关于python CGI 上传大文件的问题

wudiliusha 2010-11-23 04:11:03

想写一个动态的python CGI网页程序，功能是实现上传较大文件，大概在20M左右，但是如果是一般的代码这样是行不通的，以下是代码，如果小文件还是没问题的。

#!/usr/bin/python

from cgi import FieldStorage

from os import environ

from cStringIO import StringIO

from urllib import quote, unquote

from string import capwords, strip, split, join

from time import ctime



class AdvCGI(object):



  header = 'Content-Type: text/html\n\n'  #定义头部

  url = 'upload.py'  #处理上传的文件名



  formhtml = '''<HTML><HEAD><TITLE>

    Advanced CGI Demo</TITLE></HEAD>

    <BODY><H2>Advanced CGI Demo Form</H2>

    <FORM METHOD=post ACTION="%s" ENCTYPE="multipart/form-data">

    <H3>Enter file to upload</H3>

    <INPUT TYPE=file NAME=upfile VALUE="%s" SIZE=45>

    <P><INPUT TYPE=submit>

    </FORM></BODY></HTML>'''  #表单基本html



  def showForm(self): # 显示上传表单

    print AdvCGI.header + AdvCGI.formhtml % (AdvCGI.url,'NONE')



  errhtml = '''<HTML><HEAD><TITLE>

      Advanced CGI Demo</TITLE></HEAD>

      <BODY><H3>ERROR</H3>

      <B>%s</B><P>

      <FORM><INPUT TYPE=button VALUE=Back

      ONCLICK="window.history.back()"></FORM>

      </BODY></HTML>'''



  def showError(self):  #显示错误提示

    print AdvCGI.header + AdvCGI.errhtml % (self.error)



  reshtml = '''<HTML><HEAD><TITLE>

      Advanced CGI Demo</TITLE></HEAD>

      <BODY><H2>Your Uploaded Data</H2>

      <H3>Your uploaded file...<BR>

      Name: <I>%s</I><BR>

      Click <A HREF="%s"><B>here</B></A> to return to form.

      </BODY></HTML>'''





  def doResults(self):# 显示结果函数

    MAXBYTES = 1024000 #定义上传文件大小函数，单位为b

    filedata = ''  #初始化文件内容

    stop = ''  #初始化判断

    filename = self.fn  #获取文件名

    n = ctime()

    tmpname = '-'.join(n.split()[-1:]+n.split()[3].split(':'))+'.webtmp'  #设置需要保存文件名称，按日期保存

    

    while len(filedata) < MAXBYTES:# 读文件

      data = self.fp.readline()

      if data == '': break

      filedata += data

    else: # 如果超出文件大小

      error =  '... <B><I>(file truncated due to size)</I></B>' #提示

      self.showError() #显示错误信息

      stop = 'True' #停止

    self.fp.close() #关闭文件

    if filedata == '': #如果文件值为空

      filedata = \

       '<B><I>(file upload error or file not given)</I></B>'

      filename = self.fn

    if stop != 'True':  #这一步作判断，如果为真则保存文件，如果文件超出大小则不保存

      temp=open(tmpname,'w+')

      temp.write(filedata)

      temp.close()

      print AdvCGI.header + AdvCGI.reshtml % \

      (filename, AdvCGI.url)



  def go(self): # determine which page to return

    self.error = ''

    form = FieldStorage()

    if form.keys() == []:

      self.showForm()

      return



    if form.has_key('upfile'):

      upfile = form["upfile"]

      self.fn = upfile.filename or ''

      if upfile.file:

        self.fp = upfile.file

      else:

        self.fp = StringIO('(no data)')

    else:

      self.fp = StringIO('(no file)')

      self.fn = ''



    if not self.error:

      self.doResults()

    else:

      self.showError()



if __name__ == '__main__':

  page = AdvCGI()

  page.go()