def route_management():
"""
Manages the routes according to the request type:
POST: Create new route
DELETE: Remove existing route
GET: List existing routes
"""
try:
session_id = request.cookies[settings.HBP_COOKIE]
except KeyError:
session_id = 'demo'
if request.method == 'GET':
try:
response = route_manager.get_route(session_id)
return make_response(response, 200)
except KeyError as e:
return make_response(str(e), 404)
if request.method == 'POST':
if request.data is None:
response = 'Error: Data must be provided for POST operations'
log.error(response)
return make_response(response, 401)
json_data = json.loads(request.data)
uri = json_data['uri']
log.info(1, 'Creating new route for ' + uri)
response = route_manager.create_route(session_id, uri)
return make_response(response, 201)
else:
return route_manager.delete_route(session_id)
def route_management():
"""
Manages the routes according to the request type:
POST: Create new route
DELETE: Remove existing route
GET: List existing routes
"""
try:
session_id = request.cookies[settings.HBP_COOKIE]
except KeyError:
session_id = 'demo'
if request.method == 'GET':
try:
response = route_manager.get_route(session_id)
return make_response(response, 200)
except KeyError as e:
return make_response(str(e), 404)
if request.method == 'POST':
if request.data is None:
response = 'Error: Data must be provided for POST operations'
log.error(response)
return make_response(response, 401)
json_data = json.loads(request.data)
uri = json_data['uri']
log.info(1, 'Creating new route for ' + uri)
response = route_manager.create_route(session_id, uri)
return make_response(response, 201)
else:
return route_manager.delete_route(session_id)
def get_frame(self):
"""
Returns the current image generated by the remote rendering resource
"""
time.sleep(1 / HISS_FRAMES_PER_SECOND)
try:
response = requests.get(
url=self.uri, timeout=HISS_REQUEST_TIMEOUT,
headers={'Content-Type': 'application/json'})
status = response.status_code
response.close()
if status == 200:
json_image_b64 = json.loads(response.content)
return base64.decodestring(json_image_b64['data'])
except requests.exceptions.ReadTimeout as e:
log.error('Connection error: ' + str(e))
return None
def streamer(session_id, frame_grabber):
"""
Serves a given image stream
:param session_id: Id of the session to stream
:param frame_grabber: Implementation of the class in charge of fetching the images
"""
while route_manager.get_route(session_id):
with application.app_context():
frame = None
try:
frame = frame_grabber.get_frame()
# Optimization: Generate an MD5 for the current frame and push
# it to the client only if it is different from the previous
# one
if frame is not None:
frame_md5 = int(hashlib.md5(frame).hexdigest(), 16)
if route_manager.get_frame_md5(session_id) != frame_md5:
route_manager.set_frame_md5(session_id, frame_md5)
yield (b'--frame\r\n'
b'Content-Type: image/jpeg\r\n\r\n' + frame + b'\r\n')
except KeyError:
# Returns an empty frame
frame = frame_not_found
except ValueError as e:
log.error(str(e))
except requests.exceptions as e:
log.error('Removing route for session ' + str(session_id))
route_manager.delete_route(session_id)
break
except IOError:
log.error('Lost connection with rendering resource. ' +
'Removing route for session ' +
str(session_id))
route_manager.delete_route(session_id)
break
def get_frame(self):
"""
Returns the current image generated by the remote rendering resource
"""
try:
start = datetime.datetime.now()
response = requests.get(
url=self._uri,
timeout=HISS_REQUEST_TIMEOUT,
headers={'Content-Type': 'application/json'})
duration = datetime.datetime.now() - start
delay = 1e6 / float(HISS_FRAMES_PER_SECOND) - duration.microseconds
if delay > 0:
import time
time.sleep(delay / 1e6)
status = response.status_code
response.close()
if status == 200:
json_image_b64 = json.loads(response.content)
return base64.decodestring(json_image_b64['data'])
except requests.exceptions.ReadTimeout as e:
log.error('Connection error: ' + str(e))
return None
def streamer(session_id, frame_grabber):
"""
Serves a given image stream
:param session_id: Id of the session to stream
:param frame_grabber: Implementation of the class in charge of fetching the images
"""
while route_manager.get_route(session_id):
with application.app_context():
try:
frame = frame_grabber.get_frame()
# Optimization: Generate an MD5 for the current frame and push
# it to the client only if it is different from the previous
# one
if frame is not None:
push_frame = True
if settings.HISS_STREAMING_OPTIMIZATION:
frame_md5 = int(hashlib.md5(frame).hexdigest(), 16)
if route_manager.get_frame_md5(
session_id) != frame_md5:
route_manager.set_frame_md5(session_id, frame_md5)
else:
push_frame = False
if push_frame:
yield (b'--frame\r\n'
b'Content-Type: image/jpeg\r\n\r\n' + frame +
b'\r\n')
except KeyError:
# Returns an empty frame
yield (b'--frame\r\n'
b'Content-Type: image/jpeg\r\n\r\n' + frame_not_found +
b'\r\n')
except ValueError as e:
log.error(str(e))
except requests.exceptions as e:
log.error('Removing route for session ' + str(session_id))
route_manager.delete_route(session_id)
break
except IOError:
log.error('Lost connection with rendering resource. ' +
'Removing route for session ' + str(session_id))
route_manager.delete_route(session_id)
break
