lua-lluv-curl

Make asyncronus requests using libuv and libcurl

This module provide async version of curl multi class. Also module implement async request queue class which allows control number of parallel requests.

Examples

Basic asyncronus request using easy handle

local uv   = require "lluv"
local curl = require "lluv.curl"

local easy = curl.easy{
  url = "http://example.com";
  writefunction = io.write;
}

local multi = curl.multi()

multi:add_handle(easy, function(easy, err)
  print("Done:", err or easy:getinfo_response_code())
end)

uv.run()

Implementation of uvwget example from An Introduction to libuv book

local curl = require "lluv.curl"

-- Create request queue object
local queue = curl.queue{
  -- Allow up to 10 parallel requests
  concurent = 10;
  -- Default options for easy handles
  defaults = { -- this is valuses used by defualt
    fresh_connect = true;
    forbid_reuse  = true;
  };
}

for i, url in ipairs(arg) do
  local path, file = tostring(i) .. '.download'
  -- this function actually put reques in queue
  -- and returns special `request` object.
  -- Also it is possible pass any `cURL` options.
  queue:perform(url, {followlocation = true}, function(request) request
    -- Here we can configure created request object before it will be used

    -- calls after configuration done but before actually start perform
    :on('start', function(_, _, easy)
      file = assert(io.open(path, 'wb+'))
      easy:setopt_writefunction(file)
    end)
    -- calls in any case when task is finish
    :on('close', function()
      if file then file:close() end
    end)
     -- Some error (e.g. SSL fail or user interupted)
    :on('error', function(_, _, err)
      io.stderr:write(url ..  ' - FAIL: ' .. tostring(err) .. '\n')
    end)
    -- This means that request done without any error
    :on('done', function(_, _, easy)
      local code = easy:getinfo_response_code()
      io.stdout:write(url ..  ' - DONE: ' .. tostring(code) .. '; Path: ' ..path .. '\n')
    end)
  end)
end