snapshot of https://github.com/golang-migrate/migrate.git (master, 2026-09-15; blobs > 131072B omitted)

2026-09-15 21:52:57 +05:00
commit 9f3bffc2d3
405 changed files with 27657 additions and 0 deletions
--- a/database/clickhouse/clickhouse.go
+++ b/database/clickhouse/clickhouse.go
@@ -0,0 +1,311 @@
+package clickhouse
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"io"
+	"net/url"
+	"strconv"
+	"strings"
+	"sync/atomic"
+	"time"
+
+	"github.com/golang-migrate/migrate/v4"
+	"github.com/golang-migrate/migrate/v4/database"
+	"github.com/golang-migrate/migrate/v4/database/multistmt"
+)
+
+var (
+	multiStmtDelimiter = []byte(";")
+
+	DefaultMigrationsTable       = "schema_migrations"
+	DefaultMigrationsTableEngine = "TinyLog"
+	DefaultMultiStatementMaxSize = 10 * 1 << 20 // 10 MB
+
+	ErrNilConfig = fmt.Errorf("no config")
+)
+
+type Config struct {
+	DatabaseName          string
+	ClusterName           string
+	MigrationsTable       string
+	MigrationsTableEngine string
+	MultiStatementEnabled bool
+	MultiStatementMaxSize int
+}
+
+func init() {
+	database.Register("clickhouse", &ClickHouse{})
+}
+
+func WithInstance(conn *sql.DB, config *Config) (database.Driver, error) {
+	if config == nil {
+		return nil, ErrNilConfig
+	}
+
+	if err := conn.Ping(); err != nil {
+		return nil, err
+	}
+
+	ch := &ClickHouse{
+		conn:   conn,
+		config: config,
+	}
+
+	if err := ch.init(); err != nil {
+		return nil, err
+	}
+
+	return ch, nil
+}
+
+type ClickHouse struct {
+	conn     *sql.DB
+	config   *Config
+	isLocked atomic.Bool
+}
+
+func (ch *ClickHouse) Open(dsn string) (database.Driver, error) {
+	purl, err := url.Parse(dsn)
+	if err != nil {
+		return nil, err
+	}
+	q := migrate.FilterCustomQuery(purl)
+	q.Scheme = "tcp"
+	conn, err := sql.Open("clickhouse", q.String())
+	if err != nil {
+		return nil, err
+	}
+
+	multiStatementMaxSize := DefaultMultiStatementMaxSize
+	if s := purl.Query().Get("x-multi-statement-max-size"); len(s) > 0 {
+		multiStatementMaxSize, err = strconv.Atoi(s)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	migrationsTableEngine := DefaultMigrationsTableEngine
+	if s := purl.Query().Get("x-migrations-table-engine"); len(s) > 0 {
+		migrationsTableEngine = s
+	}
+
+	ch = &ClickHouse{
+		conn: conn,
+		config: &Config{
+			MigrationsTable:       purl.Query().Get("x-migrations-table"),
+			MigrationsTableEngine: migrationsTableEngine,
+			DatabaseName:          purl.Query().Get("database"),
+			ClusterName:           purl.Query().Get("x-cluster-name"),
+			MultiStatementEnabled: purl.Query().Get("x-multi-statement") == "true",
+			MultiStatementMaxSize: multiStatementMaxSize,
+		},
+	}
+
+	if err := ch.init(); err != nil {
+		return nil, err
+	}
+
+	return ch, nil
+}
+
+func (ch *ClickHouse) init() error {
+	if len(ch.config.DatabaseName) == 0 {
+		if err := ch.conn.QueryRow("SELECT currentDatabase()").Scan(&ch.config.DatabaseName); err != nil {
+			return err
+		}
+	}
+
+	if len(ch.config.MigrationsTable) == 0 {
+		ch.config.MigrationsTable = DefaultMigrationsTable
+	}
+
+	if ch.config.MultiStatementMaxSize <= 0 {
+		ch.config.MultiStatementMaxSize = DefaultMultiStatementMaxSize
+	}
+
+	if len(ch.config.MigrationsTableEngine) == 0 {
+		ch.config.MigrationsTableEngine = DefaultMigrationsTableEngine
+	}
+
+	return ch.ensureVersionTable()
+}
+
+func (ch *ClickHouse) Run(r io.Reader) error {
+	if ch.config.MultiStatementEnabled {
+		var err error
+		if e := multistmt.Parse(r, multiStmtDelimiter, ch.config.MultiStatementMaxSize, func(m []byte) bool {
+			tq := strings.TrimSpace(string(m))
+			if tq == "" {
+				return true
+			}
+			if _, e := ch.conn.Exec(string(m)); e != nil {
+				err = database.Error{OrigErr: e, Err: "migration failed", Query: m}
+				return false
+			}
+			return true
+		}); e != nil {
+			return e
+		}
+		return err
+	}
+
+	migration, err := io.ReadAll(r)
+	if err != nil {
+		return err
+	}
+
+	if _, err := ch.conn.Exec(string(migration)); err != nil {
+		return database.Error{OrigErr: err, Err: "migration failed", Query: migration}
+	}
+
+	return nil
+}
+func (ch *ClickHouse) Version() (int, bool, error) {
+	var (
+		version int
+		dirty   uint8
+		query   = "SELECT version, dirty FROM `" + ch.config.MigrationsTable + "` ORDER BY sequence DESC LIMIT 1"
+	)
+	if err := ch.conn.QueryRow(query).Scan(&version, &dirty); err != nil {
+		if err == sql.ErrNoRows {
+			return database.NilVersion, false, nil
+		}
+		return 0, false, &database.Error{OrigErr: err, Query: []byte(query)}
+	}
+	return version, dirty == 1, nil
+}
+
+func (ch *ClickHouse) SetVersion(version int, dirty bool) error {
+	var (
+		bool = func(v bool) uint8 {
+			if v {
+				return 1
+			}
+			return 0
+		}
+		tx, err = ch.conn.Begin()
+	)
+	if err != nil {
+		return err
+	}
+
+	query := "INSERT INTO " + ch.config.MigrationsTable + " (version, dirty, sequence) VALUES (?, ?, ?)"
+	if _, err := tx.Exec(query, version, bool(dirty), time.Now().UnixNano()); err != nil {
+		return &database.Error{OrigErr: err, Query: []byte(query)}
+	}
+
+	return tx.Commit()
+}
+
+// ensureVersionTable checks if versions table exists and, if not, creates it.
+// Note that this function locks the database, which deviates from the usual
+// convention of "caller locks" in the ClickHouse type.
+func (ch *ClickHouse) ensureVersionTable() (err error) {
+	if err = ch.Lock(); err != nil {
+		return err
+	}
+
+	defer func() {
+		if e := ch.Unlock(); e != nil {
+			err = errors.Join(err, e)
+		}
+	}()
+
+	var (
+		table string
+		query = "SHOW TABLES FROM " + quoteIdentifier(ch.config.DatabaseName) + " LIKE '" + ch.config.MigrationsTable + "'"
+	)
+	// check if migration table exists
+	if err := ch.conn.QueryRow(query).Scan(&table); err != nil {
+		if err != sql.ErrNoRows {
+			return &database.Error{OrigErr: err, Query: []byte(query)}
+		}
+	} else {
+		return nil
+	}
+
+	// if not, create the empty migration table
+	if len(ch.config.ClusterName) > 0 {
+		query = fmt.Sprintf(`
+			CREATE TABLE %s ON CLUSTER %s (
+				version    Int64,
+				dirty      UInt8,
+				sequence   UInt64
+			) Engine=%s`, ch.config.MigrationsTable, ch.config.ClusterName, ch.config.MigrationsTableEngine)
+	} else {
+		query = fmt.Sprintf(`
+			CREATE TABLE %s (
+				version    Int64,
+				dirty      UInt8,
+				sequence   UInt64
+			) Engine=%s`, ch.config.MigrationsTable, ch.config.MigrationsTableEngine)
+	}
+
+	if strings.HasSuffix(ch.config.MigrationsTableEngine, "Tree") {
+		query = fmt.Sprintf(`%s ORDER BY sequence`, query)
+	}
+
+	if _, err := ch.conn.Exec(query); err != nil {
+		return &database.Error{OrigErr: err, Query: []byte(query)}
+	}
+	return nil
+}
+
+func (ch *ClickHouse) Drop() (err error) {
+	query := "SHOW TABLES FROM " + quoteIdentifier(ch.config.DatabaseName)
+	tables, err := ch.conn.Query(query)
+
+	if err != nil {
+		return &database.Error{OrigErr: err, Query: []byte(query)}
+	}
+	defer func() {
+		if errClose := tables.Close(); errClose != nil {
+			err = errors.Join(err, errClose)
+		}
+	}()
+
+	for tables.Next() {
+		var table string
+		if err := tables.Scan(&table); err != nil {
+			return err
+		}
+
+		query = "DROP TABLE IF EXISTS " + quoteIdentifier(ch.config.DatabaseName) + "." + quoteIdentifier(table)
+
+		if _, err := ch.conn.Exec(query); err != nil {
+			return &database.Error{OrigErr: err, Query: []byte(query)}
+		}
+	}
+	if err := tables.Err(); err != nil {
+		return &database.Error{OrigErr: err, Query: []byte(query)}
+	}
+
+	return nil
+}
+
+func (ch *ClickHouse) Lock() error {
+	if !ch.isLocked.CompareAndSwap(false, true) {
+		return database.ErrLocked
+	}
+
+	return nil
+}
+func (ch *ClickHouse) Unlock() error {
+	if !ch.isLocked.CompareAndSwap(true, false) {
+		return database.ErrNotLocked
+	}
+
+	return nil
+}
+func (ch *ClickHouse) Close() error { return ch.conn.Close() }
+
+// Copied from lib/pq implementation: https://github.com/lib/pq/blob/v1.9.0/conn.go#L1611
+func quoteIdentifier(name string) string {
+	end := strings.IndexRune(name, 0)
+	if end > -1 {
+		name = name[:end]
+	}
+	return `"` + strings.ReplaceAll(name, `"`, `""`) + `"`
+}