cancel.lua

--[[

Copyright 2015 Wanderu, Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

--]]

--[[

cancel <ns> , <jobid>

Keys:
    ns: Namespace under which queue data exists.

Args:
    jobid: Job identifier.

Returns: 1 if canceled correctly.
Errors: UNKNOWN_JOB_ID, JOB_IN_WORK

--]]

local fname = "cancel"
local sep = ":"

local log_warn = function (message)
    redis.log(redis.LOG_WARNING, "<" .. fname .. ">" .. " " .. message)
end

local log_verbose = function (message)
    redis.log(redis.LOG_VERBOSE, "<" .. fname .. ">" .. " " .. message)
end

local is_error = function(result)
    return type(result) == 'table' and result.err
end

local ns = KEYS[1]
local jobid = ARGV[1]

local kworking   = ns .. sep .. "WORKING"   -- Jobs that have been consumed
local kqueued    = ns .. sep .. "QUEUED"
local kscheduled = ns .. sep .. "SCHEDULED" -- Scheduled Queue
local kfailed    = ns .. sep .. "FAILED"    -- Failed Queue

local kjob = ns .. sep .. "JOBS" .. sep .. jobid

-- if it's in work, can't cancel
-- local result = tonumber(redis.call("ZSCORE", kworking, jobid))
-- if result ~= nil then
local state = redis.call("HGET", kjob, "state")
if state == "working" then
    log_warn("Job already in work, cannot remove/cancel. " .. kjob)
    return redis.error_reply("JOB_IN_WORK")
end

redis.call("ZREM", kqueued, jobid)
redis.call("ZREM", kscheduled, jobid)
redis.call("ZREM", kfailed, jobid)

local exists = tonumber(redis.call("EXISTS", kjob))
if exists == nil then
    return redis.error_reply("UNKNOWN_JOB_ID")
end

local result = redis.call("DEL", kjob);
return result