Add BLB_write function to allow modification of data in a BLOB

[Noremos]

This PR is part of the JSON implementation. Efficiently writing binary JSON requires modifying a blob. Otherwise, TempSpace is required to use it and convert the data to a blob, significantly increasing overhead.

[hvlad]

Whats wrong or not enough with seek + putSegment ?

[Noremos]

Whats wrong or not enough with seek + putSegment ?

BLB_lseek works only for BLB_get_segment

[hvlad]

Whats wrong or not enough with seek + putSegment ?

BLB_lseek works only for BLB_get_segment

So why not make it work with put too? I suppose it's been done in your PR anyway.

[Noremos]

Whats wrong or not enough with seek + putSegment ?

BLB_lseek works only for BLB_get_segment

So why not make it work with put too? I suppose it's been done in your PR anyway.

Initially, I wanted to implement the same read/write interface as for TempSpace. But I can do this within the BLB_get_segment function.

[hvlad]

Whats wrong or not enough with seek + putSegment ?

BLB_lseek works only for BLB_get_segment

So why not make it work with put too? I suppose it's been done in your PR anyway.

Initially, I wanted to implement the same read/write interface as for TempSpace.

You still speak about blobs here ?

But I can do this within the BLB_get_segment function.

I'm lost your point here, sorry. How it answers on my question ?

[hvlad]

BTW, code in blb.cpp (at least) requires comments. It have none too small useful comments, imo.