Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/catwell/luajit-msgpack-pure
MessagePack for LuaJIT (using FFI, no bindings, V4 API)
https://github.com/catwell/luajit-msgpack-pure
lua luajit messagepack
Last synced: 3 months ago
JSON representation
MessagePack for LuaJIT (using FFI, no bindings, V4 API)
- Host: GitHub
- URL: https://github.com/catwell/luajit-msgpack-pure
- Owner: catwell
- License: mit
- Archived: true
- Created: 2011-12-18T17:11:16.000Z (almost 13 years ago)
- Default Branch: master
- Last Pushed: 2019-09-11T09:20:18.000Z (about 5 years ago)
- Last Synced: 2024-02-15T05:34:40.500Z (9 months ago)
- Topics: lua, luajit, messagepack
- Language: Lua
- Homepage:
- Size: 43 KB
- Stars: 71
- Watchers: 11
- Forks: 14
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE.txt
Awesome Lists containing this project
- awesome-resty - luajit-msgpack-pure
README
# luajit-msgpack-pure
## Warning
This library implements MessagePack [spec v4](https://github.com/msgpack/msgpack/blob/814275fb2760d794f9f899b0a5b85db0f80c3332/spec-old.md) with some extensions compatible with [msgpack-js](https://github.com/creationix/msgpack-js). *It does not implement [spec v5](https://github.com/msgpack/msgpack/blob/814275fb2760d794f9f899b0a5b85db0f80c3332/spec.md).* If you need support for spec v5 (including STR8, BIN types, etc), see [alternatives](#alternatives).
## Presentation
This is yet another implementation of MessagePack for LuaJIT.
However, unlike [luajit-msgpack](https://github.com/catwell/cw-lua/tree/master/luajit-msgpack),
luajit-msgpack-pure does not depend on the MessagePack C library.
Everything is re-implemented in LuaJIT code (using the FFI but only to
manipulate data structures).
## Alternatives
If I had to pick a single MessagePack implementation, it would be [lua-MessagePack](https://fperrad.frama.io/lua-MessagePack/). It is pure Lua, its performance is very close to luajit-msgpack-pure and it supports the latest revision of the standard. If it had existed earlier, I would not have written this one. *If you start a new project, use it.*
Another interesting implementation is [lua-cmsgpack](https://github.com/antirez/lua-cmsgpack), written in C specifically for use in Redis.
Other implementations:
- [lua-msgpack](https://github.com/kengonakajima/lua-msgpack) (pure Lua)
- [lua-msgpack-native](https://github.com/kengonakajima/lua-msgpack-native)
(Lua-specific C implementation targeting luvit)
- [MPLua](https://github.com/nobu-k/mplua) (binding)
Before luajit-msgpack-pure, I had written [luajit-msgpack](https://github.com/catwell/cw-lua/tree/master/luajit-msgpack), a FFI binding which is now deprecated.
## TODO
- Missing datatype tests
- Comparison tests vs. other implementations
## Usage
### Basics
```lua
local mp = require "luajit-msgpack-pure"
local my_data = {this = {"is",4,"test"}}
local encoded = mp.pack(my_data)
local offset,decoded = mp.unpack(encoded)
assert(offset == #encoded)
```
### Concatenating encoded data
```lua
local mp = require "luajit-msgpack-pure"
local my_data_1 = 42
local my_data_2 = "foo"
local encoded = mp.pack(my_data_1) .. mp.pack(my_data_2)
local offset_1,decoded_1 = mp.unpack(encoded)
assert(decoded_1 == 42)
local offset_2,decoded_2 = mp.unpack(encoded,offset_1)
assert(decoded_2 == "foo")
local offset_3,decoded_3 = mp.unpack(encoded,offset_2)
assert((not offset_3) and (decoded_3 == nil))
```
### Setting floating point precision
```lua
local mp = require "luajit-msgpack-pure"
local my_data = math.pi
local encoded_1 = mp.pack(my_data) -- default is double
local offset_1,decoded_1 = mp.unpack(encoded_1)
assert(offset_1 == 9) -- 1 byte overhead + 8 bytes double
assert(decoded_1 == math.pi)
mp.set_fp_type("float")
local encoded_2 = mp.pack(my_data)
local offset_2,decoded_2 = mp.unpack(encoded_2)
assert(offset_2 == 5) -- 1 byte overhead + 5 bytes float
assert(decoded_2 ~= math.pi) -- loss of precision
mp.set_fp_type("double") -- back to double precision
local encoded_3 = mp.pack(my_data)
local offset_3,decoded_3 = mp.unpack(encoded_3)
assert((offset_3 == 9) and (decoded_3 == math.pi))
```
## Copyright
Copyright (c) 2011-2019 Pierre Chapuis