scripts/rpc: split JSONRPCClient.call into send and recv

Sending multiple request is doable now. Note that, stream of responses
is not supported yet.

Change-Id: I9c49dbf033c67074e603f2e48a469142c3c63653
Signed-off-by: Pawel Wodkowski <pawelx.wodkowski@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/435481
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Karol Latecki <karol.latecki@intel.com>
Reviewed-by: Pawel Kaminski <pawelx.kaminski@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>

scripts/rpc/client.py

@@ -15,6 +15,7 @@ class JSONRPCException(Exception):
 
 class JSONRPCClient(object):
     def __init__(self, addr, port=None, verbose=False, timeout=60.0):
+        self.sock = None
         self.verbose = verbose
         self.timeout = timeout
         self.request_id = 0
@@ -35,69 +36,69 @@ class JSONRPCClient(object):
                                    "Error details: %s" % (addr, ex))
 
     def __del__(self):
-        self.sock.close()
+        if self.sock:
+            self.sock.close()
 
-    def call(self, method, params={}, verbose=False):
+    def send(self, method, params=None):
         self.request_id += 1
-        req = {}
-        req['jsonrpc'] = '2.0'
-        req['method'] = method
-        req['id'] = self.request_id
-        if (params):
+        req = {
+            'jsonrpc': '2.0',
+            'method': method,
+            'id': self.request_id
+        }
+
+        if params:
             req['params'] = params
+
         reqstr = json.dumps(req)
-
-        verbose = verbose or self.verbose
-
-        if verbose:
+        if self.verbose:
             print("request:")
             print(json.dumps(req, indent=2))
 
         self.sock.sendall(reqstr.encode("utf-8"))
-        buf = ''
-        closed = False
-        response = {}
-        start_time = time.clock()
+        return req
 
-        while not closed:
+    def recv(self):
+        start_time = time.clock()
+        response = None
+        buf = ''
+        while not response:
             try:
                 timeout = self.timeout - (time.clock() - start_time)
-                if timeout <= 0.0:
-                    break
-
                 self.sock.settimeout(timeout)
                 newdata = self.sock.recv(4096)
-                if (newdata == b''):
-                    closed = True
-
+                if not newdata:
+                    self.sock.close()
+                    self.sock = None
+                    raise JSONRPCException("Connection closed with partial response:\n%s\n" % buf)
                 buf += newdata.decode("utf-8")
                 response = json.loads(buf)
             except socket.timeout:
-                break
+                break  # throw exception after loop to avoid Python freaking out about nested exceptions
             except ValueError:
                 continue  # incomplete response; keep buffering
-            break
 
         if not response:
-            if method == "kill_instance":
-                return {}
-            if closed:
-                msg = "Connection closed with partial response:"
-            else:
-                msg = "Timeout while waiting for response:"
-            msg = "\n".join([msg, buf])
-            raise JSONRPCException(msg)
+            raise JSONRPCException("Timeout while waiting for response:\n%s\n" % buf)
 
-        if verbose:
+        if self.verbose:
             print("response:")
             print(json.dumps(response, indent=2))
 
         if 'error' in response:
             msg = "\n".join(["Got JSON-RPC error response",
-                             "request:",
-                             json.dumps(req, indent=2),
                              "response:",
                              json.dumps(response['error'], indent=2)])
             raise JSONRPCException(msg)
+        return response
 
-        return response['result']
+    def call(self, method, params=None):
+        self.send(method, params)
+        try:
+            return self.recv()['result']
+        except JSONRPCException as e:
+            """ Don't expect response to kill """
+            if not self.sock and method == "kill_instance":
+                return {}
+            else:
+                raise e