Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
branch: master
Fetching contributors…

Octocat-spinner-32-eaf2f5

Cannot retrieve contributors at this time

file 443 lines (368 sloc) 12.896 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442
module('Redis', package.seeall)

local socket = require('socket') -- requires LuaSocket as a dependency
local uri = require('socket.url')

local redis_commands = {}
local network, request, response = {}, {}, {}, {}

local defaults = { host = '127.0.0.1', port = 6379 }
local protocol = { newline = '\r\n', ok = 'OK', err = 'ERR', null = 'nil' }

local function toboolean(value) return value == 1 end

local function load_methods(proto, methods)
    local redis = setmetatable ({}, getmetatable(proto))
    for i, v in pairs(proto) do redis[i] = v end

    for i, v in pairs(methods) do redis[i] = v end
    return redis
end

-- ############################################################################

function network.write(client, buffer)
    local _, err = client.socket:send(buffer)
    if err then error(err) end
end

function network.read(client, len)
    if len == nil then len = '*l' end
    local line, err = client.socket:receive(len)
    if not err then return line else error('Connection error: ' .. err) end
end

-- ############################################################################

function response.read(client)
    local res = network.read(client)
    local prefix = res:sub(1, -#res)
    local response_handler = protocol.prefixes[prefix]

    if not response_handler then
        error("Unknown response prefix: " .. prefix)
    else
        return response_handler(client, res)
    end
end

function response.status(client, data)
    local sub = data:sub(2)
    if sub == protocol.ok then return true else return sub end
end

function response.error(client, data)
    local err_line = data:sub(2)

    if err_line:sub(1, 3) == protocol.err then
        error("Redis error: " .. err_line:sub(5))
    else
        error("Redis error: " .. err_line)
    end
end

function response.bulk(client, data)
    local str = data:sub(2)
    local len = tonumber(str)

    if not len then
        error('Cannot parse ' .. str .. ' as data length.')
    else
        if len == -1 then return nil end
        local next_chunk = network.read(client, len + 2)
        return next_chunk:sub(1, -3);
    end
end

function response.multibulk(client, data)
    local str = data:sub(2)

    -- TODO: add a check if the returned value is indeed a number
    local list_count = tonumber(str)

    if list_count == -1 then
        return nil
    else
        local list = {}

        if list_count > 0 then
            for i = 1, list_count do
                table.insert(list, i, response.bulk(client, network.read(client)))
            end
        end

        return list
    end
end

function response.integer(client, data)
    local res = data:sub(2)
    local number = tonumber(res)

    if not number then
        if res == protocol.null then
            return nil
        else
            error('Cannot parse ' .. res .. ' as numeric response.')
        end
    end

    return number
end

protocol.prefixes = {
    ['+'] = response.status,
    ['-'] = response.error,
    ['$'] = response.bulk,
    ['*'] = response.multibulk,
    [':'] = response.integer,
}

-- ############################################################################

function request.raw(client, buffer)
    -- TODO: optimize
    local bufferType = type(buffer)

    if bufferType == 'string' then
        network.write(client, buffer)
    elseif bufferType == 'table' then
        network.write(client, table.concat(buffer))
    else
        error('Argument error: ' .. bufferType)
    end

    return response.read(client)
end

function request.inline(client, command, ...)
    if arg.n == 0 then
        network.write(client, command .. protocol.newline)
    else
        local arguments = arg
        arguments.n = nil

        if #arguments > 0 then
            arguments = table.concat(arguments, ' ')
        else
            arguments = ''
        end

        network.write(client, command .. ' ' .. arguments .. protocol.newline)
    end

    return response.read(client)
end

function request.bulk(client, command, ...)
    local arguments = arg
    local data = tostring(table.remove(arguments))
    arguments.n = nil

    -- TODO: optimize
    if #arguments > 0 then
        arguments = table.concat(arguments, ' ')
    else
        arguments = ''
    end

    return request.raw(client, {
        command, ' ', arguments, ' ', #data, protocol.newline, data, protocol.newline
    })
end

function request.multibulk(client, command, ...)
    local buffer = { }
    local arguments = { }
    local args_len = 1

    if arg.n == 1 and type(arg[1]) == 'table' then
        for k, v in pairs(arg[1]) do
            table.insert(arguments, k)
            table.insert(arguments, v)
            args_len = args_len + 2
        end
    else
        arguments = arg
        args_len = args_len + arg.n
        arguments.n = nil
    end
 
    table.insert(buffer, '*' .. tostring(args_len) .. protocol.newline)
    table.insert(buffer, '$' .. #command .. protocol.newline .. command .. protocol.newline)

    for _, argument in pairs(arguments) do
        s_argument = tostring(argument)
        table.insert(buffer, '$' .. #s_argument .. protocol.newline .. s_argument .. protocol.newline)
    end

    return request.raw(client, buffer)
end

-- ############################################################################

local function custom(command, send, parse)
    return function(self, ...)
        local reply = send(self, command, ...)
        if parse then
            return parse(reply, command, ...)
        else
            return reply
        end
    end
end

local function bulk(command, reader)
    return custom(command, request.bulk, reader)
end

local function multibulk(command, reader)
    return custom(command, request.multibulk, reader)
end

local function inline(command, reader)
    return custom(command, request.inline, reader)
end

-- ############################################################################

function connect(...)
    local host, port = defaults.host, defaults.port

    if arg.n == 1 then
        local server = uri.parse(arg[1])
        if server.scheme then
            if server.scheme ~= 'redis' then
                error('"' .. server.scheme .. '" is an invalid scheme')
            end
            host, port = server.host, server.port or defaults.port
        else
            host, port = server.path, defaults.port
        end
    elseif arg.n > 1 then
        host, port = arg[1], arg[2]
    end

    if host == nil then
        error('please specify the address of running redis instance')
    end

    local client_socket = socket.connect(host, tonumber(port))
    if not client_socket then
        error('Could not connect to ' .. host .. ':' .. port)
    end

    local redis_client = {
        socket = client_socket,
        raw_cmd = function(self, buffer)
            return request.raw(self, buffer .. protocol.newline)
        end,
    }

    return load_methods(redis_client, redis_commands)
end

-- ############################################################################

redis_commands = {
    -- miscellaneous commands
    ping = inline('PING',
        function(response)
            if response == 'PONG' then return 'PONG' end
        end
    ),
    echo = bulk('ECHO'),
    -- TODO: the server returns an empty -ERR on authentication failure
    auth = inline('AUTH'),

    -- connection handling
    quit = custom('QUIT', fire_and_forget),

    -- commands operating on string values
    set = bulk('SET'),
    setnx = bulk('SETNX', toboolean),
    mset = multibulk('MSET'),
    msetnx = multibulk('MSETNX', toboolean),
    get = inline('GET'),
    mget = inline('MGET'),
    getset = bulk('GETSET'),
    incr = inline('INCR'),
    incrby = inline('INCRBY'),
    decr = inline('DECR'),
    decrby = inline('DECRBY'),
    exists = inline('EXISTS', toboolean),
    del = inline('DEL', toboolean),
    type = inline('TYPE'),

    -- commands operating on the key space
    keys = inline('KEYS',
        function(response)
            local keys = {}
            response:gsub('[^%s]+', function(key)
                table.insert(keys, key)
            end)
            return keys
        end
    ),
    randomkey = inline('RANDOMKEY'),
    rename = inline('RENAME'),
    renamenx = inline('RENAMENX'),
    expire = inline('EXPIRE', toboolean),
    expireat = inline('EXPIREAT', toboolean),
    dbsize = inline('DBSIZE'),
    ttl = inline('TTL'),

    -- commands operating on lists
    rpush = bulk('RPUSH'),
    lpush = bulk('LPUSH'),
    llen = inline('LLEN'),
    lrange = inline('LRANGE'),
    ltrim = inline('LTRIM'),
    lindex = inline('LINDEX'),
    lset = bulk('LSET'),
    lrem = bulk('LREM'),
    lpop = inline('LPOP'),
    rpop = inline('RPOP'),
    rpoplpush = bulk('RPOPLPUSH'),

    -- commands operating on sets
    sadd = bulk('SADD'),
    srem = bulk('SREM'),
    smove = bulk('SMOVE'),
    scard = inline('SCARD'),
    sismember = bulk('SISMEMBER'),
    sinter = inline('SINTER'),
    sinterstore = inline('SINTERSTORE'),
    sunion = inline('SUNION'),
    sunionstore = inline('SUNIONSTORE'),
    sdiff = inline('SDIFF'),
    sdiffstore = inline('SDIFFSTORE'),
    smembers = inline('SMEMBERS'),
    srandmember = inline('SRANDMEMBER'),

    -- commands operating on sorted sets
    zadd = bulk('ZADD'),
    zincrby = bulk('ZINCRBY'),
    zrem = bulk('ZREM'),
    zrange = inline('ZRANGE'),
    zrangebyscore = inline('ZRANGEBYSCORE'),
    zrevrange = inline('ZREVRANGE'),
    zcard = inline('ZCARD'),
    zscore = bulk('ZSCORE'),
    zremrangebyscore = inline('ZREMRANGEBYSCORE'),
    zrank = bulk('ZRANK'),
    zrevrank = bulk('ZREVRANK'),
    zremrangebyrank = inline('ZREMRANGEBYRANK'),
    
    -- commands operating on hashes
    hset = bulk('HSET'),
    hget = bulk('HGET'),
    hsetnx = bulk('HSETNX' toboolean),
    hmset = bulk('HMSET'),
    hincrby = inline('HINCRBY'),
    hexists = inline('HEXISTS', toboolean),
    hdel = inline('HDEL', toboolean),
    hlen = bulk('HLEN'),
    hkeys = inline('KEYS',
        function(response)
            local keys = {}
            response:gsub('[^%s]+', function(key)
                table.insert(keys, key)
            end)
            return keys
        end
    ),

    -- multiple databases handling commands
    select = inline('SELECT'),
    move = inline('MOVE'),
    flushdb = inline('FLUSHDB'),
    flushall = inline('FLUSHALL'),

    -- sorting
    --[[ params = {
by = 'weight_*',
get = 'object_*',
limit = { 0, 10 },
sort = 'desc',
alpha = true,
}
--]]
    sort = custom('SORT',
        function(client, command, key, params)
            local query = { key }

            if params then
                if params.by then
                    table.insert(query, 'BY ' .. params.by)
                end

                if type(params.limit) == 'table' then
                    -- TODO: check for lower and upper limits
                    table.insert(query, 'LIMIT ' .. params.limit[1] .. ' ' .. params.limit[2])
                end

                if params.get then
                    table.insert(query, 'GET ' .. params.get)
                end

                if params.sort then
                    table.insert(query, params.sort)
                end

                if params.alpha == true then
                    table.insert(query, 'ALPHA')
                end

                if params.store then
                    table.insert(query, 'STORE ' .. params.store)
                end
            end

            return request.inline(client, command, table.concat(query, ' '))
        end
    ),

    -- persistence control commands
    save = inline('SAVE'),
    bgsave = inline('BGSAVE'),
    lastsave = inline('LASTSAVE'),

    -- remote server control commands
    info = inline('INFO',
        function(response)
            local info = {}
            response:gsub('([^\r\n]*)\r\n', function(kv)
                local k,v = kv:match(('([^:]*):([^:]*)'):rep(1))
                info[k] = v
            end)
            return info
        end
    ),
}
Something went wrong with that request. Please try again.