Fix bucket reclamation.

The bucket page is allocated separately from the rest of the pages but the old bucket pages were
not being added to the freelist. This change fixes that and adds a simple check for database
consistency. More advanced consistency checks can be added in the future.

Fixes #82.

1 files changed, 47 insertions, 5 deletions

diff --git a/db_test.go b/db_test.go
index df17f94..a2df9d3 100644
--- a/db_test.go
+++ b/db_test.go
@@ -244,11 +244,11 @@ func TestDBStat(t *testing.T) {
 		// Obtain stats.
 		stat, err := db.Stat()
 		assert.NoError(t, err)
-		assert.Equal(t, stat.PageCount, 128)
-		assert.Equal(t, stat.FreePageCount, 2)
-		assert.Equal(t, stat.PageSize, 4096)
-		assert.Equal(t, stat.MmapSize, 4194304)
-		assert.Equal(t, stat.TxCount, 2)
+		assert.Equal(t, 126, stat.PageCount)
+		assert.Equal(t, 3, stat.FreePageCount)
+		assert.Equal(t, 4096, stat.PageSize)
+		assert.Equal(t, 4194304, stat.MmapSize)
+		assert.Equal(t, 2, stat.TxCount)
 
 		// Close readers.
 		t0.Rollback()
@@ -282,6 +282,48 @@ func TestDBMmapSize(t *testing.T) {
 	assert.Equal(t, db.mmapSize(1<<30), 1<<31)
 }
 
+// Ensure that database pages are in expected order and type.
+func TestDBConsistency(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			return tx.CreateBucket("widgets")
+		})
+
+		for i := 0; i < 10; i++ {
+			db.Update(func(tx *Tx) error {
+				assert.NoError(t, tx.Bucket("widgets").Put([]byte("foo"), []byte("bar")))
+				return nil
+			})
+		}
+		db.Update(func(tx *Tx) error {
+			if p, _ := tx.Page(0); assert.NotNil(t, p) {
+				assert.Equal(t, "meta", p.Type)
+			}
+			if p, _ := tx.Page(1); assert.NotNil(t, p) {
+				assert.Equal(t, "meta", p.Type)
+			}
+			if p, _ := tx.Page(2); assert.NotNil(t, p) {
+				assert.Equal(t, "freelist", p.Type)
+			}
+			if p, _ := tx.Page(3); assert.NotNil(t, p) {
+				assert.Equal(t, "free", p.Type)
+			}
+			if p, _ := tx.Page(4); assert.NotNil(t, p) {
+				assert.Equal(t, "buckets", p.Type)
+			}
+			if p, _ := tx.Page(5); assert.NotNil(t, p) {
+				assert.Equal(t, "leaf", p.Type)
+			}
+			if p, _ := tx.Page(6); assert.NotNil(t, p) {
+				assert.Equal(t, "free", p.Type)
+			}
+			p, _ := tx.Page(7)
+			assert.Nil(t, p)
+			return nil
+		})
+	})
+}
+
 // Ensure that a database can return a string representation of itself.
 func TestDBString(t *testing.T) {
 	db := &DB{path: "/tmp/foo"}