Browse Source

Replace pyCurl with Requests

Only tested with v1.1.0.  It's not clear how well older versions will
work.
tags/nilmdb-1.2
Jim Paris 11 years ago
parent
commit
50a4a60786
5 changed files with 91 additions and 213 deletions
  1. +2
    -3
      nilmdb/client/client.py
  2. +57
    -164
      nilmdb/client/httpclient.py
  3. +6
    -7
      nilmdb/server/server.py
  4. +21
    -34
      tests/test_client.py
  5. +5
    -5
      tests/test_cmdline.py

+ 2
- 3
nilmdb/client/client.py View File

@@ -156,7 +156,7 @@ class Client(object):
params["start"] = float_to_string(start)
if end is not None:
params["end"] = float_to_string(end)
return self.http.get_gen("stream/intervals", params, retjson = True)
return self.http.get_gen("stream/intervals", params)

def stream_extract(self, path, start = None, end = None, count = False):
"""
@@ -176,8 +176,7 @@ class Client(object):
params["end"] = float_to_string(end)
if count:
params["count"] = 1

return self.http.get_gen("stream/extract", params, retjson = False)
return self.http.get_gen("stream/extract", params)

def stream_count(self, path, start = None, end = None):
"""


+ 57
- 164
nilmdb/client/httpclient.py View File

@@ -6,21 +6,7 @@ from nilmdb.client.errors import ClientError, ServerError, Error

import simplejson as json
import urlparse
import pycurl
import cStringIO
import threading

import warnings # can remove

class HTTPClientLock(object):
def __init__(self):
self.lock = threading.Lock()
def __enter__(self):
if not self.lock.acquire(False):
raise Exception("Client is already performing a request, and "
"nested or concurrent calls are not supported.")
def __exit__(self, exc_type, exc_value, traceback):
self.lock.release()
import requests

class HTTPClient(object):
"""Class to manage and perform HTTP requests from the client"""
@@ -32,42 +18,19 @@ class HTTPClient(object):
if '://' not in reparsed:
reparsed = urlparse.urlparse("http://" + baseurl).geturl()
self.baseurl = reparsed
self.multi = pycurl.CurlMulti()
self.curl = pycurl.Curl()
# Add and remove the handle to workaround a curl bug (debian #701713)
self.multi.add_handle(self.curl)
self.multi.remove_handle(self.curl)
#self.multi = nilmdb.utils.threadsafety.verify_proxy(pycurl.CurlMulti)()
#self.curl = nilmdb.utils.threadsafety.verify_proxy(pycurl.Curl)()
self.curl.setopt(pycurl.SSL_VERIFYHOST, 2)
self.curl.setopt(pycurl.FOLLOWLOCATION, 1)
self.curl.setopt(pycurl.MAXREDIRS, 5)
self.curl.setopt(pycurl.NOSIGNAL, 1)
self.lock = HTTPClientLock()
self._setup_url()

def _setup_url(self, url = "", params = None, post = False):
url = urlparse.urljoin(self.baseurl, url)
if params is None:
encoded = ""
else:
encoded = nilmdb.utils.urllib.urlencode(params)
self.curl.setopt(pycurl.POST, 1 if post else 0)
if post:
self.curl.setopt(pycurl.POSTFIELDS, encoded)
else:
if encoded:
url = urlparse.urljoin(url, '?' + encoded)
self.curl.setopt(pycurl.URL, url)
self.url = url
# Build Requests session object, enable SSL verification
self.session = requests.Session()
self.session.verify = True

# Saved headers, for tests to check
self._headers = {}

def _check_error(self, code, body):
def _handle_error(self, url, code, body):
# Default variables for exception. We use the entire body as
# the default message, in case we can't extract it from a JSON
# response.
if code == 200:
return
args = { "url" : self.url,
args = { "url" : url,
"status" : str(code),
"message" : body,
"traceback" : None }
@@ -91,137 +54,67 @@ class HTTPClient(object):
else:
raise Error(**args)

def _req_generator(self, url, params, post_params = False):
"""
Like self._req(), but returns a generator that spits out
arbitrary-sized chunks of the resulting data.
"""
self._setup_url(url, params, post_params)
data = []
error_body = []
self.headers = cStringIO.StringIO()
req_status = [None]
req_expect_status = [True]
def header_callback(data):
"""Process header data as it comes in, so we can strip out
the status line."""
# This weirdness is to handle the fact that
# there can be a "HTTP/1.1 100 Continue" block before
# the real response. Save all statuses that we see.
if req_expect_status[0]:
req_status[0] = int(data.split(" ")[1])
req_expect_status[0] = False
elif data == "\r\n":
req_expect_status[0] = True
self.headers.write(data)
self.curl.setopt(pycurl.HEADERFUNCTION, header_callback)
def close(self):
self.session.close()

# Use the Multi object so we don't have to block in a callback
def write_callback(newdata):
data.append(newdata)
self.curl.setopt(pycurl.WRITEFUNCTION, write_callback)
self.multi.add_handle(self.curl)
def _do_req(self, method, url, query_data, body_data, stream):
url = urlparse.urljoin(self.baseurl, url)
try:
while True:
self.multi.select()
with nilmdb.utils.Timer("perform"):
(ret, handles) = self.multi.perform()
# Check data first
if len(data):
if req_status[0] == 200:
# If we had a 200 response, yield the data to caller.
yield "".join(data)
else:
# Otherwise, collect it into an error string.
error_body.extend(data)
data = []
# If we got data, we're doing well; call perform again
continue
(in_queue, ok_objects, error_objects) = self.multi.info_read()
if error_objects:
raise ServerError(status = "502 Error",
url = self.url,
message = error_objects[0][2])
if ret == pycurl.E_CALL_MULTI_PERFORM:
continue
if handles == 0:
break
finally:
# Have to pull out info before removing handle
self._num_connects = self.curl.getinfo(pycurl.NUM_CONNECTS)
code = self.curl.getinfo(pycurl.RESPONSE_CODE)
# Remove handle
self.multi.remove_handle(self.curl)
self._check_error(code, "".join(error_body))

def _req(self, url, params, post_params = False):
"""
GET or POST that returns raw data. Returns the body
data as a string, or raises an error if it contained an error.
"""
print "_req", url, params, post_params
body = []
for data in self._req_generator(url, params, post_params):
body.append(data)
return "".join(body)

def close(self):
with self.lock:
self.curl.close()
response = self.session.request(method, url,
params = query_data,
data = body_data)
except requests.RequestException as e:
raise ServerError(status = "502 Error", url = url,
message = str(e.message))
if response.status_code != 200:
self._handle_error(url, response.status_code, response.content)
self._headers = response.headers
if response.headers["content-type"] in ("application/json",
"application/x-json-stream"):
return (response, True)
else:
return (response, False)

def _iterate_lines(self, it):
# Normal versions that return data directly
def _req(self, method, url, query = None, body = None):
"""
Given an iterator that returns arbitrarily-sized chunks
of data, return '\n'-delimited lines of text
Make a request and return the body data as a string or parsed
JSON object, or raise an error if it contained an error.
"""
partial = ""
for chunk in it:
partial += chunk
lines = partial.split("\n")
for line in lines[0:-1]:
yield line
partial = lines[-1]
if partial != "":
yield partial

def _maybe_json(self, retjson, str):
"""Parse str as JSON if retjson is true, otherwise return
it directly."""
if retjson:
return json.loads(str)
return str
(response, isjson) = self._do_req(method, url, query, body, False)
if isjson:
return json.loads(response.content)
return response.content

# Normal versions that return data directly
def get(self, url, params = None, retjson = True):
def get(self, url, params = None):
"""Simple GET (parameters in URL)"""
with self.lock:
self.curl.setopt(pycurl.UPLOAD, 0)
self.curl.setopt(pycurl.READFUNCTION, lambda: None)
return self._maybe_json(retjson, self._req(url, params, False))
return self._req("GET", url, params, None)

def post(self, url, params = None, retjson = True):
def post(self, url, params = None):
"""Simple POST (parameters in body)"""
with self.lock:
self.curl.setopt(pycurl.UPLOAD, 0)
self.curl.setopt(pycurl.READFUNCTION, lambda: None)
return self._maybe_json(retjson, self._req(url, params, True))
return self._req("POST", url, None, params)

def put(self, url, data, params = None, retjson = True):
def put(self, url, data, params = None):
"""Simple PUT (parameters in URL, data in body)"""
with self.lock:
self.curl.setopt(pycurl.UPLOAD, 1)
data = cStringIO.StringIO(data)
self.curl.setopt(pycurl.READFUNCTION, data.read)
return self._maybe_json(retjson, self._req(url, params, False))
return self._req("PUT", url, params, data)

# Generator versions that return data one line at a time.
def get_gen(self, url, params = None, retjson = True):
"""Simple GET that yields one resonse line at a time"""
with self.lock:
self.curl.setopt(pycurl.UPLOAD, 0)
self.curl.setopt(pycurl.READFUNCTION, lambda: None)
for line in self._iterate_lines(self._req_generator(url, params)):
yield self._maybe_json(retjson, line)
def _req_gen(self, method, url, query = None, body = None):
"""
Make a request and return a generator that gives back strings
or JSON decoded lines of the body data, or raise an error if
it contained an eror.
"""
(response, isjson) = self._do_req(method, url, query, body, True)
for line in response.iter_lines():
if isjson:
yield json.loads(line)
else:
yield line

def get_gen(self, url, params = None):
"""Simple GET (parameters in URL) returning a generator"""
return self._req_gen("GET", url, params)

# Not much use for a POST or PUT generator, since they don't
# return much data.

+ 6
- 7
nilmdb/server/server.py View File

@@ -277,17 +277,16 @@ class Stream(NilmApp):
# /stream/intervals?path=/newton/prep&start=1234567890.0&end=1234567899.0
@cherrypy.expose
@chunked_response
@response_type("text/plain")
@response_type("application/x-json-stream")
def intervals(self, path, start = None, end = None):
"""
Get intervals from backend database. Streams the resulting
intervals as JSON strings separated by newlines. This may
intervals as JSON strings separated by CR LF pairs. This may
make multiple requests to the nilmdb backend to avoid causing
it to block for too long.

Note that the response type is set to 'text/plain' even
though we're sending back JSON; this is because we're not
really returning a single JSON object.
Note that the response type is the non-standard
'application/x-json-stream' for lack of a better option.
"""
if start is not None:
start = float(start)
@@ -307,8 +306,8 @@ class Stream(NilmApp):
def content(start, end):
# Note: disable chunked responses to see tracebacks from here.
while True:
(intervals, restart) = self.db.stream_intervals(path, start, end)
response = ''.join([ json.dumps(i) + "\n" for i in intervals ])
(ints, restart) = self.db.stream_intervals(path, start, end)
response = ''.join([ json.dumps(i) + "\r\n" for i in ints ])
yield response
if restart == 0:
break


+ 21
- 34
tests/test_client.py View File

@@ -275,13 +275,6 @@ class TestClient(object):
with assert_raises(ClientError) as e:
client.stream_remove("/newton/prep", 123, 120)

# Test the exception we get if we nest requests
with assert_raises(Exception) as e:
for data in client.stream_extract("/newton/prep"):
for line in client.stream_intervals("/newton/prep"):
pass
in_("not supported", str(e.exception))

# Test count
eq_(client.stream_count("/newton/prep"), 14400)

@@ -311,16 +304,6 @@ class TestClient(object):
with assert_raises(ServerError) as e:
client.http.get_gen("http://nosuchurl/").next()

# Check non-json version of string output
eq_(json.loads(client.http.get("/stream/list",retjson=False)),
client.http.get("/stream/list",retjson=True))

# Check non-json version of generator output
aa = list(client.http.get_gen("/stream/list",retjson=False))
bb = list(client.http.get_gen("/stream/list",retjson=True))
for (a, b) in itertools.izip(aa, bb):
eq_(json.loads(a), b)

# Check 404 for missing streams
for function in [ client.stream_intervals, client.stream_extract ]:
with assert_raises(ClientError) as e:
@@ -339,37 +322,41 @@ class TestClient(object):
client = nilmdb.Client(url = testurl)
http = client.http

# Use a warning rather than returning a test failure, so that we can
# still disable chunked responses for debugging.
# Use a warning rather than returning a test failure for the
# transfer-encoding, so that we can still disable chunked
# responses for debugging.

def headers():
h = ""
for (k, v) in http._headers.items():
h += k + ": " + v + "\n"
return h.lower()

# Intervals
x = http.get("stream/intervals", { "path": "/newton/prep" },
retjson=False)
headers = http._headers.getvalue()
lines_(x, 1)
if "Transfer-Encoding: chunked" not in headers:
x = http.get("stream/intervals", { "path": "/newton/prep" })
if "transfer-encoding: chunked" not in headers():
warnings.warn("Non-chunked HTTP response for /stream/intervals")
if "Content-Type: text/plain;charset=utf-8" not in headers:
raise AssertionError("/stream/intervals is not text/plain:\n" +
headers)
if "content-type: application/x-json-stream" not in headers():
raise AssertionError("/stream/intervals content type "
"is not application/x-json-stream:\n" +
headers())

# Extract
x = http.get("stream/extract",
{ "path": "/newton/prep",
"start": "123",
"end": "124" }, retjson=False)
headers = http._headers.getvalue()
if "Transfer-Encoding: chunked" not in headers:
"end": "124" })
if "transfer-encoding: chunked" not in headers():
warnings.warn("Non-chunked HTTP response for /stream/extract")
if "Content-Type: text/plain;charset=utf-8" not in headers:
if "content-type: text/plain;charset=utf-8" not in headers():
raise AssertionError("/stream/extract is not text/plain:\n" +
headers)
headers())

# Make sure Access-Control-Allow-Origin gets set
if "Access-Control-Allow-Origin: " not in headers:
if "access-control-allow-origin: " not in headers():
raise AssertionError("No Access-Control-Allow-Origin (CORS) "
"header in /stream/extract response:\n" +
headers)
headers())

client.close()



+ 5
- 5
tests/test_cmdline.py View File

@@ -163,16 +163,16 @@ class TestCmdline(object):

# try some URL constructions
self.fail("--url http://nosuchurl/ info")
self.contain("Couldn't resolve host 'nosuchurl'")
self.contain("error connecting to server")

self.fail("--url nosuchurl info")
self.contain("Couldn't resolve host 'nosuchurl'")
self.contain("error connecting to server")

self.fail("-u nosuchurl/foo info")
self.contain("Couldn't resolve host 'nosuchurl'")
self.contain("error connecting to server")

self.fail("-u localhost:0 info")
self.contain("couldn't connect to host")
self.fail("-u localhost:1 info")
self.contain("error connecting to server")

self.ok("-u localhost:12380 info")
self.ok("info")


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