fix: 修复写队列 busy 恢复、关闭安全、备份与配置构建问题

internal/store/queue_test.go

@@ -5,6 +5,9 @@ import (
 	"database/sql"
 	"errors"
 	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -148,6 +151,119 @@ func TestWriteQueueNoBacklogAt200PerSec(t *testing.T) {
 	}
 }
 
+func TestWriteQueueRecoversReadyAfterBusy(t *testing.T) {
+	t.Parallel()
+	dir := t.TempDir()
+	db, err := Open(dir, "FULL")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() { _ = db.Close() }()
+
+	db.Queue.markBusy(errors.New("injected busy"))
+	if db.Queue.IsReady() {
+		t.Fatal("expected not ready after markBusy")
+	}
+
+	ctx := context.Background()
+	if err := db.Queue.Do(ctx, func(tx *sql.Tx) error {
+		_, e := tx.Exec(
+			`INSERT INTO settings(key, value, updated_at) VALUES(?, ?, ?)`,
+			"after_busy", "1", time.Now().UnixMilli(),
+		)
+		return e
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if !db.Queue.IsReady() {
+		t.Fatalf("expected ready after successful Do, last=%v", db.Queue.LastWriteError())
+	}
+}
+
+func TestWriteQueueCloseConcurrentDoNoPanic(t *testing.T) {
+	t.Parallel()
+	dir := t.TempDir()
+	db, err := Open(dir, "FULL")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() { _ = db.Close() }()
+
+	ctx := context.Background()
+	const n = 1000
+	var wg sync.WaitGroup
+	wg.Add(n)
+	for i := 0; i < n; i++ {
+		i := i
+		go func() {
+			defer wg.Done()
+			_ = db.Queue.Do(ctx, func(tx *sql.Tx) error {
+				_, e := tx.Exec(
+					`INSERT INTO settings(key, value, updated_at) VALUES(?, ?, ?)
+ON CONFLICT(key) DO UPDATE SET value = excluded.value, updated_at = excluded.updated_at`,
+					fmt.Sprintf("close_%d", i%50), "1", time.Now().UnixMilli(),
+				)
+				return e
+			})
+		}()
+	}
+	time.Sleep(2 * time.Millisecond)
+	if err := db.Queue.Close(); err != nil {
+		t.Fatal(err)
+	}
+	wg.Wait()
+
+	err = db.Queue.Do(ctx, func(tx *sql.Tx) error { return nil })
+	if !errors.Is(err, ErrQueueClosed) {
+		t.Fatalf("want ErrQueueClosed, got %v", err)
+	}
+}
+
+func TestQueueCheckpointTruncatesWAL(t *testing.T) {
+	t.Parallel()
+	dir := t.TempDir()
+	db, err := Open(dir, "FULL")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() { _ = db.Close() }()
+
+	ctx := context.Background()
+	payload := strings.Repeat("x", 4096)
+	for i := 0; i < 300; i++ {
+		i := i
+		if err := db.Queue.Do(ctx, func(tx *sql.Tx) error {
+			_, e := tx.Exec(
+				`INSERT INTO settings(key, value, updated_at) VALUES(?, ?, ?)`,
+				fmt.Sprintf("wal_%d", i), payload, time.Now().UnixMilli(),
+			)
+			return e
+		}); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	walPath := filepath.Join(dir, DBFileName+"-wal")
+	before, statErr := os.Stat(walPath)
+	if err := db.Checkpoint(ctx); err != nil {
+		t.Fatal(err)
+	}
+	if statErr != nil {
+		return
+	}
+	after, err := os.Stat(walPath)
+	if err != nil {
+		// TRUNCATE 后 WAL 可能被删掉，视为回落成功。
+		if os.IsNotExist(err) {
+			return
+		}
+		t.Fatal(err)
+	}
+	if before.Size() > 0 && after.Size() >= before.Size() {
+		t.Fatalf("WAL did not shrink: before=%d after=%d", before.Size(), after.Size())
+	}
+}
+
 func BenchmarkWriteQueue200PerSec(b *testing.B) {
 	dir := b.TempDir()
 	db, err := Open(dir, "FULL")