简而言之,您没有任何合法的方法可以从 netbox/vshard 调用中返回元组。
它是如何工作的:
-- You have a tuple
tuple = box.tuple.new({1, 2, 3})
tarantool> box.tuple.is(tuple) -- It's tuple, cdata object
---
- true
...
-- In order to transfer your tuple via network you need convert
-- them to binary form
msgpack = require('msgpack')
tarantool> msgpack.encode(tuple)
---
- !!binary kwECAw==
...
-- But you don't know after that it was a tuple or simple lua table
tarantool> msgpack.encode({1, 2, 3}) -- The same, but input is a lua table
---
- !!binary kwECAw==
...
-- After receive you need to decode you tuple/table back to lua object
tarantool> msgpack.decode(msgpack.encode({1, 2, 3}))
---
- [1, 2, 3]
- 5
...
tarantool> msgpack.decode(msgpack.encode(tuple))
---
- [1, 2, 3]
- 5
...
tarantool> box.tuple.is(msgpack.decode(msgpack.encode(tuple)))
---
- false
...
但是如果你使用连接,你可以直接调用“select/insert/...”函数。由于 Tarantool 2.2 这样的元组甚至有格式。有关详细信息,请参阅问题。
box.cfg{listen = 3302}
box.schema.user.grant('guest','read, write, execute', 'space')
box.schema.user.grant('guest', 'create', 'space')
box.schema.create_space("named", {format = {{name = "id"}}})
box.space.named:create_index('id', {parts = {{1, 'unsigned'}}})
box.space.named:insert({1})
require('net.box').connect('localhost', 3302).space.named:get(1).id
Result:
tarantool> require('net.box').connect('localhost', 3302).space.named:get(1).id
---
- 1
...
如果需要将 lua 表转换为元组,可以使用box.tuple.new()函数。但这将是没有格式的元组。
tarantool> tbl = {1, 2, 3}
---
...
tarantool> box.tuple.is(tbl)
---
- false
...
tarantool> tuple = box.tuple.new(tbl)
---
...
tarantool> box.tuple.is(tuple)
---
- true
...
在这里我应该完成我的回答。但是你有从 netbox 调用返回格式化元组的非法方法。
netbox = require('net.box')
netboxlib = require('net.box.lib')
buffer = require('buffer')
msgpackffi = require('msgpackffi')
msgpack = require('msgpack')
ffi = require('ffi')
box.cfg{listen = 3301}
box.schema.user.passwd('admin', 'test')
s = box.schema.space.create('test')
s:format({{name = 'id', type = 'string'}, {name = 'value', type = 'string'}})
s:create_index('pk')
s:replace({'key', 'value'})
c = netbox.connect('admin:test@localhost:3301')
function get()
return s:select()
end
call_buffer = buffer.ibuf()
c:call('get', {}, {buffer = call_buffer, skip_header = true})
len, call_buffer.rpos = msgpack.decode_array_header(call_buffer.rpos, call_buffer:size())
buf = buffer.ibuf()
encode_fix = msgpackffi.internal.encode_fix
encode_r = msgpackffi.internal.encode_r
encode_fix(buf, 0x80, 1)
encode_r(buf, 0x30, 1)
wpos = buf:alloc(call_buffer:size())
ffi.copy(wpos, call_buffer.rpos, call_buffer:size())
tarantool> netboxlib.decode_select(buf.rpos, nil, c.space.test._format_cdata)
---
- - ['key', 'value']
- 'cdata<char *>: 0x010586803e'
...
tarantool> tuples = netboxlib.decode_select(buf.rpos, nil, c.space.test._format_cdata)
---
...
tarantool> tuples
---
- - ['key', 'value']
...
tarantool> tuples[1]
---
- ['key', 'value']
...
tarantool> tuples[1]:tomap()
---
- 1: key
2: value
value: value
id: key
...
这段代码从 Tarantool 2.2 开始工作,并且由于它使用了一些内部的 Tarantool 函数,因此将来很容易被破坏。我不建议您使用它们。我希望在这个问题得到解决后会有所改变。