rocksdb: enable support for lite mode

See: https://github.com/facebook/rocksdb/blob/master/ROCKSDB_LITE.md

pkgs/development/libraries/rocksdb/default.nix

···
 
 # Malloc implementation
 , jemalloc ? null, gperftools ? null
+
+, enableLite ? false
 }:
 
 let
···
   USE_SSE = "1";
   CMAKE_CXX_FLAGS = "-std=gnu++11";
   JEMALLOC_LIB = stdenv.lib.optionalString (malloc == jemalloc) "-ljemalloc";
+
+  ${if enableLite then "LIBNAME" else null} = "librocksdb_lite";
+  ${if enableLite then "CXXFLAGS" else null} = "-DROCKSDB_LITE=1";
 
   buildFlags = [
     "DEBUG_LEVEL=0"

pkgs/top-level/all-packages.nix

···
 
   rocksdb = callPackage ../development/libraries/rocksdb { };
 
+  rocksdb_lite = rocksdb.override { enableLite = true; };
+
   rote = callPackage ../development/libraries/rote { };
 
   ronn = callPackage ../development/tools/ronn { };