feat: add support for batch puts

[hugomrdias]

This PR add a new method to put Blocks in batch to the datastore.

supports: https://github.com/ipfs/js-ipfs-unixfs-importer/pull/38

[codecov[bot]]

Codecov Report

Merging #238 into master will decrease coverage by 1.68%. The diff coverage is 80%.

@@            Coverage Diff             @@
##           master     #238      +/-   ##
==========================================
- Coverage   86.84%   85.16%   -1.69%     
==========================================
  Files           2        2              
  Lines         152      155       +3     
==========================================
  Hits          132      132              
- Misses         20       23       +3

Impacted Files	Coverage Δ
src/index.js	83.45% <80%> (-1.85%)	:arrow_down:

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[achingbrain]

Could you expand on the use case for this a little? My impression of the API for this module was that it abstracts interactions with the block store, encapsulating node serialization, etc so it seems weird to be passing blocks directly into it.

It also already has putMany (though it's essentially serial as implemented so needs improving).

[hugomrdias]

Could you expand on the use case for this a little? My impression of the API for this module was that it abstracts interactions with the block store, encapsulating node serialization, etc so it seems weird to be passing blocks directly into it.

Yep for me it was weird to have blockstore inside IPLD, it shouldn't handle persistence only data formats. Also it made no sense to create another Array with map when we can send Blocks directly. This is related to performance work in unixfs so it made sense.

It also already has putMany (though it's essentially serial as implemented so needs improving).

Yes putMany its.. well as you said needs improving.

[vmx]

The problem this PR is addressing will be solved on a different layer. For more information see https://github.com/ipfs/js-ipfs-unixfs-importer/pull/38.