Source code for oss2.http
# -*- coding: utf-8 -*-
"""
oss2.http
~~~~~~~~
这个模块包含了HTTP Adapters。尽管OSS Python SDK内部使用requests库进行HTTP通信,但是对使用者是透明的。
该模块中的 `Session` 、 `Request` 、`Response` 对requests的对应的类做了简单的封装。
"""
import platform
import requests
from requests.structures import CaseInsensitiveDict
from . import __version__, defaults
from .compat import to_bytes
from .exceptions import RequestError
from .utils import file_object_remaining_bytes, SizedFileAdapter
_USER_AGENT = 'aliyun-sdk-python/{0}({1}/{2}/{3};{4})'.format(
__version__, platform.system(), platform.release(), platform.machine(), platform.python_version())
[docs]class Session(object):
"""属于同一个Session的请求共享一组连接池,如有可能也会重用HTTP连接。"""
def __init__(self):
self.session = requests.Session()
psize = defaults.connection_pool_size
self.session.mount('http://', requests.adapters.HTTPAdapter(pool_connections=psize, pool_maxsize=psize))
self.session.mount('https://', requests.adapters.HTTPAdapter(pool_connections=psize, pool_maxsize=psize))
[docs] def do_request(self, req, timeout):
try:
return Response(self.session.request(req.method, req.url,
data=req.data,
params=req.params,
headers=req.headers,
stream=True,
timeout=timeout))
except requests.RequestException as e:
raise RequestError(e)
[docs]class Request(object):
def __init__(self, method, url,
data=None,
params=None,
headers=None,
app_name=''):
self.method = method
self.url = url
self.data = _convert_request_body(data)
self.params = params or {}
if not isinstance(headers, CaseInsensitiveDict):
self.headers = CaseInsensitiveDict(headers)
else:
self.headers = headers
# tell requests not to add 'Accept-Encoding: gzip, deflate' by default
if 'Accept-Encoding' not in self.headers:
self.headers['Accept-Encoding'] = None
if 'User-Agent' not in self.headers:
if app_name:
self.headers['User-Agent'] = _USER_AGENT + '/' + app_name
else:
self.headers['User-Agent'] = _USER_AGENT
_CHUNK_SIZE = 8 * 1024
[docs]class Response(object):
def __init__(self, response):
self.response = response
self.status = response.status_code
self.headers = response.headers
# When a response contains no body, iter_content() cannot
# be run twice (requests.exceptions.StreamConsumedError will be raised).
# For details of the issue, please see issue #82
#
# To work around this issue, we simply return b'' when everything has been read.
#
# Note you cannot use self.response.raw.read() to implement self.read(), because
# raw.read() does not uncompress response body when the encoding is gzip etc., and
# we try to avoid depends on details of self.response.raw.
self.__all_read = False
[docs] def read(self, amt=None):
if self.__all_read:
return b''
if amt is None:
content_list = []
for chunk in self.response.iter_content(_CHUNK_SIZE):
content_list.append(chunk)
content = b''.join(content_list)
self.__all_read = True
return content
else:
try:
return next(self.response.iter_content(amt))
except StopIteration:
self.__all_read = True
return b''
def __iter__(self):
return self.response.iter_content(_CHUNK_SIZE)
# requests对于具有fileno()方法的file object,会用fileno()的返回值作为Content-Length。
# 这对于已经读取了部分内容,或执行了seek()的file object是不正确的。
#
# _convert_request_body()对于支持seek()和tell() file object,确保是从
# 当前位置读取,且只读取当前位置到文件结束的内容。
def _convert_request_body(data):
data = to_bytes(data)
if hasattr(data, '__len__'):
return data
if hasattr(data, 'seek') and hasattr(data, 'tell'):
return SizedFileAdapter(data, file_object_remaining_bytes(data))
return data