Python Queue.task_done方法代码示例

# 需要导入模块: from eventlet import Queue [as 别名]
# 或者: from eventlet.Queue import task_done [as 别名]
class ECWriter(object):
    """
    Writes an EC chunk
    """
    def __init__(self, chunk, conn):
        self._chunk = chunk
        self._conn = conn
        self.failed = False
        self.bytes_transferred = 0
        self.checksum = hashlib.md5()

    @property
    def chunk(self):
        return self._chunk

    @property
    def conn(self):
        return self._conn

    @classmethod
    def connect(cls, chunk, sysmeta, reqid=None):
        raw_url = chunk["url"]
        parsed = urlparse(raw_url)
        chunk_path = parsed.path.split('/')[-1]
        h = {}
        h["transfer-encoding"] = "chunked"
        h[chunk_headers["content_id"]] = sysmeta['id']
        h[chunk_headers["content_path"]] = sysmeta['content_path']
        h[chunk_headers["content_chunkmethod"]] = sysmeta['chunk_method']
        h[chunk_headers["container_id"]] = sysmeta['container_id']
        h[chunk_headers["chunk_pos"]] = chunk["pos"]
        h[chunk_headers["chunk_id"]] = chunk_path
        h[chunk_headers["content_policy"]] = sysmeta['policy']
        h[chunk_headers["content_version"]] = sysmeta['version']
        if reqid:
            h['X-oio-req-id'] = reqid

        # in the trailer
        # metachunk_size & metachunk_hash
        h["Trailer"] = (chunk_headers["metachunk_size"],
                        chunk_headers["metachunk_hash"])
        with ConnectionTimeout(io.CONNECTION_TIMEOUT):
            conn = io.http_connect(
                parsed.netloc, 'PUT', parsed.path, h)
            conn.chunk = chunk
        return cls(chunk, conn)

    def start(self, pool):
        # we use eventlet Queue to pass data to the send coroutine
        self.queue = Queue(io.PUT_QUEUE_DEPTH)
        # spawn the send coroutine
        pool.spawn(self._send)

    def _send(self):
        # this is the send coroutine loop
        while True:
            # fetch input data from the queue
            d = self.queue.get()
            # use HTTP transfer encoding chunked
            # to write data to RAWX
            if not self.failed:
                # format the chunk
                to_send = "%x\r\n%s\r\n" % (len(d), d)
                try:
                    with ChunkWriteTimeout(io.CHUNK_TIMEOUT):
                        self.conn.send(to_send)
                        self.bytes_transferred += len(d)
                except (Exception, ChunkWriteTimeout) as e:
                    self.failed = True
                    msg = str(e)
                    logger.warn("Failed to write to %s (%s)", self.chunk, msg)
                    self.chunk['error'] = msg

            self.queue.task_done()

    def wait(self):
        # wait until all data in the queue
        # has been processed by the send coroutine
        if self.queue.unfinished_tasks:
            self.queue.join()

    def send(self, data):
        # do not send empty data because
        # this will end the chunked body
        if not data:
            return
        # put the data to send into the queue
        # it will be processed by the send coroutine
        self.queue.put(data)

    def finish(self, metachunk_size, metachunk_hash):
        parts = [
            '0\r\n',
            '%s: %s\r\n' % (chunk_headers['metachunk_size'],
                            metachunk_size),
            '%s: %s\r\n' % (chunk_headers['metachunk_hash'],
                            metachunk_hash),
            '\r\n'
        ]
        to_send = "".join(parts)
#.........这里部分代码省略.........

# 需要导入模块: from eventlet import Queue [as 别名]
# 或者: from eventlet.Queue import task_done [as 别名]
class Crawler(object):
    """
    A crawler will traverse all the pages of a site and process the content
    in a defined way.

    :param init_urls: the very first urls to start with.
    :param q: the queue that stores all urls to be crawled
    :param urls: a set stores all urls already crawled
    """

    def __init__(self, init_urls, max_workers=200):
        self.init_urls = init_urls
        self.max_workers = max_workers
        self.q = Queue()
        self.urls = set()
        self.s = requests.Session()
        self.root_hosts = set()
        for url in init_urls:
            self.q.put(url)
            self.urls.add(url)
            self.root_hosts.add(get_netloc(url))

    def url_allowed(self, url):
        """Check if given url will be crawled.

        Current, only if the url belongs to the same host as init_urls.
        """
        return get_netloc(url) in self.root_hosts


    def save(self, response):
        """Save data at the given url."""
        raise NotImplementedError(
            "Please implement your own save logic in subclass.")

    def parse(self, response):
        self.save(response)

        new_links = set()

        for url in self.find_links(response):
            if url not in self.urls and self.url_allowed(url):
                new_links.add(url)
                self.urls.add(url)
                self.q.put(url)
        if len(new_links) != 0:
            print("Find %d new urls to crawl" % len(new_links))


    def fetch(self, url):
        """Fetch content of the url from network."""

        response = self.s.get(url)
        print("Getting content from %s, length: %d" % (url,
                                                       len(response.content)))
        return response

    def work(self, i):
        """Define the work process.

        Retrieve a url from queue, fetch the content from it,
        process it and get new urls to crawl.
        Continue the process until all pages are crawled.

        :param i: indicate the worker number
        """
        while True:
            url = self.q.get()
            print("Worker %d: Getting url %s from queue." % (i, url))
            response = self.fetch(url)
            self.parse(response)
            self.q.task_done()

    def run(self):
        """Start the crawling process.

        This is the main entrance for our crawler. It will start several
        workers, crawling in parallel.
        """
        pool = eventlet.GreenPool()
        start = time.time()
        for i in range(self.max_workers):
            pool.spawn(self.work, i)

        self.q.join()
        end = time.time()

        print("Finished crawling, takes %s seconds." % str(end - start))
        print("Have fun hacking!")