lib/DbaDatabase.php

   1 <?php
   2
   3 require_once 'lib/ErrorManager.php';
   4
   5 if (isWindows())
   6     define('DBA_DATABASE_DEFAULT_TIMEOUT', 60);
   7 else
   8     define('DBA_DATABASE_DEFAULT_TIMEOUT', 5);
   9
  10 class DbaDatabase
  11 {
  12     public $_file;
  13     public $_handler;
  14     public $_timeout;
  15     /**
  16      * @var resource
  17      */
  18     public $_dbh;
  19     public $readonly;
  20     public $_dba_open_error;
  21
  22     /**
  23      * @param string $filename
  24      * @param bool $mode
  25      * @param string $handler
  26      */
  27     function __construct($filename, $mode = false, $handler = 'gdbm')
  28     {
  29         $this->_file = $filename;
  30         $this->_handler = $handler;
  31         $this->_timeout = DBA_DATABASE_DEFAULT_TIMEOUT;
  32         $this->_dbh = false;
  33         if (!in_array($handler, dba_handlers()))
  34             $this->_error(
  35                 sprintf(
  36                     _("The DBA handler %s is unsupported!") . "\n" .
  37                         _("Supported handlers are: %s"),
  38                     $handler, join(",", dba_handlers())));
  39         $this->readonly = false;
  40         if ($mode)
  41             $this->open($mode);
  42     }
  43
  44     function set_timeout($timeout)
  45     {
  46         $this->_timeout = $timeout;
  47     }
  48
  49     function open($mode = 'w')
  50     {
  51         if ($this->_dbh)
  52             return true; // already open.
  53
  54         $watchdog = $this->_timeout;
  55
  56         global $ErrorManager;
  57         $this->_dba_open_error = false;
  58         $ErrorManager->pushErrorHandler(new WikiMethodCb($this, '_dba_open_error_handler'));
  59
  60         // oops, you don't have DBA support.
  61         if (!function_exists("dba_open")) {
  62             echo "You don't seem to have DBA support compiled into PHP.";
  63         }
  64
  65         if (READONLY) {
  66             $mode = 'r';
  67         }
  68
  69         if ((strlen($mode) == 1)) {
  70             // PHP 4.3.x Windows lock bug workaround: http://bugs.php.net/bug.php?id=23975
  71             if (isWindows()) {
  72                 $mode .= "-"; // suppress locking, or
  73             } elseif ($this->_handler != 'gdbm') { // gdbm does it internally
  74                 $mode .= "d"; // else use internal locking
  75             }
  76         }
  77         while (($dbh = dba_open($this->_file, $mode, $this->_handler)) < 1) {
  78             if ($watchdog <= 0)
  79                 break;
  80             // "c" failed, try "w" instead.
  81             if ($mode == "w"
  82                 and file_exists($this->_file)
  83                     and (isWindows() or !is_writable($this->_file))
  84             ) {
  85                 // try to continue with read-only
  86                 if (!defined("READONLY"))
  87                     define("READONLY", true);
  88                 $GLOBALS['request']->_dbi->readonly = true;
  89                 $this->readonly = true;
  90                 $mode = "r";
  91             }
  92             if (substr($mode, 0, 1) == "c" and file_exists($this->_file) and !READONLY)
  93                 $mode = "w";
  94             // conflict: wait some random time to unlock (as with ethernet)
  95             $secs = 0.5 + ((double)rand(1, 32767) / 32767);
  96             sleep($secs);
  97             $watchdog -= $secs;
  98             if (strlen($mode) == 2) $mode = substr($mode, 0, -1);
  99         }
 100         $ErrorManager->popErrorHandler();
 101
 102         if (!$dbh) {
 103             if (($error = $this->_dba_open_error)) {
 104                 $error->errno = E_USER_ERROR;
 105                 $error->errstr .= "\nfile: " . $this->_file
 106                     . "\nmode: " . $mode
 107                     . "\nhandler: " . $this->_handler;
 108                 // try to continue with read-only
 109                 if (!defined("READONLY"))
 110                     define("READONLY", true);
 111                 $GLOBALS['request']->_dbi->readonly = true;
 112                 $this->readonly = true;
 113                 if (!file_exists($this->_file)) {
 114                     $ErrorManager->handleError($error);
 115                     flush();
 116                 }
 117             } else {
 118                 trigger_error("dba_open failed", E_USER_ERROR);
 119             }
 120         }
 121         $this->_dbh = $dbh;
 122         return !empty($dbh);
 123     }
 124
 125     function close()
 126     {
 127         if ($this->_dbh)
 128             dba_close($this->_dbh);
 129         $this->_dbh = false;
 130     }
 131
 132     function exists($key)
 133     {
 134         return dba_exists($key, $this->_dbh);
 135     }
 136
 137     function fetch($key)
 138     {
 139         $val = dba_fetch($key, $this->_dbh);
 140         if ($val === false) {
 141             $this->_error("fetch($key)");
 142         }
 143         return $val;
 144     }
 145
 146     function insert($key, $val)
 147     {
 148         if (!dba_insert($key, $val, $this->_dbh))
 149             $this->_error("insert($key)");
 150     }
 151
 152     function replace($key, $val)
 153     {
 154         if (!dba_replace($key, $val, $this->_dbh))
 155             $this->_error("replace($key)");
 156     }
 157
 158     function firstkey()
 159     {
 160         return dba_firstkey($this->_dbh);
 161     }
 162
 163     function nextkey()
 164     {
 165         return dba_nextkey($this->_dbh);
 166     }
 167
 168     function delete($key)
 169     {
 170         if ($this->readonly)
 171             return;
 172         if (!dba_delete($key, $this->_dbh))
 173             $this->_error("delete($key)");
 174     }
 175
 176     function get($key)
 177     {
 178         return dba_fetch($key, $this->_dbh);
 179     }
 180
 181     function set($key, $val)
 182     {
 183         $dbh = &$this->_dbh;
 184         if ($this->readonly)
 185             return;
 186         if (dba_exists($key, $dbh)) {
 187             if ($val !== false) {
 188                 if (!dba_replace($key, $val, $dbh))
 189                     $this->_error("store[replace]($key)");
 190             } else {
 191                 if (!dba_delete($key, $dbh))
 192                     $this->_error("store[delete]($key)");
 193             }
 194         } else {
 195             if (!dba_insert($key, $val, $dbh))
 196                 $this->_error("store[insert]($key)");
 197         }
 198     }
 199
 200     function sync()
 201     {
 202         if (!dba_sync($this->_dbh))
 203             $this->_error("sync()");
 204     }
 205
 206     function optimize()
 207     {
 208         if (!dba_optimize($this->_dbh))
 209             $this->_error("optimize()");
 210         return 1;
 211     }
 212
 213     private function _error($mes)
 214     {
 215         trigger_error("$this->_file: dba error: $mes", E_USER_ERROR);
 216     }
 217
 218     function _dump()
 219     {
 220         $dbh = &$this->_dbh;
 221         for ($key = $this->firstkey($dbh); $key; $key = $this->nextkey($dbh))
 222             printf("%10s: %s\n", $key, $this->fetch($key));
 223     }
 224
 225     function _dba_open_error_handler($error)
 226     {
 227         $this->_dba_open_error = $error;
 228         return true;
 229     }
 230 }
 231
 232 // Local Variables:
 233 // mode: php
 234 // tab-width: 8
 235 // c-basic-offset: 4
 236 // c-hanging-comment-ender-p: nil
 237 // indent-tabs-mode: nil
 238 // End: