Add rocksdb sources to the go package

[anatol]

Hi y'all,

I am trying to use this package for my go project and I found its installation/setup procedure quite complicated. By default the package gives following compilation error:

➜  rocksdb go build
# github.com/linxGnu/grocksdb
../../go/pkg/mod/github.com/linx!gnu/[email protected]/array.go:4:11: fatal error: rocksdb/c.h: No such file or directory
    4 | // #include "rocksdb/c.h"
      |           ^~~~~~~~~~~~~
compilation terminated.

To use grocksdb bindings additional steps are required to compile rocksdb and its dependencies.

A better solution would be to let cgo compile the rocksdb sources. Similar to how sqlite3 go bindings do. cgo just picks *.c files stored together with go sources then compiles and automatically links it.

This requires an amalgamation file (i.e. a single file that contains all project sources) to be provided by rocksdb project (like sqlite does). It turns out rocksdb has a tool for that https://github.com/facebook/rocksdb/blob/main/build_tools/amalgamate.py that aim to achieve what we need.

[linxGnu]

@anatol Adding rocksdb and its dependency code base makes the repository heavy and makes compile time much higher than before.

Not only that, RocksDB is not C but C++. Making go <> c++ interoperability is very high cost.

[anatol]

@anatol Adding rocksdb and its dependency code base makes the repository heavy and makes compile time much higher than before.

True, rocksdb is a heavy dependency and requires a lot of time to compile unfortunately.

Not only that, RocksDB is not C but C++. Making go <> c++ interoperability is very high cost.

You already use this C++-C bridge with your CGO method. Using amalgamated sources does not change anything here. In fact, joining sources into one compilation unit allows compiler to use more optimizations.

[yihuang]

it's pretty easy to manage c dependencies with nix, but need this small change though: #100

[linxGnu]

I will close this ticket. Thank you all for the suggestion.