Initial commit: SRDB - High-performance LSM-Tree database

- Core engine with MemTable, SST, WAL
- B+Tree indexing for SST files  
- Leveled compaction strategy
- Multi-table database management
- Schema validation and secondary indexes
- Query builder with complex conditions
- Web UI with HTMX for data visualization
- Command-line tools for diagnostics

wal/wal_test.go

@@ -0,0 +1,130 @@
+package wal
+
+import (
+	"os"
+	"testing"
+)
+
+func TestWAL(t *testing.T) {
+	// 1. 创建 WAL
+	wal, err := Open("test.wal")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.Remove("test.wal")
+
+	// 2. 写入数据
+	for i := int64(1); i <= 100; i++ {
+		entry := &Entry{
+			Type: EntryTypePut,
+			Seq:  i,
+			Data: []byte("value_" + string(rune(i))),
+		}
+		err := wal.Append(entry)
+		if err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	// 3. Sync
+	err = wal.Sync()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	wal.Close()
+
+	t.Log("Written 100 entries")
+
+	// 4. 读取数据
+	reader, err := NewReader("test.wal")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer reader.Close()
+
+	entries, err := reader.Read()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(entries) != 100 {
+		t.Errorf("Expected 100 entries, got %d", len(entries))
+	}
+
+	// 验证数据
+	for i, entry := range entries {
+		expectedSeq := int64(i + 1)
+		if entry.Seq != expectedSeq {
+			t.Errorf("Entry %d: expected Seq=%d, got %d", i, expectedSeq, entry.Seq)
+		}
+		if entry.Type != EntryTypePut {
+			t.Errorf("Entry %d: expected Type=%d, got %d", i, EntryTypePut, entry.Type)
+		}
+	}
+
+	t.Log("All tests passed!")
+}
+
+func TestWALTruncate(t *testing.T) {
+	// 创建 WAL
+	wal, err := Open("test_truncate.wal")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.Remove("test_truncate.wal")
+
+	// 写入数据
+	for i := int64(1); i <= 10; i++ {
+		entry := &Entry{
+			Type: EntryTypePut,
+			Seq:  i,
+			Data: []byte("value"),
+		}
+		wal.Append(entry)
+	}
+
+	// Truncate
+	err = wal.Truncate()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	wal.Close()
+
+	// 验证文件为空
+	reader, err := NewReader("test_truncate.wal")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer reader.Close()
+
+	entries, err := reader.Read()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(entries) != 0 {
+		t.Errorf("Expected 0 entries after truncate, got %d", len(entries))
+	}
+
+	t.Log("Truncate test passed!")
+}
+
+func BenchmarkWALAppend(b *testing.B) {
+	wal, _ := Open("bench.wal")
+	defer os.Remove("bench.wal")
+	defer wal.Close()
+
+	entry := &Entry{
+		Type: EntryTypePut,
+		Seq:  1,
+		Data: make([]byte, 100),
+	}
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		entry.Seq = int64(i)
+		wal.Append(entry)
+	}
+}