# fLua

**Repository Path**: mirrors/fLua

## Basic Information

- **Project Name**: fLua
- **Description**: fLua 是 Lua的增量修改和合并库，同时支持纯Lua和CPP
- **Primary Language**: C/C++
- **License**: MIT
- **Default Branch**: master
- **Homepage**: https://www.oschina.net/p/flua
- **GVP Project**: No

## Statistics

- **Stars**: 1
- **Forks**: 0
- **Created**: 2023-04-13
- **Last Updated**: 2025-10-11

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# fLua

[<img src="https://img.shields.io/github/license/esrrhs/fLua">](https://github.com/esrrhs/fLua)
[<img src="https://img.shields.io/github/languages/top/esrrhs/fLua">](https://github.com/esrrhs/fLua)
[<img src="https://img.shields.io/github/actions/workflow/status/esrrhs/fLua/cmake.yml?branch=master">](https://github.com/esrrhs/fLua/actions)

Lua的增量修改和合并库，同时支持纯Lua和CPP

# 使用
### 纯Lua使用
参考[pure_lua_test.lua](pure_lua_test.lua)中的示例，运行方式：
```shell
lua pure_lua_test.lua
```
原始table为：
```lua
local src = {
    a = 1,
    b = "2",
    c = 3.3,
    d = true,
    sub = {
        a = 11,
        b = "22",
        c = 33.3,
        d = true,
    },
    array = { 1, 2, 3, 4 },
    obj_array = {
        { id = 1, a = 1, b = 2 },
        { id = 2, a = 3, b = 4 },
        { id = 3, a = 5, b = 6 },
        { id = 4, a = 7, b = 8 },
    }
}
```
新的table为：
```lua
local dst = {
    b = "2",
    c = 3.4,
    d = false,
    sub = {
        a = 12,
        b = "11",
    },
    array = { 2, 3 },
    obj_array = {
        { id = 2, a = 3, b = 4 },
        { id = 3, a = 5, b = 6 },
        { id = 4, a = 70, b = 80 },
    }
}
```
计算diff：
```lua
local diff = lua_diff(src, dst, get_id)
```
注意：这里的get_id，是用来针对obj_array中的每个元素，获取其唯一标识的函数。目的是为了尽量减少大Obj数组的diff差异。这里的示例中，我们假设obj_array中的每个元素都有一个id字段，用来唯一标识该元素，所以get_id函数就是：
```lua
local get_id = function(v)
    return v.id
end
```
当然，如果obj_array中的元素没有id字段，那么get_id函数就可以返回nil，这样就会对obj_array进行全量diff，这样的话，diff结果就会比较大。

最终的diff结果为：
```lua
{
    ['d'] = false,
    ['c'] = 3.4,
    ['sub'] = {
        ['b'] = '11',
        ['a'] = 12,
        ['__diff_lua_del'] = {
            [1] = 'd',
            [2] = 'c'
        }
    },
    ['obj_array'] = {
        [4] = {
            ['b'] = 80,
            ['a'] = 70
        },
        ['__diff_lua_array'] = true,
        ['__diff_lua_del'] = {
            [1] = 1
        }
    },
    ['array'] = {
        [1] = 2,
        [2] = 3,
        ['__diff_lua_del'] = {
            [1] = 3,
            [2] = 4
        }
    },
    ['__diff_lua_del'] = {
        [1] = 'a'
    }
}
```
然后可以将diff应用到原始table上，得到新的table：
```lua
local new_dst = lua_patch(src, diff, get_id)
```
最终新的table与dst是相等的，注意这里obj_array里的元素顺序不一定是完全一致的
```lua
{
	['b'] = '2',
	['d'] = false,
	['c'] = 3.4,
	['obj_array'] = {
		[1] = {
			['b'] = 4,
			['a'] = 3,
			['id'] = 2
		},
		[2] = {
			['b'] = 6,
			['a'] = 5,
			['id'] = 3
		},
		[3] = {
			['b'] = 80,
			['a'] = 70,
			['id'] = 4
		}
	},
	['array'] = {
		[1] = 2,
		[2] = 3
	},
	['sub'] = {
		['b'] = '11',
		['a'] = 12
	}
}
```

### 纯CPP使用
参考[main.cpp](./test/main.cpp)中的pure_cpp_test函数，使用和算法与Lua版本一样。计算diff：
```cpp
#include "diff_lua.h"

auto diff = CalDiff(src, dst, get_id, new_func);
```
输出结果diff与Lua一致，然后patch：
```cpp
auto new_dst = PatchDiff(src, diff, get_id, new_func);
```
最终new_dst与dst是相等的

### CPP+Lua混合使用
参考[main.cpp](./test/main.cpp)中的mix_cpp_test函数和[mix_cpp_test.lua](./mix_cpp_test.lua)，在Lua中调用CPP计算diff：
```lua
local libdifflua = require("libdifflua")
local diff = libdifflua.cal_diff(src, dst, _G.lua_get_id, _G.lua_new_func)
```
CPP会把Lua table转成内置数据结构，计算diff，然后再转回Lua Table。

Lua调用CPP进行patch：
```lua
lualocal new_dst = libdifflua.patch_diff(src, diff, _G.lua_get_id, _G.lua_new_func)
```
最终new_dst与dst是相等的

## 其他
[lua全家桶](https://github.com/esrrhs/lua-family-bucket)