Basic storage with C interop (#1)

* writer command design

* dune build with shared core lib

* port c lib project inside ocaml

* os specific dynamic link

* fix project name on flake

* fix: cmake cxx version breaking merklecpp

* finish write to disk and update maps func

* add non atomic commit to transaction graph

* merkle tree binding for generating root hash

* disk module refactor

---------

Co-authored-by: Renan Lopes <renans.l@icloud.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/lib/interop.ml b/lib/interop.ml
new file mode 100644
index 0000000..fdfde5f
--- /dev/null
+++ b/lib/interop.ml
@@ -0,0 +1,19 @@
+open Ctypes
+
+module Sha256 = struct
+  let compute_hash content =
+    let size_with_null_terminator = C.Types.hash_size + 1 in
+    let buf = Ctypes.allocate_n char ~count:size_with_null_terminator in
+    let () = C.Functions.compute_hash buf (Bytes.to_string content) in
+    Ctypes.coerce (ptr char) Ctypes.string buf
+end
+
+module Merkle = struct
+  let merkle_generate_root hashes =
+    let size_with_null_terminator = C.Types.hash_size + 1 in
+    let buf = Ctypes.allocate_n char ~count:size_with_null_terminator in
+    let len = List.length hashes in
+    let hashes = CArray.of_list string hashes in
+    C.Functions.merkle_generate_root (CArray.start hashes) len buf;
+    Ctypes.coerce (ptr char) Ctypes.string buf
+end