close channel

[minaevmike]

Hi,
could you tell is it a bug or not. In your test

cocaine-framework-go/cocaine12/service_test.go

Line 70 in 0678e6e

defer ch.Call(ctx, "close")

you add defer to close
https://github.com/cocaine/cocaine-framework-go/blob/master/cocaine12/locator.go#L65 there is no defer, is ok, or defer in nessesary?

[noxiouz]

Not a bug. It depends on the protocol transition.

[minaevmike]

Hm, ok, is there any rule to choose call defer ch.Call(ctx, "close") or not?
Am i right that if i go to service(like elliptics) i don't need to call it, and if i go to application i need?

[noxiouz]

@minaevmike let me explain on examples.
A point is, that the trasition graph can be three types: recursive one (None), a step to another level and a dead way ({}). The idea is to lead a branch of a dispatch tree to a dead way ({}).
For example, locator's graph:

{
 0: ['resolve', {}, {0: ['value', {}], 1: ['error', {}]}], 
 1: ['connect', {}, {0: ['write', None], 1: ['error', {}], 2: ['close', {}]}], 
 2: ['refresh', {}, {0: ['value', {}], 1: ['error', {}]}], 
 3: ['cluster', {}, {0: ['value', {}], 1: ['error', {}]}], 
 4: ['publish', {0: ['discard', {}]}, {0: ['value', {}], 1: ['error', {}]}],
 5: ['routing', {0: ['discard', {}]}, {0: ['write', None], 1: ['error', {}], 2: ['close', {}]}]
}

if you call resolve, client will step to {} point, so you should close anything.
if you call publish to close you stream you have to call discard.

Application's graph:

{
 0: ['enqueue', {0: ['write', None], 1: ['error', {}], 2: ['close', {}]}, {0: ['write', None], 1: ['error', {}], 2: ['close', {}]}], 
 1: ['info', {}, {0: ['value', {}], 1: ['error', {}]}], 2: ['control', {0: ['write', None], 1: ['error', {}], 2: ['close' {}]
}

if you call enqueue, you move to the point where write, error, close are available. It's client's stream. Calling write returns you to the same point (None). It means you can write as many chunks as you want. To close the stream you must call either close or error.