Merge pull request #5481 from bottlepay/kvdb-tests

kvdb: generalize etcd tests

kvdb/bolt_fixture.go

@@ -0,0 +1,44 @@
+package kvdb
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/btcsuite/btcwallet/walletdb"
+	"github.com/stretchr/testify/require"
+)
+
+type boltFixture struct {
+	t       *testing.T
+	tempDir string
+}
+
+func NewBoltFixture(t *testing.T) *boltFixture {
+	tempDir, err := ioutil.TempDir("", "test")
+	require.NoError(t, err)
+
+	return &boltFixture{
+		t:       t,
+		tempDir: tempDir,
+	}
+}
+
+func (b *boltFixture) Cleanup() {
+	os.RemoveAll(b.tempDir)
+}
+
+func (b *boltFixture) NewBackend() walletdb.DB {
+	dbPath := filepath.Join(b.tempDir)
+
+	db, err := GetBoltBackend(&BoltBackendConfig{
+		DBPath:         dbPath,
+		DBFileName:     "test.db",
+		NoFreelistSync: true,
+		DBTimeout:      DefaultDBTimeout,
+	})
+	require.NoError(b.t, err)
+
+	return db
+}

kvdb/bolt_test.go

@@ -0,0 +1,80 @@
+package kvdb
+
+import (
+	"testing"
+
+	"github.com/btcsuite/btcwallet/walletdb"
+)
+
+func TestBolt(t *testing.T) {
+	tests := []struct {
+		name string
+		test func(*testing.T, walletdb.DB)
+	}{
+		{
+			name: "read cursor empty interval",
+			test: testReadCursorEmptyInterval,
+		},
+		{
+			name: "read cursor non empty interval",
+			test: testReadCursorNonEmptyInterval,
+		},
+		{
+			name: "read write cursor",
+			test: testReadWriteCursor,
+		},
+		{
+			name: "read write cursor with bucket and value",
+			test: testReadWriteCursorWithBucketAndValue,
+		},
+		{
+			name: "bucket creation",
+			test: testBucketCreation,
+		},
+		{
+			name: "bucket deletion",
+			test: testBucketDeletion,
+		},
+		{
+			name: "bucket for each",
+			test: testBucketForEach,
+		},
+		{
+			name: "bucket for each with error",
+			test: testBucketForEachWithError,
+		},
+		{
+			name: "bucket sequence",
+			test: testBucketSequence,
+		},
+		{
+			name: "key clash",
+			test: testKeyClash,
+		},
+		{
+			name: "bucket create delete",
+			test: testBucketCreateDelete,
+		},
+		{
+			name: "tx manual commit",
+			test: testTxManualCommit,
+		},
+		{
+			name: "tx rollback",
+			test: testTxRollback,
+		},
+	}
+
+	for _, test := range tests {
+		test := test
+
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
+			f := NewBoltFixture(t)
+			defer f.Cleanup()
+
+			test.test(t, f.NewBackend())
+		})
+	}
+}

kvdb/etcd/bucket.go

@@ -90,3 +90,42 @@ func getKeyVal(kv *KV) ([]byte, []byte) {
 
 	return getKey(kv.key), val
 }
+
+// BucketKey is a helper functon used in tests to create a bucket key from
+// passed bucket list.
+func BucketKey(buckets ...string) string {
+	var bucketKey []byte
+
+	rootID := makeBucketID([]byte(etcdDefaultRootBucketId))
+	parent := rootID[:]
+
+	for _, bucketName := range buckets {
+		bucketKey = makeBucketKey(parent, []byte(bucketName))
+		id := makeBucketID(bucketKey)
+		parent = id[:]
+	}
+
+	return string(bucketKey)
+}
+
+// BucketVal is a helper function used in tests to create a bucket value (the
+// value for a bucket key) from the passed bucket list.
+func BucketVal(buckets ...string) string {
+	id := makeBucketID([]byte(BucketKey(buckets...)))
+	return string(id[:])
+}
+
+// ValueKey is a helper function used in tests to create a value key from the
+// passed key and bucket list.
+func ValueKey(key string, buckets ...string) string {
+	rootID := makeBucketID([]byte(etcdDefaultRootBucketId))
+	bucket := rootID[:]
+
+	for _, bucketName := range buckets {
+		bucketKey := makeBucketKey(bucket, []byte(bucketName))
+		id := makeBucketID(bucketKey)
+		bucket = id[:]
+	}
+
+	return string(makeValueKey(bucket, []byte(key)))
+}

kvdb/etcd/bucket_test.go

@@ -1,42 +0,0 @@
-// +build kvdb_etcd
-
-package etcd
-
-// bkey is a helper functon used in tests to create a bucket key from passed
-// bucket list.
-func bkey(buckets ...string) string {
-	var bucketKey []byte
-
-	rootID := makeBucketID([]byte(etcdDefaultRootBucketId))
-	parent := rootID[:]
-
-	for _, bucketName := range buckets {
-		bucketKey = makeBucketKey(parent, []byte(bucketName))
-		id := makeBucketID(bucketKey)
-		parent = id[:]
-	}
-
-	return string(bucketKey)
-}
-
-// bval is a helper function used in tests to create a bucket value (the value
-// for a bucket key) from the passed bucket list.
-func bval(buckets ...string) string {
-	id := makeBucketID([]byte(bkey(buckets...)))
-	return string(id[:])
-}
-
-// vkey is a helper function used in tests to create a value key from the
-// passed key and bucket list.
-func vkey(key string, buckets ...string) string {
-	rootID := makeBucketID([]byte(etcdDefaultRootBucketId))
-	bucket := rootID[:]
-
-	for _, bucketName := range buckets {
-		bucketKey := makeBucketKey(bucket, []byte(bucketName))
-		id := makeBucketID(bucketKey)
-		bucket = id[:]
-	}
-
-	return string(makeValueKey(bucket, []byte(key)))
-}

kvdb/etcd/db_test.go

@@ -38,8 +38,8 @@ func TestCopy(t *testing.T) {
 	require.Nil(t, err)
 
 	expected := map[string]string{
-		bkey("apple"):        bval("apple"),
+		BucketKey("apple"):        BucketVal("apple"),
-		vkey("key", "apple"): "val",
+		ValueKey("key", "apple"): "val",
 	}
 	require.Equal(t, expected, f.Dump())
 }

kvdb/etcd/fixture.go

@@ -9,6 +9,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/btcsuite/btcwallet/walletdb"
+	"github.com/stretchr/testify/require"
 	"go.etcd.io/etcd/clientv3"
 	"go.etcd.io/etcd/clientv3/namespace"
 )
@@ -76,6 +78,13 @@ func NewEtcdTestFixture(t *testing.T) *EtcdTestFixture {
 	}
 }
 
+func (f *EtcdTestFixture) NewBackend() walletdb.DB {
+	db, err := newEtcdBackend(context.TODO(), f.BackendConfig())
+	require.NoError(f.t, err)
+
+	return db
+}
+
 // Put puts a string key/value into the test etcd database.
 func (f *EtcdTestFixture) Put(key, value string) {
 	ctx, cancel := context.WithTimeout(context.TODO(), testEtcdTimeout)

kvdb/etcd/readwrite_cursor.go

@@ -96,11 +96,6 @@ func (c *readWriteCursor) Prev() (key, value []byte) {
 // not exist, the cursor is moved to the next key after seek.  Returns
 // the new pair.
 func (c *readWriteCursor) Seek(seek []byte) (key, value []byte) {
-	// Return nil if trying to seek to an empty key.
-	if seek == nil {
-		return nil, nil
-	}
-
 	// Seek to the first key with prefix + seek. If that key is not present
 	// STM will seek to the next matching key with prefix.
 	kv, err := c.bucket.tx.stm.Seek(c.prefix, c.prefix+string(seek))

kvdb/etcd/readwrite_tx_test.go

@@ -10,70 +10,6 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func TestTxManualCommit(t *testing.T) {
-	t.Parallel()
-
-	f := NewEtcdTestFixture(t)
-	defer f.Cleanup()
-
-	db, err := newEtcdBackend(context.TODO(), f.BackendConfig())
-	require.NoError(t, err)
-
-	tx, err := db.BeginReadWriteTx()
-	require.NoError(t, err)
-	require.NotNil(t, tx)
-
-	committed := false
-
-	tx.OnCommit(func() {
-		committed = true
-	})
-
-	apple, err := tx.CreateTopLevelBucket([]byte("apple"))
-	require.NoError(t, err)
-	require.NotNil(t, apple)
-	require.NoError(t, apple.Put([]byte("testKey"), []byte("testVal")))
-
-	banana, err := tx.CreateTopLevelBucket([]byte("banana"))
-	require.NoError(t, err)
-	require.NotNil(t, banana)
-	require.NoError(t, banana.Put([]byte("testKey"), []byte("testVal")))
-	require.NoError(t, tx.DeleteTopLevelBucket([]byte("banana")))
-
-	require.NoError(t, tx.Commit())
-	require.True(t, committed)
-
-	expected := map[string]string{
-		bkey("apple"):            bval("apple"),
-		vkey("testKey", "apple"): "testVal",
-	}
-	require.Equal(t, expected, f.Dump())
-}
-
-func TestTxRollback(t *testing.T) {
-	t.Parallel()
-
-	f := NewEtcdTestFixture(t)
-	defer f.Cleanup()
-
-	db, err := newEtcdBackend(context.TODO(), f.BackendConfig())
-	require.NoError(t, err)
-
-	tx, err := db.BeginReadWriteTx()
-	require.Nil(t, err)
-	require.NotNil(t, tx)
-
-	apple, err := tx.CreateTopLevelBucket([]byte("apple"))
-	require.Nil(t, err)
-	require.NotNil(t, apple)
-
-	require.NoError(t, apple.Put([]byte("testKey"), []byte("testVal")))
-
-	require.NoError(t, tx.Rollback())
-	require.Error(t, walletdb.ErrTxClosed, tx.Commit())
-	require.Equal(t, map[string]string{}, f.Dump())
-}
-
 func TestChangeDuringManualTx(t *testing.T) {
 	t.Parallel()
 
@@ -94,12 +30,12 @@ func TestChangeDuringManualTx(t *testing.T) {
 	require.NoError(t, apple.Put([]byte("testKey"), []byte("testVal")))
 
 	// Try overwriting the bucket key.
-	f.Put(bkey("apple"), "banana")
+	f.Put(BucketKey("apple"), "banana")
 
 	// TODO: translate error
 	require.NotNil(t, tx.Commit())
 	require.Equal(t, map[string]string{
-		bkey("apple"): "banana",
+		BucketKey("apple"): "banana",
 	}, f.Dump())
 }
 
@@ -122,8 +58,8 @@ func TestChangeDuringUpdate(t *testing.T) {
 		require.NoError(t, apple.Put([]byte("key"), []byte("value")))
 
 		if count == 0 {
-			f.Put(vkey("key", "apple"), "new_value")
+			f.Put(ValueKey("key", "apple"), "new_value")
-			f.Put(vkey("key2", "apple"), "value2")
+			f.Put(ValueKey("key2", "apple"), "value2")
 		}
 
 		cursor := apple.ReadCursor()
@@ -149,9 +85,9 @@ func TestChangeDuringUpdate(t *testing.T) {
 	require.Equal(t, count, 2)
 
 	expected := map[string]string{
-		bkey("apple"):         bval("apple"),
+		BucketKey("apple"):         BucketVal("apple"),
-		vkey("key", "apple"):  "value",
+		ValueKey("key", "apple"):  "value",
-		vkey("key2", "apple"): "value2",
+		ValueKey("key2", "apple"): "value2",
 	}
 	require.Equal(t, expected, f.Dump())
 }

kvdb/etcd_test.go

@@ -0,0 +1,154 @@
+// +build kvdb_etcd
+
+package kvdb
+
+import (
+	"testing"
+
+	"github.com/btcsuite/btcwallet/walletdb"
+	"github.com/lightningnetwork/lnd/kvdb/etcd"
+	"github.com/stretchr/testify/require"
+)
+
+var (
+	bkey = etcd.BucketKey
+	bval = etcd.BucketVal
+	vkey = etcd.ValueKey
+)
+
+func TestEtcd(t *testing.T) {
+	tests := []struct {
+		name       string
+		test       func(*testing.T, walletdb.DB)
+		expectedDb map[string]string
+	}{
+		{
+			name: "read cursor empty interval",
+			test: testReadCursorEmptyInterval,
+		},
+		{
+			name: "read cursor non empty interval",
+			test: testReadCursorNonEmptyInterval,
+		},
+		{
+			name: "read write cursor",
+			test: testReadWriteCursor,
+			expectedDb: map[string]string{
+				bkey("apple"):       bval("apple"),
+				vkey("a", "apple"):  "0",
+				vkey("c", "apple"):  "3",
+				vkey("cx", "apple"): "x",
+				vkey("cy", "apple"): "y",
+				vkey("da", "apple"): "3",
+				vkey("f", "apple"):  "5",
+			},
+		},
+		{
+			name: "read write cursor with bucket and value",
+			test: testReadWriteCursorWithBucketAndValue,
+			expectedDb: map[string]string{
+				bkey("apple"):           bval("apple"),
+				bkey("apple", "banana"): bval("apple", "banana"),
+				bkey("apple", "pear"):   bval("apple", "pear"),
+				vkey("key", "apple"):    "val",
+			},
+		},
+		{
+			name: "bucket creation",
+			test: testBucketCreation,
+			expectedDb: map[string]string{
+				bkey("apple"):                   bval("apple"),
+				bkey("apple", "banana"):         bval("apple", "banana"),
+				bkey("apple", "mango"):          bval("apple", "mango"),
+				bkey("apple", "banana", "pear"): bval("apple", "banana", "pear"),
+			},
+		},
+		{
+			name: "bucket deletion",
+			test: testBucketDeletion,
+			expectedDb: map[string]string{
+				bkey("apple"):                   bval("apple"),
+				bkey("apple", "banana"):         bval("apple", "banana"),
+				vkey("key1", "apple", "banana"): "val1",
+				vkey("key3", "apple", "banana"): "val3",
+			},
+		},
+		{
+			name: "bucket for each",
+			test: testBucketForEach,
+			expectedDb: map[string]string{
+				bkey("apple"):                   bval("apple"),
+				bkey("apple", "banana"):         bval("apple", "banana"),
+				vkey("key1", "apple"):           "val1",
+				vkey("key2", "apple"):           "val2",
+				vkey("key3", "apple"):           "val3",
+				vkey("key1", "apple", "banana"): "val1",
+				vkey("key2", "apple", "banana"): "val2",
+				vkey("key3", "apple", "banana"): "val3",
+			},
+		},
+		{
+			name: "bucket for each with error",
+			test: testBucketForEachWithError,
+			expectedDb: map[string]string{
+				bkey("apple"):           bval("apple"),
+				bkey("apple", "banana"): bval("apple", "banana"),
+				bkey("apple", "pear"):   bval("apple", "pear"),
+				vkey("key1", "apple"):   "val1",
+				vkey("key2", "apple"):   "val2",
+			},
+		},
+		{
+			name: "bucket sequence",
+			test: testBucketSequence,
+		},
+		{
+			name: "key clash",
+			test: testKeyClash,
+			expectedDb: map[string]string{
+				bkey("apple"):           bval("apple"),
+				bkey("apple", "banana"): bval("apple", "banana"),
+				vkey("key", "apple"):    "val",
+			},
+		},
+		{
+			name: "bucket create delete",
+			test: testBucketCreateDelete,
+			expectedDb: map[string]string{
+				vkey("banana", "apple"): "value",
+				bkey("apple"):           bval("apple"),
+			},
+		},
+		{
+			name: "tx manual commit",
+			test: testTxManualCommit,
+			expectedDb: map[string]string{
+				bkey("apple"):            bval("apple"),
+				vkey("testKey", "apple"): "testVal",
+			},
+		},
+		{
+			name:       "tx rollback",
+			test:       testTxRollback,
+			expectedDb: map[string]string{},
+		},
+	}
+
+	for _, test := range tests {
+		test := test
+
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
+			f := etcd.NewEtcdTestFixture(t)
+			defer f.Cleanup()
+
+			test.test(t, f.NewBackend())
+
+			if test.expectedDb != nil {
+				dump := f.Dump()
+				require.Equal(t, test.expectedDb, dump)
+			}
+		})
+	}
+}

kvdb/go.sum

@@ -7,12 +7,17 @@ github.com/antihax/optional v0.0.0-20180407024304-ca021399b1a6/go.mod h1:V8iCPQY
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/beorn7/perks v1.0.0 h1:HWo1m869IqiPhD389kmkxeTalrjNbbJTC8LXupb+sl0=
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/bgentry/speakeasy v0.1.0/go.mod h1:+zsyZBPWlz7T6j88CTgSN5bM796AkVf0kBD4zp0CCIs=
 github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f h1:bAs4lUbRJpnnkd9VhRV3jjAVU7DJVjMaK+IsvSeZvFo=
 github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f/go.mod h1:TdznJufoqS23FtqVCzL0ZqgP5MqXbb4fg/WgDys70nA=
 github.com/btcsuite/btcwallet/walletdb v1.3.5-0.20210513043850-3a2f12e3a954 h1:CB6chiHPhZWmbCL7kFCADDf15V6I3EUNDgGC25jbptc=
 github.com/btcsuite/btcwallet/walletdb v1.3.5-0.20210513043850-3a2f12e3a954/go.mod h1:oJDxAEUHVtnmIIBaa22wSBPTVcs6hUp5NKWmI8xDwwU=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
+github.com/cespare/xxhash/v2 v2.1.1 h1:6MnRN8NT7+YBpUIWxHtefFZOKTAPgGjpQSxqLNn0+qY=
+github.com/cespare/xxhash/v2 v2.1.1/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/clbanning/x2j v0.0.0-20191024224557-825249438eec/go.mod h1:jMjuTZXRI4dUb/I5gc9Hdhagfvm9+RyrPryS/auMzxE=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/cockroachdb/datadriven v0.0.0-20190809214429-80d97fb3cbaa h1:OaNxuTZr7kxeODyLWsRMC+OD03aFUH+mW6r2d+MWa5Y=
 github.com/cockroachdb/datadriven v0.0.0-20190809214429-80d97fb3cbaa/go.mod h1:zn76sxSg3SzpJ0PPJaLDCu+Bu0Lg3sKTORVIj19EIF8=
@@ -109,7 +114,6 @@ github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3Rllmb
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/olekukonko/tablewriter v0.0.0-20170122224234-a0225b3f23b5/go.mod h1:vsDQFd/mU46D+Z4whnwzcISnGGzXWMclvtLoiIKAKIo=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
-github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
@@ -137,6 +141,7 @@ github.com/spf13/cobra v0.0.3/go.mod h1:1l0Ry5zgKvJasoi3XT1TypsSe7PqH0Sj9dhYf7v3
 github.com/spf13/pflag v1.0.1 h1:aCvUg6QPl3ibpQUxyLkrEkCHtPqYJL4x9AuhqVqFis4=
 github.com/spf13/pflag v1.0.1/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.1.1 h1:2vfRuCMp5sSVIDSqO8oNnWJq7mPa6KVP3iPIwFBuy8A=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
@@ -160,7 +165,6 @@ go.uber.org/atomic v1.6.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
 go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
 go.uber.org/multierr v1.5.0 h1:KCa4XfM8CWFCpxXRGok+Q0SS/0XBhMDbHHGABQLvD2A=
 go.uber.org/multierr v1.5.0/go.mod h1:FeouvMocqHpRaaGuG9EjoKcStLC43Zu/fmqdUMPcKYU=
-go.uber.org/tools v0.0.0-20190618225709-2cfd321de3ee h1:0mgffUl7nfd+FpvXMVz4IDEaUSmT1ysygQC7qYo7sG4=
 go.uber.org/tools v0.0.0-20190618225709-2cfd321de3ee/go.mod h1:vJERXedbb3MVM5f9Ejo0C68/HhF8uaILCdgjnY+goOA=
 go.uber.org/zap v1.10.0/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
 go.uber.org/zap v1.14.1 h1:nYDKopTbvAPq/NrUVZwT15y2lpROBiLLyoRTbXOYWOo=
@@ -174,7 +178,6 @@ golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20190227174305-5b3e6a55c961/go.mod h1:wehouNa3lNwaWXcvxsM5YxQ5yQlVC4a0KAMCusXpPoU=
 golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
-golang.org/x/lint v0.0.0-20190930215403-16217165b5de h1:5hukYrvBGR8/eNkX5mdUezrA6JiaEZDtJb9Ei+1LlBs=
 golang.org/x/lint v0.0.0-20190930215403-16217165b5de/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
 golang.org/x/mod v0.0.0-20190513183733-4bf6d317e70e/go.mod h1:mXi4GBBbnImb6dmsKGUJ2LatrhH/nqhxcFungHvyanc=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -217,7 +220,6 @@ golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3
 golang.org/x/tools v0.0.0-20190524140312-2c0ae7006135/go.mod h1:RgjU9mgBXZiqYHBnxXauZ1Gv1EHHAz9KjViQ78xBX0Q=
 golang.org/x/tools v0.0.0-20190621195816-6e04913cbbac/go.mod h1:/rFqwRUd4F7ZHNgwSSTFct+R/Kf4OFW1sUzUTQQTgfc=
 golang.org/x/tools v0.0.0-20191029041327-9cc4af7d6b2c/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
-golang.org/x/tools v0.0.0-20191029190741-b9c20aec41a5 h1:hKsoRgsbwY1NafxrwTs+k64bikrLBkAgPir1TNCj3Zs=
 golang.org/x/tools v0.0.0-20191029190741-b9c20aec41a5/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
@@ -233,7 +235,6 @@ google.golang.org/grpc v1.26.0 h1:2dTRdpdFEEhJYQD8EMLB61nnrzSCTbG38PhqdhvOltg=
 google.golang.org/grpc v1.26.0/go.mod h1:qbnxyOmOxrQa7FizSgH+ReBfzJrCY1pSN7KXBS8abTk=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/cheggaaa/pb.v1 v1.0.25/go.mod h1:V/YB90LKu/1FcN3WVnfiiE5oMCibMjukxqG/qStrOgw=
 gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
@@ -247,7 +248,6 @@ gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
-honnef.co/go/tools v0.0.1-2019.2.3 h1:3JgtbtFHMiCmsznwGVTUWbgGov+pVqnlf1dEJTNAXeM=
 honnef.co/go/tools v0.0.1-2019.2.3/go.mod h1:a3bituU0lyd329TUQxRnasdCoJDkEUEAqEt0JzvZhAg=
 sigs.k8s.io/yaml v1.1.0 h1:4A07+ZFc2wgJwo8YNlQpr1rVlgUDlxXHhPJciaPY5gs=
 sigs.k8s.io/yaml v1.1.0/go.mod h1:UJmg0vDUVViEyp3mgSv9WPwZCDxu4rQW1olrI1uml+o=

kvdb/readwrite_bucket_test.go

@@ -1,9 +1,6 @@
-// +build kvdb_etcd
+package kvdb
-
-package etcd
 
 import (
-	"context"
 	"fmt"
 	"math"
 	"testing"
@@ -12,16 +9,8 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func TestBucketCreation(t *testing.T) {
+func testBucketCreation(t *testing.T, db walletdb.DB) {
-	t.Parallel()
+	err := Update(db, func(tx walletdb.ReadWriteTx) error {
-
-	f := NewEtcdTestFixture(t)
-	defer f.Cleanup()
-
-	db, err := newEtcdBackend(context.TODO(), f.BackendConfig())
-	require.NoError(t, err)
-
-	err = db.Update(func(tx walletdb.ReadWriteTx) error {
 		// empty bucket name
 		b, err := tx.CreateTopLevelBucket(nil)
 		require.Error(t, walletdb.ErrBucketNameRequired, err)
@@ -83,26 +72,10 @@ func TestBucketCreation(t *testing.T) {
 	}, func() {})
 
 	require.Nil(t, err)
-
-	expected := map[string]string{
-		bkey("apple"):                   bval("apple"),
-		bkey("apple", "banana"):         bval("apple", "banana"),
-		bkey("apple", "mango"):          bval("apple", "mango"),
-		bkey("apple", "banana", "pear"): bval("apple", "banana", "pear"),
-	}
-	require.Equal(t, expected, f.Dump())
 }
 
-func TestBucketDeletion(t *testing.T) {
+func testBucketDeletion(t *testing.T, db walletdb.DB) {
-	t.Parallel()
+	err := Update(db, func(tx walletdb.ReadWriteTx) error {
-
-	f := NewEtcdTestFixture(t)
-	defer f.Cleanup()
-
-	db, err := newEtcdBackend(context.TODO(), f.BackendConfig())
-	require.NoError(t, err)
-
-	err = db.Update(func(tx walletdb.ReadWriteTx) error {
 		// "apple"
 		apple, err := tx.CreateTopLevelBucket([]byte("apple"))
 		require.Nil(t, err)
@@ -178,41 +151,16 @@ func TestBucketDeletion(t *testing.T) {
 		// "apple/pear" deleted
 		require.Nil(t, apple.NestedReadWriteBucket([]byte("pear")))
 
-		// "apple/pear/cherry" deleted
-		require.Nil(t, pear.NestedReadWriteBucket([]byte("cherry")))
-
-		// Values deleted too.
-		for _, kv := range kvs {
-			require.Nil(t, pear.Get([]byte(kv.key)))
-			require.Nil(t, cherry.Get([]byte(kv.key)))
-		}
-
 		// "aple/banana" exists
 		require.NotNil(t, apple.NestedReadWriteBucket([]byte("banana")))
 		return nil
 	}, func() {})
 
 	require.Nil(t, err)
-
-	expected := map[string]string{
-		bkey("apple"):                   bval("apple"),
-		bkey("apple", "banana"):         bval("apple", "banana"),
-		vkey("key1", "apple", "banana"): "val1",
-		vkey("key3", "apple", "banana"): "val3",
-	}
-	require.Equal(t, expected, f.Dump())
 }
 
-func TestBucketForEach(t *testing.T) {
+func testBucketForEach(t *testing.T, db walletdb.DB) {
-	t.Parallel()
+	err := Update(db, func(tx walletdb.ReadWriteTx) error {
-
-	f := NewEtcdTestFixture(t)
-	defer f.Cleanup()
-
-	db, err := newEtcdBackend(context.TODO(), f.BackendConfig())
-	require.NoError(t, err)
-
-	err = db.Update(func(tx walletdb.ReadWriteTx) error {
 		// "apple"
 		apple, err := tx.CreateTopLevelBucket([]byte("apple"))
 		require.Nil(t, err)
@@ -265,30 +213,10 @@ func TestBucketForEach(t *testing.T) {
 	}, func() {})
 
 	require.Nil(t, err)
-
-	expected := map[string]string{
-		bkey("apple"):                   bval("apple"),
-		bkey("apple", "banana"):         bval("apple", "banana"),
-		vkey("key1", "apple"):           "val1",
-		vkey("key2", "apple"):           "val2",
-		vkey("key3", "apple"):           "val3",
-		vkey("key1", "apple", "banana"): "val1",
-		vkey("key2", "apple", "banana"): "val2",
-		vkey("key3", "apple", "banana"): "val3",
-	}
-	require.Equal(t, expected, f.Dump())
 }
 
-func TestBucketForEachWithError(t *testing.T) {
+func testBucketForEachWithError(t *testing.T, db walletdb.DB) {
-	t.Parallel()
+	err := Update(db, func(tx walletdb.ReadWriteTx) error {
-
-	f := NewEtcdTestFixture(t)
-	defer f.Cleanup()
-
-	db, err := newEtcdBackend(context.TODO(), f.BackendConfig())
-	require.NoError(t, err)
-
-	err = db.Update(func(tx walletdb.ReadWriteTx) error {
 		// "apple"
 		apple, err := tx.CreateTopLevelBucket([]byte("apple"))
 		require.Nil(t, err)
@@ -358,27 +286,10 @@ func TestBucketForEachWithError(t *testing.T) {
 	}, func() {})
 
 	require.Nil(t, err)
-
-	expected := map[string]string{
-		bkey("apple"):           bval("apple"),
-		bkey("apple", "banana"): bval("apple", "banana"),
-		bkey("apple", "pear"):   bval("apple", "pear"),
-		vkey("key1", "apple"):   "val1",
-		vkey("key2", "apple"):   "val2",
-	}
-	require.Equal(t, expected, f.Dump())
 }
 
-func TestBucketSequence(t *testing.T) {
+func testBucketSequence(t *testing.T, db walletdb.DB) {
-	t.Parallel()
+	err := Update(db, func(tx walletdb.ReadWriteTx) error {
-
-	f := NewEtcdTestFixture(t)
-	defer f.Cleanup()
-
-	db, err := newEtcdBackend(context.TODO(), f.BackendConfig())
-	require.NoError(t, err)
-
-	err = db.Update(func(tx walletdb.ReadWriteTx) error {
 		apple, err := tx.CreateTopLevelBucket([]byte("apple"))
 		require.Nil(t, err)
 		require.NotNil(t, apple)
@@ -408,19 +319,11 @@ func TestBucketSequence(t *testing.T) {
 // TestKeyClash tests that one cannot create a bucket if a value with the same
 // key exists and the same is true in reverse: that a value cannot be put if
 // a bucket with the same key exists.
-func TestKeyClash(t *testing.T) {
+func testKeyClash(t *testing.T, db walletdb.DB) {
-	t.Parallel()
-
-	f := NewEtcdTestFixture(t)
-	defer f.Cleanup()
-
-	db, err := newEtcdBackend(context.TODO(), f.BackendConfig())
-	require.NoError(t, err)
-
 	// First:
 	// put: /apple/key -> val
 	// create bucket: /apple/banana
-	err = db.Update(func(tx walletdb.ReadWriteTx) error {
+	err := Update(db, func(tx walletdb.ReadWriteTx) error {
 		apple, err := tx.CreateTopLevelBucket([]byte("apple"))
 		require.Nil(t, err)
 		require.NotNil(t, apple)
@@ -439,7 +342,7 @@ func TestKeyClash(t *testing.T) {
 	// Next try to:
 	// put: /apple/banana -> val => will fail (as /apple/banana is a bucket)
 	// create bucket: /apple/key => will fail (as /apple/key is a value)
-	err = db.Update(func(tx walletdb.ReadWriteTx) error {
+	err = Update(db, func(tx walletdb.ReadWriteTx) error {
 		apple, err := tx.CreateTopLevelBucket([]byte("apple"))
 		require.Nil(t, err)
 		require.NotNil(t, apple)
@@ -461,31 +364,12 @@ func TestKeyClash(t *testing.T) {
 	}, func() {})
 
 	require.Nil(t, err)
-
-	// Except that the only existing items in the db are:
-	// bucket: /apple
-	// bucket: /apple/banana
-	// value: /apple/key -> val
-	expected := map[string]string{
-		bkey("apple"):           bval("apple"),
-		bkey("apple", "banana"): bval("apple", "banana"),
-		vkey("key", "apple"):    "val",
-	}
-	require.Equal(t, expected, f.Dump())
-
 }
 
 // TestBucketCreateDelete tests that creating then deleting then creating a
 // bucket suceeds.
-func TestBucketCreateDelete(t *testing.T) {
+func testBucketCreateDelete(t *testing.T, db walletdb.DB) {
-	t.Parallel()
+	err := Update(db, func(tx walletdb.ReadWriteTx) error {
-	f := NewEtcdTestFixture(t)
-	defer f.Cleanup()
-
-	db, err := newEtcdBackend(context.TODO(), f.BackendConfig())
-	require.NoError(t, err)
-
-	err = db.Update(func(tx walletdb.ReadWriteTx) error {
 		apple, err := tx.CreateTopLevelBucket([]byte("apple"))
 		require.NoError(t, err)
 		require.NotNil(t, apple)
@@ -498,7 +382,7 @@ func TestBucketCreateDelete(t *testing.T) {
 	}, func() {})
 	require.NoError(t, err)
 
-	err = db.Update(func(tx walletdb.ReadWriteTx) error {
+	err = Update(db, func(tx walletdb.ReadWriteTx) error {
 		apple := tx.ReadWriteBucket([]byte("apple"))
 		require.NotNil(t, apple)
 		require.NoError(t, apple.DeleteNestedBucket([]byte("banana")))
@@ -507,7 +391,7 @@ func TestBucketCreateDelete(t *testing.T) {
 	}, func() {})
 	require.NoError(t, err)
 
-	err = db.Update(func(tx walletdb.ReadWriteTx) error {
+	err = Update(db, func(tx walletdb.ReadWriteTx) error {
 		apple := tx.ReadWriteBucket([]byte("apple"))
 		require.NotNil(t, apple)
 		require.NoError(t, apple.Put([]byte("banana"), []byte("value")))
@@ -515,10 +399,4 @@ func TestBucketCreateDelete(t *testing.T) {
 		return nil
 	}, func() {})
 	require.NoError(t, err)
-
-	expected := map[string]string{
-		vkey("banana", "apple"): "value",
-		bkey("apple"):           bval("apple"),
-	}
-	require.Equal(t, expected, f.Dump())
 }

kvdb/readwrite_cursor_test.go

@@ -1,25 +1,14 @@
-// +build kvdb_etcd
+package kvdb
-
-package etcd
 
 import (
-	"context"
 	"testing"
 
 	"github.com/btcsuite/btcwallet/walletdb"
 	"github.com/stretchr/testify/require"
 )
 
-func TestReadCursorEmptyInterval(t *testing.T) {
+func testReadCursorEmptyInterval(t *testing.T, db walletdb.DB) {
-	t.Parallel()
+	err := Update(db, func(tx walletdb.ReadWriteTx) error {
-
-	f := NewEtcdTestFixture(t)
-	defer f.Cleanup()
-
-	db, err := newEtcdBackend(context.TODO(), f.BackendConfig())
-	require.NoError(t, err)
-
-	err = db.Update(func(tx walletdb.ReadWriteTx) error {
 		b, err := tx.CreateTopLevelBucket([]byte("apple"))
 		require.NoError(t, err)
 		require.NotNil(t, b)
@@ -28,7 +17,7 @@ func TestReadCursorEmptyInterval(t *testing.T) {
 	}, func() {})
 	require.NoError(t, err)
 
-	err = db.View(func(tx walletdb.ReadTx) error {
+	err = View(db, func(tx walletdb.ReadTx) error {
 		b := tx.ReadBucket([]byte("apple"))
 		require.NotNil(t, b)
 
@@ -54,15 +43,7 @@ func TestReadCursorEmptyInterval(t *testing.T) {
 	require.NoError(t, err)
 }
 
-func TestReadCursorNonEmptyInterval(t *testing.T) {
+func testReadCursorNonEmptyInterval(t *testing.T, db walletdb.DB) {
-	t.Parallel()
-
-	f := NewEtcdTestFixture(t)
-	defer f.Cleanup()
-
-	db, err := newEtcdBackend(context.TODO(), f.BackendConfig())
-	require.NoError(t, err)
-
 	testKeyValues := []KV{
 		{"b", "1"},
 		{"c", "2"},
@@ -70,7 +51,7 @@ func TestReadCursorNonEmptyInterval(t *testing.T) {
 		{"e", "4"},
 	}
 
-	err = db.Update(func(tx walletdb.ReadWriteTx) error {
+	err := Update(db, func(tx walletdb.ReadWriteTx) error {
 		b, err := tx.CreateTopLevelBucket([]byte("apple"))
 		require.NoError(t, err)
 		require.NotNil(t, b)
@@ -83,7 +64,7 @@ func TestReadCursorNonEmptyInterval(t *testing.T) {
 
 	require.NoError(t, err)
 
-	err = db.View(func(tx walletdb.ReadTx) error {
+	err = View(db, func(tx walletdb.ReadTx) error {
 		b := tx.ReadBucket([]byte("apple"))
 		require.NotNil(t, b)
 
@@ -118,8 +99,8 @@ func TestReadCursorNonEmptyInterval(t *testing.T) {
 
 		// Seek to nonexisting key.
 		k, v = cursor.Seek(nil)
-		require.Nil(t, k)
+		require.Equal(t, "b", string(k))
-		require.Nil(t, v)
+		require.Equal(t, "1", string(v))
 
 		k, v = cursor.Seek([]byte("x"))
 		require.Nil(t, k)
@@ -131,15 +112,7 @@ func TestReadCursorNonEmptyInterval(t *testing.T) {
 	require.NoError(t, err)
 }
 
-func TestReadWriteCursor(t *testing.T) {
+func testReadWriteCursor(t *testing.T, db walletdb.DB) {
-	t.Parallel()
-
-	f := NewEtcdTestFixture(t)
-	defer f.Cleanup()
-
-	db, err := newEtcdBackend(context.TODO(), f.BackendConfig())
-	require.NoError(t, err)
-
 	testKeyValues := []KV{
 		{"b", "1"},
 		{"c", "2"},
@@ -150,7 +123,7 @@ func TestReadWriteCursor(t *testing.T) {
 	count := len(testKeyValues)
 
 	// Pre-store the first half of the interval.
-	require.NoError(t, db.Update(func(tx walletdb.ReadWriteTx) error {
+	require.NoError(t, Update(db, func(tx walletdb.ReadWriteTx) error {
 		b, err := tx.CreateTopLevelBucket([]byte("apple"))
 		require.NoError(t, err)
 		require.NotNil(t, b)
@@ -165,13 +138,13 @@ func TestReadWriteCursor(t *testing.T) {
 		return nil
 	}, func() {}))
 
-	err = db.Update(func(tx walletdb.ReadWriteTx) error {
+	err := Update(db, func(tx walletdb.ReadWriteTx) error {
 		b := tx.ReadWriteBucket([]byte("apple"))
 		require.NotNil(t, b)
 
 		// Store the second half of the interval.
 		for i := count / 2; i < count; i++ {
-			err = b.Put(
+			err := b.Put(
 				[]byte(testKeyValues[i].key),
 				[]byte(testKeyValues[i].val),
 			)
@@ -280,32 +253,14 @@ func TestReadWriteCursor(t *testing.T) {
 	}, func() {})
 
 	require.NoError(t, err)
-
-	expected := map[string]string{
-		bkey("apple"):       bval("apple"),
-		vkey("a", "apple"):  "0",
-		vkey("c", "apple"):  "3",
-		vkey("cx", "apple"): "x",
-		vkey("cy", "apple"): "y",
-		vkey("da", "apple"): "3",
-		vkey("f", "apple"):  "5",
-	}
-	require.Equal(t, expected, f.Dump())
 }
 
-// TestReadWriteCursorWithBucketAndValue tests that cursors are able to iterate
+// testReadWriteCursorWithBucketAndValue tests that cursors are able to iterate
 // over both bucket and value keys if both are present in the iterated bucket.
-func TestReadWriteCursorWithBucketAndValue(t *testing.T) {
+func testReadWriteCursorWithBucketAndValue(t *testing.T, db walletdb.DB) {
-	t.Parallel()
-
-	f := NewEtcdTestFixture(t)
-	defer f.Cleanup()
-
-	db, err := newEtcdBackend(context.TODO(), f.BackendConfig())
-	require.NoError(t, err)
 
 	// Pre-store the first half of the interval.
-	require.NoError(t, db.Update(func(tx walletdb.ReadWriteTx) error {
+	require.NoError(t, Update(db, func(tx walletdb.ReadWriteTx) error {
 		b, err := tx.CreateTopLevelBucket([]byte("apple"))
 		require.NoError(t, err)
 		require.NotNil(t, b)
@@ -323,7 +278,7 @@ func TestReadWriteCursorWithBucketAndValue(t *testing.T) {
 		return nil
 	}, func() {}))
 
-	err = db.View(func(tx walletdb.ReadTx) error {
+	err := View(db, func(tx walletdb.ReadTx) error {
 		b := tx.ReadBucket([]byte("apple"))
 		require.NotNil(t, b)
 
@@ -358,12 +313,4 @@ func TestReadWriteCursorWithBucketAndValue(t *testing.T) {
 	}, func() {})
 
 	require.NoError(t, err)
-
-	expected := map[string]string{
-		bkey("apple"):           bval("apple"),
-		bkey("apple", "banana"): bval("apple", "banana"),
-		bkey("apple", "pear"):   bval("apple", "pear"),
-		vkey("key", "apple"):    "val",
-	}
-	require.Equal(t, expected, f.Dump())
 }

kvdb/readwrite_tx_test.go

@@ -0,0 +1,49 @@
+package kvdb
+
+import (
+	"testing"
+
+	"github.com/btcsuite/btcwallet/walletdb"
+	"github.com/stretchr/testify/require"
+)
+
+func testTxManualCommit(t *testing.T, db walletdb.DB) {
+	tx, err := db.BeginReadWriteTx()
+	require.NoError(t, err)
+	require.NotNil(t, tx)
+
+	committed := false
+
+	tx.OnCommit(func() {
+		committed = true
+	})
+
+	apple, err := tx.CreateTopLevelBucket([]byte("apple"))
+	require.NoError(t, err)
+	require.NotNil(t, apple)
+	require.NoError(t, apple.Put([]byte("testKey"), []byte("testVal")))
+
+	banana, err := tx.CreateTopLevelBucket([]byte("banana"))
+	require.NoError(t, err)
+	require.NotNil(t, banana)
+	require.NoError(t, banana.Put([]byte("testKey"), []byte("testVal")))
+	require.NoError(t, tx.DeleteTopLevelBucket([]byte("banana")))
+
+	require.NoError(t, tx.Commit())
+	require.True(t, committed)
+}
+
+func testTxRollback(t *testing.T, db walletdb.DB) {
+	tx, err := db.BeginReadWriteTx()
+	require.Nil(t, err)
+	require.NotNil(t, tx)
+
+	apple, err := tx.CreateTopLevelBucket([]byte("apple"))
+	require.Nil(t, err)
+	require.NotNil(t, apple)
+
+	require.NoError(t, apple.Put([]byte("testKey"), []byte("testVal")))
+
+	require.NoError(t, tx.Rollback())
+	require.Error(t, walletdb.ErrTxClosed, tx.Commit())
+}

kvdb/test.go

@@ -0,0 +1,14 @@
+package kvdb
+
+type KV struct {
+	key string
+	val string
+}
+
+func reverseKVs(a []KV) []KV {
+	for i, j := 0, len(a)-1; i < j; i, j = i+1, j-1 {
+		a[i], a[j] = a[j], a[i]
+	}
+
+	return a
+}