replace Redis with an embedded SQLite string->string KV store (group commit, in-tx events, SQL search)

internal/storage/schema_version.go

@@ -1,83 +1,70 @@
 package storage
 
 import (
-	"context"
 	"fmt"
 	"strconv"
-	"time"
 
-	"github.com/redis/go-redis/v9"
+	"github.com/metazla/meta-core/internal/kv"
 )
 
-// SchemaVersion is the Redis-layout version this build of meta-core expects.
+// SchemaVersion is the key-layout version this build of meta-core expects.
 // Distinct from the snapshot manifest version (which is on-disk format);
-// this number describes the in-memory Redis schema — primarily, "are roots
-// UUIDs or content-hash tokens, and do reverse-index keys cid:* exist?"
+// this number describes the record layout — primarily, "are roots UUIDs or
+// content-hash tokens, and do reverse-index keys cid:* exist?"
 //
-// Bump only when a Redis-layout change can't be detected from the data
-// itself or healed by the auto-alias hooks. Each bump is a flag day in
-// alpha: operators wipe and restart.
+// The Redis → SQLite move did not change the record layout (file:<rid>/<field>,
+// cid:<cid>), so it did not bump this: the one-time migration copied records
+// verbatim.
+//
+// Bump only when a layout change can't be detected from the data itself or
+// healed by the write path. Each bump is a flag day in alpha: operators wipe
+// and restart.
 const SchemaVersion = 2
 
-// SchemaVersionKey is the sentinel under which we record SchemaVersion in
-// Redis. Checked on every meta-core boot.
+// SchemaVersionKey is the sentinel under which we record SchemaVersion.
+// Checked on every meta-core boot.
 const SchemaVersionKey = "meta-core:schema-version"
 
-// EnsureSchemaVersion verifies the Redis store matches the expected schema
-// version. Called once at startup, before any other reads/writes.
+// EnsureSchemaVersion verifies the store matches the expected schema version.
+// Called once at startup, before any other reads/writes.
 //
 // Behavior:
 //   - sentinel present and matches expected → OK
-//   - sentinel missing AND file:__index__ empty → fresh store, stamp sentinel
-//   - sentinel missing AND file:__index__ non-empty → legacy data, refuse
+//   - sentinel missing AND no roots → fresh store, stamp sentinel
+//   - sentinel missing AND roots exist → legacy data, refuse
 //   - sentinel present but mismatched → refuse, point operator at clean:all
 //
 // Refusal is hard-fail; the caller is expected to log.Fatalf and exit.
 // The error message names the wipe remediation because in alpha there
 // is no automated migration — operators bring up a clean store.
 func (c *Client) EnsureSchemaVersion(expected int) error {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-
-	if c.client == nil {
-		return fmt.Errorf("not connected")
-	}
-
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-	defer cancel()
-
-	key := c.buildKey(SchemaVersionKey)
-	have, err := c.client.Get(ctx, key).Result()
-	if err != nil && err != redis.Nil {
-		return fmt.Errorf("get schema version: %w", err)
-	}
-
-	if err == redis.Nil {
-		// Sentinel absent. Fresh store iff there's no file:__index__ membership.
-		n, sErr := c.client.SCard(ctx, c.buildIndexKey()).Result()
-		if sErr != nil && sErr != redis.Nil {
-			return fmt.Errorf("scard file:__index__: %w", sErr)
+	return c.update(func(tx *kv.Tx) error {
+		ctx := tx.Context()
+		have, ok, err := tx.Get(ctx, SchemaVersionKey)
+		if err != nil {
+			return fmt.Errorf("get schema version: %w", err)
 		}
-		if n > 0 {
-			return fmt.Errorf(
-				"redis has %d indexed roots but no %q sentinel — this is alpha "+
-					"data from before the UUID-rooted schema landed. Run "+
-					"`pnpm run clean:all` (or `docker exec metacore-app redis-cli FLUSHDB`) "+
-					"to wipe and restart, or downgrade meta-core to a compatible build",
-				n, SchemaVersionKey)
+		if !ok {
+			n, err := tx.Count(ctx, rootsNS)
+			if err != nil {
+				return fmt.Errorf("count roots: %w", err)
+			}
+			if n > 0 {
+				return fmt.Errorf(
+					"the store has %d indexed roots but no %q sentinel — this is alpha "+
+						"data from before the UUID-rooted schema landed. Delete the "+
+						"database file to wipe and restart, or downgrade meta-core to a compatible build",
+					n, SchemaVersionKey)
+			}
+			return tx.Put(SchemaVersionKey, strconv.Itoa(expected))
 		}
-		if err := c.client.Set(ctx, key, strconv.Itoa(expected), 0).Err(); err != nil {
-			return fmt.Errorf("set schema version: %w", err)
+		if have == strconv.Itoa(expected) {
+			return nil
 		}
-		return nil
-	}
-
-	if have == strconv.Itoa(expected) {
-		return nil
-	}
-	return fmt.Errorf(
-		"redis schema version is %q, this build of meta-core expects %d. "+
-			"Run `pnpm run clean:all` to wipe and restart, or use a meta-core "+
-			"build that matches the existing data",
-		have, expected)
+		return fmt.Errorf(
+			"store schema version is %q, this build of meta-core expects %d. "+
+				"Delete the database file to wipe and restart, or use a meta-core "+
+				"build that matches the existing data",
+			have, expected)
+	})
 }