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https://github.com/bungle/lua-resty-libcjson

LuaJIT FFI-based cJSON library for OpenResty.
https://github.com/bungle/lua-resty-libcjson

Last synced: 19 days ago
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LuaJIT FFI-based cJSON library for OpenResty.

Host: GitHub
URL: https://github.com/bungle/lua-resty-libcjson
Owner: bungle
License: bsd-2-clause
Created: 2014-02-19T00:08:00.000Z (over 10 years ago)
Default Branch: master
Last Pushed: 2016-11-25T00:29:25.000Z (almost 8 years ago)
Last Synced: 2024-02-14T03:31:27.910Z (9 months ago)
Language: Lua
Size: 43 KB
Stars: 52
Watchers: 10
Forks: 24
Open Issues: 2
Metadata Files:
- Readme: README.md
- Changelog: CHANGES
- License: LICENSE

Awesome Lists containing this project

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awesome-nginx - lua-resty-libcjson - LuaJIT FFI-based cJSON library for OpenResty. (Rust Modules / Lua Modules)

README

# lua-resty-libcjson

`lua-resty-libcjson` is a LuaJIT FFI-based cJSON library (tested with OpenResty too).

## Installation

Just place [`libcjson.lua`](https://github.com/bungle/lua-resty-libcjson/blob/master/lib/resty/libcjson.lua) somewhere in your `package.path`, preferably under `resty` directory. If you are using OpenResty, the default location would be `/usr/local/openresty/lualib/resty`.

### Compiling and Installing cJSON C-library

These are just rudimentary notes. Better installation instructions will follow:

1. First clone this repo: https://github.com/DaveGamble/cJSON
2. Unzip / Extract the archive
3. Run `gcc cJSON.c -O3 -o libcjson.so -shared -fPIC` (on Linux) or `gcc cJSON.c -O3 -o libcjson.dylib -shared` (OS X)
4. Place `libcjson.so` somewhere in the default search path for dynamic libraries of your operating system (or modify `libcjson.lua` and point `ffi_load "cjson"` with full path to `libcjson.so`, e.g. `local json = ffi_load("/usr/local/lib/lua/5.1/libcjson.so")`).

### Using LuaRocks or MoonRocks

If you are using LuaRocks >= 2.2:

```Shell
$ luarocks install lua-resty-libcjson
```

If you are using LuaRocks < 2.2:

```Shell
$ luarocks install --server=http://rocks.moonscript.org moonrocks
$ moonrocks install lua-resty-libcjson
```

MoonRocks repository for `lua-resty-libcjson` is located here: https://rocks.moonscript.org/modules/bungle/lua-resty-libcjson.

## Lua API
#### mixed json.decode(value)

Decodes JSON value or structure (JSON array or object), and returns either Lua `table` or some simple value (e.g. `boolean`, `string`, `number`, `nil` or `json.null` (when running in context of OpenResty the `json.null` is the same as `ngx.null`).

##### Example

```lua
local json = require "resty.libcjson"
local obj = json.decode "{}" -- table (with obj.__jsontype == "object")
local arr = json.decode "[]" -- table (with arr.__jsontype == "array")
local nbr = json.decode "1" -- 1
local bln = json.decode "true" -- true
local str = json.decode '"test"' -- "test"
local str = json.decode '""' -- ""
local num = json.decode(5) -- 5
local num = json.decode(math) -- math
local num = json.decode(json.null) -- json.null
local nul = json.decode "null" -- json.null
local nul = json.decode "" -- nil
local nul = json.decode(nil) -- nil
local nul = json.decode() -- nil
```

Nested JSON structures are parsed as nested Lua tables.

#### string json.encode(value, formatted)

Encodes Lua value or table, and returns equivalent JSON value or structure as a string. Optionally you may pass `formatted` argument with value of `false` to get unformatted JSON string as output.

##### Example

```lua
local json = require "resty.libcjson"
local str = json.encode{} -- "[]"
local str = json.encode(setmetatable({}, json.object)) -- "{}"
local str = json.encode(1) -- "1"
local str = json.encode(1.1) -- "1.100000"
local str = json.encode "test" -- '"test"'
local str = json.encode "" -- '""'
local str = json.encode(false) -- "false"
local str = json.encode(nil) -- "null"
local str = json.encode(json.null) -- "null"
local str = json.encode() -- "null"
local str = json.encode{ a = "b" } -- '{ "a": "b" }'
local str = json.encode{ "a", b = 1 } -- '{ "1": "a", "b": 1 }'
local str = json.encode{ 1, 1.1, "a", "", false } -- '[1, 1.100000, "a", "", false]'
```

Nested Lua tables are encoded as nested JSON structures (JSON objects or arrays).

#### About JSON Arrays and Object Encoding and Decoding

See this comment: https://github.com/bungle/lua-resty-libcjson/issues/1#issuecomment-38567447.

## Benchmarks

About 190 MB citylots.json:

```bash
# Lua cJSON
Decoding Time: 5.882825
Encoding Time: 4.902301
# lua-resty-libcjson
Decoding Time: 6.409872
Encoding Time: (takes forever)
```

## License

`lua-resty-libcjson` uses two clause BSD license.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.

* Redistributions in binary form must reproduce the above copyright notice, this
list of conditions and the following disclaimer in the documentation and/or
other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
```