PyLSPClient/pylspclient/json_rpc_endpoint.py

79 lines
2.3 KiB
Python

from __future__ import print_function
import json
import re
from pylspclient import lsp_structs
import threading
JSON_RPC_REQ_FORMAT = "Content-Length: {json_string_len}\r\n\r\n{json_string}"
JSON_RPC_RES_REGEX = "Content-Length: ([0-9]*)\r\n"
# TODO: add content-type
class MyEncoder(json.JSONEncoder):
"""
Encodes an object in JSON
"""
def default(self, o):
return o.__dict__
class JsonRpcEndpoint(object):
'''
Thread safe JSON RPC endpoint implementation. Responsible to recieve and send JSON RPC messages, as described in the
protocol. More information can be found: https://www.jsonrpc.org/
'''
def __init__(self, stdin, stdout):
self.stdin = stdin
self.stdout = stdout
self.read_lock = threading.Lock()
self.write_lock = threading.Lock()
@staticmethod
def __add_header(json_string):
'''
Adds a header for the given json string
:param str json_string: The string
:return: the string with the header
'''
return JSON_RPC_REQ_FORMAT.format(json_string_len=len(json_string), json_string=json_string)
def send_request(self, message):
'''
Sends the given message.
:param dict message: The message to send.
'''
json_string = json.dumps(message, cls=MyEncoder)
jsonrpc_req = self.__add_header(json_string)
with self.write_lock:
self.stdin.write(jsonrpc_req.encode())
self.stdin.flush()
def recv_response(self):
'''
Recives a message.
:return: a message
'''
with self.read_lock:
line = self.stdout.readline()
if not line:
return None
line = line.decode()
# TODO: handle content type as well.
match = re.match(JSON_RPC_RES_REGEX, line)
if match is None or not match.groups():
raise RuntimeError("Bad header: " + line)
size = int(match.groups()[0])
line = self.stdout.readline()
if not line:
return None
line = line.decode()
if line != "\r\n":
raise RuntimeError("Bad header: missing newline")
jsonrpc_res = self.stdout.read(size)
return json.loads(jsonrpc_res)