fix: 按完成时刻分批清理并限制读连接池

internal/store/db.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"time"
 
 	_ "modernc.org/sqlite"
 )
@@ -134,6 +135,9 @@ func OpenReader(dataDir, synchronous string) (*sql.DB, error) {
 	if err != nil {
 		return nil, fmt.Errorf("open sqlite reader: %w", err)
 	}
+	db.SetMaxOpenConns(64)
+	db.SetMaxIdleConns(16)
+	db.SetConnMaxIdleTime(5 * time.Minute)
 	if err := db.Ping(); err != nil {
 		_ = db.Close()
 		return nil, fmt.Errorf("ping sqlite reader: %w", err)
@@ -157,6 +161,8 @@ func buildDSN(dataDir, synchronous string, writer bool) (string, error) {
 	)
 	if writer {
 		dsn += "&_txlock=immediate"
+	} else {
+		dsn += "&_pragma=query_only(1)"
 	}
 	return dsn, nil
 }

internal/store/db_pool_test.go

@@ -0,0 +1,48 @@
+package store
+
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+	"testing"
+)
+
+func TestReaderPoolCapAndQueryOnly(t *testing.T) {
+	t.Parallel()
+	dir := t.TempDir()
+	db, err := Open(dir, "FULL")
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { _ = db.Close() })
+
+	ctx := context.Background()
+	if _, err := db.Read.ExecContext(ctx, `INSERT INTO settings(key,value,updated_at) VALUES('x','y',1)`); err == nil {
+		t.Fatal("query_only reader accepted write")
+	}
+
+	var maxOpen atomic.Int32
+	var wg sync.WaitGroup
+	for i := 0; i < 200; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			var one int
+			if qErr := db.Read.QueryRowContext(ctx, `SELECT 1`).Scan(&one); qErr != nil {
+				t.Errorf("read: %v", qErr)
+				return
+			}
+			n := int32(db.Read.Stats().OpenConnections)
+			for {
+				cur := maxOpen.Load()
+				if n <= cur || maxOpen.CompareAndSwap(cur, n) {
+					break
+				}
+			}
+		}()
+	}
+	wg.Wait()
+	if maxOpen.Load() > 64 {
+		t.Fatalf("open connections %d exceed 64", maxOpen.Load())
+	}
+}

internal/store/db_test.go

@@ -19,7 +19,7 @@ func TestOpenEmptyDirCreatesTables(t *testing.T) {
 	}
 	defer func() { _ = db.Close() }()
 
-	assertMigrationCount(t, db.Write, 2)
+	assertMigrationCount(t, db.Write, 3)
 	for _, table := range []string{
 		"endpoints", "settings", "talk_grants", "groups", "group_members",
 		"messages", "message_bodies", "deliveries", "receipts", "send_keys",
@@ -41,7 +41,7 @@ func TestOpenIdempotentNoRemigrate(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	assertMigrationCount(t, db1.Write, 2)
+	assertMigrationCount(t, db1.Write, 3)
 	_ = db1.Close()
 
 	db2, err := Open(dir, "FULL")
@@ -49,7 +49,7 @@ func TestOpenIdempotentNoRemigrate(t *testing.T) {
 		t.Fatal(err)
 	}
 	defer func() { _ = db2.Close() }()
-	assertMigrationCount(t, db2.Write, 2)
+	assertMigrationCount(t, db2.Write, 3)
 
 	if entries, readErr := os.ReadDir(filepath.Join(dir, "backup")); readErr == nil && len(entries) > 0 {
 		t.Fatalf("idempotent reopen should not backup: %v", entries)
@@ -83,7 +83,7 @@ CREATE TABLE schema_migrations (
 	}
 	defer func() { _ = db.Close() }()
 
-	assertMigrationCount(t, db.Write, 2)
+	assertMigrationCount(t, db.Write, 3)
 	assertTableExists(t, db.Write, "endpoints")
 	assertTableExists(t, db.Write, "api_tokens")
 
@@ -96,7 +96,7 @@ CREATE TABLE schema_migrations (
 	var names []string
 	for _, e := range entries {
 		names = append(names, e.Name())
-		if e.Name() == "pre-migrate-v1-to-v2.db" {
+		if e.Name() == "pre-migrate-v1-to-v4.db" {
 			found = true
 			info, statErr := e.Info()
 			if statErr != nil {
@@ -108,7 +108,7 @@ CREATE TABLE schema_migrations (
 		}
 	}
 	if !found {
-		t.Fatalf("expected pre-migrate-v1-to-v2.db, got %v", names)
+		t.Fatalf("expected pre-migrate-v1-to-v4.db, got %v", names)
 	}
 }
 

internal/store/migrate_test.go

@@ -36,7 +36,7 @@ func TestFailingMigrationReusesBackup(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if len(first) != 1 || first[0].Name() != "pre-migrate-v2-to-v9999.db" {
+	if len(first) != 1 || first[0].Name() != "pre-migrate-v4-to-v9999.db" {
 		t.Fatalf("first backups=%v", dirNames(first))
 	}
 

internal/store/migrations/0004_cleanup_indexes.sql

@@ -0,0 +1,11 @@
+-- C-03：完成时刻列与清理索引（编号避开 U-02 的 0003）
+ALTER TABLE messages ADD COLUMN completed_at INTEGER;
+
+UPDATE messages SET completed_at = COALESCE(
+  (SELECT MAX(d.updated_at) FROM deliveries d WHERE d.seq = messages.seq),
+  send_at
+) WHERE state = 'completed' AND completed_at IS NULL;
+
+CREATE INDEX IF NOT EXISTS idx_messages_completed_at ON messages(completed_at);
+CREATE INDEX IF NOT EXISTS idx_receipts_created ON receipts(created_at);
+CREATE INDEX IF NOT EXISTS idx_send_keys_created ON send_keys(created_at);