Question

我在python中有一个curl请求，它向writefunction（CURLOPT_WRITEFUNCTION）输出大量数据。如果满足某个条件，我希望能够从writefunction中取消curl请求。我已经尝试过使用ch.close（），但是错误说它在执行时无法关闭请求。还有其他方法让它停止写函数吗？继承我的代码：

    self.ch = pycurl.Curl()

    self.ch.setopt(pycurl.URL, file_url)
    self.ch.setopt(pycurl.CONNECTTIMEOUT, 60)
    self.ch.setopt(pycurl.WRITEFUNCTION, self.WriteWrapper)
    self.ch.setopt(pycurl.HEADERFUNCTION, self.ParseHeaders)
    self.ch.setopt(pycurl.FOLLOWLOCATION, True)
    self.ch.setopt(pycurl.COOKIE, cookies[file_host])
    self.ch.setopt(pycurl.HTTPHEADER, self.headers_received)

    self.ch.perform()
    self.ch.close()


def do_POST(self):
    return self.do_GET()

def WriteWrapper(self, data):
    if self.do_curl_request:
        try:
            return self.wfile.write(data)
        except:
            self.ch.close() # This doesn't work :(

Answer 1

如果从write函数返回的数字不等于它认为正在编写的数字，那么

pycurl会引发错误，因此返回-1或在write函数内引发异常将导致它引发pycurl.error。请注意，返回“无”将被解释为'all bytes written'.

>>> class Writer:
...   def __init__(self):
...     self.count = 0
...   def write(self, data):
...     print "Write called", len(data)
...     return -1
...
>>> curl = pycurl.Curl()
>>> writer = Writer()
>>> curl.setopt(pycurl.WRITEFUNCTION, writer.write)
>>> curl.setopt(pycurl.URL, "file:///some_big_file.txt")
>>> curl.perform()
Write called 16383
pycurl.error: invalid return value for write callback -1 16383
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
pycurl.error: (23, 'Failed writing body (0 != 16383)')

如何取消WRITEFUNCTION的卷曲请求？

1 个答案: