channeldb: convert to uniformly use new kvdb abstractions

In this commit, we migrate all the code in `channeldb` to only reference
the new `kvdb` package rather than `bbolt` directly.

In many instances, we need to add two version to fetch a bucket as both
read and write when needed. As an example, we add a new
`fetchChanBucketRw` function. This function is identical to
`fetchChanBucket`, but it will be used to fetch the main channel bucket
for all _write_ transactions. We need a new method as you can pass a
write transaction where a read is accepted, but not the other way around
due to the stronger typing of the new `kvdb` package.

channeldb/meta_test.go

@@ -5,8 +5,8 @@ import (
 	"io/ioutil"
 	"testing"
 
-	"github.com/coreos/bbolt"
 	"github.com/go-errors/errors"
+	"github.com/lightningnetwork/lnd/channeldb/kvdb"
 )
 
 // applyMigration is a helper test function that encapsulates the general steps
@@ -121,11 +121,11 @@ func TestOrderOfMigrations(t *testing.T) {
 	versions := []version{
 		{0, nil},
 		{1, nil},
-		{2, func(tx *bbolt.Tx) error {
+		{2, func(tx kvdb.RwTx) error {
 			appliedMigration = 2
 			return nil
 		}},
-		{3, func(tx *bbolt.Tx) error {
+		{3, func(tx kvdb.RwTx) error {
 			appliedMigration = 3
 			return nil
 		}},
@@ -197,21 +197,23 @@ func TestMigrationWithPanic(t *testing.T) {
 	beforeMigrationFunc := func(d *DB) {
 		// Insert data in database and in order then make sure that the
 		// key isn't changes in case of panic or fail.
-		d.Update(func(tx *bbolt.Tx) error {
-			bucket, err := tx.CreateBucketIfNotExists(bucketPrefix)
+		err := kvdb.Update(d, func(tx kvdb.RwTx) error {
+			bucket, err := tx.CreateTopLevelBucket(bucketPrefix)
 			if err != nil {
 				return err
 			}
 
-			bucket.Put(keyPrefix, beforeMigration)
-			return nil
+			return bucket.Put(keyPrefix, beforeMigration)
 		})
+		if err != nil {
+			t.Fatalf("unable to insert: %v", err)
+		}
 	}
 
 	// Create migration function which changes the initially created data and
 	// throw the panic, in this case we pretending that something goes.
-	migrationWithPanic := func(tx *bbolt.Tx) error {
-		bucket, err := tx.CreateBucketIfNotExists(bucketPrefix)
+	migrationWithPanic := func(tx kvdb.RwTx) error {
+		bucket, err := tx.CreateTopLevelBucket(bucketPrefix)
 		if err != nil {
 			return err
 		}
@@ -231,8 +233,8 @@ func TestMigrationWithPanic(t *testing.T) {
 			t.Fatal("migration panicked but version is changed")
 		}
 
-		err = d.Update(func(tx *bbolt.Tx) error {
-			bucket, err := tx.CreateBucketIfNotExists(bucketPrefix)
+		err = kvdb.Update(d, func(tx kvdb.RwTx) error {
+			bucket, err := tx.CreateTopLevelBucket(bucketPrefix)
 			if err != nil {
 				return err
 			}
@@ -268,22 +270,24 @@ func TestMigrationWithFatal(t *testing.T) {
 	afterMigration := []byte("aftermigration")
 
 	beforeMigrationFunc := func(d *DB) {
-		d.Update(func(tx *bbolt.Tx) error {
-			bucket, err := tx.CreateBucketIfNotExists(bucketPrefix)
+		err := kvdb.Update(d, func(tx kvdb.RwTx) error {
+			bucket, err := tx.CreateTopLevelBucket(bucketPrefix)
 			if err != nil {
 				return err
 			}
 
-			bucket.Put(keyPrefix, beforeMigration)
-			return nil
+			return bucket.Put(keyPrefix, beforeMigration)
 		})
+		if err != nil {
+			t.Fatalf("unable to insert pre migration key: %v", err)
+		}
 	}
 
 	// Create migration function which changes the initially created data and
 	// return the error, in this case we pretending that something goes
 	// wrong.
-	migrationWithFatal := func(tx *bbolt.Tx) error {
-		bucket, err := tx.CreateBucketIfNotExists(bucketPrefix)
+	migrationWithFatal := func(tx kvdb.RwTx) error {
+		bucket, err := tx.CreateTopLevelBucket(bucketPrefix)
 		if err != nil {
 			return err
 		}
@@ -303,8 +307,8 @@ func TestMigrationWithFatal(t *testing.T) {
 			t.Fatal("migration failed but version is changed")
 		}
 
-		err = d.Update(func(tx *bbolt.Tx) error {
-			bucket, err := tx.CreateBucketIfNotExists(bucketPrefix)
+		err = kvdb.Update(d, func(tx kvdb.RwTx) error {
+			bucket, err := tx.CreateTopLevelBucket(bucketPrefix)
 			if err != nil {
 				return err
 			}
@@ -341,8 +345,8 @@ func TestMigrationWithoutErrors(t *testing.T) {
 
 	// Populate database with initial data.
 	beforeMigrationFunc := func(d *DB) {
-		d.Update(func(tx *bbolt.Tx) error {
-			bucket, err := tx.CreateBucketIfNotExists(bucketPrefix)
+		kvdb.Update(d, func(tx kvdb.RwTx) error {
+			bucket, err := tx.CreateTopLevelBucket(bucketPrefix)
 			if err != nil {
 				return err
 			}
@@ -353,8 +357,8 @@ func TestMigrationWithoutErrors(t *testing.T) {
 	}
 
 	// Create migration function which changes the initially created data.
-	migrationWithoutErrors := func(tx *bbolt.Tx) error {
-		bucket, err := tx.CreateBucketIfNotExists(bucketPrefix)
+	migrationWithoutErrors := func(tx kvdb.RwTx) error {
+		bucket, err := tx.CreateTopLevelBucket(bucketPrefix)
 		if err != nil {
 			return err
 		}
@@ -375,8 +379,8 @@ func TestMigrationWithoutErrors(t *testing.T) {
 				"successfully applied migration")
 		}
 
-		err = d.Update(func(tx *bbolt.Tx) error {
-			bucket, err := tx.CreateBucketIfNotExists(bucketPrefix)
+		err = kvdb.Update(d, func(tx kvdb.RwTx) error {
+			bucket, err := tx.CreateTopLevelBucket(bucketPrefix)
 			if err != nil {
 				return err
 			}
@@ -419,7 +423,7 @@ func TestMigrationReversion(t *testing.T) {
 
 	// Update the database metadata to point to one more than the highest
 	// known version.
-	err = cdb.Update(func(tx *bbolt.Tx) error {
+	err = kvdb.Update(cdb, func(tx kvdb.RwTx) error {
 		newMeta := &Meta{
 			DbVersionNumber: getLatestDBVersion(dbVersions) + 1,
 		}