]>
Commit | Line | Data |
---|---|---|
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 | ?> |