lib/DbaDatabase.php

   1 <?php rcs_id('$Id: DbaDatabase.php,v 1.19 2006-06-18 11:01:25 rurban Exp $');
   2
   3 require_once('lib/ErrorManager.php');
   4
   5 define('DBA_DATABASE_DEFAULT_TIMEOUT', 5);
   6
   7 class DbaDatabase
   8 {
   9     function DbaDatabase($filename, $mode = false, $handler = 'gdbm') {
  10         $this->_file = $filename;
  11         $this->_handler = $handler;
  12         $this->_timeout = DBA_DATABASE_DEFAULT_TIMEOUT;
  13         $this->_dbh = false;
  14         if (function_exists("dba_handlers")) { // since 4.3.0
  15             if (!in_array($handler, dba_handlers()))
  16                 $this->_error(
  17                     sprintf(
  18                             _("The DBA handler %s is unsupported!")."\n".
  19                             _("Supported handlers are: %s"),
  20                             $handler, join(",",dba_handlers())));
  21         }
  22         if ($mode)
  23             $this->open($mode);
  24     }
  25
  26     function set_timeout($timeout) {
  27         $this->_timeout = $timeout;
  28     }
  29
  30     function open($mode = 'w') {
  31         if ($this->_dbh)
  32             return;             // already open.
  33
  34         $watchdog = $this->_timeout;
  35
  36         global $ErrorManager;
  37         $this->_dba_open_error = false;
  38         $ErrorManager->pushErrorHandler(new WikiMethodCb($this, '_dba_open_error_handler'));
  39
  40         // oops, you don't have DBA support.
  41         if (!function_exists("dba_open")) {
  42             echo "You don't seem to have DBA support compiled into PHP.";
  43         }
  44
  45         // lock supported since 4.3.0:
  46         if (check_php_version(4,3,0) and (strlen($mode) == 1)) {
  47             // PHP 4.3.x Windows lock bug workaround: http://bugs.php.net/bug.php?id=23975
  48             if (isWindows()) {
  49                 $mode .= "-";                   // suppress locking, or
  50             } elseif ($this->_handler != 'gdbm') {      // gdbm does it internally
  51                 $mode .= "d";                   // else use internal locking
  52             }
  53         }
  54         while (($dbh = dba_open($this->_file, $mode, $this->_handler)) < 1) {
  55             if ($watchdog <= 0)
  56                 break;
  57             flush();
  58             // "c" failed, try "w" instead.
  59             if (substr($mode,0,1) == "c" and file_exists($this->_file))
  60                 $mode = "w";
  61             // conflict: wait some random time to unlock (see ethernet)
  62             $secs = 0.5 + ((double)rand(1,32767)/32767);
  63             sleep($secs);
  64             $watchdog -= $secs;
  65             if (strlen($mode) == 2) $mode = substr($mode,0,-1);
  66         }
  67         $ErrorManager->popErrorHandler();
  68
  69         if (!$dbh) {
  70             if ( ($error = $this->_dba_open_error) ) {
  71                 $error->errno = E_USER_ERROR;
  72                 $error->errstr .= "\nfile: " . $this->_file
  73                                .  "\nmode: " . $mode
  74                                .  "\nhandler: " . $this->_handler;
  75                 $ErrorManager->handleError($error);
  76             }
  77             else {
  78                 trigger_error("dba_open failed", E_USER_ERROR);
  79             }
  80         }
  81         $this->_dbh = $dbh;
  82         return !empty($dbh);
  83     }
  84
  85     function close() {
  86         if ($this->_dbh)
  87             dba_close($this->_dbh);
  88         $this->_dbh = false;
  89     }
  90
  91     function exists($key) {
  92         return dba_exists($key, $this->_dbh);
  93     }
  94
  95     function fetch($key) {
  96         $val = dba_fetch($key, $this->_dbh);
  97         if ($val === false)
  98             return $this->_error("fetch($key)");
  99         return $val;
 100     }
 101
 102     function insert($key, $val) {
 103         if (!dba_insert($key, $val, $this->_dbh))
 104             return $this->_error("insert($key)");
 105     }
 106
 107     function replace($key, $val) {
 108         if (!dba_replace($key, $val, $this->_dbh))
 109             return $this->_error("replace($key)");
 110     }
 111
 112
 113     function firstkey() {
 114         return dba_firstkey($this->_dbh);
 115     }
 116
 117     function nextkey() {
 118         return dba_nextkey($this->_dbh);
 119     }
 120
 121     function delete($key) {
 122         if (!dba_delete($key, $this->_dbh))
 123             return $this->_error("delete($key)");
 124     }
 125
 126     function get($key) {
 127         return dba_fetch($key, $this->_dbh);
 128     }
 129
 130     function set($key, $val) {
 131         $dbh = &$this->_dbh;
 132         if (dba_exists($key, $dbh)) {
 133             if ($val !== false) {
 134                 if (!dba_replace($key, $val, $dbh))
 135                     return $this->_error("store[replace]($key)");
 136             }
 137             else {
 138                 if (!dba_delete($key, $dbh))
 139                     return $this->_error("store[delete]($key)");
 140             }
 141         }
 142         else {
 143             if (!dba_insert($key, $val, $this->_dbh))
 144                 return $this->_error("store[insert]($key)");
 145         }
 146     }
 147
 148     function sync() {
 149         if (!dba_sync($this->_dbh))
 150             return $this->_error("sync()");
 151     }
 152
 153     function optimize () {
 154         if (!dba_optimize($this->_dbh))
 155             return $this->_error("optimize()");
 156         return 1;
 157     }
 158
 159     function _error($mes) {
 160         //trigger_error("DbaDatabase: $mes", E_USER_WARNING);
 161         //return false;
 162         trigger_error("$this->_file: dba error: $mes", E_USER_ERROR);
 163     }
 164
 165     function _dump() {
 166         $dbh = &$this->_dbh;
 167         for ($key = $this->firstkey($dbh); $key; $key = $this->nextkey($dbh))
 168             printf("%10s: %s\n", $key, $this->fetch($key));
 169     }
 170
 171     function _dba_open_error_handler ($error) {
 172         $this->_dba_open_error = $error;
 173         return true;
 174     }
 175 }
 176
 177 // $Log: not supported by cvs2svn $
 178
 179 // (c-file-style: "gnu")
 180 // Local Variables:
 181 // mode: php
 182 // tab-width: 8
 183 // c-basic-offset: 4
 184 // c-hanging-comment-ender-p: nil
 185 // indent-tabs-mode: nil
 186 // End:
 187 ?>