gnu-social/classes/File_redirection.php
2015-07-07 19:59:43 +02:00

397 lines
16 KiB
PHP

<?php
/*
* StatusNet - the distributed open-source microblogging tool
* Copyright (C) 2008, 2009, StatusNet, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
if (!defined('GNUSOCIAL')) { exit(1); }
/**
* Table Definition for file_redirection
*/
class File_redirection extends Managed_DataObject
{
###START_AUTOCODE
/* the code below is auto generated do not remove the above tag */
public $__table = 'file_redirection'; // table name
public $urlhash; // varchar(64) primary_key not_null
public $url; // text
public $file_id; // int(4)
public $redirections; // int(4)
public $httpcode; // int(4)
public $modified; // timestamp() not_null default_CURRENT_TIMESTAMP
/* the code above is auto generated do not remove the tag below */
###END_AUTOCODE
public static function schemaDef()
{
return array(
'fields' => array(
'urlhash' => array('type' => 'varchar', 'length' => 64, 'not null' => true, 'description' => 'sha256 hash of the URL'),
'url' => array('type' => 'text', 'description' => 'short URL (or any other kind of redirect) for file (id)'),
'file_id' => array('type' => 'int', 'description' => 'short URL for what URL/file'),
'redirections' => array('type' => 'int', 'description' => 'redirect count'),
'httpcode' => array('type' => 'int', 'description' => 'HTTP status code (20x, 30x, etc.)'),
'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
),
'primary key' => array('urlhash'),
'foreign keys' => array(
'file_redirection_file_id_fkey' => array('file' => array('file_id' => 'id')),
),
);
}
static public function getByUrl($url)
{
return self::getByPK(array('urlhash' => File::hashurl($url)));
}
static function _commonHttp($url, $redirs) {
$request = new HTTPClient($url);
$request->setConfig(array(
'connect_timeout' => 10, // # seconds to wait
'max_redirs' => $redirs, // # max number of http redirections to follow
'follow_redirects' => true, // Follow redirects
'store_body' => false, // We won't need body content here.
));
return $request;
}
/**
* Check if this URL is a redirect and return redir info.
*
* Most code should call File_redirection::where instead, to check if we
* already know that redirection and avoid extra hits to the web.
*
* The URL is hit and any redirects are followed, up to 10 levels or until
* a protected URL is reached.
*
* @param string $in_url
* @return mixed one of:
* string - target URL, if this is a direct link or can't be followed
* array - redirect info if this is an *unknown* redirect:
* associative array with the following elements:
* code: HTTP status code
* redirects: count of redirects followed
* url: URL string of final target
* type (optional): MIME type from Content-Type header
* size (optional): byte size from Content-Length header
* time (optional): timestamp from Last-Modified header
*/
static function lookupWhere($short_url, $redirs = 10, $protected = false) {
if ($redirs < 0) return false;
if(strpos($short_url,'://') === false){
return $short_url;
}
try {
$request = self::_commonHttp($short_url, $redirs);
// Don't include body in output
$request->setMethod(HTTP_Request2::METHOD_HEAD);
$response = $request->send();
if (405 == $response->getStatus() || 204 == $response->getStatus()) {
// HTTP 405 Unsupported Method
// Server doesn't support HEAD method? Can this really happen?
// We'll try again as a GET and ignore the response data.
//
// HTTP 204 No Content
// YFrog sends 204 responses back for our HEAD checks, which
// seems like it may be a logic error in their servers. If
// we get a 204 back, re-run it as a GET... if there's really
// no content it'll be cheap. :)
$request = self::_commonHttp($short_url, $redirs);
$response = $request->send();
}
} catch (Exception $e) {
// Invalid URL or failure to reach server
common_log(LOG_ERR, "Error while following redirects for $short_url: " . $e->getMessage());
return $short_url;
}
if ($response->getRedirectCount() && File::isProtected($response->getUrl())) {
// Bump back up the redirect chain until we find a non-protected URL
return self::lookupWhere($short_url, $response->getRedirectCount() - 1, true);
}
$ret = array('code' => $response->getStatus()
, 'redirects' => $response->getRedirectCount()
, 'url' => $response->getUrl());
$type = $response->getHeader('Content-Type');
if ($type) $ret['type'] = $type;
if ($protected) $ret['protected'] = true;
$size = $response->getHeader('Content-Length'); // @fixme bytes?
if ($size) $ret['size'] = $size;
$time = $response->getHeader('Last-Modified');
if ($time) $ret['time'] = strtotime($time);
return $ret;
}
/**
* Check if this URL is a redirect and return redir info.
* If a File record is present for this URL, it is not considered a redirect.
* If a File_redirection record is present for this URL, the recorded target is returned.
*
* If no File or File_redirect record is present, the URL is hit and any
* redirects are followed, up to 10 levels or until a protected URL is
* reached.
*
* @param string $in_url
* @param boolean $discover true to attempt dereferencing the redirect if we don't know it already
* @return mixed one of:
* string - target URL, if this is a direct link or a known redirect
* array - redirect info if this is an *unknown* redirect:
* associative array with the following elements:
* code: HTTP status code
* redirects: count of redirects followed
* url: URL string of final target
* type (optional): MIME type from Content-Type header
* size (optional): byte size from Content-Length header
* time (optional): timestamp from Last-Modified header
*/
static function where($in_url, $discover=true) {
// let's see if we know this...
try {
$a = File::getByUrl($in_url);
// this is a direct link to $a->url
return $a->url;
} catch (NoResultException $e) {
try {
$b = File_redirection::getByUrl($in_url);
// this is a redirect to $b->file_id
$a = File::getByID($b->file_id);
return $a->url;
} catch (NoResultException $e) {
// Oh well, let's keep going
}
}
if ($discover) {
$ret = File_redirection::lookupWhere($in_url);
return $ret;
}
// No manual dereferencing; leave the unknown URL as is.
return $in_url;
}
/**
* Shorten a URL with the current user's configured shortening
* options, if applicable.
*
* If it cannot be shortened or the "short" URL is longer than the
* original, the original is returned.
*
* If the referenced item has not been seen before, embedding data
* may be saved.
*
* @param string $long_url
* @param User $user whose shortening options to use; defaults to the current web session user
* @return string
*/
function makeShort($long_url, $user=null)
{
$canon = File_redirection::_canonUrl($long_url);
$short_url = File_redirection::_userMakeShort($canon, $user);
// Did we get one? Is it shorter?
if (!empty($short_url)) {
return $short_url;
} else {
return $long_url;
}
}
/**
* Shorten a URL with the current user's configured shortening
* options, if applicable.
*
* If it cannot be shortened or the "short" URL is longer than the
* original, the original is returned.
*
* If the referenced item has not been seen before, embedding data
* may be saved.
*
* @param string $long_url
* @return string
*/
function forceShort($long_url, $user)
{
$canon = File_redirection::_canonUrl($long_url);
$short_url = File_redirection::_userMakeShort($canon, $user, true);
// Did we get one? Is it shorter?
if (!empty($short_url)) {
return $short_url;
} else {
return $long_url;
}
}
static function _userMakeShort($long_url, User $user=null, $force = false) {
$short_url = common_shorten_url($long_url, $user, $force);
if (!empty($short_url) && $short_url != $long_url) {
$short_url = (string)$short_url;
// store it
$file = File::getKV('url', $long_url);
if ($file instanceof File) {
$file_id = $file->getID();
} else {
// Check if the target URL is itself a redirect...
$redir_data = File_redirection::where($long_url);
if (is_array($redir_data)) {
// We haven't seen the target URL before.
// Save file and embedding data about it!
$file = File::saveNew($redir_data, $long_url);
$file_id = $file->getID();
} else if (is_string($redir_data)) {
// The file is a known redirect target.
$file = File::getKV('url', $redir_data);
if (empty($file)) {
// @fixme should we save a new one?
// this case was triggering sometimes for redirects
// with unresolvable targets; found while fixing
// "can't linkify" bugs with shortened links to
// SSL sites with cert issues.
return null;
}
$file_id = $file->getID();
}
}
$file_redir = File_redirection::getKV('url', $short_url);
if (!$file_redir instanceof File_redirection) {
$file_redir = new File_redirection;
$file_redir->urlhash = File::hashurl($short_url);
$file_redir->url = $short_url;
$file_redir->file_id = $file_id;
$file_redir->insert();
}
return $short_url;
}
return null;
}
/**
* Basic attempt to canonicalize a URL, cleaning up some standard variants
* such as funny syntax or a missing path. Used internally when cleaning
* up URLs for storage and following redirect chains.
*
* Note that despite being on File_redirect, this function DOES NOT perform
* any dereferencing of redirects.
*
* @param string $in_url input URL
* @param string $default_scheme if given a bare link; defaults to 'http://'
* @return string
*/
static function _canonUrl($in_url, $default_scheme = 'http://') {
if (empty($in_url)) return false;
$out_url = $in_url;
$p = parse_url($out_url);
if (empty($p['host']) || empty($p['scheme'])) {
list($scheme) = explode(':', $in_url, 2);
switch (strtolower($scheme)) {
case 'fax':
case 'tel':
$out_url = str_replace('.-()', '', $out_url);
break;
case 'mailto':
case 'magnet':
case 'aim':
case 'jabber':
case 'xmpp':
// don't touch anything
break;
default:
$out_url = $default_scheme . ltrim($out_url, '/');
$p = parse_url($out_url);
if (empty($p['scheme'])) return false;
break;
}
}
if (('ftp' == $p['scheme']) || ('ftps' == $p['scheme']) || ('http' == $p['scheme']) || ('https' == $p['scheme'])) {
if (empty($p['host'])) return false;
if (empty($p['path'])) {
$out_url .= '/';
}
}
return $out_url;
}
static function saveNew($data, $file_id, $url) {
$file_redir = new File_redirection;
$file_redir->urlhash = File::hashurl($short_url);
$file_redir->url = $url;
$file_redir->file_id = $file_id;
$file_redir->redirections = intval($data['redirects']);
$file_redir->httpcode = intval($data['code']);
$file_redir->insert();
}
static public function beforeSchemaUpdate()
{
$table = strtolower(get_called_class());
$schema = Schema::get();
$schemadef = $schema->getTableDef($table);
// 2015-02-19 We have to upgrade our table definitions to have the urlhash field populated
if (isset($schemadef['fields']['urlhash']) && in_array('urlhash', $schemadef['primary key'])) {
// We already have the urlhash field, so no need to migrate it.
return;
}
echo "\nFound old $table table, upgrading it to contain 'urlhash' field...";
// We have to create a urlhash that is _not_ the primary key,
// transfer data and THEN run checkSchema
$schemadef['fields']['urlhash'] = array (
'type' => 'varchar',
'length' => 64,
'not null' => true,
'description' => 'sha256 hash of the URL',
);
$schemadef['fields']['url'] = array (
'type' => 'text',
'description' => 'short URL (or any other kind of redirect) for file (id)',
);
unset($schemadef['primary key']);
$schema->ensureTable($table, $schemadef);
echo "DONE.\n";
$classname = ucfirst($table);
$tablefix = new $classname;
// urlhash is hash('sha256', $url) in the File table
echo "Updating urlhash fields in $table table...";
// Maybe very MySQL specific :(
$tablefix->query(sprintf('UPDATE %1$s SET %2$s=%3$s;',
$schema->quoteIdentifier($table),
'urlhash',
// The line below is "result of sha256 on column `url`"
'SHA2(url, 256)'));
echo "DONE.\n";
echo "Resuming core schema upgrade...";
}
}