kvdb/sqlbase: fix build errors

We copy the `sqldb/sqlerrors.go` into `kvdb/sqlbase` to avoid import
cycles.

kvdb/go.mod

@@ -6,6 +6,8 @@ require (
 	github.com/davecgh/go-spew v1.1.1
 	github.com/fergusstrange/embedded-postgres v1.10.0
 	github.com/google/btree v1.0.1
+	github.com/jackc/pgconn v1.14.0
+	github.com/jackc/pgerrcode v0.0.0-20220416144525-469b46aa5efa
 	github.com/jackc/pgx/v4 v4.18.1
 	github.com/lightningnetwork/lnd/healthcheck v1.0.0
 	github.com/stretchr/testify v1.8.2
@@ -37,7 +39,6 @@ require (
 	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0 // indirect
 	github.com/grpc-ecosystem/grpc-gateway v1.16.0 // indirect
 	github.com/jackc/chunkreader/v2 v2.0.1 // indirect
-	github.com/jackc/pgconn v1.14.0 // indirect
 	github.com/jackc/pgio v1.0.0 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgproto3/v2 v2.3.2 // indirect

kvdb/go.sum

@@ -143,6 +143,8 @@ github.com/jackc/pgconn v1.9.0/go.mod h1:YctiPyvzfU11JFxoXokUOOKQXQmDMoJL9vJzHH8
 github.com/jackc/pgconn v1.9.1-0.20210724152538-d89c8390a530/go.mod h1:4z2w8XhRbP1hYxkpTuBjTS3ne3J48K83+u0zoyvg2pI=
 github.com/jackc/pgconn v1.14.0 h1:vrbA9Ud87g6JdFWkHTJXppVce58qPIdP7N8y0Ml/A7Q=
 github.com/jackc/pgconn v1.14.0/go.mod h1:9mBNlny0UvkgJdCDvdVHYSjI+8tD2rnKK69Wz8ti++E=
+github.com/jackc/pgerrcode v0.0.0-20220416144525-469b46aa5efa h1:s+4MhCQ6YrzisK6hFJUX53drDT4UsSW3DEhKn0ifuHw=
+github.com/jackc/pgerrcode v0.0.0-20220416144525-469b46aa5efa/go.mod h1:a/s9Lp5W7n/DD0VrVoyJ00FbP2ytTPDVOivvn2bMlds=
 github.com/jackc/pgio v1.0.0 h1:g12B9UwVnzGhueNavwioyEEpAmqMe1E/BN9ES+8ovkE=
 github.com/jackc/pgio v1.0.0/go.mod h1:oP+2QK2wFfUWgr+gxjoBH9KGBb31Eio69xUb0w5bYf8=
 github.com/jackc/pgmock v0.0.0-20190831213851-13a1b77aafa2/go.mod h1:fGZlG77KXmcq05nJLRkk0+p82V8B8Dw8KN2/V9c/OAE=

kvdb/sqlbase/db.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"io"
 	"math"
+	"math/rand"
 	"sync"
 	"time"
 
@@ -37,12 +38,6 @@ const (
 	DefaultMaxRetryDelay = time.Second * 5
 )
 
-var (
-	// ErrRetriesExceeded is returned when a transaction is retried more
-	// than the max allowed valued without a success.
-	ErrRetriesExceeded = errors.New("db tx retries exceeded")
-)
-
 // Config holds a set of configuration options of a sql database connection.
 type Config struct {
 	// DriverName is the string that defines the registered sql driver that
@@ -238,7 +233,7 @@ func randRetryDelay(initialRetryDelay, maxRetryDelay time.Duration,
 	attempt int) time.Duration {
 
 	halfDelay := initialRetryDelay / 2
-	randDelay := prand.Int63n(int64(initialRetryDelay)) //nolint:gosec
+	randDelay := rand.Int63n(int64(initialRetryDelay)) //nolint:gosec
 
 	// 50% plus 0%-100% gives us the range of 50%-150%.
 	initialDelay := halfDelay + time.Duration(randDelay)
@@ -286,11 +281,11 @@ func (db *db) executeTransaction(f func(tx walletdb.ReadWriteTx) error,
 		select {
 		// Before we try again, we'll wait with a random backoff based
 		// on the retry delay.
-		case time.After(retryDelay):
+		case <-time.After(retryDelay):
 			return true
 
 		// If the daemon is shutting down, then we'll exit early.
-		case <-db.Context.Done():
+		case <-db.ctx.Done():
 			return false
 		}
 	}

kvdb/sqlbase/sqlerrors.go

@@ -0,0 +1,115 @@
+//go:build kvdb_postgres || (kvdb_sqlite && !(windows && (arm || 386)) && !(linux && (ppc64 || mips || mipsle || mips64)))
+
+package sqlbase
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/jackc/pgconn"
+	"github.com/jackc/pgerrcode"
+	"modernc.org/sqlite"
+	sqlite3 "modernc.org/sqlite/lib"
+)
+
+var (
+	// ErrRetriesExceeded is returned when a transaction is retried more
+	// than the max allowed valued without a success.
+	ErrRetriesExceeded = errors.New("db tx retries exceeded")
+)
+
+// MapSQLError attempts to interpret a given error as a database agnostic SQL
+// error.
+func MapSQLError(err error) error {
+	// Attempt to interpret the error as a sqlite error.
+	var sqliteErr *sqlite.Error
+	if errors.As(err, &sqliteErr) {
+		return parseSqliteError(sqliteErr)
+	}
+
+	// Attempt to interpret the error as a postgres error.
+	var pqErr *pgconn.PgError
+	if errors.As(err, &pqErr) {
+		return parsePostgresError(pqErr)
+	}
+
+	// Return original error if it could not be classified as a database
+	// specific error.
+	return err
+}
+
+// parsePostgresError attempts to parse a sqlite error as a database agnostic
+// SQL error.
+func parseSqliteError(sqliteErr *sqlite.Error) error {
+	switch sqliteErr.Code() {
+	// Handle unique constraint violation error.
+	case sqlite3.SQLITE_CONSTRAINT_UNIQUE:
+		return &ErrSQLUniqueConstraintViolation{
+			DBError: sqliteErr,
+		}
+
+	// Database is currently busy, so we'll need to try again.
+	case sqlite3.SQLITE_BUSY:
+		return &ErrSerializationError{
+			DBError: sqliteErr,
+		}
+
+	default:
+		return fmt.Errorf("unknown sqlite error: %w", sqliteErr)
+	}
+}
+
+// parsePostgresError attempts to parse a postgres error as a database agnostic
+// SQL error.
+func parsePostgresError(pqErr *pgconn.PgError) error {
+	switch pqErr.Code {
+	// Handle unique constraint violation error.
+	case pgerrcode.UniqueViolation:
+		return &ErrSQLUniqueConstraintViolation{
+			DBError: pqErr,
+		}
+
+	// Unable to serialize the transaction, so we'll need to try again.
+	case pgerrcode.SerializationFailure:
+		return &ErrSerializationError{
+			DBError: pqErr,
+		}
+
+	default:
+		return fmt.Errorf("unknown postgres error: %w", pqErr)
+	}
+}
+
+// ErrSQLUniqueConstraintViolation is an error type which represents a database
+// agnostic SQL unique constraint violation.
+type ErrSQLUniqueConstraintViolation struct {
+	DBError error
+}
+
+func (e ErrSQLUniqueConstraintViolation) Error() string {
+	return fmt.Sprintf("sql unique constraint violation: %v", e.DBError)
+}
+
+// ErrSerializationError is an error type which represents a database agnostic
+// error that a transaction couldn't be serialized with other concurrent db
+// transactions.
+type ErrSerializationError struct {
+	DBError error
+}
+
+// Unwrap returns the wrapped error.
+func (e ErrSerializationError) Unwrap() error {
+	return e.DBError
+}
+
+// Error returns the error message.
+func (e ErrSerializationError) Error() string {
+	return e.DBError.Error()
+}
+
+// IsSerializationError returns true if the given error is a serialization
+// error.
+func IsSerializationError(err error) bool {
+	var serializationError *ErrSerializationError
+	return errors.As(err, &serializationError)
+}