Commit | Line | Data |
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bc13d5d6 H |
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: 0.3 | |
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 | * Mapgie 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->error( | |
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 | $data = fread( $fp, filesize($cache_file) ); | |
97 | $rss = $this->unserialize( $data ); | |
98 | ||
99 | return $rss; | |
100 | } | |
101 | ||
102 | /*=======================================================================*\ | |
103 | Function: check_cache | |
104 | Purpose: check a url for membership in the cache | |
105 | and whether the object is older then MAX_AGE (ie. STALE) | |
106 | Input: url from wich the rss file was fetched | |
107 | Output: cached object on HIT, false on MISS | |
108 | \*=======================================================================*/ | |
109 | function check_cache ( $url ) { | |
110 | $this->ERROR = ""; | |
111 | $filename = $this->file_name( $url ); | |
112 | ||
113 | if ( file_exists( $filename ) ) { | |
114 | // find how long ago the file was added to the cache | |
115 | // and whether that is longer then MAX_AGE | |
116 | $mtime = filemtime( $filename ); | |
117 | $age = time() - $mtime; | |
118 | if ( $this->MAX_AGE > $age ) { | |
119 | // object exists and is current | |
120 | return 'HIT'; | |
121 | } | |
122 | else { | |
123 | // object exists but is old | |
124 | return 'STALE'; | |
125 | } | |
126 | } | |
127 | else { | |
128 | // object does not exist | |
129 | return 'MISS'; | |
130 | } | |
131 | } | |
132 | ||
133 | /*=======================================================================*\ | |
134 | Function: serialize | |
135 | \*=======================================================================*/ | |
136 | function serialize ( $rss ) { | |
137 | return serialize( $rss ); | |
138 | } | |
139 | ||
140 | /*=======================================================================*\ | |
141 | Function: unserialize | |
142 | \*=======================================================================*/ | |
143 | function unserialize ( $data ) { | |
144 | return unserialize( $data ); | |
145 | } | |
146 | ||
147 | /*=======================================================================*\ | |
148 | Function: file_name | |
149 | Purpose: map url to location in cache | |
150 | Input: url from wich the rss file was fetched | |
151 | Output: a file name | |
152 | \*=======================================================================*/ | |
153 | function file_name ($url) { | |
154 | $filename = md5( $url ); | |
155 | return join( DIRECTORY_SEPARATOR, array( $this->BASE_CACHE, $filename ) ); | |
156 | } | |
157 | ||
158 | /*=======================================================================*\ | |
159 | Function: error | |
160 | Purpose: register error | |
161 | \*=======================================================================*/ | |
162 | function error ($errormsg, $lvl=E_USER_WARNING) { | |
163 | // append PHP's error message if track_errors enabled | |
164 | if ( $php_errormsg ) { | |
165 | $errormsg .= " ($php_errormsg)"; | |
166 | } | |
167 | $this->ERROR = $errormsg; | |
168 | if ( MAGPIE_DEBUG ) { | |
169 | trigger_error( $errormsg, $lvl); | |
170 | } | |
171 | else { | |
172 | error_log( $errormsg, 0); | |
173 | } | |
174 | } | |
175 | } | |
176 | ||
177 | ?> |