Code import

venv/lib/python2.7/site-packages/engineio/payload.py

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+import six
+
+from . import packet
+
+
+class Payload(object):
+    """Engine.IO payload."""
+    def __init__(self, packets=None, encoded_payload=None):
+        self.packets = packets or []
+        if encoded_payload is not None:
+            self.decode(encoded_payload)
+
+    def encode(self, b64=False):
+        """Encode the payload for transmission."""
+        encoded_payload = b''
+        for pkt in self.packets:
+            encoded_packet = pkt.encode(b64=b64)
+            packet_len = len(encoded_packet)
+            if b64:
+                encoded_payload += str(packet_len).encode('utf-8') + b':' + \
+                    encoded_packet
+            else:
+                binary_len = b''
+                while packet_len != 0:
+                    binary_len = six.int2byte(packet_len % 10) + binary_len
+                    packet_len = int(packet_len / 10)
+                if not pkt.binary:
+                    encoded_payload += b'\0'
+                else:
+                    encoded_payload += b'\1'
+                encoded_payload += binary_len + b'\xff' + encoded_packet
+        return encoded_payload
+
+    def decode(self, encoded_payload):
+        """Decode a transmitted payload."""
+        fixed_double_encode = False
+        self.packets = []
+        while encoded_payload:
+            if six.byte2int(encoded_payload[0:1]) <= 1:
+                packet_len = 0
+                i = 1
+                while six.byte2int(encoded_payload[i:i + 1]) != 255:
+                    packet_len = packet_len * 10 + six.byte2int(
+                        encoded_payload[i:i + 1])
+                    i += 1
+                self.packets.append(packet.Packet(
+                    encoded_packet=encoded_payload[i + 1:i + 1 + packet_len]))
+            else:
+                i = encoded_payload.find(b':')
+                if i == -1:
+                    raise ValueError('invalid payload')
+                # the packet_len below is given in utf-8 characters, but we
+                # receive the payload as bytes, so down below this length is
+                # adjusted to reflect byte length
+                packet_len = int(encoded_payload[0:i])
+                if not fixed_double_encode:
+                    # the engine.io javascript client sends text payloads with
+                    # a double UTF-8 encoding. Here we try to fix that mess and
+                    # restore the original packet
+                    try:
+                        # first we remove one UTF-8 encoding layer
+                        fixed_payload = encoded_payload.decode(
+                            'utf-8').encode('raw_unicode_escape')
+
+                        # then we make sure the result can be decoded a second
+                        # time (this will raise an exception if not)
+                        fixed_payload.decode('utf-8')
+
+                        # if a second utf-8 decode worked, then this appears to
+                        # be a double encoded packet, so here we keep the
+                        # packet after a single decode, since the packet class
+                        # will perform a decode as well, and in this case it is
+                        # not necessary to adjust the packet length
+                        encoded_payload = fixed_payload
+                    except:
+                        # if we couldn't apply a double utf-8 decode then
+                        # the packet must have been correct, so we just adjust
+                        # the packet length to be in bytes and not utf-8
+                        # characters and keep going
+                        packet_len += len(encoded_payload) - len(fixed_payload)
+                    fixed_double_encode = True
+                pkt = encoded_payload[i + 1: i + 1 + packet_len]
+                self.packets.append(packet.Packet(encoded_packet=pkt))
+            encoded_payload = encoded_payload[i + 1 + packet_len:]