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# Copyright 2012 the V8 project authors. All rights reserved.
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above
# copyright notice, this list of conditions and the following
# disclaimer in the documentation and/or other materials provided
# with the distribution.
# * Neither the name of Google Inc. nor the names of its
# contributors may be used to endorse or promote products derived
# from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
import cStringIO as StringIO
try:
import ujson as json
except ImportError:
print("You should install UltraJSON, it is much faster!")
import json
import os
import struct
import zlib
from . import constants
def Send(obj, sock):
"""
Sends a JSON encodable object over the specified socket (zlib-compressed).
"""
obj = json.dumps(obj)
compression_level = 2 # 1 = fastest, 9 = best compression
compressed = zlib.compress(obj, compression_level)
payload = struct.pack('>i', len(compressed)) + compressed
sock.sendall(payload)
class Receiver(object):
def __init__(self, sock):
self.sock = sock
self.data = StringIO.StringIO()
self.datalength = 0
self._next = self._GetNext()
def IsDone(self):
return self._next == None
def Current(self):
return self._next
def Advance(self):
try:
self._next = self._GetNext()
except:
raise
def _GetNext(self):
try:
while self.datalength < constants.SIZE_T:
try:
chunk = self.sock.recv(8192)
except:
raise
if not chunk: return None
self._AppendData(chunk)
size = self._PopData(constants.SIZE_T)
size = struct.unpack(">i", size)[0]
while self.datalength < size:
try:
chunk = self.sock.recv(8192)
except:
raise
if not chunk: return None
self._AppendData(chunk)
result = self._PopData(size)
result = zlib.decompress(result)
result = json.loads(result)
if result == constants.END_OF_STREAM:
return None
return result
except:
raise
def _AppendData(self, new):
self.data.seek(0, os.SEEK_END)
self.data.write(new)
self.datalength += len(new)
def _PopData(self, length):
self.data.seek(0)
chunk = self.data.read(length)
remaining = self.data.read()
self.data.close()
self.data = StringIO.StringIO()
self.data.write(remaining)
assert self.datalength - length == len(remaining)
self.datalength = len(remaining)
return chunk
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