Introduction to Stars

Brief

This engine come from an online project called Si Mei Ren.

Road Map

• adapt spring framework
• simplify the serialization/re-serialization of request/respond
• use aop, e.g. verify pre-condition of request
• change the distribution framework (like dubbo)

Architecture

Introduction to Game Server

Overview

Player and Module

Lifecycle of Module

Decouple between Modules

Red Point

Abstract Data

Data Loading and Persisting

Common Service

An Expression

Overview

This expression util supply the basic operation for game, including most used relation operator, logic operator and a simple select operator. There are some example as follows.

level > 0                       // the level of player is greater than 0
1 + 2 == 3                      // the sum of 1 and 2 is equal to 3
level > 10 && vip > 0           // the level of player is greater than 10 and the vip is greater than 0
level in (10, 11, 12)           // the level of player is 10, or 11, or 12
level between (10, 20)          // the level of player is between 10(inclusive) and 20(inclusive)
[itemBag, quality > 10] > 20    // the count of item in itemBag where quality is greater than 10 is greater than 20
{isopen, 'friend'}              // call the 'isopen' function, passing the parameter 'friend'

Priority

Operator	Description
()	parentheses
[]
{}
^	pow
*、/、%	mul, div, mod
+、-	add, sub
==、!=、>、>=、<、<=、in、between	eq, ne, gt, ge, lt, le, in, btween
not、!	not
and、&&	and
or、||	or

Basic Rules

• There are two types in the expression, number and string, which to long and String in Java.
• The result of relational operation and logical operation will turn into number, non-zero for true, 0 for false.
• Because number is just long in Java, number behave as what long like in Java.
• The in operator use for a range check. x in (u, v, w) means that x == u || x == v || x == w.
• The between operator use for a range check. x between (y, z) means that x >= y && x <= z.
• The [] operator like select in SQL. [itemBag, quality > 10] means that select count(1) from itemBag where quality > 10. Be notice that it is a time consuming operation.
• The {} operator use for a function invocation. {ismoduleopen, 'friend'} means that call the function ismoduleopen and pass a parameter 'friend'.

Usages

ExprNode expr = new ExprParser(new ExprLexer("1 + 1")).parse();
long result = (long) expr.eval();

Extension Mechanism

Extent Value

Extent Data Set

Extent Function

Introduction to Fight Server

Overview