On Friday, 16 October 2015 at 09:01:57 UTC, yawniek wrote:
hi,
i'm reading in a stream of data that is deserialized into
individual frames.
a frame is either of:
a) a specific D datastructure ( struct with a few
ulong,string,string[string] etc members), known at compile time
b) json (preferably stdx.data.json)
i now want to implement something where i can dynamically
add lua filters that then get data out of these frames, create
a new lua object
send it back to D code where its either sent to another lua
filter or at last
being serialized again to json und then being processed
further.
ideally i would not like to copy all the data into a lua object
but directly access it
from lua.
is there an elegant approach to do this and support both a and
b cases?
so far i did some benchmarks, mainly with string comparisons
and it turned out
that luaD is about 10x faster than mruby and python D bridges.
You could use the Lua C API directly. I have a small project
where I use DerelictLua[1] and access the Lua C API directly for
fast processing (cf. http://www.lua.org/manual/5.3/ or
http://www.lua.org/manual/5.2/ "C API").
Another performance trick is to compile lua functions and store
them in memory, rather than having lua read and execute
everything.
lua_State* L = luaL_newstate();
auto func = luaL_loadstring(L, "Lua code as C-string\0"); // Lua
file compiled as a function
Later you call the function with the Lua C API like "lua_pcall(L,
0, 1, 0);". It's a bit tricky to move things around on the Lua
stack, but you'll get there! ;)
[1] https://github.com/DerelictOrg/DerelictLua
