Subversion Repositories Applications.papyrus

Rev

Rev 1372 | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
770 florian 1
<?php
2
/*
3
 * Project:     MagpieRSS: a simple RSS integration tool
4
 * File:        rss_cache.inc, a simple, rolling(no GC), cache
5
 *              for RSS objects, keyed on URL.
6
 * Author:      Kellan Elliott-McCrea <kellan@protest.net>
7
 * Version:     0.51
8
 * License:     GPL
9
 *
10
 * The lastest version of MagpieRSS can be obtained from:
11
 * http://magpierss.sourceforge.net
12
 *
13
 * For questions, help, comments, discussion, etc., please join the
14
 * Magpie mailing list:
15
 * http://lists.sourceforge.net/lists/listinfo/magpierss-general
16
 *
17
 */
18
 
19
class RSSCache {
20
    var $BASE_CACHE = './cache';    // where the cache files are stored
21
    var $MAX_AGE    = 3600;         // when are files stale, default one hour
22
    var $ERROR      = "";           // accumulate error messages
23
 
24
    function RSSCache ($base='', $age='') {
25
        if ( $base ) {
26
            $this->BASE_CACHE = $base;
27
        }
28
        if ( $age ) {
29
            $this->MAX_AGE = $age;
30
        }
31
 
32
        // attempt to make the cache directory
33
        if ( ! file_exists( $this->BASE_CACHE ) ) {
34
            $status = @mkdir( $this->BASE_CACHE, 0755 );
35
 
36
            // if make failed
37
            if ( ! $status ) {
38
                $this->error(
39
                    "Cache couldn't make dir '" . $this->BASE_CACHE . "'."
40
                );
41
            }
42
        }
43
    }
44
 
45
/*=======================================================================*\
46
    Function:   set
47
    Purpose:    add an item to the cache, keyed on url
48
    Input:      url from wich the rss file was fetched
49
    Output:     true on sucess
50
\*=======================================================================*/
51
    function set ($url, $rss) {
52
        $this->ERROR = "";
53
        $cache_file = $this->file_name( $url );
54
        $fp = @fopen( $cache_file, 'w' );
55
 
56
        if ( ! $fp ) {
57
            $this->error(
58
                "Cache unable to open file for writing: $cache_file"
59
            );
60
            return 0;
61
        }
62
 
63
 
64
        $data = $this->serialize( $rss );
65
        fwrite( $fp, $data );
66
        fclose( $fp );
67
 
68
        return $cache_file;
69
    }
70
 
71
/*=======================================================================*\
72
    Function:   get
73
    Purpose:    fetch an item from the cache
74
    Input:      url from wich the rss file was fetched
75
    Output:     cached object on HIT, false on MISS
76
\*=======================================================================*/
77
    function get ($url) {
78
        $this->ERROR = "";
79
        $cache_file = $this->file_name( $url );
80
 
81
        if ( ! file_exists( $cache_file ) ) {
82
            $this->debug(
83
                "Cache doesn't contain: $url (cache file: $cache_file)"
84
            );
85
            return 0;
86
        }
87
 
88
        $fp = @fopen($cache_file, 'r');
89
        if ( ! $fp ) {
90
            $this->error(
91
                "Failed to open cache file for reading: $cache_file"
92
            );
93
            return 0;
94
        }
95
 
96
        if ($filesize = filesize($cache_file) ) {
97
        	$data = fread( $fp, filesize($cache_file) );
98
        	$rss = $this->unserialize( $data );
99
 
100
        	return $rss;
101
    	}
102
 
103
    	return 0;
104
    }
105
 
106
/*=======================================================================*\
107
    Function:   check_cache
108
    Purpose:    check a url for membership in the cache
109
                and whether the object is older then MAX_AGE (ie. STALE)
110
    Input:      url from wich the rss file was fetched
111
    Output:     cached object on HIT, false on MISS
112
\*=======================================================================*/
113
    function check_cache ( $url ) {
114
        $this->ERROR = "";
115
        $filename = $this->file_name( $url );
116
 
117
        if ( file_exists( $filename ) ) {
118
            // find how long ago the file was added to the cache
119
            // and whether that is longer then MAX_AGE
120
            $mtime = filemtime( $filename );
121
            $age = time() - $mtime;
122
            if ( $this->MAX_AGE > $age ) {
123
                // object exists and is current
124
                return 'HIT';
125
            }
126
            else {
127
                // object exists but is old
128
                return 'STALE';
129
            }
130
        }
131
        else {
132
            // object does not exist
133
            return 'MISS';
134
        }
135
    }
136
 
137
	function cache_age( $cache_key ) {
138
		$filename = $this->file_name( $url );
139
		if ( file_exists( $filename ) ) {
140
			$mtime = filemtime( $filename );
141
            $age = time() - $mtime;
142
			return $age;
143
		}
144
		else {
145
			return -1;
146
		}
147
	}
148
 
149
/*=======================================================================*\
150
    Function:   serialize
151
\*=======================================================================*/
152
    function serialize ( $rss ) {
153
        return serialize( $rss );
154
    }
155
 
156
/*=======================================================================*\
157
    Function:   unserialize
158
\*=======================================================================*/
159
    function unserialize ( $data ) {
160
        return unserialize( $data );
161
    }
162
 
163
/*=======================================================================*\
164
    Function:   file_name
165
    Purpose:    map url to location in cache
166
    Input:      url from wich the rss file was fetched
167
    Output:     a file name
168
\*=======================================================================*/
169
    function file_name ($url) {
170
        $filename = md5( $url );
171
        return join( DIRECTORY_SEPARATOR, array( $this->BASE_CACHE, $filename ) );
172
    }
173
 
174
/*=======================================================================*\
175
    Function:   error
176
    Purpose:    register error
177
\*=======================================================================*/
178
    function error ($errormsg, $lvl=E_USER_WARNING) {
179
        // append PHP's error message if track_errors enabled
180
        if ( isset($php_errormsg) ) {
181
            $errormsg .= " ($php_errormsg)";
182
        }
183
        $this->ERROR = $errormsg;
184
        if ( MAGPIE_DEBUG ) {
185
            trigger_error( $errormsg, $lvl);
186
        }
187
        else {
188
            error_log( $errormsg, 0);
189
        }
190
    }
191
 
192
    function debug ($debugmsg, $lvl=E_USER_NOTICE) {
193
        if ( MAGPIE_DEBUG ) {
194
            $this->error("MagpieRSS [debug] $debugmsg", $lvl);
195
        }
196
    }
197
 
198
}
199
 
200
?>