# M5a task 08: the index

**Branch:** `m5a` (run `git switch m5a`; `git status --short` must be empty, otherwise stop)
**Commit subject:** `memoryd: the FTS5 index over session logs and notes, with labels`

## Goal

`index/memory.sqlite3` (M5a spec, section 6): an SQLite FTS5 table of text and a table of where
each came from. Indexed: the owner's messages, the assistant's replies, and each tool call by name
and arguments; **never a tool's result**. Each record is labelled with the session's label **at
that point in its log** (the highest class of any earlier tool result, and whether any was
untrusted). Records above `[index] max_class` are left out. It keeps, per log, how many records
it has read, so it only reads what is new; and it can be rebuilt whole into a new file renamed
over the old one.

The `rusqlite` calls you need, checked on docs.rs for 0.40.2: `Connection::open(path)`,
`conn.execute_batch(sql)`, `conn.execute(sql, params![..])`, `conn.query_row(sql, params![..],
|row| row.get(0))`, `conn.last_insert_rowid()`. `u64` and `usize` are **not** SQL types in
rusqlite: pass `i64` (the skeleton's `int` does that).

## Files

- Copy (skeleton): `crates/memoryd/src/index.rs`
- Copy (tests): `crates/memoryd/tests/index.rs`, `crates/memoryd/tests/support/logs.rs`
- Modify: `crates/memoryd/src/lib.rs` (`pub mod index;` after `pub mod files;`),
  `docs/implementer-log.md`

## The skeleton

Written: `SCHEMA`, `Source`, `Counts`, `Index`, `db`, `class_name`, `class_of`, `int`, and
`Index::conn`. Fill: `open`, `progress`, `add`, `set_progress`, `index_record`, `index_log`,
`index_notes`, `catch_up`, `logs`, `rebuild`.

## Steps

- [ ] **1. Copy** the three files; edit `lib.rs`.
- [ ] **2. See it fail.** `cargo test -p memoryd --test index`: 6 failed.
- [ ] **3. Fill** the functions in the order listed. `cargo fmt --all`.
- [ ] **4. See it pass.** The same command, three times: 6 passed each time.
- [ ] **5. Run the gate.** `make gate`: `gate: ok`, 6 more tests than before (about 906).
- [ ] **6. Log and commit.** `git add -A crates/memoryd docs/implementer-log.md Cargo.lock && git commit`

## Done when

- `make gate` prints `gate: ok`.

## Stop and report if

- A test fails after the functions follow their comments exactly. Do not edit a test.