class camera_receiver(object):
def __init__(self, name, topic, msgtype, verbose=False):
self.topic = topic
self.msgtype = msgtype
self.name = name
self.bridge = CvBridge()
self.convertor = self.convertor_query()
self.verbose = verbose
self.subthread = None
self.ros_image = LifoQueue(maxsize=5)
def callback(self, image):
if self.ros_image.full():
#self.ros_image.get()
self.ros_image.empty()
self.ros_image.put(image)
def __call__(self):
def monitor(threadnam):
# disable_signals could set to be true in the future
#rospy.init_node(self.name,anonymous=True)
rospy.Subscriber(self.topic, self.msgtype, self.callback)
#monitor()
#rospy.spin()
self.subthread = thread.start_new_thread(monitor, (self.name, ))
def convertor_query(self):
if self.msgtype == Image:
def bridge(image, **args):
return self.bridge.imgmsg_to_cv2(image, **args)
return bridge
elif self.msgtype == CompressedImage:
def bridge(image, **args):
img_array_1d = np.fromstring(image.data, np.uint8)
cv_img = cv2.imdecode(img_array_1d,
1) #cv2.CV_LOAD_IMAGE_COLOR)
return cv_img
return bridge
else:
print(
"the msgtype for this receiver in only support sensor_msgs.msg.Image and sensor_msgs.msg.CompressedImage"
)
self.__del__()
def spit(self, **args):
# desired_encoding="passthrough"
if self.verbose:
print('received image of type: "%s"' % ros_data.format)
screen = self.convertor(self.ros_image.get(), **args)
return screen
def __del__(self):
print("the camera_receiver {} was deleted".format(self.name))
class Stack(object):
"""docstring for stack"""
def __init__(self, maxsize):
if maxsize > 65535:
self.throw('StackOverflowError')
self.queue = LifoQueue(maxsize)
# 栈顶元素出栈，并将其返回
def pop(self):
isEmpty = self.queue.empty()
if isEmpty:
self.throw('this stack is null ')
else:
return self.queue.get()
# 推送一个元素至栈顶
def push(self, value):
isFull = self.queue.full()
if isFull:
self.throw('this stack is full')
else:
self.queue.put(value)
def throw(self, msg):
raise BaseException(msg)
# 获取queue的队列内容
def list(self):
return self.queue.queue
# 清空队列
def clear(self):
isEmpty = self.queue.empty()
if not isEmpty:
self.queue.get()
self.clear()
from Queue import Queue, LifoQueue, PriorityQueue
q = Queue(maxsize=5)
lq = LifoQueue(maxsize=6)
pq = PriorityQueue(maxsize=5)
for i in range(5):
q.put(i)
lq.put(i)
pq.put(i)
print "FIFO queue: %s, is empty: %s, size: %s, is full: %s" %(q.queue,q.empty(),q.qsize(),q.full())
print "LIFO queue: %s, is empty: %s, size: %s, is full: %s" %(lq.queue,lq.empty(),lq.qsize(),lq.full())
print "Priority queue: %s, is empty: %s, size: %s, is full: %s" %(pq.queue,pq.empty(),pq.qsize(),pq.full())
print q.get(), lq.get(), pq.get()
print "FIFO queue: %s, is empty: %s, size: %s, is full: %s" %(q.queue,q.empty(),q.qsize(),q.full())
print "LIFO queue: %s, is empty: %s, size: %s, is full: %s" %(lq.queue,lq.empty(),lq.qsize(),lq.full())
print "Priority queue: %s, is empty: %s, size: %s, is full: %s" %(pq.queue,pq.empty(),pq.qsize(),pq.full())
from Queue import LifoQueue
stack = LifoQueue(maxsize=3)
print(stack.qsize())
stack.put('a')
stack.put('b')
stack.put('c')
print("Full: ", stack.full())
print("Size: ", stack.qsize())
print('\nElements poped from the stack')
print(stack.get())
print(stack.get())
print(stack.get())
print("Empty: ", stack.empty())
