Small fixes & cleanups

Author: cristaloleg

dbump.go

@@ -69,14 +69,6 @@ type Migration struct {
 	Revert string // Revert query
 }
 
-// MigrationFn gives ability to use Go functions as migrations.
-type MigrationFn func(ctx context.Context, conn Conn) error
-
-// Conn represents a connection to the database.
-type Conn interface {
-	Exec(ctx context.Context, query string, args ...interface{}) error
-}
-
 // MigratorMode to change migration flow.
 type MigratorMode int
 
@@ -89,7 +81,7 @@ const (
 	modeMaxPossible
 )
 
-// AsLocklessMigrator makes given migrator to not take a lock in database.
+// AsLocklessMigrator makes given migrator to not take a lock on database.
 func AsLocklessMigrator(m Migrator) Migrator {
 	return &locklessMigrator{m}
 }
@@ -126,7 +118,7 @@ func (m *mig) run(ctx context.Context) error {
 	if err != nil {
 		return fmt.Errorf("load: %w", err)
 	}
-	return m.runMigration(ctx, migrations)
+	return m.runMigrations(ctx, migrations)
 }
 
 func (m *mig) load() ([]*Migration, error) {
@@ -152,7 +144,7 @@ func (m *mig) load() ([]*Migration, error) {
 	return ms, nil
 }
 
-func (m *mig) runMigration(ctx context.Context, ms []*Migration) (err error) {
+func (m *mig) runMigrations(ctx context.Context, ms []*Migration) (err error) {
 	if err := m.Init(ctx); err != nil {
 		return fmt.Errorf("init: %w", err)
 	}
@@ -174,11 +166,11 @@ func (m *mig) runMigration(ctx context.Context, ms []*Migration) (err error) {
 		}
 	}()
 
-	err = m.runMigrationLocked(ctx, ms)
+	err = m.runMigrationsLocked(ctx, ms)
 	return err
 }
 
-func (m *mig) runMigrationLocked(ctx context.Context, ms []*Migration) error {
+func (m *mig) runMigrationsLocked(ctx context.Context, ms []*Migration) error {
 	curr, target, err := m.getCurrAndTargetVersions(ctx, len(ms))
 	if err != nil {
 		return err
@@ -330,9 +322,9 @@ func (llm *locklessMigrator) SetVersion(ctx context.Context, version int) error
 	return llm.m.SetVersion(ctx, version)
 }
 
-func (llm *locklessMigrator) Begin(ctx context.Context) error    { return llm.Begin(ctx) }
-func (llm *locklessMigrator) Commit(ctx context.Context) error   { return llm.Commit(ctx) }
-func (llm *locklessMigrator) Rollback(ctx context.Context) error { return llm.Rollback(ctx) }
+func (llm *locklessMigrator) Begin(ctx context.Context) error    { return llm.m.Begin(ctx) }
+func (llm *locklessMigrator) Commit(ctx context.Context) error   { return llm.m.Commit(ctx) }
+func (llm *locklessMigrator) Rollback(ctx context.Context) error { return llm.m.Rollback(ctx) }
 
 func (llm *locklessMigrator) Exec(ctx context.Context, query string, args ...interface{}) error {
 	return llm.m.Exec(ctx, query, args...)

dbump_ch/clickhouse.go

@@ -0,0 +1,51 @@
+package dbump_ch
+
+import (
+	"context"
+	"database/sql"
+)
+
+// MigratorClickHouse to migrate ClickHouse.
+type MigratorClickHouse struct {
+	db           *sql.DB
+	versionTable string
+}
+
+// NewMigratorClickHouse instantiates new MigratorClickHouse.
+func NewMigratorClickHouse(db *sql.DB) *MigratorClickHouse {
+	return &MigratorClickHouse{
+		db:           db,
+		versionTable: "_dbump_schema_version",
+	}
+}
+
+// LockDB is a method for Migrator interface.
+func (ch *MigratorClickHouse) LockDB(ctx context.Context) error {
+	// TODO: currently no-op
+	return nil
+}
+
+// UnlockDB is a method for Migrator interface.
+func (ch *MigratorClickHouse) UnlockDB(ctx context.Context) error {
+	// TODO: currently no-op
+	return nil
+}
+
+// Version is a method for Migrator interface.
+func (ch *MigratorClickHouse) Version(ctx context.Context) (version int, err error) {
+	row := ch.db.QueryRowContext(ctx, "SELECT version FROM "+ch.versionTable)
+	err = row.Scan(&version)
+	return version, err
+}
+
+// SetVersion is a method for Migrator interface.
+func (ch *MigratorClickHouse) SetVersion(ctx context.Context, version int) error {
+	_, err := ch.db.ExecContext(ctx, "UPDATE "+ch.versionTable+" SET version = $1", version)
+	return err
+}
+
+// Exec is a method for Migrator interface.
+func (ch *MigratorClickHouse) Exec(ctx context.Context, query string, args ...interface{}) error {
+	_, err := ch.db.ExecContext(ctx, query)
+	return err
+}

dbump_ch/go.mod

@@ -0,0 +1,7 @@
+module github.com/cristalhq/dbump/dbump_ch
+
+go 1.16
+
+require (
+	github.com/cristalhq/dbump v0.1.1
+)

dbump_ch/go.sum

@@ -0,0 +1,2 @@
+github.com/cristalhq/dbump v0.1.1 h1:cRbnpydrF19ML0wNO2pGsY6qwEVH/rtwnN64VwZpy9M=
+github.com/cristalhq/dbump v0.1.1/go.mod h1:rAjULuStbuNPCLrJT62Eu7Sp/2gVt/4URUvsnPK1yFA=

dbump_mysql/go.mod

@@ -0,0 +1,8 @@
+module github.com/cristalhq/dbump/dbump_mysql
+
+go 1.16
+
+require (
+	github.com/cristalhq/dbump v0.1.1
+	github.com/lib/pq v1.10.5
+)

dbump_mysql/go.sum

@@ -0,0 +1,4 @@
+github.com/cristalhq/dbump v0.1.1 h1:cRbnpydrF19ML0wNO2pGsY6qwEVH/rtwnN64VwZpy9M=
+github.com/cristalhq/dbump v0.1.1/go.mod h1:rAjULuStbuNPCLrJT62Eu7Sp/2gVt/4URUvsnPK1yFA=
+github.com/lib/pq v1.10.5 h1:J+gdV2cUmX7ZqL2B0lFcW0m+egaHC2V3lpO8nWxyYiQ=
+github.com/lib/pq v1.10.5/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=

dbump_mysql/mysql.go

@@ -0,0 +1,65 @@
+package dbump_mysql
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+)
+
+// to prevent multiple migrations running at the same time
+const lockNum int64 = 777_777_777
+
+// Migrator to migrate MySQL.
+type Migrator struct {
+	db           *sql.DB
+	versionTable string
+}
+
+// NewMigrator instantiates new Migrator.
+func NewMigrator(db *sql.DB) *Migrator {
+	return &Migrator{
+		db:           db,
+		versionTable: "_dbump_schema_version",
+	}
+}
+
+// Init migrator.
+func (pg *Migrator) Init(ctx context.Context) error {
+	query := fmt.Sprintf(`CREATE TABLE IF NOT EXISTS %s (
+	version    BIGINT NOT NULL PRIMARY KEY,
+	created_at TIMESTAMP NOT NULL
+);`, pg.versionTable)
+	_, err := pg.db.ExecContext(ctx, query)
+	return err
+}
+
+// LockDB is a method for Migrator interface.
+func (my *Migrator) LockDB(ctx context.Context) error {
+	_, err := my.db.ExecContext(ctx, `SELECT GET_LOCK(?, 10)`, lockNum)
+	return err
+}
+
+// UnlockDB is a method for Migrator interface.
+func (my *Migrator) UnlockDB(ctx context.Context) error {
+	_, err := my.db.ExecContext(ctx, "SELECT RELEASE_LOCK(?)", lockNum)
+	return err
+}
+
+// Version is a method for Migrator interface.
+func (my *Migrator) Version(ctx context.Context) (version int, err error) {
+	row := my.db.QueryRowContext(ctx, "SELECT version FROM "+my.versionTable)
+	err = row.Scan(&version)
+	return version, err
+}
+
+// SetVersion is a method for Migrator interface.
+func (my *Migrator) SetVersion(ctx context.Context, version int) error {
+	_, err := my.db.ExecContext(ctx, "UPDATE "+my.versionTable+" SET version = $1", version)
+	return err
+}
+
+// Exec is a method for Migrator interface.
+func (my *Migrator) Exec(ctx context.Context, query string, args ...interface{}) error {
+	_, err := my.db.ExecContext(ctx, query)
+	return err
+}

dbump_mysql/mysql_test.go

@@ -0,0 +1,7 @@
+package dbump_mysql_test
+
+import (
+	"context"
+	"database/sql"
+	"testing"
+)