lua-laxjson

Lua binding to liblaxjson for LuaJIT using FFI.

The library liblaxjson is a relaxed streaming JSON parser written in C. You don't have to buffer the entire JSON string in memory before parsing it.

Usage

``lua -- name: ctan_packages.lua -- run "resty ctan_packages.lua"

local ffi = require "ffi" local laxjson = require "laxjson" local requests = require "resty.requests"

local on_arr, count = false, 0

local laxj = laxjson.new { on_begin = function (ctx, jtype) if jtype == laxjson.LaxJsonTypeArray then on_arr = true elseif on_arr then count = count + 1 end return laxjson.LaxJsonErrorNone -- 0 end, on_end = function (ctx, jtype) if jtype == laxjson.LaxJsonTypeArray then on_arr = false end return laxjson.LaxJsonErrorNone end }

local url = "https://ctan.org/json/2.0/packages" local r, err = requests.get(url) if not r then print(err) return end

local chunk local ok, l, c, err while true do chunk, err = r:iter_content(2^13) -- reads by 8K bytes if not chunk then if err == "eof" then ok, l, c, err = laxj:lax_json_eof() if not ok then print("Line: "..l.." Column: "..c..", "..err) end else print(err) end break end ok, l, c, err = laxj:lax_json_feed(#chunk, chunk) if not ok then print("Line: "..l.." Column: "..c..", "..err) break end end

if ok then print("CTAN has "..count.." packages.") end

laxj:free() ``

Installation

To install lua-laxjson you need to install liblaxjson with shared libraries firtst. Then you can install it by placing laxjson.lua to your lua library path.

Methods

new

syntax: laxj = laxjson.new(obj)

Create laxjson context.

free

syntax: laxj:free()

Destroy laxjson context.

feed

syntax: ok, line, column, err = laxj:feed(size, buf)

Feed string to parse by size bytes.

eof

syntax: ok, line, column, err = laxj:eof()

Check EOF.

parse

syntax: ok, line, column, err = laxj:feed(json_file, size)

Parse json file. The json file is read by size bytes.

Author

Soojin Nam jsunam@gmail.com

License

Public Domain