php利用SPL实现针对大文件的读取

<?php

/*php 利用SPL实现针对大文件的读取*/header("Content-type: text/html; charset=utf-8");set_time_limit(0);class CsvReader {    private $csv_file;    private $spl_object = null;    private $error;    public function __construct($csv_file = '') {        if($csv_file && file_exists($csv_file)) {            $this->csv_file = $csv_file;        }    }    public function set_csv_file($csv_file) {        if(!$csv_file || !file_exists($csv_file)) {            $this->error = 'File invalid';            return false;        }        $this->csv_file = $csv_file;        $this->spl_object = null;    }    public function get_csv_file() {        return $this->csv_file;    }    private function _file_valid($file = '') {        $file = $file ? $file : $this->csv_file;        if(!$file || !file_exists($file)) {            return false;        }        if(!is_readable($file)) {            return false;        }        return true;    }    private function _open_file() {        if(!$this->_file_valid()) {            $this->error = 'File invalid';            return false;        }        if($this->spl_object == null) {            $this->spl_object = new SplFileObject($this->csv_file, 'rb');        }        return true;    }    public function get_data($length = 0, $start = 0) {        if(!$this->_open_file()) {            return false;        }        $length = $length ? $length : $this->get_lines();        $start = $start - 1;        $start = ($start < 0) ? 0 : $start;        $data = array();        $this->spl_object->seek($start);        while ($length-- && !$this->spl_object->eof()) {            $data[] = $this->spl_object->fgetcsv();            $this->spl_object->next();        }        return $data;    }    public function get_lines() {        if(!$this->_open_file()) {            return false;        }        $this->spl_object->seek(filesize($this->csv_file));        return $this->spl_object->key();    }    public function get_error() {        return $this->error;    }}$csv_file = 'aaa.csv';$csvreader = new CsvReader($csv_file);$line_number = $csvreader->get_lines();$page = isset($_GET['p']) ? intval($_GET['p']) : 1;if($page == 1){    @unlink('./result.txt');    @unlink('./error_info_not_find.txt');}$num = 100;$total_page = ceil($line_number/$num);if($page > $total_page){    echo "处理结束";exit();}$current_num = ($page-1)*$num+1;$data = $csvreader->get_data($num,$current_num);foreach($data as $key=>$value){    $catId = $value[0];    $Id = $value[1];    $time = strtotime($value[5]);    if($catId != "" && $Id !="" && $time !=""){        $url = 'http://fj.china.com.cn/'.date('Y-m/d',$time).'/content_'.$Id.'.htm';        file_put_contents('./result.txt',$url.PHP_EOL,FILE_APPEND);    }else{        file_put_contents('./error_info_not_find.txt',"catId:$catId Id:$Id time:$time".PHP_EOL,FILE_APPEND);    }}echo "总共:$total_page 页 当前$page 页 完成度 ".round($page/$total_page*100,2)."%";echo '<script language="javascript" type="text/javascript">window.location.href="./a.php?p='.++$page.'"</script>';?>