1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
|
<?php
/**
* TSqliteCache class file
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @link https://github.com/pradosoft/prado
* @copyright Copyright © 2005-2015 The PRADO Group
* @license https://github.com/pradosoft/prado/blob/master/COPYRIGHT
* @package System.Caching
*/
/**
* TSqliteCache class
*
* TSqliteCache implements a cache application module based on SQLite database.
*
* THIS CLASS IS DEPRECATED since it relies on the sqlite PHP extension, that is
* no longer loaded by default since PHP 5.1. You are discouraged from using it:
* use {@link TDbCache} instead.
*
* Since PRADO v3.1.0, a new DB-based cache module called {@link TDbCache}
* is provided. If you have PDO extension installed, you may consider using
* the new cache module instead as it allows you to use different database
* to store the cached data.
*
* The database file is specified by the {@link setDbFile DbFile} property.
* If not set, the database file will be created under the system state path.
* If the specified database file does not exist, it will be created automatically.
* Make sure the directory containing the specified DB file and the file itself is
* writable by the Web server process.
*
* The following basic cache operations are implemented:
* - {@link get} : retrieve the value with a key (if any) from cache
* - {@link set} : store the value with a key into cache
* - {@link add} : store the value only if cache does not have this key
* - {@link delete} : delete the value with the specified key from cache
* - {@link flush} : delete all values from cache
*
* Each value is associated with an expiration time. The {@link get} operation
* ensures that any expired value will not be returned. The expiration time by
* the number of seconds. A expiration time 0 represents never expire.
*
* By definition, cache does not ensure the existence of a value
* even if it never expires. Cache is not meant to be an persistent storage.
*
* Do not use the same database file for multiple applications using TSqliteCache.
* Also note, cache is shared by all user sessions of an application.
*
* Some usage examples of TSqliteCache are as follows,
* <code>
* $cache=new TSqliteCache; // TSqliteCache may also be loaded as a Prado application module
* $cache->setDbFile($dbFilePath);
* $cache->init(null);
* $cache->add('object',$object);
* $object2=$cache->get('object');
* </code>
*
* If loaded, TSqliteCache will register itself with {@link TApplication} as the
* cache module. It can be accessed via {@link TApplication::getCache()}.
*
* TSqliteCache may be configured in application configuration file as follows
* <code>
* <module id="cache" class="System.Caching.TSqliteCache" DbFile="Application.Data.site" />
* </code>
* where {@link getDbFile DbFile} is a property specifying the location of the
* SQLite DB file (in the namespace format).
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @package System.Caching
* @since 3.0
*/
class TSqliteCache extends TCache
{
/**
* name of the table storing cache data
*/
const CACHE_TABLE='cache';
/**
* extension of the db file name
*/
const DB_FILE_EXT='.db';
/**
* @var boolean if the module has been initialized
*/
private $_initialized=false;
/**
* @var SQLiteDatabase the sqlite database instance
*/
private $_db=null;
/**
* @var string the database file name
*/
private $_file=null;
/**
* Destructor.
* Disconnect the db connection.
*/
public function __destruct()
{
$this->_db=null;
}
/**
* Initializes this module.
* This method is required by the IModule interface. It checks if the DbFile
* property is set, and creates a SQLiteDatabase instance for it.
* The database or the cache table does not exist, they will be created.
* Expired values are also deleted.
* @param TXmlElement configuration for this module, can be null
* @throws TConfigurationException if sqlite extension is not installed,
* DbFile is set invalid, or any error happens during creating database or cache table.
*/
public function init($config)
{
if(!function_exists('sqlite_open'))
throw new TConfigurationException('sqlitecache_extension_required');
if($this->_file===null)
$this->_file=$this->getApplication()->getRuntimePath().'/sqlite.cache';
$error='';
if(($this->_db=new SQLiteDatabase($this->_file,0666,$error))===false)
throw new TConfigurationException('sqlitecache_connection_failed',$error);
if(@$this->_db->query('DELETE FROM '.self::CACHE_TABLE.' WHERE expire<>0 AND expire<'.time())===false)
{
if($this->_db->query('CREATE TABLE '.self::CACHE_TABLE.' (key CHAR(128) PRIMARY KEY, value BLOB, expire INT)')===false)
throw new TConfigurationException('sqlitecache_table_creation_failed',sqlite_error_string(sqlite_last_error()));
}
$this->_initialized=true;
parent::init($config);
}
/**
* @return string database file path (in namespace form)
*/
public function getDbFile()
{
return $this->_file;
}
/**
* @param string database file path (in namespace form)
* @throws TInvalidOperationException if the module is already initialized
* @throws TConfigurationException if the file is not in proper namespace format
*/
public function setDbFile($value)
{
if($this->_initialized)
throw new TInvalidOperationException('sqlitecache_dbfile_unchangeable');
else if(($this->_file=Prado::getPathOfNamespace($value,self::DB_FILE_EXT))===null)
throw new TConfigurationException('sqlitecache_dbfile_invalid',$value);
}
/**
* Retrieves a value from cache with a specified key.
* This is the implementation of the method declared in the parent class.
* @param string a unique key identifying the cached value
* @return string the value stored in cache, false if the value is not in the cache or expired.
*/
protected function getValue($key)
{
$sql='SELECT value FROM '.self::CACHE_TABLE.' WHERE key=\''.$key.'\' AND (expire=0 OR expire>'.time().') LIMIT 1';
if(($ret=$this->_db->query($sql))!=false && ($row=$ret->fetch(SQLITE_ASSOC))!==false)
return unserialize($row['value']);
else
return false;
}
/**
* Stores a value identified by a key in cache.
* This is the implementation of the method declared in the parent class.
*
* @param string the key identifying the value to be cached
* @param string the value to be cached
* @param integer the number of seconds in which the cached value will expire. 0 means never expire.
* @return boolean true if the value is successfully stored into cache, false otherwise
*/
protected function setValue($key,$value,$expire)
{
$expire=($expire<=0)?0:time()+$expire;
$sql='REPLACE INTO '.self::CACHE_TABLE.' VALUES(\''.$key.'\',\''.sqlite_escape_string(serialize($value)).'\','.$expire.')';
return $this->_db->query($sql)!==false;
}
/**
* Stores a value identified by a key into cache if the cache does not contain this key.
* This is the implementation of the method declared in the parent class.
*
* @param string the key identifying the value to be cached
* @param string the value to be cached
* @param integer the number of seconds in which the cached value will expire. 0 means never expire.
* @return boolean true if the value is successfully stored into cache, false otherwise
*/
protected function addValue($key,$value,$expire)
{
$expire=($expire<=0)?0:time()+$expire;
$sql='INSERT INTO '.self::CACHE_TABLE.' VALUES(\''.$key.'\',\''.sqlite_escape_string(serialize($value)).'\','.$expire.')';
return @$this->_db->query($sql)!==false;
}
/**
* Deletes a value with the specified key from cache
* This is the implementation of the method declared in the parent class.
* @param string the key of the value to be deleted
* @return boolean if no error happens during deletion
*/
protected function deleteValue($key)
{
$sql='DELETE FROM '.self::CACHE_TABLE.' WHERE key=\''.$key.'\'';
return $this->_db->query($sql)!==false;
}
/**
* Deletes all values from cache.
* Be careful of performing this operation if the cache is shared by multiple applications.
*/
public function flush()
{
return $this->_db->query('DELETE FROM '.self::CACHE_TABLE)!==false;
}
}
|
