From 998cf183c45e604430b4a80425bd2332fb30cfe1 Mon Sep 17 00:00:00 2001
From: Marcos Magueta <maguetamarcos@gmail.com>
Date: Sun, 29 Jun 2025 01:33:13 -0300
Subject: base serialization and command reorganization

---
 .envrc                    |   1 +
 README.org                |   3 +++
 client.el                 |   2 +-
 lib/disk.ml               |  20 ++++++++++++++++----
 lib/protocol.ml           |   2 ++
 lib/server.ml             |  13 ++++++++++---
 sources/Geometry64x64.png | Bin 0 -> 1017 bytes
 7 files changed, 33 insertions(+), 8 deletions(-)
 create mode 100644 .envrc
 create mode 100644 sources/Geometry64x64.png

diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..3550a30
--- /dev/null
+++ b/.envrc
@@ -0,0 +1 @@
+use flake
diff --git a/README.org b/README.org
index dcd2b7c..737ae19 100644
--- a/README.org
+++ b/README.org
@@ -4,6 +4,9 @@
 This is a relational engine.
 
 * Roadmap
+- [ ] State
+  - [ ] Add the schema modifications to the commit state hash
+  - [ ] Save a history of the schema
 - [ ] Filesystem [0/6]
   - [ ] Durability
   - [ ] Immutable storage
diff --git a/client.el b/client.el
index bb8eaa7..8656306 100644
--- a/client.el
+++ b/client.el
@@ -8,7 +8,7 @@
     (message "Received: %s" response)    
     (delete-process process)))
 
-(setq relational-engine-address "localhost")
+(setq relational-engine-address "/tmp/relational_engine.socket")
 (setq relational-engine-port 7524)
 
 (defun relational-client (content)
diff --git a/lib/disk.ml b/lib/disk.ml
index 8d9d062..6996b2d 100644
--- a/lib/disk.ml
+++ b/lib/disk.ml
@@ -129,6 +129,8 @@ module Executor = struct
         (tup2 (list string) string)
   end
 
+  open Sexplib0.Sexp_conv
+
   type relational_type =
     | Text
     | Integer32
@@ -137,7 +139,7 @@ module Executor = struct
     (* | DiscriminatedUnion of (string * relational_type option) list * string *)
       (* [("MemberA", None); ("MemberB", Some Integer32)], "NameOfDU" *)
     | Relation of string
-  [@@deriving show]
+  [@@deriving show, sexp]
 
   type relational_literal =
     | LText of string
@@ -443,7 +445,13 @@ module Command = struct
     type': Executor.relational_type;
   }
 
-  type t = SequentialRead of { relation_name : string }
+  open Sexplib0.Sexp_conv
+
+  type t =
+    | SequentialRead of { relation_name : string }
+    | SpecifyRelation of { relation_name: string;
+                           attributes: (string*Executor.relational_type) list }
+  [@@deriving sexp]
   
   let command_encoding =
     conv
@@ -526,9 +534,13 @@ module Command = struct
     | Some _, None -> Error "Cannot write an entity without its referential."
     | None, _ -> Ok ((commit, locations), Nothing)
   
-  let perform (commit : Executor.commit) (locations : Executor.locations)
-      (command : t) =
+  let perform (commit : Executor.commit) (locations : Executor.locations) (command : t) =
     match command with
+    | SpecifyRelation {relation_name; attributes} ->
+       (* If it already exists under the relation name key, it will be replaced *)
+       Ok (({ commit with
+              schema = commit.schema
+                       |> Executor.StringMap.add relation_name attributes}, locations), Nothing)
     | SequentialRead { relation_name } ->
         let relation_name = List.hd @@ String.split_on_char '/' relation_name in
         let entities : (string * Executor.relational_type * string) list Executor.IntMap.t =
diff --git a/lib/protocol.ml b/lib/protocol.ml
index 79ed8d0..5fe29d1 100644
--- a/lib/protocol.ml
+++ b/lib/protocol.ml
@@ -3,6 +3,8 @@ open Sexplib0.Sexp_conv
 
 type tuple = string list [@@deriving sexp, protocol ~driver:(module Xml_light)]
 
+type command = Disk.Command.t [@@deriving sexp]
+
 type relation = {
   attribute_name : string;
   attribute_type : string;
diff --git a/lib/server.ml b/lib/server.ml
index 4a99b29..4af94fb 100644
--- a/lib/server.ml
+++ b/lib/server.ml
@@ -25,9 +25,16 @@ let client_read sock maxlen =
     let acc = acc ^ Bytes.to_string (Bytes.sub str 0 recvlen) in
     if recvlen <= maxlen then Lwt.return acc else _read sock acc
   in
-  _read sock String.empty >>= fun _ ->
-  match Relation.write_and_retrieve () with
-  | Ok (last_commit, locations) ->
+  _read sock String.empty >>= fun x ->
+  print_string "RECEIVED: ";
+  print_endline x;
+  let command = Protocol.command_of_sexp (Sexplib0.Sexp_conv.sexp_of_string x) in
+  match
+    (* Relation.write_and_retrieve () *)
+    command
+  with
+  | Disk.Command.SequentialRead {relation}
+  (* | Ok (last_commit, locations) -> *)
       (* let (first_names, last_names) = (Planner.Scan.execute last_commit locations "user/first-name", Planner.Scan.execute last_commit locations "user/last-name") in *)
       (* let tuples = Planner.Join.execute first_names last_names locations in *)
       let fname, lname = List.split [] in
diff --git a/sources/Geometry64x64.png b/sources/Geometry64x64.png
new file mode 100644
index 0000000..d256e49
Binary files /dev/null and b/sources/Geometry64x64.png differ
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