RPC: break out high level JSON-RPC req/resp into their own functions

This prepares for JSON-RPC 2.0 batches.

src/bitcoinrpc.cpp

@@ -2552,7 +2552,7 @@ string JSONRPCRequest(const string& strMethod, const Array& params, const Value&
     return write_string(Value(request), false) + "\n";
 }
 
-string JSONRPCReply(const Value& result, const Value& error, const Value& id)
+Object JSONRPCReplyObj(const Value& result, const Value& error, const Value& id)
 {
     Object reply;
     if (error.type() != null_type)
@@ -2561,6 +2561,12 @@ string JSONRPCReply(const Value& result, const Value& error, const Value& id)
         reply.push_back(Pair("result", result));
     reply.push_back(Pair("error", error));
     reply.push_back(Pair("id", id));
+    return reply;
+}
+
+string JSONRPCReply(const Value& result, const Value& error, const Value& id)
+{
+    Object reply = JSONRPCReplyObj(result, error, id);
     return write_string(Value(reply), false) + "\n";
 }
 
@@ -2905,6 +2911,47 @@ void ThreadRPCServer2(void* parg)
     StopRequests();
 }
 
+class JSONRequest
+{
+public:
+    Value id;
+    string strMethod;
+    Array params;
+
+    JSONRequest() { id = Value::null; }
+    void parse(const Value& valRequest);
+};
+
+void JSONRequest::parse(const Value& valRequest)
+{
+    // Parse request
+    if (valRequest.type() != obj_type)
+        throw JSONRPCError(-32600, "Invalid Request object");
+    const Object& request = valRequest.get_obj();
+
+    // Parse id now so errors from here on will have the id
+    id = find_value(request, "id");
+
+    // Parse method
+    Value valMethod = find_value(request, "method");
+    if (valMethod.type() == null_type)
+        throw JSONRPCError(-32600, "Missing method");
+    if (valMethod.type() != str_type)
+        throw JSONRPCError(-32600, "Method must be a string");
+    strMethod = valMethod.get_str();
+    if (strMethod != "getwork" && strMethod != "getmemorypool")
+        printf("ThreadRPCServer method=%s\n", strMethod.c_str());
+
+    // Parse params
+    Value valParams = find_value(request, "params");
+    if (valParams.type() == array_type)
+        params = valParams.get_array();
+    else if (valParams.type() == null_type)
+        params = Array();
+    else
+        throw JSONRPCError(-32600, "Params must be an array");
+}
+
 static CCriticalSection cs_THREAD_RPCHANDLER;
 
 void ThreadRPCServer3(void* parg)
@@ -2954,52 +3001,30 @@ void ThreadRPCServer3(void* parg)
         if (mapHeaders["connection"] == "close")
             fRun = false;
 
-        Value id = Value::null;
+        JSONRequest jreq;
         try
         {
             // Parse request
             Value valRequest;
             if (!read_string(strRequest, valRequest) || valRequest.type() != obj_type)
                 throw JSONRPCError(-32700, "Parse error");
-            const Object& request = valRequest.get_obj();
-
-            // Parse id now so errors from here on will have the id
-            id = find_value(request, "id");
-
-            // Parse method
-            Value valMethod = find_value(request, "method");
-            if (valMethod.type() == null_type)
-                throw JSONRPCError(-32600, "Missing method");
-            if (valMethod.type() != str_type)
-                throw JSONRPCError(-32600, "Method must be a string");
-            string strMethod = valMethod.get_str();
-            if (strMethod != "getwork" && strMethod != "getmemorypool")
-                printf("ThreadRPCServer method=%s\n", strMethod.c_str());
-
-            // Parse params
-            Value valParams = find_value(request, "params");
-            Array params;
-            if (valParams.type() == array_type)
-                params = valParams.get_array();
-            else if (valParams.type() == null_type)
-                params = Array();
-            else
-                throw JSONRPCError(-32600, "Params must be an array");
 
-            Value result = tableRPC.execute(strMethod, params);
+            jreq.parse(valRequest);
+
+            Value result = tableRPC.execute(jreq.strMethod, jreq.params);
 
             // Send reply
-            string strReply = JSONRPCReply(result, Value::null, id);
+            string strReply = JSONRPCReply(result, Value::null, jreq.id);
             conn->stream() << HTTPReply(200, strReply, fRun) << std::flush;
         }
         catch (Object& objError)
         {
-            ErrorReply(conn->stream(), objError, id);
+            ErrorReply(conn->stream(), objError, jreq.id);
             break;
         }
         catch (std::exception& e)
         {
-            ErrorReply(conn->stream(), JSONRPCError(-32700, e.what()), id);
+            ErrorReply(conn->stream(), JSONRPCError(-32700, e.what()), jreq.id);
             break;
         }
     }