fed-sx-m1: Step 3a — in-memory log:open/append/tip/replay + 12 tests

next/kernel/log.erl

@@ -0,0 +1,63 @@
+-module(log).
+-export([open/2, append/2, tip/1, replay/3, entries/1]).
+
+%% Per-actor activity log — the canonical record of everything an
+%% actor has emitted, in chronological order. Per design §15.2 this
+%% lives on disk as a JSONL segment file; v1 starts with an in-memory
+%% backend so the API and seq-number machinery can be locked down
+%% before the on-disk format is added (Step 3b).
+%%
+%% State shape (a property list):
+%%   [{actor, ActorId}, {base, BasePath}, {seq, NextSeq}, {entries, [Act|...]}]
+%%
+%% `entries` stores activities in append order — i.e. oldest first.
+%% `seq` is the next sequence number that will be assigned by append.
+%% `base` is kept on the state for forward-compatibility with 3b
+%% (where it becomes the segment-file directory).
+%%
+%% open/2 takes ActorId + BasePath and returns {ok, LogState} starting
+%% with seq=0 and no entries.
+%%
+%% append/2 returns {ok, NewLogState, AssignedSeq}.
+%%
+%% tip/1 returns the next seq the log would assign (== count of entries).
+%%
+%% replay/3 folds Fun(Activity, AssignedSeq, Acc) over every entry in
+%% append order. Three-arity rather than two-arity because the plan's
+%% example test is "sequence numbers gap-free across replay" — having
+%% the seq number visible in the fold makes that test direct.
+%%
+%% entries/1 is a debug accessor returning [Activity, ...] in append
+%% order. Not part of the public API contract.
+
+open(ActorId, BasePath) ->
+    {ok, [{actor, ActorId}, {base, BasePath}, {seq, 0}, {entries, []}]}.
+
+append(LogState, Activity) ->
+    Seq = field(seq, LogState),
+    Entries = field(entries, LogState),
+    NewState = replace_field(seq, Seq + 1,
+                  replace_field(entries, Entries ++ [Activity], LogState)),
+    {ok, NewState, Seq}.
+
+tip(LogState) ->
+    field(seq, LogState).
+
+replay(LogState, InitAcc, Fun) ->
+    Entries = field(entries, LogState),
+    replay_loop(Entries, 0, InitAcc, Fun).
+
+replay_loop([], _, Acc, _) -> Acc;
+replay_loop([Act | Rest], Seq, Acc, Fun) ->
+    replay_loop(Rest, Seq + 1, Fun(Act, Seq, Acc), Fun).
+
+entries(LogState) ->
+    field(entries, LogState).
+
+field(K, [{K, V} | _]) -> V;
+field(K, [_ | Rest]) -> field(K, Rest);
+field(_, []) -> erlang:error(badkey).
+
+replace_field(K, V, []) -> [{K, V}];
+replace_field(K, V, [{K, _} | Rest]) -> [{K, V} | Rest];
+replace_field(K, V, [P | Rest]) -> [P | replace_field(K, V, Rest)].

next/tests/log_memory.sh

@@ -0,0 +1,123 @@
+#!/usr/bin/env bash
+# next/tests/log_memory.sh — Step 3a acceptance test.
+#
+# Exercises the in-memory log API: open/2, append/2, tip/1, replay/3,
+# entries/1. On-disk persistence is the job of Step 3b. 11 cases.
+
+set -uo pipefail
+cd "$(git rev-parse --show-toplevel)"
+
+SX_SERVER="${SX_SERVER:-hosts/ocaml/_build/default/bin/sx_server.exe}"
+if [ ! -x "$SX_SERVER" ]; then
+  SX_SERVER="/root/rose-ash/hosts/ocaml/_build/default/bin/sx_server.exe"
+fi
+if [ ! -x "$SX_SERVER" ]; then
+  echo "ERROR: sx_server.exe not found." >&2
+  exit 1
+fi
+
+VERBOSE="${1:-}"
+PASS=0; FAIL=0; ERRORS=""
+TMPFILE=$(mktemp); trap "rm -f $TMPFILE" EXIT
+
+cat > "$TMPFILE" <<'EPOCHS'
+(epoch 1)
+(load "lib/erlang/tokenizer.sx")
+(load "lib/erlang/parser.sx")
+(load "lib/erlang/parser-core.sx")
+(load "lib/erlang/parser-expr.sx")
+(load "lib/erlang/parser-module.sx")
+(load "lib/erlang/transpile.sx")
+(load "lib/erlang/runtime.sx")
+(load "lib/erlang/vm/dispatcher.sx")
+
+(epoch 2)
+(eval "(get (erlang-load-module (file-read \"next/kernel/log.erl\")) :name)")
+
+;; Fresh log: tip is 0
+(epoch 10)
+(eval "(get (erlang-eval-ast \"{ok, L} = log:open(alice, base), log:tip(L) =:= 0\") :name)")
+
+;; Fresh log: entries empty
+(epoch 11)
+(eval "(get (erlang-eval-ast \"{ok, L} = log:open(alice, base), log:entries(L) =:= []\") :name)")
+
+;; First append returns seq 0; tip advances to 1
+(epoch 12)
+(eval "(get (erlang-eval-ast \"{ok, L0} = log:open(alice, base), {ok, L1, S} = log:append(L0, act_a), {S, log:tip(L1)} =:= {0, 1}\") :name)")
+
+;; Two appends: seq 0,1; tip = 2
+(epoch 13)
+(eval "(get (erlang-eval-ast \"{ok, L0} = log:open(alice, base), {ok, L1, S0} = log:append(L0, a), {ok, L2, S1} = log:append(L1, b), {S0, S1, log:tip(L2)} =:= {0, 1, 2}\") :name)")
+
+;; Five appends: seq sequence gap-free
+(epoch 14)
+(eval "(get (erlang-eval-ast \"{ok, L0} = log:open(alice, base), {ok, L1, S0} = log:append(L0, a), {ok, L2, S1} = log:append(L1, b), {ok, L3, S2} = log:append(L2, c), {ok, L4, S3} = log:append(L3, d), {ok, L5, S4} = log:append(L4, e), {S0,S1,S2,S3,S4,log:tip(L5)} =:= {0,1,2,3,4,5}\") :name)")
+
+;; entries/1 returns activities in append order
+(epoch 15)
+(eval "(get (erlang-eval-ast \"{ok, L0} = log:open(alice, base), {ok, L1, _} = log:append(L0, a), {ok, L2, _} = log:append(L1, b), {ok, L3, _} = log:append(L2, c), log:entries(L3) =:= [a, b, c]\") :name)")
+
+;; Round-trip: appended activity is recoverable byte-for-byte
+(epoch 16)
+(eval "(get (erlang-eval-ast \"Act = [{id,1},{type,create},{actor,alice}], {ok, L0} = log:open(alice, base), {ok, L1, _} = log:append(L0, Act), log:entries(L1) =:= [Act]\") :name)")
+
+;; Per-actor isolation: two logs are independent
+(epoch 17)
+(eval "(get (erlang-eval-ast \"{ok, LA0} = log:open(alice, base), {ok, LB0} = log:open(bob, base), {ok, LA1, _} = log:append(LA0, a), {ok, LB1, _} = log:append(LB0, b1), {ok, LB2, _} = log:append(LB1, b2), {log:tip(LA1), log:tip(LB2)} =:= {1, 2}\") :name)")
+
+;; replay/3 visits all activities in append order with monotonic seqs
+(epoch 18)
+(eval "(get (erlang-eval-ast \"{ok, L0} = log:open(alice, base), {ok, L1, _} = log:append(L0, a), {ok, L2, _} = log:append(L1, b), {ok, L3, _} = log:append(L2, c), log:replay(L3, [], fun (A, S, Acc) -> [{S, A} | Acc] end) =:= [{2,c},{1,b},{0,a}]\") :name)")
+
+;; replay over empty log: InitAcc returned unchanged
+(epoch 19)
+(eval "(get (erlang-eval-ast \"{ok, L} = log:open(alice, base), log:replay(L, init_acc, fun (_, _, A) -> A end) =:= init_acc\") :name)")
+
+;; replay can compute a derived state (sum of integer activities)
+(epoch 20)
+(eval "(get (erlang-eval-ast \"{ok, L0} = log:open(alice, base), {ok, L1, _} = log:append(L0, 10), {ok, L2, _} = log:append(L1, 20), {ok, L3, _} = log:append(L2, 30), log:replay(L3, 0, fun (V, _, Acc) -> V + Acc end) =:= 60\") :name)")
+EPOCHS
+
+OUTPUT=$(timeout 120 "$SX_SERVER" < "$TMPFILE" 2>/dev/null)
+
+check() {
+  local epoch="$1" desc="$2" expected="$3"
+  local actual
+  actual=$(echo "$OUTPUT" | awk -v e="$epoch" '
+    $0 ~ "^\\(ok-len " e " " { getline; print; exit }
+    $0 ~ "^\\(ok " e " "     { print; exit }
+    $0 ~ "^\\(error " e " "  { print; exit }
+  ')
+  [ -z "$actual" ] && actual="<no output for epoch $epoch>"
+  if echo "$actual" | grep -qF -- "$expected"; then
+    PASS=$((PASS+1))
+    [ "$VERBOSE" = "-v" ] && echo "  ok $desc"
+  else
+    FAIL=$((FAIL+1))
+    ERRORS+="  FAIL [$desc] (epoch $epoch) expected: $expected | actual: $actual
+"
+  fi
+}
+
+check  2  "module load name"                  "log"
+check 10  "fresh log tip is 0"                "true"
+check 11  "fresh log entries empty"           "true"
+check 12  "append returns seq 0, tip 1"       "true"
+check 13  "two appends seq 0,1; tip 2"        "true"
+check 14  "five appends gap-free"             "true"
+check 15  "entries in append order"           "true"
+check 16  "round-trip activity"               "true"
+check 17  "per-actor isolation"               "true"
+check 18  "replay visits all in order"        "true"
+check 19  "replay over empty log"             "true"
+check 20  "replay computes derived state"     "true"
+
+TOTAL=$((PASS+FAIL))
+if [ $FAIL -eq 0 ]; then
+  echo "ok $PASS/$TOTAL next/tests/log_memory.sh passed"
+else
+  echo "FAIL $PASS/$TOTAL passed, $FAIL failed:"
+  echo "$ERRORS"
+fi
+[ $FAIL -eq 0 ]

plans/fed-sx-milestone-1.md

@@ -195,6 +195,11 @@ verify_signature(Activity, ActorState) ->
 
 ## Step 3 — JSONL log + sequence numbers
 
+**Sub-deliverables:**
+- [x] **3a** — `log:open/2` + `log:append/2` + `log:tip/1` + `log:replay/3` + `log:entries/1` over an in-memory log state (per-actor seq; replay in append order; round-trip the stored activity). `next/tests/log_memory.sh` (12 cases).
+- [ ] **3b** — Term codec + on-disk persistence: serializer/parser writing each activity as a JSONL-style line; restart-resumes-tip from the segment file. Blocker risk: `atom_to_list`/`integer_to_list` return SX strings (not Erlang charlists) and there is no `binary_to_list`, so a term-to-binary path needs a workaround.
+- [ ] **3c** — Segment rotation at size threshold + gen_server-mediated concurrent appends.
+
 **Deliverables:**
 
 ```erlang
@@ -937,6 +942,7 @@ A few things still under-specified; resolve as work begins.
 Newest first. One line per sub-deliverable commit. Erlang conformance gate
 (`bash lib/erlang/conformance.sh`) must remain 729/729 on every entry.
 
+- **2026-05-27** — Step 3a: `log:open/2 append/2 tip/1 replay/3 entries/1` over an in-memory state (per-actor seq, replay in append order, round-trip activities). `next/tests/log_memory.sh` 12/12. Pivoted from on-disk in this iteration: this port's `atom_to_list`/`integer_to_list` return SX strings rather than Erlang charlists, `binary_to_list` is unregistered, and `$X` char literals decode to nil — so a term codec needs a workaround. Captured as the Step 3b risk note in the plan. Erlang conformance 729/729.
 - **2026-05-26** — Step 2c: `envelope:verify_signature/2` — time-aware key lookup over `public_keys` (created ≤ published < superseded_at), MAC recompute via `crypto:hash(sha256, KeyMaterial ++ canonical_bytes)`, compared against `signature.value`. Returns ok or one of `no_signature | no_key_id | no_published | no_keys | no_active_key | bad_signature`. `next/tests/envelope_sig.sh` 11/11 pass. Erlang conformance 729/729.
 - **2026-05-26** — Step 2b: `envelope:canonical_bytes/1` — strip signature, insertion-sort property list by key, return host-CID-string as deterministic byte form (dag-cbor stand-in). `next/tests/envelope_canonical.sh` 8/8 pass. Erlang conformance 729/729 preserved.
 - **2026-05-26** — Step 2a: `next/kernel/envelope.erl` `validate_shape/1` + `get_field/2` over property-list envelopes (Erlang `#{}` maps not supported in this port). `next/tests/envelope_shape.sh` 15/15 pass. Erlang conformance 729/729 preserved.