms, ["Sqlite3"]);
}
/**
* Used to determine if an action involves just one yioop instance on
* the current local machine or not
*
* @param array $machine_urls urls of yioop instances to which the action
* applies
* @param string $index_timestamp if timestamp exists checks if the index
* has declared itself to be a no network index.
* @return bool whether it involves a single local yioop instance (true)
* or not (false)
*/
public function isSingleLocalhost($machine_urls, $index_timestamp = -1)
{
if ($index_timestamp >= 0) {
$index_archive_name = self::index_data_base_name . $index_timestamp;
if (file_exists(C\CRAWL_DIR .
"/cache/$index_archive_name/no_network.txt")) {
return true;
}
}
$name_path = UrlParser::getPath(C\NAME_SERVER);
foreach ($machine_urls as $url) {
if (!UrlParser::isLocalhostUrl($url) ||
$name_path != UrlParser::getPath($url)) {
return false;
}
}
if (is_array($machine_urls) && count($machine_urls) == 1 &&
C\NAME_SERVER == $machine_urls[0]) {
$mirror_table_name = C\CRAWL_DIR . "/" . self::mirror_table_name;
if (file_exists($mirror_table_name) &&
time() - filemtime($mirror_table_name) <
2 * C\MIRROR_NOTIFY_FREQUENCY) {
return false;
}
}
return true;
}
/**
* Used to get the translation of a string_id stored in the database to
* the given locale.
*
* @param string $string_id id to translate
* @param string $locale_tag to translate to
* @return mixed translation if found, $string_id, otherwise
*/
public function translateDb($string_id, $locale_tag)
{
static $lookup = [];
$db = $this->db;
if (isset($lookup[$string_id])) {
return $lookup[$string_id];
}
$sql = "
SELECT TL.TRANSLATION AS TRANSLATION
FROM TRANSLATION T, LOCALE L, TRANSLATION_LOCALE TL
WHERE T.IDENTIFIER_STRING = :string_id AND
L.LOCALE_TAG = :locale_tag AND
L.LOCALE_ID = TL.LOCALE_ID AND
T.TRANSLATION_ID = TL.TRANSLATION_ID " . $db->limitOffset(1);
$result = $db->execute($sql,
[":string_id" => $string_id, ":locale_tag" => $locale_tag]);
$row = $db->fetchArray($result);
if (isset($row['TRANSLATION'])) {
return $row['TRANSLATION'];
}
return $string_id;
}
/**
* Get the user_id associated with a given username
* (In base class as used as an internal method in both signin and
* user models)
*
* @param string $username the username to look up
* @return string the corresponding userid
*/
public function getUserId($username)
{
$db = $this->db;
$sql = "SELECT USER_ID FROM USERS WHERE
LOWER(USER_NAME) = LOWER(?) ". $db->limitOffset(1);
$result = $db->execute($sql, [$username]);
if (!$result) {
return false;
}
$row = $db->fetchArray($result);
$user_id = $row['USER_ID'] ?? false;
return $user_id;
}
/**
* Creates the WHERE and ORDER BY clauses for a query of a Yioop
* table such as USERS, ROLE, GROUP, which have associated search web
* forms. Searches are case insensitive
*
* @param array $search_array each element of this is a quadruple
* name of a field, what comparison to perform, a value to check,
* and an order (ascending/descending) to sort by
* @param array $any_fields these fields if present in search array
* but with value "-1" will be skipped as part of the where clause
* but will be used for order by clause
* @return array string for where clause, string for order by clause
*/
public function searchArrayToWhereOrderClauses($search_array,
$any_fields = ['status'])
{
$db = $this->db;
$where = "";
$order_by = "";
$order_by_comma = "";
$where_and = "";
$sort_types = ["ASC", "DESC"];
foreach ($search_array as $row) {
if (isset($this->search_table_column_map[$row[0]])) {
$field_name = $this->search_table_column_map[$row[0]];
} else {
$field_name = $row[0];
}
if (in_array($row[1], ['BETWEEN', 'NOT_BETWEEN'])) {
list(, $comparison, $value_low, $value_high, $sort_dir,) = $row;
if ($value_low != "" || $value_high != "") {
if ($where == "") {
$where = " WHERE ";
}
$where .= $where_and;
if ($value_low != "" && $value_high == "") {
$where .= "$field_name >= '" .
$db->escapeString($value_low) . "'";
} else if ($value_low == "" && $value_high != "") {
$where .= "$field_name <= '" .
$db->escapeString($value_high) . "'";
} else if ($value_low != "" && $value_high != "") {
$where .= $field_name . " ". $comparison . " '" .
$db->escapeString($value_low) . "' AND '".
$db->escapeString($value_high) . "'";
}
$where_and = " AND ";
}
} else {
list(, $comparison, $value, $sort_dir,) = $row;
$trim_value = trim($value);
if ((!empty($trim_value) || $value === "0") &&
(!in_array($row[0], $any_fields)
|| $value != "-1")) {
if ($where == "") {
$where = " WHERE ";
}
$where .= $where_and;
switch ($comparison) {
case "=":
case "!=":
case "<":
case ">":
case "<=":
case ">=":
$where .= "$field_name$comparison'" .
$db->escapeString($value) . "'";
break;
case "CONTAINS":
$where .= "LOWER($field_name) LIKE LOWER('%".
$db->escapeString($value)."%')";
break;
case "NOT CONTAINS":
$where .= "NOT LOWER($field_name) LIKE LOWER('%".
$db->escapeString($value)."%')";
break;
case "BEGINS WITH":
$where .= "LOWER($field_name) LIKE LOWER('".
$db->escapeString($value)."%')";
break;
case "NOT BEGINS WITH":
$where .= "NOT LOWER($field_name) LIKE LOWER('".
$db->escapeString($value)."%')";
break;
case "ENDS WITH":
$where .= "LOWER($field_name) LIKE LOWER('%".
$db->escapeString($value)."')";
break;
case "NOT ENDS WITH":
$where .= "NOT LOWER($field_name) LIKE LOWER('%".
$db->escapeString($value)."')";
break;
}
$where_and = " AND ";
}
}
if (in_array($sort_dir, $sort_types)) {
if ($order_by == "") {
$order_by = " ORDER BY ";
}
$order_by .= $order_by_comma . $field_name . " " . $sort_dir;
$order_by_comma = ", ";
}
}
return [$where, $order_by];
}
/**
* Gets a range of rows which match the provided search criteria from
* $th provided table
*
* @param int $limit starting row from the potential results to return
* @param int $num number of rows after start row to return
* @param int &$total gets set with the total number of rows that
* can be returned by the given database query
* @param array $search_array each element of this is a
* quadruple name of a field, what comparison to perform, a value to
* check, and an order (ascending/descending) to sort by
* @param array $args additional values which may be used to get rows
* (what these are will typically depend on the subclass
* implementation)
* @return array
*/
public function getRows($limit, $num, &$total,
$search_array = [], $args = null)
{
$db = $this->db;
$tables = $this->fromCallback($args);
$limit = $db->limitOffset($limit, $num);
list($where, $order_by) =
$this->searchArrayToWhereOrderClauses($search_array,
$this->any_fields);
$more_conditions = $this->whereCallback($args);
if ($more_conditions) {
$add_where = " WHERE ";
if ($where != "") {
$add_where = " AND ";
}
$where .= $add_where. $more_conditions;
}
$count_column = "*";
if (isset($this->search_table_column_map['key'])) {
$count_column = "DISTINCT " . $this->search_table_column_map['key'];
}
$sql = "SELECT COUNT($count_column) AS NUM FROM $tables $where";
$result = $db->execute($sql);
$row = $db->fetchArray($result);
$total = $row['NUM'];
$select_columns = $this->selectCallback($args);
$sql = "SELECT $select_columns FROM ".
"$tables $where $order_by $limit";
$result = $db->execute($sql);
$i = 0;
$rows = [];
$row_callback = false;
if ($result) {
while ($rows[$i] = $db->fetchArray($result)) {
$rows[$i] = $this->rowCallback($rows[$i], $args);
$i++;
}
unset($rows[$i]); //last one will be null
}
$rows = $this->postQueryCallback($rows);
return $rows;
}
/**
* Controls which columns and the names of those columns from the tables
* underlying the given model should be return from a getRows call.
* This defaults to *, but in general will be overridden in subclasses of
* Model
*
* @param mixed $args any additional arguments which should be used to
* determine the columns
* @return string a comma separated list of columns suitable for a SQL
* query
*/
public function selectCallback($args = null)
{
return "*";
}
/**
* Controls which tables and the names of tables
* underlie the given model and should be used in a getRows call
* This defaults to the single table whose name is whatever is before
* Model in the name of the model. For example, by default on FooModel
* this method would return "FOO". If a different behavior, this can be
* overridden in subclasses of Model
*
* @param mixed $args any additional arguments which should be used to
* determine these tables
* @return string a comma separated list of tables suitable for a SQL
* query
*/
public function fromCallback($args = null)
{
$name = strtoupper(get_class($this));
$name = substr($name, strlen(C\NS_MODELS), -strlen("Model"));
return $name;
}
/**
* Controls the WHERE clause of the SQL query that
* underlies the given model and should be used in a getRows call.
* This defaults to an empty WHERE clause.
*
* @param mixed $args additional arguments that might be used to construct
* the WHERE clause.
* @return string a SQL WHERE clause
*/
public function whereCallback($args = null)
{
return "";
}
/**
* Called after as row is retrieved by getRows from the database to
* perform some manipulation that would be useful for this model.
* For example, in CrawlModel, after a row representing a crawl mix
* has been gotten, this is used to perform an additional query to marshal
* its components. By default this method just returns this row unchanged.
*
* @param array $row row as retrieved from database query
* @param mixed $args additional arguments that might be used by this
* callback
* @return array $row after callback manipulation
*/
public function rowCallback($row, $args)
{
return $row;
}
/**
* Called after getRows has retrieved all the rows that it would retrieve
* but before they are returned to give one last place where they could
* be further manipulated. For example, in MachineModel this callback
* is used to make parallel network calls to get the status of each machine
* returned by getRows. The default for this method is to leave the
* rows that would be returned unchanged
*
* @param array $rows that have been calculated so far by getRows
* @return array $rows after this final manipulation
*
*/
public function postQueryCallback($rows)
{
return $rows;
}
}