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某文本数据库blog作者写的文本数据库操作类，很不错

程序员文章站 2024-01-18 20:24:40
...

数据|数据库

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 $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 {
$min=$res[len]-$len;
$find=$i;
}
}
}
if ($find)
{
$res=$this->getLeft($find);
if ($res[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 ($lenminLen) $len=$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.'
';
$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 ($id$this->maxID or $this->rcdCnt $left=1;
$right=$this->rcdCnt;
while($left {
$mid=(int)(($left+$right)/2);
if ($mid==$left or $mid==$right) break;
$rcd=$this->getRcd($mid);
if ($rcd[id]==$id) return $mid;
else if($id 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] {
$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 $id.'
'.$content.'
'.$len;
}
function selectByRid($rid)
{
$res=array('id'=>0,'content'=>'');
if ($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 $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 {
$min=$res[len]-$len;
$find=$i;
}
}
}
if ($find)
{
$res=$this->getLeft($find);
if ($res[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 ($lenminLen) $len=$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.'
';
$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 ($id$this->maxID or $this->rcdCnt $left=1;
$right=$this->rcdCnt;
while($left {
$mid=(int)(($left+$right)/2);
if ($mid==$left or $mid==$right) break;
$rcd=$this->getRcd($mid);
if ($rcd[id]==$id) return $mid;
else if($id 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] {
$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 $id.'
'.$content.'
'.$len;
}
function selectByRid($rid)
{
$res=array('id'=>0,'content'=>'');
if ($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');
}
}

?>




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