Improve README and demo

demo/pysearpc-demo-client.py

@@ -0,0 +1,57 @@
+
+import sys
+import socket
+from struct import pack, unpack
+
+from pysearpc import SearpcClient, searpc_func
+
+SERVER_ADDR = '127.0.0.1'
+SERVER_PORT = 12345
+
+def recv_all(sock, length):
+    """
+    read all n bytes of data from sock
+    """
+
+    data = ''
+    while len(data) < length:
+        more = sock.recv(length - len(data))
+        if not more:
+            raise EOFError('socket closed %d bytes into a %d-byte message' % (len(data), length))
+        data += more
+    return data
+
+class SampleRpcClient(SearpcClient):
+    
+    def call_remote_func_sync(self, fcall_str):
+        """
+        called by searpc_func to send the request and receive the result
+        """
+        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        # connect to server
+        s.connect((SERVER_ADDR, SERVER_PORT))
+        # send the header
+        header = pack('!h', len(fcall_str)); 
+        s.sendall(header)
+        # send the JSON data
+        s.sendall(fcall_str)
+
+        # read the returned header
+        header_r = recv_all(s, 2)
+        #read the result
+        ret_len = list(unpack('!h', header_r))[0]
+        if ret_len <= 0:
+            raise AssertionError, "returned data length <=  0"
+
+        ret_str = recv_all(s, ret_len)
+        return ret_str
+
+    @searpc_func("int", ["string"])
+    def searpc_strlen(self):
+        pass
+
+client = SampleRpcClient()
+res = client.searpc_strlen("hello world")
+print 'result from server:', res
+