[PR-1071-5] refactor internalSend

[gunli]

(If this PR fixes a github issue, please add Fixes #<xyz>.)

Fixes #1071

(or if this PR is one task of a github issue, please add Master Issue: #<xyz> to link to the master issue.)

Master Issue: #1071

Motivation

Spilt PR #1071 into multiple ones, this is the FIFTH one.

#1071 is a BIG PR, it refactor the sending logic, here we just refactor internalSend(), send the message out.

As described in #1071, we need to apply the semaphore and memeory, get the schema meta, encoding and compress before we put the sendRequest into p.dataChan, or it will lead to inaccurate chunk count and wrong memory limit controlling, and we have move these logic into internalSendAsync().

And here in internalSend(), we just check if the message should send in batch or not, single chunk or multi chunks, send it accordingly.

Here we use the Defensive Programming manner to refactor the func, to reduce code indentation, to make the code looks more cleaner(too many if/else in the original code).

Modifications

Describe the modifications you've done.

Verifying this change

• Make sure that the change passes the CI checks.

(Please pick either of the following options)

This change is a trivial rework / code cleanup without any test coverage.

(or)

This change is already covered by existing tests, such as (please describe tests).

(or)

This change added tests and can be verified as follows:

(example:)

• Added integration tests for end-to-end deployment with large payloads (10MB)
• Extended integration test for recovery after broker failure

Does this pull request potentially affect one of the following parts:

If yes was chosen, please highlight the changes

• Dependencies (does it add or upgrade a dependency): (yes / no)
• The public API: (yes / no)
• The schema: (yes / no / don't know)
• The default values of configurations: (yes / no)
• The wire protocol: (yes / no)

Documentation

• Does this pull request introduce a new feature? (yes / no)
• If yes, how is the feature documented? (not applicable / docs / GoDocs / not documented)
• If a feature is not applicable for documentation, explain why?
• If a feature is not documented yet in this PR, please create a followup issue for adding the documentation

[gunli]

@tisonkun @RobertIndie @Gleiphir2769 @nodece

[tisonkun]

CI not pass. Closed. I'll try to take it over.