[转]某文本数据库blog作者写的文本数据库操作类，很不错

 

作者的1.0版:

<?
/*
本代码开源，您可以对其进行修改.
下面文字请不要修改.
*********************************************
php文本数据库类1.0版
powerd by bpns
mysite:http://space.tju.cn/site/redboy/
2006-4-20
*********************************************

为了您的数据库安全,请在此程序中更改您的数据默认目录

将function TxtDB($name,$mod='w',$path='my_dbm')
中$path='my_dbm'修改成你自己设定的目录，如$path='abc123_dbm',
并将根目录下的my_dbm文件夹对行对应的更名.
*/

class TxtDB
{
  var $name='';//文本数据库名
  var $path='';
  var $minLen=20;
  var $isError;
  var $dbh;
  var $indxh;
  var $lfth;
  var $lckh;
  var $rcdCnt=0;
  var $maxID=0;
  var $leftCnt=0;
  var $DBend=0;
  var $mod='w';
  function TxtDB($name,$mod='w',$path='bpns_dbm')//修改数据库的默认文件夹在此修改
  {
    $this->name=$name;
    $this->path=$path.'/'.$name;
    $this->isError=0;
    $this->mod=$mod;
    $path=$this->path;
    if ($name!='')
    {
    @mkdir($this->path,0777);
    if (!file_exists($path.'/'.$name.'.tdb')) $this->dbh=fopen($this->path.'/'.$name.'.tdb','w+');
    else $this->dbh=fopen($path.'/'.$name.'.tdb','r+');
    if (!file_exists($path.'/'.$name.'.indx')) $this->indxh=fopen($this->path.'/'.$name.'.indx','w+');
    else $this->indxh=fopen($path.'/'.$name.'.indx','r+');
    if (!file_exists($path.'/'.$name.'.lft')) $this->lfth=fopen($this->path.'/'.$name.'.lft','w+');
    else $this->lfth=fopen($this->path.'/'.$name.'.lft','r+');
    if ($this->mod=='w')
    {
     $this->lckh=fopen($this->path.'/'.$name.'.lck','w');
     flock($this->lckh,2);
     fwrite($this->lckh,'lck');//lock the datebase
    }
    $rcd=$this->getRcd(0);
    $this->rcdCnt=$rcd[id];
    $this->maxID=$rcd[loc];
    $this->DBend=$rcd[len];
    $rcd=$this->getLeft(0);
    $this->leftCnt=$rcd[loc];
    }
    else $this->isError=1;
  }
  function setRcd($rid,$id,$loc,$len)
  {
    fseek($this->indxh,$rid*12);
    $str=pack('III',$id,$loc,$len);
    fwrite($this->indxh,$str,12);
  }
  function getRcd($rid)
  {
    fseek($this->indxh,$rid*12);
    $str=fread($this->indxh,12);
    $rcd=array();
    $rcd[id]=str2int($str);
    $rcd[loc]=str2int(substr($str,4,4));
    $rcd[len]=str2int(substr($str,8,4));
    return $rcd;
  }
  function setLeft($lid,$loc,$len)
  {
    fseek($this->lfth,$lid*8);
    $str=pack('II',$loc,$len);
    fwrite($this->lfth,$str,8);
  }
  function getLeft($lid)
  {
    fseek($this->lfth,$lid*8);
    $str=fread($this->lfth,8);
    $rcd[loc]=str2int($str);
    $rcd[len]=str2int(substr($str,4,4));
    return $rcd;
  }
  
  function clear()
  {
    $this->setRcd(0,0,0,0);
    $this->setLeft(0,0,0);
  }
  function close()
  {
    @fclose($this->dbh);
    @fclose($this->indxh);
    @fclose($this->lfth);
    @fclose($this->lckh);
  }
  
  function seekSpace($len)
  {
    $res=array('loc'=>0,'len'=>0);
    if ($this->leftCnt<1) return $res;
    $find=0;
    $min=1000000;
    for ($i=$this->leftCnt;$i>0;$i--)
    {
      $res=$this->getLeft($i);
      if ($res[len]==$len) {$find=$i;break;}
      else if($res[len]>$len)
      {
         if ($res[len]-$len<$min)
         {
           $min=$res[len]-$len;
           $find=$i;
         }
      }
    }
    if ($find)
    {
      $res=$this->getLeft($find);
      if ($res[len]<2*$len)
      {
       fseek($this->lfth,($find+1)*8);
       $str=fread($this->lfth,($this->leftCnt-$find)*8);
       fseek($this->lfth,$find*8);
       fwrite($this->lfth,$str);
       $this->leftCnt--;
       $this->setLeft(0,$this->leftCnt,0);
       return $res;
      }
      else
      {
        $rs=array();
        $rs[loc]=$res[loc];
        $rs[len]=$len;
        $res[loc]+=$len;
        $this->setLeft($find,$res[loc],$res[len]-$len);
        return $rs;
      }
    }
    else//fail
    {
      $res[len]=0;
      return $res;
    }
  }
  function insert($content,$len=0)//return with record id
  {
    $res=array('loc'=>0);
    if ($this->mod!='w') return 0;
    if (!$len) $len=strlen($content); 
    if ($len<$this->minLen) $len=$this->minLen;
    if ($this->leftCnt) $res=$this->seekSpace($len);
    if (!$res[len])
    {
      $res[loc]=$this->DBend;
      $res[len]=$len;
    }
    if ($res[loc]+$res[len]>$this->DBend) $this->DBend=$res[loc]+$res[len];
    //echo $this->DBend.'<br>';
    $this->maxID++;
    $this->rcdCnt++;
    $this->setRcd(0,$this->rcdCnt,$this->maxID,$this->DBend);
    $this->setRcd($this->rcdCnt,$this->maxID,$res[loc],$res[len]);
    fseek($this->dbh,$res[loc]);
    fwrite($this->dbh,$content,$len);
    return $this->maxID;
  }
  function findByID($id)
  {
    if ($id<1 or $id>$this->maxID or $this->rcdCnt<1) return 0;
    $left=1;
    $right=$this->rcdCnt;
    while($left<$right)
    {
      $mid=(int)(($left+$right)/2);
      if ($mid==$left or $mid==$right) break;
      $rcd=$this->getRcd($mid);
      if ($rcd[id]==$id) return $mid;
      else if($id<$rcd[id]) $right=$mid;
      else $left=$mid;
    }
    //$rcd=$this->getRcd($mid);
    //if ($rcd[id]==$id) return $mid;
    $rcd=$this->getRcd($left);
    if ($rcd[id]==$id) return $left;
    $rcd=$this->getRcd($right);
    if ($rcd[id]==$id) return $right;
    return 0;
  }
  function delete($id)
  {
    if ($this->mod!='w') return 0;
    $rid=$this->findByID($id);
    if (!$rid) return;
    $res=$this->getRcd($rid);
    fseek($this->indxh,($rid+1)*12);
    $str=fread($this->indxh,($this->rcdCnt-$i)*12);
    fseek($this->indxh,$rid*12);
    fwrite($this->indxh,$str);
    $this->rcdCnt--;
    if ($res[loc]+$res[len]==$this->DBend)
    {
      $this->DBend=$res[loc];
      $this->setRcd(0,$this->rcdCnt,$this->maxID,$this->DBend);
    }
    else
    {
     $this->setRcd(0,$this->rcdCnt,$this->maxID,$this->DBend);
     $this->leftCnt++;
     $this->setLeft(0,$this->leftCnt,0);
     $this->setLeft($this->leftCnt,$res[loc],$res[len]);
    }
  }
  function update($id,$newcontent,$len=0)
  {
    if ($this->mod!='w') return;
    $rid=$this->findByID($id);
    if (!$rid) return;
    if (!$len) $len=strlen($newcontent); 
    $rcd=$this->getRcd($rid);
    if ($rcd[len]<$len)
    {
      $this->leftCnt++;
      $this->setLeft(0,$this->leftCnt,0);
      $this->setLeft($this->leftCnt,$rcd[loc],$rcd[len]);
      $rcd[loc]=$this->DBend;
      $rcd[len]=$len;
      $this->DBend+=$len;
      $this->setRcd(0,$this->rcdCnt,$this->maxID,$this->DBend);
      $this->setRcd($rid,$rcd[id],$rcd[loc],$rcd[len]);
    }
    fseek($this->dbh,$rcd[loc]);
    fwrite($this->dbh,$newcontent,$len);
    //echo $id.'<br>'.$content.'<br>'.$len;
  }
  function selectByRid($rid)
  {
    $res=array('id'=>0,'content'=>'');
    if ($rid<1 or $rid>$this->rcdCnt) return $res;
    else $rcd=$this->getRcd($rid);
    $res[id]=$rcd[id];
    $res[len]=$rcd[len];
    fseek($this->dbh,$rcd[loc]);
    $res[content]=fread($this->dbh,$rcd[len]);
    return $res;
  }
  function select($id)
  {
    return $this->selectByRid($this->findByID($id));
  }
  function backup()
  {
    copy($this->path.'/'.$this->name.'.tdb',$this->path.'/'.$this->name.'.tdb.bck');
    copy($this->path.'/'.$this->name.'.indx',$this->path.'/'.$this->name.'.indx.bck');
    copy($this->path.'/'.$this->name.'.lft',$this->path.'/'.$this->name.'.lft.bck');
  }
  function recover()
  {
    copy($this->path.'/'.$this->name.'.tdb.bck',$this->path.'/'.$this->name.'.tdb');
    copy($this->path.'/'.$this->name.'.indx.bck',$this->path.'/'.$this->name.'.indx');
    copy($this->path.'/'.$this->name.'.lft.bck',$this->path.'/'.$this->name.'.lft');
  }
}
?>

作者的2.0版，生成dbm：

<?
class TxtDB
{
  var $name='';//文本数据库名
  var $path='';
  var $minLen=20;
  var $isError;
  var $dbh;
  var $indxh;
  var $lfth;
  var $lckh;
  var $rcdCnt=0;
  var $maxID=0;
  var $leftCnt=0;
  var $DBend=0;
  var $mod='w';
  function TxtDB($name,$mod='w',$path='bpns_dbm')
  {
    $this->name=$name;
    $this->path=$path.'/'.$name;
    $this->isError=0;
    $this->mod=$mod;
    $path=$this->path;
    if ($name!='')
    {
    @mkdir($this->path,0777);
    if (!file_exists($path.'/'.$name.'.tdb')) $this->dbh=fopen($this->path.'/'.$name.'.tdb','w+');
    else $this->dbh=fopen($path.'/'.$name.'.tdb','r+');
    if (!file_exists($path.'/'.$name.'.indx')) $this->indxh=fopen($this->path.'/'.$name.'.indx','w+');
    else $this->indxh=fopen($path.'/'.$name.'.indx','r+');
    if (!file_exists($path.'/'.$name.'.lft')) $this->lfth=fopen($this->path.'/'.$name.'.lft','w+');
    else $this->lfth=fopen($this->path.'/'.$name.'.lft','r+');
    if ($this->mod=='w')
    {
     $this->lckh=fopen($this->path.'/'.$name.'.lck','w');
     flock($this->lckh,2);
     fwrite($this->lckh,'lck');//lock the datebase
    }
    $rcd=$this->getRcd(0);
    $this->rcdCnt=$rcd[id];
    $this->maxID=$rcd[loc];
    $this->DBend=$rcd[len];
    $rcd=$this->getLeft(0);
    $this->leftCnt=$rcd[loc];
    }
    else $this->isError=1;
  }
  function setRcd($rid,$id,$loc,$len)
  {
    fseek($this->indxh,$rid*12);
    $str=pack('III',$id,$loc,$len);
    fwrite($this->indxh,$str,12);
  }
  function getRcd($rid)
  {
    fseek($this->indxh,$rid*12);
    $str=fread($this->indxh,12);
    $rcd=array();
    $rcd[id]=str2int($str);
    $rcd[loc]=str2int(substr($str,4,4));
    $rcd[len]=str2int(substr($str,8,4));
    return $rcd;
  }
  function setLeft($lid,$loc,$len)
  {
    fseek($this->lfth,$lid*8);
    $str=pack('II',$loc,$len);
    fwrite($this->lfth,$str,8);
  }
  function getLeft($lid)
  {
    fseek($this->lfth,$lid*8);
    $str=fread($this->lfth,8);
    $rcd[loc]=str2int($str);
    $rcd[len]=str2int(substr($str,4,4));
    return $rcd;
  }
  
  function clear()
  {
    $this->setRcd(0,0,0,0);
    $this->setLeft(0,0,0);
  }
  function close()
  {
    @fclose($this->dbh);
    @fclose($this->indxh);
    @fclose($this->lfth);
    @fclose($this->lckh);
  }
  
  function seekSpace($len)
  {
    $res=array('loc'=>0,'len'=>0);
    if ($this->leftCnt<1) return $res;
    $find=0;
    $min=1000000;
    for ($i=$this->leftCnt;$i>0;$i--)
    {
      $res=$this->getLeft($i);
      if ($res[len]==$len) {$find=$i;break;}
      else if($res[len]>$len)
      {
         if ($res[len]-$len<$min)
         {
           $min=$res[len]-$len;
           $find=$i;
         }
      }
    }
    if ($find)
    {
      $res=$this->getLeft($find);
      if ($res[len]<2*$len)
      {
       fseek($this->lfth,($find+1)*8);
       $str=fread($this->lfth,($this->leftCnt-$find)*8);
       fseek($this->lfth,$find*8);
       fwrite($this->lfth,$str);
       $this->leftCnt--;
       $this->setLeft(0,$this->leftCnt,0);
       return $res;
      }
      else
      {
        $rs=array();
        $rs[loc]=$res[loc];
        $rs[len]=$len;
        $res[loc]+=$len;
        $this->setLeft($find,$res[loc],$res[len]-$len);
        return $rs;
      }
    }
    else//fail
    {
      $res[len]=0;
      return $res;
    }
  }
  function insert($content,$len=0)//return with record id
  {
    $res=array('loc'=>0);
    if ($this->mod!='w') return 0;
    if (!$len) $len=strlen($content); 
    if ($len<$this->minLen) $len=$this->minLen;
    if ($this->leftCnt) $res=$this->seekSpace($len);
    if (!$res[len])
    {
      $res[loc]=$this->DBend;
      $res[len]=$len;
    }
    if ($res[loc]+$res[len]>$this->DBend) $this->DBend=$res[loc]+$res[len];
    //echo $this->DBend.'<br>';
    $this->maxID++;
    $this->rcdCnt++;
    $this->setRcd(0,$this->rcdCnt,$this->maxID,$this->DBend);
    $this->setRcd($this->rcdCnt,$this->maxID,$res[loc],$res[len]);
    fseek($this->dbh,$res[loc]);
    fwrite($this->dbh,$content,$len);
    return $this->maxID;
  }
  function findByID($id)
  {
    if ($id<1 or $id>$this->maxID or $this->rcdCnt<1) return 0;
    $left=1;
    $right=$this->rcdCnt;
    while($left<$right)
    {
      $mid=(int)(($left+$right)/2);
      if ($mid==$left or $mid==$right) break;
      $rcd=$this->getRcd($mid);
      if ($rcd[id]==$id) return $mid;
      else if($id<$rcd[id]) $right=$mid;
      else $left=$mid;
    }
    //$rcd=$this->getRcd($mid);
    //if ($rcd[id]==$id) return $mid;
    $rcd=$this->getRcd($left);
    if ($rcd[id]==$id) return $left;
    $rcd=$this->getRcd($right);
    if ($rcd[id]==$id) return $right;
    return 0;
  }
  function delete($id)
  {
    if ($this->mod!='w') return 0;
    $rid=$this->findByID($id);
    if (!$rid) return;
    $res=$this->getRcd($rid);
    fseek($this->indxh,($rid+1)*12);
    $str=fread($this->indxh,($this->rcdCnt-$i)*12);
    fseek($this->indxh,$rid*12);
    fwrite($this->indxh,$str);
    $this->rcdCnt--;
    if ($res[loc]+$res[len]==$this->DBend)
    {
      $this->DBend=$res[loc];
      $this->setRcd(0,$this->rcdCnt,$this->maxID,$this->DBend);
    }
    else
    {
     $this->setRcd(0,$this->rcdCnt,$this->maxID,$this->DBend);
     $this->leftCnt++;
     $this->setLeft(0,$this->leftCnt,0);
     $this->setLeft($this->leftCnt,$res[loc],$res[len]);
    }
  }
  function update($id,$newcontent,$len=0)
  {
    if ($this->mod!='w') return;
    $rid=$this->findByID($id);
    if (!$rid) return;
    if (!$len) $len=strlen($newcontent); 
    $rcd=$this->getRcd($rid);
    if ($rcd[len]<$len)
    {
      $this->leftCnt++;
      $this->setLeft(0,$this->leftCnt,0);
      $this->setLeft($this->leftCnt,$rcd[loc],$rcd[len]);
      $rcd[loc]=$this->DBend;
      $rcd[len]=$len;
      $this->DBend+=$len;
      $this->setRcd(0,$this->rcdCnt,$this->maxID,$this->DBend);
      $this->setRcd($rid,$rcd[id],$rcd[loc],$rcd[len]);
    }
    fseek($this->dbh,$rcd[loc]);
    fwrite($this->dbh,$newcontent,$len);
    //echo $id.'<br>'.$content.'<br>'.$len;
  }
  function selectByRid($rid)
  {
    $res=array('id'=>0,'content'=>'');
    if ($rid<1 or $rid>$this->rcdCnt) return $res;
    else $rcd=$this->getRcd($rid);
    $res[id]=$rcd[id];
    $res[len]=$rcd[len];
    fseek($this->dbh,$rcd[loc]);
    $res[content]=fread($this->dbh,$rcd[len]);
    //$res[rid]=$rid;
    return $res;
  }
  function select($id)
  {
    return $this->selectByRid($this->findByID($id));
  }
  function backup()
  {
    copy($this->path.'/'.$this->name.'.tdb',$this->path.'/'.$this->name.'.tdb.bck');
    copy($this->path.'/'.$this->name.'.indx',$this->path.'/'.$this->name.'.indx.bck');
    copy($this->path.'/'.$this->name.'.lft',$this->path.'/'.$this->name.'.lft.bck');
  }
  function recover()
  {
    copy($this->path.'/'.$this->name.'.tdb.bck',$this->path.'/'.$this->name.'.tdb');
    copy($this->path.'/'.$this->name.'.indx.bck',$this->path.'/'.$this->name.'.indx');
    copy($this->path.'/'.$this->name.'.lft.bck',$this->path.'/'.$this->name.'.lft');
  }
}

?>