<?php
class CtbClass {

var $file;
var $index;

//建立一个文件并写入输入
function null_write($new)
{
$f=fopen($this->file,"w");
flock($f,LOCK_EX);
fputs($f,$new);
fclose($f);
}
// 添加数据记录到文件末端
function add_write($new) {
$f=fopen($this->file,"a");
flock($f,LOCK_EX);
fputs($f,$new);
fclose($f);
}
// 配合readfile()的返回一起使用,把一行数据转换为一维数组
function make_array($line) {
$array = explode("\x0E",$line);
return $array;
}

//把为一维数组转换一行数据
function join_array($line) {
$array = join("\x0E",$line);
return $array;
}
// 返回数据文件的总行数
function getlines() {
$f=file($this->file);
return count($f);
}
// 返回下一行的数据记录(备用)
function next_line() {
$this->index=$this->index++;
return $this->get();
}

// 返回上一行的数据记录(备用)
function prev_line() {
$this->index=$this->index--;
return $this->get();
}
// 返回当前行的数据记录数据较小
function get() {
$f=fopen($this->file,"r");
flock($f,LOCK_SH);
for($i=0;$i<=$this->index;$i++) {
$rec=fgets($f,1024);
}
$line=explode("\x0E",$rec);
fclose($f);
return $line;
}
// 返回当前行的数据记录数据较大
function get_big_file() {
$f=fopen($this->file,"r");
flock($f,LOCK_SH);
for($i=0;$i<=$this->index;$i++) {
$rec=fgets($f,1024*5);
}
$line=explode("\x0E",$rec);
fclose($f);
return $line;
}
// 打开数据文件---以一维数组返回文件内容
function read_file() {
if (file_exists($this->file)) {
$line =file($this->file);
}
return $line;
}
// 打开数据文件---以二维数组返回文件内容
function openFile() {
if (file_exists($this->file)) {
$f =file($this->file);
$lines = array();
foreach ($f as $rawline) {
$tmpline = explode("\x0E",$rawline);
array_push($lines, $tmpline);
}
}
return $lines;
}
// 传入一个数组,合并成一行数据,重写整个文件
function overwrite($array){
$newline = implode("\x0E",$array);
$f = fopen($this->file,"w");
flock($f,LOCK_EX);
fputs($f,$newline);
fclose($f);
}

// 添加一行数据记录到文件末端
function add_line($array,$check_n=1) {
$s=implode("\x0E",$array);
$f=fopen($this->file,"a");
flock($f,LOCK_EX);
fputs($f,$s);
if ($check_n==1) fputs($f,"\n");
fclose($f);
}

// 插入一行数据记录到文件最前面
function insert_line($array) {
$newfile = implode("\x0E",$array);
$f = fopen($this->file,"r");
flock($f,LOCK_SH);
while ($line = fgets($f,1024)) {
$newfile .= $line;
}
fclose($f);
$f = fopen($this->file,"w");
flock($f,LOCK_EX);
fputs($f,$newfile);
fclose($f);
}

// 更新所有符合条件的数据记录,适用于每行字节数据较大的情况
function update($column,$query_string,$update_array) {
$update_string = implode("\x0E",$update_array);
$newfile = "";
$fc=file($this->file);
$f=fopen($this->file,"r");
flock($f,LOCK_SH);
for ($i=0;$i<count($fc);$i++) {
$list = explode("\x0E",$fc[$i]);
if ($list[$column] != $query_string) {
$newfile = $newfile.chop($fc[$i])."\n";
} else {
$newfile = $newfile.$update_string;
}
}
fclose($f);
$f=fopen($this->file,"w");
flock($f,LOCK_EX);
fputs($f,$newfile);
fclose($f);
}

// 更新所有符合条件的数据记录,适用于每行字节数据较小的情况
function update2($column,$query_string,$update_array) {
$newline = implode("\x0E",$update_array);
$newfile = "";
$f = fopen($this->file,"r");
flock($f,LOCK_SH);
while ($line = fgets($f,1024)) {
$tmpLine = explode("\x0E",$line);
if ($tmpLine[$column] == $query_string) {
$newfile .= $newline;
} else {
$newfile .= $line;
}
}
fclose($f);
$f = fopen($this->file,"w");
flock($f,LOCK_EX);
fputs($f,$newfile);
fclose($f);
}

// 删除所有符合条件的数据记录,适用于每行字节数据较大的情况
function delete($column,$query_string) {
$newfile = "";
$fc=file($this->file);
$f=fopen($this->file,"r");
flock($f,LOCK_SH);
for ($i=0;$i<count($fc);$i++) {
$list = explode("\x0E",$fc[$i]);
if ($list[$column] != $query_string) {
$newfile = $newfile.chop($fc[$i])."\n";
}
}
fclose($f);
$f=fopen($this->file,"w");
flock($f,LOCK_EX);
fputs($f,$newfile);
fclose($f);
}

// 删除所有符合条件的数据记录,适用于每行字节数据较小的情况
function delete2($column,$query_string){
$newfile = "";
$f = fopen($this->file,"r");
flock($f,LOCK_SH);
while ($line = fgets($f,1024)) {
$tmpLine = explode("\x0E",$line);
if ($tmpLine[$column] != $query_string) {
$newfile .= $line;
}
}
fclose($f);
$f = fopen($this->file,"w");
flock($f,LOCK_EX);
fputs($f,$newfile);
fclose($f);
}

//取得一个文件里某个字段的最大值
function get_max_value($column) {
$tlines = file($this->file);
for ($i=0;$i<=count($tlines);$i++) {
$line=explode("\x0E",$tlines[$i]);
$get_value[]=$line[$column];
}
$get_max_value = max($get_value);
return $get_max_value;
}


// 根据数据文件的某个字段是否包含$query_string进行查询,以二维数组返回所有符合条件的数据
function select($column, $query_string) {
$tline = $this->openfile();
$lines = array();
foreach ($tline as $line) {
if ($line[$column] == $query_string) {
array_push($lines, $line);
}
}

return $lines;
}

// 功能与function select()一样,速度可能略有提升
function select2($column, $query_string) {
if (file_exists($this->file)) {
$tline = $this->read_file();
foreach ($tline as $tmpLine) {
$line = $this->make_array($tmpLine);
if ($line[$column] == $query_string) {
$lines[]=$tmpLine;
}
}
}

return $lines;
}

// 根据数据文件的某个字段是否包含$query_string进行查询,以一维数组返回第一个符合条件的数据
function select_line($column, $query_string) {
$tline = $this->read_file();
foreach ($tline as $tmpLine) {
$line = $this->make_array($tmpLine);
if ($line[$column] == $query_string) {
return $line;
break;
}
}
}
// select next/prev line(next_prev ==> 1/next, 2/prev) by cx
function select_next_prev_line($column, $query_string, $next_prev) {
$tline = $this->read_file();
$line_key_end = count($tline) - 1;
$line_key = -1;
foreach ($tline as $tmpLine) {
$line_key++;
$line = $this->make_array($tmpLine);
if ($next_prev == 1) { // next?
if ($line[$column] == $query_string) {
if ($line_key == 0) {
return 0;
} else {
$line_key_up = $line_key - 1;
return $up_line;
}
} else {
$up_line = $line;
}
} elseif ($next_prev == 2) { // prev?
if ($line[$column] == $query_string) {
if ($line_key == $line_key_end) {
return 0;
} else {
$line_key_down = $line_key + 1;
break;
}
}
} else {
return 0;
}
}
$down_line = $this->make_array($tline[$line_key_down]);
return $down_line;
}


}
?>