From ffead3986c0eec5886607e69369ef202f46bd3c3 Mon Sep 17 00:00:00 2001 From: Markus Fritsche Date: Wed, 13 May 2026 04:50:43 +0000 Subject: [PATCH] =?UTF-8?q?docs/PHASE4:=20review=20fold-in=20=E2=80=94=20f?= =?UTF-8?q?lock=20for=20race,=20Norris=20suppression,=20summarizer=20self-?= =?UTF-8?q?amp?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Independent review found 1 BLOCKER + 3 CONCERNs + 4 NITs. R-B1 (BLOCKER): TOCTOU race on memory.jsonl — two aish processes scanning the same file compute identical next_ids. Resolution: flock(LOCK_EX | LOCK_NB) on the fd in M.open_memory, held until close. Bundled into commit #1 (per reviewer: cannot defer because adding flock retroactively means reopening the handle). Requires ffi/libc.lua extension: flock cdef + LOCK_EX/LOCK_NB/LOCK_UN constants + M.flock wrapper. R-C1 (CONCERN, closes Q33): [background] block suppressed when ctx.norris_active. Avoids ~16K of redundant tokens per 8-step Norris run. Norris already anchors via its goal in the NORRIS suffix; memory items rarely change step-to-step planning. R-C2 (CONCERN): summarizer self-amplification — running :memory summarize twice in one session would feed the prior summarize call's assistant turn into the next input. Resolution: operate on the session log file (history.load(session_path)) instead of ctx:to_messages(), and tag prior summarize turns with meta="summarize" so they're filterable. R-C3 (CONCERN, cosmetic): §5 diagram clarified that DEFAULT_SYSTEM_PROMPT already carries the Phase 2 MCP block statically — not a separate dynamic block in v1. NITs N1-N4 folded inline: N1 forget no-op for unknown id surfaces a status N2 path note: memory.jsonl is sibling of sessions/, no collision N3 item-id invariants: id >= 1; meta header has no id; tombstones with non-matching targets are no-ops N4 :memory inject semantics explicit (replace ctx.memory_items from a fresh load + LRU-by-ts truncation) §3 module-changes table grew a new ffi/libc.lua row. §12 commit #1 description tightened — flock work bundled inline. Co-Authored-By: Claude Opus 4.7 (1M context) --- docs/PHASE4.md | 128 +++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 103 insertions(+), 25 deletions(-) diff --git a/docs/PHASE4.md b/docs/PHASE4.md index 8da394c..f845035 100644 --- a/docs/PHASE4.md +++ b/docs/PHASE4.md @@ -2,9 +2,53 @@ **Project:** aish — AI-augmented conversational shell **Document:** Phase 4 Requirements, Architecture & Design Decisions -**Status:** Analyze (formulate complete; current tree at `bea7175` probed) +**Status:** Plan (review fold-in 2026-05-13 — TOCTOU race + Norris suppression + summarizer self-amp resolved) **Date:** 2026-05-13 +**Review fold-in (2026-05-13):** + +R-B1. **TOCTOU race on memory.jsonl** — two aish processes against the + same `history.dir` would each compute the same `next_id` and + produce duplicate ids; tombstones become ambiguous. Resolution: + `M.open_memory` takes an `flock(LOCK_EX | LOCK_NB)` advisory lock + on the file descriptor. Held until handle close. Failure to + acquire → `nil, "memory.jsonl held by another aish process"`. + Requires extending `ffi/libc.lua` with `flock(2)` — one cdef + + two constants (LOCK_EX=2, LOCK_NB=4). The lock is the *enforcement* + of the single-writer assumption stated in §2; documented in §2 row. + +R-C1. **System-prompt growth under Norris** — over an 8-step Norris run, + a 2KB [background] block adds ~16K redundant tokens. The Phase 0 + §8 sliding window evicts user/asst pairs but keeps the system + prompt, so big system prompts displace conversation. Resolution + (Q33 closed): suppress [background] when `ctx.norris_active == true`. + Memory items rarely change Norris-step planning, and Norris has + its goal anchor via the NORRIS suffix already. §5 + §11 reflect. + +R-C2. **Summarizer self-amplification** — running `:memory summarize` + twice in one session would feed the previous summarize call's + *assistant turn* back into the input, leading to drift (re-propose + accepted items, no signal about rejections). Resolution: operate + on the session log file (`history.load(session_path)`) rather + than `ctx:to_messages()`. The session log is the authoritative + "what was discussed" stream. Skip lines tagged + `{role:"assistant", meta:"summarize"}` (a new optional field on + the JSONL turn). §6 reflects. + +R-C3. **DEFAULT_SYSTEM_PROMPT bakes MCP statically** — cosmetic. §5 + diagram now reads "DEFAULT (Phase 0 + Phase 2 MCP) → [background] + → NORRIS". No code change. + +NITs folded inline: + N1. `:memory forget ` for an already-tombstoned id → no-op + status. + N2. §2 path note: memory.jsonl is sibling of sessions/, no collision. + N3. §4 invariant: items have id ≥ 1; meta header has no id and is + ignored; tombstones with non-matching targets are no-ops. + N4. §7 `:memory inject` semantics: replaces `ctx.memory_items` from + a fresh `load_memory()` + LRU-by-ts truncation (same as startup). + +**Analyze findings (2026-05-13):** + **Analyze findings (2026-05-13):** A1. **history.lua surface is clean** — `M.open`/`Session:append`/ @@ -88,7 +132,7 @@ Three pillars per PHASE0.md §11 row 4: | Decision | Choice | Rationale | |---|---|---| | Storage format | Append-only JSONL, one item per line | Same convention as Phase 1's session logs. Greppable, robust to truncation, no parser dependency beyond vendored dkjson. | -| Storage location | `/memory.jsonl` (sibling to `sessions/`) | Co-located with session logs; users can back up one directory. Defaults to `~/.local/share/aish/memory.jsonl`. | +| Storage location | `/memory.jsonl` (sibling to `sessions/`) | Co-located with session logs; users can back up one directory. Defaults to `~/.local/share/aish/memory.jsonl`. Path is a sibling of `sessions/` (not inside it), so `:save ` cannot collide. | | Memory-item shape | `{id, ts, kind, content, tags?, source?}` | `id` is monotonic int (counter persisted in `memory.id`); `kind ∈ {"fact","pref","context"}` lightly typed for future routing; `content` is the body text; optional `tags` array; optional `source` carrying session-id provenance when auto-extracted. | | Forget semantics | **Append a tombstone**, don't rewrite the file (`{id, ts, kind:"forget", target:}`) | Append-only preserves history. `M.load_memory` resolves tombstones during read — silently drops any item whose `id` appears as a forget-target. `:memory clear` writes one tombstone per active item; could also support a wildcard forget. | | Auto-summarize cadence | **Manual only in v1** (`:memory summarize`). Auto-trigger on `:quit` or by token count is Q-list material. | Conservative; users opt in. Avoids burning tokens on every session end. Manual surface lets the user QA candidates before they land. | @@ -97,7 +141,7 @@ Three pillars per PHASE0.md §11 row 4: | Injection budget | `cfg.memory.inject_max_chars` (default 2000 chars total — roughly 500 tokens) | Cap so memory doesn't eat the whole context. LRU-by-`ts` selection if items exceed budget. | | Pruning policy | Manual `:memory forget` + optional `cfg.memory.prune_older_than_days` (default unset — no auto-pruning) | Conservative defaults; user owns the lifecycle. | | Interaction with sessions | `memory.jsonl` is independent of `sessions/*.jsonl`. Session JSONL stays the per-conversation log; memory is the curated cross-session knowledge | Distinct concerns. Session log answers "what did we talk about last Tuesday?"; memory answers "what does aish know about me/this-project?". | -| Concurrency | Single-writer assumed (one aish process per memory dir). Reader is the same process | Same assumption as session logs. Multi-process memory sharing is out of scope. | +| Concurrency | Single-writer **enforced via `flock(LOCK_EX \| LOCK_NB)`** (R-B1) on the memory.jsonl file descriptor in `M.open_memory`. Held until close. Acquire failure → handle creation fails with a clear status message | Session logs got away with single-writer-by-uniqueness (timestamped filenames). memory.jsonl is one shared file, so the flock is the actual enforcement. The lock is advisory (Linux file-lock semantics) but every aish process honors it, which is sufficient for our trust model. | --- @@ -105,13 +149,14 @@ Three pillars per PHASE0.md §11 row 4: | File | State after Phase 3 | Phase 4 changes | |---|---|---| -| `history.lua` | `M.open(path, meta)`, `session:append(turn)`, `M.load(path)`, `M.list_sessions(dir)` | Add memory functions alongside session functions: `M.open_memory(path) -> memory_handle`; `memory:add(kind, content, tags?, source?) -> id`; `memory:forget(id)`; `M.load_memory(path) -> items_table` (resolves tombstones). `memory_handle` is similar shape to `session_handle` — internal fd + monotonic counter. | +| `history.lua` | `M.open(path, meta)`, `session:append(turn)`, `M.load(path)`, `M.list_sessions(dir)` | Add memory functions alongside session functions: `M.open_memory(path) -> handle\|nil, err`; `handle:add(kind, content, tags?, source?) -> id`; `handle:forget(id)`; `handle:close()`; `M.load_memory(path) -> items_table` (resolves tombstones). Handle internals: fd (LuaJIT FFI int), next_id (scanned from existing JSONL), held flock. | +| `ffi/libc.lua` | `chdir`, `errno`, `strerror`, plus Phase 1's waitpid/raw I/O/termios/poll, plus Phase 1's read/write/close/kill | Add `flock(2)` cdef (`int flock(int fd, int operation)`), constants `LOCK_EX = 2`, `LOCK_NB = 4`, `LOCK_UN = 8`. Wrapper `M.flock(fd, op) -> true\|false, errmsg`. Used by `history.M.open_memory` for the single-writer enforcement (R-B1). | | `context.lua` | system prompt + MCP block + NORRIS suffix toggle | Add a `memory_items` field on Context. `to_messages()` composes a dynamic "[background]" block on the system prompt when `memory_items` is non-empty AND not already in Norris mode (don't double-pile). Cap respected via the inject_max_chars budget. | | `repl.lua` | meta cmds + tool sub-loop + Norris driver | New meta: `:remember ` (shortcut for `:memory add fact `); `:memory add `; `:memory list`; `:memory forget `; `:memory clear`; `:memory summarize`. At startup, after loading config + opening session, also open memory handle and inject the top-N items into `ctx.memory_items`. | | `broker.lua` | streaming chat + opts.tools/max_tokens/timeout_ms | No structural changes. Used by the summarizer (calls broker.chat with the session log as a single user turn). | | `config.lua` | example with mcp + safety blocks | Add commented-out `memory = { ... }` example. Default behavior is "no memory injection, no auto-summarize". | | `executor.lua` | unchanged | unchanged | -| `safety.lua` | is_destructive + norris_step | unchanged | +| `safety.lua` | is_destructive + norris_step | unchanged (Norris-side suppression of background block is in context.lua, not safety.lua) | No new module files. All Phase 4 functionality grows existing files — mostly `history.lua` and `repl.lua`. @@ -145,6 +190,16 @@ list in the [background] block. Future phases may route them differently (e.g. `pref` into a system-prompt section, `context` into a user-style preamble). Today they're prose. +### Item-id invariants (N3) + +- Items have `id ≥ 1`. The optional meta header line `{"meta":{...}}` + has no `id` field and is ignored during load. +- Tombstones with non-matching `target` (id doesn't exist, or already + tombstoned) are no-ops at load — silently dropped from the active + set. The `:memory forget` meta handler also checks active-set + membership before appending a tombstone, surfacing a status when + the id isn't active. + --- ## 5. Startup Injection @@ -163,8 +218,7 @@ When aish boots and `cfg.memory` is present (or `memory.jsonl` exists): `context.to_messages()` composition: ``` - - + (Phase 0 + Phase 2 MCP block, statically embedded) [background] (memory loaded at startup; managed via :memory) - (fact) User prefers terse responses; no end-of-turn summaries. @@ -172,12 +226,17 @@ When aish boots and `cfg.memory` is present (or `memory.jsonl` exists): ``` Order of suffixes on the system prompt: -1. Default Phase 0 prompt -2. Phase 2 MCP guidance block (always present) -3. Phase 4 [background] block (when memory_items non-empty) -4. Phase 3 NORRIS MODE block (when norris_active) +1. DEFAULT_SYSTEM_PROMPT (Phase 0 + Phase 2 MCP guidance, currently + baked-in to the static constant — R-C3 note: not a separate dynamic + block in v1; future phases may split) +2. Phase 4 [background] block (when memory_items non-empty AND NOT in + Norris mode — R-C1 suppression to avoid ~16K of redundant tokens + per Norris run) +3. Phase 3 NORRIS MODE block (when norris_active) -Norris is last so its instructions take precedence when active. +When Norris is active the order becomes: DEFAULT → NORRIS (no background). +Norris's planning loop already has the goal anchored in its suffix; the +memory items rarely change step-to-step planning. --- @@ -189,14 +248,22 @@ turns and propose candidate memory items. ### Flow -1. Build a prompt: "Read the following conversation transcript. Extract +1. **Source of truth is the session log file** (R-C2), not + `ctx:to_messages()`. `history.load(session_path)` returns all + turns; filter out turns tagged `meta = "summarize"` (set on the + assistant turn that emitted a prior summarize response) so the + summarizer can't feed on its own output across multiple calls. +2. Build a prompt: "Read the following conversation transcript. Extract facts, preferences, or context worth remembering across future sessions. Output ONE candidate per line, prefixed with the kind: `fact: …`, `pref: …`, or `context: …`. Maximum 10 candidates." -2. Send `ctx:to_messages()` minus the [background] suffix (avoid - feedback) + the user prompt above. -3. Parse the response line-by-line for `(fact|pref|context): - ` shapes. +3. Send the filtered transcript as a single user turn + the + instruction above. Use `cfg.memory.summarizer_model` if set (else + the active model). The resulting assistant turn gets logged + with `meta = "summarize"` so future :memory summarize calls + exclude it. +4. Parse the response line-by-line for `(fact|pref|context): + ` shapes. Tolerate markdown bullet prefixes (`-`, `*`). 4. For each candidate, prompt the user: ``` @@ -231,7 +298,7 @@ Manual gives the user the trigger. Q-list tracks auto-cadence options. | `:memory forget ` | Append a tombstone for `` | | `:memory clear` | Forget all active items (with `[y/N]` confirm) | | `:memory summarize` | Extract candidate items from current session via LLM | -| `:memory inject` | Re-inject current memory.jsonl items into Context (after edits) | +| `:memory inject` | Replace `ctx.memory_items` from a fresh `load_memory()` + LRU-by-ts truncation. Same logic as startup injection. Useful after hand-editing `memory.jsonl` or after `:memory forget` to immediately reflect in the system prompt. | `:help` updated. @@ -303,7 +370,7 @@ Specifically out of Phase 4 scope despite proximity: |---|---|---|---| | Q31 | Auto-summarize trigger: manual only (current), automatic at `:quit`, automatic on token-budget eviction, or config-flagged threshold? | history.lua + repl.lua | Phase 4 (analyze) | | Q32 | Editing memory items in place: `:memory edit ` to rewrite content? Append-only means edit = new id + forget old. Worth the extra meta? | history.lua + UX | Phase 4 (analyze) | -| Q33 | Memory injection while in Norris mode: does the [background] block stay, get suppressed, or merge with the Norris goal? Proposal: keep both; Norris is the last block and dominates. | context.lua | Phase 4 (plan) | +| Q33 | ~~Memory injection while in Norris mode~~ | context.lua | **Resolved at review (R-C1)**: SUPPRESSED. Memory items aren't injected when `ctx.norris_active == true`. Norris has its goal anchor in the NORRIS suffix; 16K of redundant background per 8-step run is not worth the marginal context value. | | Q34 | Memory kinds: stick with fact/pref/context or split prefs into a dedicated section of the system prompt (where they're more impactful)? v1 says no — flat list. | context.lua + UX | Phase 5 if it bites | | Q35 | Privacy / redaction: `:memory summarize` could capture sensitive tokens from a chat (passwords, paths). Should it auto-redact? Strip command-history-style? | safety.lua + memory.lua | Phase 4 (verify) — review user-emergent risk | | Q36 | Memory deduplication: user adds the same fact twice. Detect and warn, dedupe silently, or allow? v1: allow (cheap; user can `:memory list` to spot). | history.lua | Phase 4 (verify) | @@ -314,12 +381,23 @@ Specifically out of Phase 4 scope despite proximity: Bottom-up, same cadence as Phase 0/1/2/3. Five commits expected: -1. **`history.lua` — memory store.** Add `M.open_memory`, - `memory:add(kind, content, tags?, source?)`, `memory:forget(id)`, - `M.load_memory(path)` with tombstone resolution. Persistent - monotonic counter via a sidecar `memory.id` file (or scan the JSONL - for max id at open time — pick at analyze). **Test in isolation**: - round-trip add/forget/load against a temp file. +1. **`history.lua` — memory store + `ffi/libc.lua` flock (R-B1 bundled).** + - `ffi/libc.lua`: cdef `flock(2)` + LOCK_EX/LOCK_NB/LOCK_UN constants + + `M.flock(fd, op)` wrapper. + - `history.lua`: `M.open_memory(path)` opens the file (creating parent + dirs + meta-header line if empty), takes `flock(LOCK_EX | LOCK_NB)` + on the fd, scans the existing JSONL for max id → handle.next_id. + Returns `(handle, nil)` on success; `(nil, errmsg)` on lock-held. + - `handle:add(kind, content, tags?, source?)`: assigns next id, + appends JSON line, returns id. + - `handle:forget(id)`: appends a tombstone for id. + - `handle:close()`: releases flock + closes fd. + - `M.load_memory(path)`: reads all lines, builds forget-target set + from kind=="forget" entries, returns active items sorted by `ts` + descending. Drops items whose id is in the forget-set OR whose id + is nil (meta header). + **Test in isolation**: round-trip add/forget/load, lock-held + detection (open twice in same process, second should fail). 2. **`context.lua` — memory injection.** Add `ctx.memory_items` and the `[background]` block composer in `to_messages()`. Cap by