# Niffler 
Niffler is a C-JIT implemented is nif binding to [libtcc](https://bellard.org/tcc/). Niffler allows converting small c fragments into nif backed functions *AT RUNTIME*.
*Warning:* Even though cute, the Niffler is very dangerous creature that when treated without enough attention can quickly cause havoc accross your whole BEAM.
# Use Cases
* Call your .dll / .so / .dylib dynamic library code from Elixir.
* Make things faster (most binary/math code is ~3x faster with the niffler)
* Create chaos in memory (seriously be careful with c-fragments)
# Module Example:
```
defmodule Example do
use Niffler
# Binaries (strings) have .data and .size
defnif :count_zeros, [str: :binary], ret: :int do
"""
while($str.size--) {
if (*$str.data++ == 0) $ret++;
}
"""
end
# If binaries return size is 0, strlen() is used to get the size
defnif :hello, [], ret: :binary do
"""
$ret.data = "Hello from C";
"""
end
end
{:ok, [2]} = Example.count_zeros(<<0,11,0>>)
{:ok, ["Hello from C"]} = Example.hello()
```
# Benchmarks
```
> mix run bench/count_zeros.exs
...
Benchmarking count_zeros_elixir...
Benchmarking count_zeros_nif...
Name ips average deviation median 99th %
count_zeros_nif 6.87 K 145.47 μs ±15.18% 141.22 μs 223.31 μs
count_zeros_elixir 3.54 K 282.68 μs ±12.06% 271.96 μs 404.90 μs
Comparison:
count_zeros_nif 6.87 K
count_zeros_elixir 3.54 K - 1.94x slower +137.22 μs
```
# Windows
I've only tried compiling & running this under windows with the [msys2](https://www.msys2.org/) toolchain. For that you need to install dlfcn and export the rebar variables:
```
msys2-64 $> pacman -S mingw-w64-x86_64-dlfcn
# and for the libgmp test:
msys2-64 $> pacman -S mingw-w64-x86_64-gmp-6.2.0-3
msys2-64 $> export REBAR_TARGET_ARCH_WORDSIZE=64
msys2-64 $> export REBAR_TARGET_ARCH=x86_64-w64-mingw32
msys2-64 $> mix deps.get
msys2-64 $> mix test
```
# Todos
This library is work in progress. Feel free to open a PR to any of these:
* Add nif options to:
* Use async thread to avoid blocking in long-running nifs
* Use mutex locks for non-thread-safe code
* Add access to useful erlang enif_* functions
