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/migtest/migtest.go

@@ -6,13 +6,13 @@ import (
 	"os"
 	"testing"
 
-	"github.com/coreos/bbolt"
+	"github.com/lightningnetwork/lnd/channeldb/kvdb"
 )
 
 // MakeDB creates a new instance of the ChannelDB for testing purposes. A
 // callback which cleans up the created temporary directories is also returned
 // and intended to be executed after the test completes.
-func MakeDB() (*bbolt.DB, func(), error) {
+func MakeDB() (kvdb.Backend, func(), error) {
 	// Create temporary database for mission control.
 	file, err := ioutil.TempFile("", "*.db")
 	if err != nil {
@@ -20,7 +20,7 @@ func MakeDB() (*bbolt.DB, func(), error) {
 	}
 
 	dbPath := file.Name()
-	db, err := bbolt.Open(dbPath, 0600, nil)
+	db, err := kvdb.Open(kvdb.BoltBackendName, dbPath, true)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -36,7 +36,7 @@ func MakeDB() (*bbolt.DB, func(), error) {
 // ApplyMigration is a helper test function that encapsulates the general steps
 // which are needed to properly check the result of applying migration function.
 func ApplyMigration(t *testing.T,
-	beforeMigration, afterMigration, migrationFunc func(tx *bbolt.Tx) error,
+	beforeMigration, afterMigration, migrationFunc func(tx kvdb.RwTx) error,
 	shouldFail bool) {
 
 	cdb, cleanUp, err := MakeDB()
@@ -47,7 +47,7 @@ func ApplyMigration(t *testing.T,
 
 	// beforeMigration usually used for populating the database
 	// with test data.
-	err = cdb.Update(beforeMigration)
+	err = kvdb.Update(cdb, beforeMigration)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -65,14 +65,14 @@ func ApplyMigration(t *testing.T,
 
 		// afterMigration usually used for checking the database state and
 		// throwing the error if something went wrong.
-		err = cdb.Update(afterMigration)
+		err = kvdb.Update(cdb, afterMigration)
 		if err != nil {
 			t.Fatal(err)
 		}
 	}()
 
 	// Apply migration.
-	err = cdb.Update(migrationFunc)
+	err = kvdb.Update(cdb, migrationFunc)
 	if err != nil {
 		t.Fatal(err)
 	}

channeldb/migtest/raw_db.go

@@ -7,7 +7,7 @@ import (
 	"fmt"
 	"strings"
 
-	"github.com/coreos/bbolt"
+	"github.com/lightningnetwork/lnd/channeldb/kvdb"
 )
 
 // DumpDB dumps go code describing the contents of the database to stdout. This
@@ -21,8 +21,8 @@ import (
 // 		hex("1111"): hex("5783492373"),
 // 	},
 // }
-func DumpDB(tx *bbolt.Tx, rootKey []byte) error {
-	bucket := tx.Bucket(rootKey)
+func DumpDB(tx kvdb.ReadTx, rootKey []byte) error {
+	bucket := tx.ReadBucket(rootKey)
 	if bucket == nil {
 		return fmt.Errorf("bucket %v not found", string(rootKey))
 	}
@@ -30,13 +30,13 @@ func DumpDB(tx *bbolt.Tx, rootKey []byte) error {
 	return dumpBucket(bucket)
 }
 
-func dumpBucket(bucket *bbolt.Bucket) error {
+func dumpBucket(bucket kvdb.ReadBucket) error {
 	fmt.Printf("map[string]interface{} {\n")
 	err := bucket.ForEach(func(k, v []byte) error {
 		key := toString(k)
 		fmt.Printf("%v: ", key)
 
-		subBucket := bucket.Bucket(k)
+		subBucket := bucket.NestedReadBucket(k)
 		if subBucket != nil {
 			err := dumpBucket(subBucket)
 			if err != nil {
@@ -58,8 +58,8 @@ func dumpBucket(bucket *bbolt.Bucket) error {
 }
 
 // RestoreDB primes the database with the given data set.
-func RestoreDB(tx *bbolt.Tx, rootKey []byte, data map[string]interface{}) error {
-	bucket, err := tx.CreateBucket(rootKey)
+func RestoreDB(tx kvdb.RwTx, rootKey []byte, data map[string]interface{}) error {
+	bucket, err := tx.CreateTopLevelBucket(rootKey)
 	if err != nil {
 		return err
 	}
@@ -67,7 +67,7 @@ func RestoreDB(tx *bbolt.Tx, rootKey []byte, data map[string]interface{}) error
 	return restoreDB(bucket, data)
 }
 
-func restoreDB(bucket *bbolt.Bucket, data map[string]interface{}) error {
+func restoreDB(bucket kvdb.RwBucket, data map[string]interface{}) error {
 	for k, v := range data {
 		key := []byte(k)
 
@@ -100,8 +100,8 @@ func restoreDB(bucket *bbolt.Bucket, data map[string]interface{}) error {
 }
 
 // VerifyDB verifies the database against the given data set.
-func VerifyDB(tx *bbolt.Tx, rootKey []byte, data map[string]interface{}) error {
-	bucket := tx.Bucket(rootKey)
+func VerifyDB(tx kvdb.ReadTx, rootKey []byte, data map[string]interface{}) error {
+	bucket := tx.ReadBucket(rootKey)
 	if bucket == nil {
 		return fmt.Errorf("bucket %v not found", string(rootKey))
 	}
@@ -109,7 +109,7 @@ func VerifyDB(tx *bbolt.Tx, rootKey []byte, data map[string]interface{}) error {
 	return verifyDB(bucket, data)
 }
 
-func verifyDB(bucket *bbolt.Bucket, data map[string]interface{}) error {
+func verifyDB(bucket kvdb.ReadBucket, data map[string]interface{}) error {
 	for k, v := range data {
 		key := []byte(k)
 
@@ -126,7 +126,7 @@ func verifyDB(bucket *bbolt.Bucket, data map[string]interface{}) error {
 
 		// Key contains a sub-bucket.
 		case map[string]interface{}:
-			subBucket := bucket.Bucket(key)
+			subBucket := bucket.NestedReadBucket(key)
 			if subBucket == nil {
 				return fmt.Errorf("bucket %v not found", k)
 			}