zlib: add sync versions for convenience methods

[seishun]

The user should have an option to run CPU-bound functions synchronously. Zlib is the only case where they don't.

This patch should be considered as a draft or a proof-of-concept. Any directions on how it could be improved will be greatly appreciated.

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[indutny]

Please try to de-dupe it, perhaps a template version of AfterWork could handle it.

[indutny]

Generally, looks good to me. But needs documentation fixes too.

[seishun]

Done.

[indutny]

I know you copied from below, but please remove braces { }

[indutny]

Yay, almost ready! :) Thank you very much. Please correct last nits and let me know

[seishun]

Done again!

[indutny]

Sorry, but one more thing. Please move it to separate function as well.

[thomseddon]

Question: fs provides synchronous API's via the *Sync() functions whereas here, synchronicity is implied by omitting callback.

Shouldn't we choose one and unify the API accordingly? And as fs is considered stable, zlib should fall in line by only providing explicit *Sync() function alternatives?

[seishun]

@thomseddon On the other hand, crypto provides synchronous functions where you omit the callback. Since crypto is CPU-bound and fs is I/O-bound, the former falls in the same category as zlib so that's what I think we should be consistent with.

[indutny]

@thomseddon I agree with @seishun

[thomseddon]

@seishun Good point well made :)

[seishun]

Okay I know this is crazy but I couldn't think of a better way to de-dupe this.

[indutny]

What?

[seishun]

I'm not sure I understand the question. I was referring to my last commit. I didn't know how the core devs would feel about the callback approach in de-duping the recursive write but the idea seemed interesting to me so I did it anyway. Also it's 2:30 AM here so I'll probably refrain from writing anything else for today.

[indutny]

Ah, you was referring to your last commit

[indutny]

Good approach! But let's try to avoid calling apply, where possible.

And additional advice, you could pass true as an argument for async write and false for a synchronous write and call writeSync/write in the _processChunk.