[tarantool-patches] Re: [PATCH v4 4/4] box: user-friendly interface to manage ck constraints

[Kirill Shcherbatov <kshcherbatov@tarantool.org>]

>>> 4. lbox_ck_constraint_what? If a function is not a getter, it should
>>> have a verb saying what the function does.
>>>
>>> What is 'i' argument? Index of space table?
>> This code is all similar to the code that is near it...
> 
> It does not mean, that it is good. Besides, you did not
> answer the question, and still did nothing in the new
> version of the patch about that place.

/**
 * Make ck_constraints available in Lua, via ck_constraint[]
 * array for space table by given index i.
 * Updata a ck_constraint table in the parent space table object
 * on the Lua stack.
 */
static void
lbox_push_ck_constraint(struct lua_State *L, struct space *space, int i)

> 
>>
>>> 5. Why do you avoid serialization? What will happen,
>>> if I will write
>>>
>>>     tarantool> s1.ck_constraint.physics
>> I don't like space_id to be show. It may differ.
> 
> You can hide it with a test-run filter, or remember it
> into a copy table, nullify space_id, and print the rest.
> Anyway, you need to check serialization.
Nice idea. I've solved this problem using filter:

test_run:cmd("push filter 'space_id: [0-9]+' to 'space_id: <ID>'")

>>> 6. The test does not check, that after a constraint is
>>> dropped, a tuple can be inserted violating the dropped
>>> constraint.
>> It is not so, actually I test exactly this case.
> 
> Where? I opened the test file, and there is only one
> place, where you drop a constraint, but after it all
> insertions fail. I do not see a successful insertion.
> This is all the code after a single ck constraint drop:
....
> All the insertions fail.
s2.ck_constraint.greater:drop()
---
...
s2:insert({1, 2})
---
- error: 'Check constraint failed ''physics'': X > Y'
...
s2:insert({2, 1})
---
- [2, 1]
...



> 
> By the way, what happens, if a constraint object is assigned
> to a local variable, then its space is dropped. What if I
> then call :drop() on the constraint object?
s2:drop()
---
...
physics_ck
---
- []
...
physics_ck:drop()
---
- error: '[string "return physics_ck:drop() "]:1: attempt to call method ''drop''
    (a nil value)'
...